阅读说明：本技术 锡须去除电路、电子终端产品及锡须去除方法 (Tin whisker removing circuit, electronic terminal product and tin whisker removing method ) 是由 袁宝成 郑力夫 陈迎 王小昆 毛森 葛凯 董守全 孟凡鹏 沈健 孔德隽 于 2020-05-12 设计创作，主要内容包括：本发明提供了一种锡须去除电路、电子终端产品及锡须去除方法,所述锡须去除电路至少包括第一电源模块、第一开关模块、第二开关模块、储能模块以及控制模块。通过锡须去除电路,能够去除电子终端产品出厂时已有的锡须以及在电子终端产品使用过程中新产生和继续生长的锡须,能够解决已出厂的电子终端产品中存在的锡须影响产品的正常使用的问题,成本低、效率高,且能够提高电子终端产品的可靠性,降低了电子终端产品运行过程中的失效概率。(The invention provides a tin whisker removing circuit, an electronic terminal product and a tin whisker removing method. The tin whisker removing circuit can remove the existing tin whiskers of the electronic terminal product when the electronic terminal product leaves a factory and the tin whiskers which are newly generated and continuously grow in the use process of the electronic terminal product, can solve the problem that the tin whiskers existing in the electronic terminal product leaving the factory influence the normal use of the product, is low in cost and high in efficiency, can improve the reliability of the electronic terminal product, and reduces the failure probability of the electronic terminal product in the operation process.)

1. A tin whisker removing circuit is used for removing tin whiskers in an electronic terminal product and a component to be protected in the same loop, and is characterized by comprising: the energy storage device comprises a first power supply module, a first switch module, a second switch module, an energy storage module and a control module;

the switch path of the first switch module is connected in a first branch circuit connected between the energy storage module and the first power supply module, the control end of the first switch module is connected with the control module, and the first switch module is used for switching on or off the first branch circuit under the control of the control module;

the switch path of the second switch module is connected to a second branch circuit of the first power supply module, which is sequentially connected with the component to be protected and the energy storage module, the control end of the second switch module is connected with the control module, and the second switch module is used for switching on or off the second branch circuit under the control of the control module;

the first power supply module is used for charging the energy storage module when the first branch circuit and/or the second branch circuit are/is conducted;

the first power supply module is also used for breaking down air gaps around the tin whiskers through the second branch circuit and burning the tin whiskers; or the tin whisker removing circuit further comprises a voltage generating module, wherein the voltage generating module is connected with two ends of the energy storage module and is used for generating voltage different from that of the first power supply module so as to break through air gaps around the tin whiskers and burn the tin whiskers.

2. The tin whisker removal circuit of claim 1, wherein the energy storage module is a battery or a capacitor.

3. The tin whisker removal circuit of claim 1, wherein the component to be protected comprises a fuse.

4. The tin whisker removing circuit of claim 1, further comprising a current limiting module, wherein the current limiting module is disposed in a circuit in which the first power module is connected to the switching path of the first switching module, and the current limiting module is configured to limit a magnitude of current charged to the energy storage module by the first power module when the switching path of the first switching module is turned on.

5. The tin whisker removal circuit of claim 1, further comprising a third switching module and a fourth switching module; the switch path of the third switch module is connected with the switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected with two ends of the energy storage module, a control end of the third switch module and a control end of the fourth switch module are both connected with the control module, and the third switch module and the fourth switch module are used for conducting or stopping according to a set switch time sequence under the control of the control module.

6. The tin whisker removing circuit of claim 5, wherein the first to fourth switch modules respectively comprise at least one electronic switch tube or an electromagnetic relay, and the electronic switch tube is an MOS transistor, a triode or an IGBT tube.

7. The tin whisker removal circuit of claim 5, wherein the voltage generation module comprises a boost module connected in series in the third branch and configured to generate a corresponding voltage spike to break down a corresponding air gap and burn the tin whisker when the third switch module and the fourth switch module are turned on or off according to a set switch timing.

8. The tin whisker removal circuit of claim 7, wherein the boost module comprises at least one inductor.

9. The tin whisker removing circuit of any one of claims 1 to 8, wherein the voltage generating module comprises a second power module and a transforming module, one end of the transforming module is connected to one end of the energy storage module, and the other end of the transforming module is connected to the second power module, and the transforming module is configured to perform a reverse operation or a forward operation under the control of the control module, so that the second power module can charge the energy storage module, and/or generate a corresponding voltage to break down a corresponding air gap and burn out the tin whisker.

10. The tin whisker removal circuit of claim 9, wherein the first power module and the second power module are dc power supplies of different voltages, and the transformer module is a dc-to-dc buck-transform module, a dc-to-dc boost-transform module, or a dc-to-dc buck-boost-transform module.

11. An electronic terminal product, characterized by comprising at least one component to be protected and the tin whisker removal circuit as claimed in any one of claims 1 to 10 connected to the component to be protected.

12. A tin whisker removing method for removing tin whiskers in the electronic terminal product of claim 11, the tin whiskers and the component to be protected being in the same circuit, the tin whisker removing method comprising:

the control module controls the switch path of the first switch module to be switched on and the switch path of the second switch module to be switched off, so that the first power supply module precharges the energy storage module until the voltage of the energy storage module is precharged to a first voltage set value;

breaking down an air gap near a tin whisker by the voltage of the first power supply module to burn the tin whisker;

and controlling the switch path of the second switch module to be conducted through the control module so that the electronic terminal product starts subsequent normal operation.

13. The tin whisker removal method of claim 12, wherein the tin whisker removal circuit of the electronic terminal product further comprises a third switch module and a fourth switch module; the switch path of the third switch module is connected with the switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected with two ends of the energy storage module, and the control end of the third switch module and the control end of the fourth switch module are both connected with the control module;

after the voltage of the energy storage module is precharged to the first voltage setting value and before the switch path of the second switch module is turned on, the tin whisker removal method further comprises the following steps: the control module controls the switch path of the third switch module and the switch path of the fourth switch module to be switched on and off according to a set switch time sequence, so that the air gap near the tin whisker is broken through by the voltage of the first power supply module to burn the tin whisker.

14. The method of removing tin whiskers of claim 12 or 13, further comprising: setting the execution frequency of the tin whisker removal method.

15. A tin whisker removing method, which is characterized in that the method is used for removing tin whiskers in the same loop with a component to be protected in the electronic terminal product of claim 11, the tin whisker removing circuit of the electronic terminal product further comprises a voltage generating module, and the voltage generating module is connected with two ends of the energy storage module; the tin whisker removing method comprises the following steps:

the control module controls the switch path of the first switch module to be switched on or switched off, so that the first power module or the voltage generation module pre-charges the energy storage module until the voltage of the energy storage module is pre-charged to a second voltage set value;

breaking down the air gap near the tin whisker by the voltage of the voltage generating module to burn the tin whisker;

and controlling the switch path of the second switch module to be conducted through the control module so that the electronic terminal product starts to operate normally subsequently.

16. The tin whisker removal method of claim 15, wherein the voltage generation module comprises a second power module and a transformation module, one end of the transformation module is connected to one end of the energy storage module, and the other end is connected to the second power module;

the step of controlling the switching path of the first switching module to be switched on or off through the control module so that the first power module or the voltage generation module pre-charges the energy storage module comprises the following steps: the control module controls the switch paths of the first switch module and the second switch module to be cut off and controls the voltage transformation module to work reversely, so that the second power supply module pre-charges the energy storage module through the voltage transformation module until the voltage of the energy storage module is pre-charged to a second voltage set value;

or, the step of controlling the switching path of the first switching module to be turned on or off by the control module so that the first power module or the voltage generating module pre-charges the energy storage module includes: firstly, the control module controls the switch path of the first switch module to be conducted, and the switch path of the second switch module is cut off, so that the first power supply module precharges the energy storage module until the voltage of the energy storage module is precharged to a third voltage set value; and then, the control module controls the transformation module to work reversely, so that the second power supply module pre-charges the energy storage module through the transformation module until the voltage of the energy storage module is pre-charged to a second voltage set value.

17. The method according to claim 16, wherein after the tin whisker is burned, the control module first controls the switch path of the first switch module to be conducted and then controls the switch path of the second switch module to be conducted.

18. The method for removing tin whiskers of claim 16, wherein the circuit for removing tin whiskers of the electronic terminal product further comprises a third switch module and a fourth switch module, a switch path of the third switch module is connected with a switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected with two ends of the energy storage module, and a control end of the third switch module and a control end of the fourth switch module are both connected with the control module;

after the voltage of the energy storage module is precharged to the second voltage setting value and before the switch path of the second switch module is turned on, the tin whisker removal method further comprises the following steps: the control module controls the switch path of the third switch module and the switch path of the fourth switch module to be conducted and cut off according to a set switch time sequence, so that the voltage of the voltage generation module breaks through an air gap near the tin whisker to burn the tin whisker.

19. The method for removing tin whiskers of claim 18, wherein the voltage generation module comprises a boost module, the boost module is connected in series in the third branch, and in the method for removing tin whiskers, when a third switch module and a fourth switch module are turned on or off according to a set switch timing sequence, the boost module generates a corresponding voltage spike to break down a corresponding air gap and burn out the tin whiskers.

20. The method of removing tin whiskers of any one of claims 15-19, further comprising: setting the execution frequency of the tin whisker removal method.

Technical Field

The invention relates to the technical field of electronic terminal products, in particular to a tin whisker removing circuit, an electronic terminal product with the tin whisker removing circuit and a tin whisker removing method.

Background

More and more regulations in the field of electronic applications currently require lead-free processes, such as RoHS (restriction of Hazardous substations, which refers to directives on limiting the use of certain harmful components such as lead, mercury, cadmium, etc. in electronic end products) in the european union. In order to meet the lead-free requirement, the traditional lead-containing process gradually changes to the lead-free process, for example, the final surface treatment is performed on the circuit surface of the printed circuit board by using lead-free solder such as tin or tin alloy, so as to ensure the solderability and other properties of the printed circuit board during the subsequent assembly and use processes, and the like. However, it is proved that, in the manufacturing process of the current electronic terminal product, due to the influence of factors such as environmental conditions, referring to fig. 1, the surface treatment process of tin or tin alloy and other tin-containing lead-free solders almost causes tin whiskers 11 on the electronic terminal product, and the existence of tin whiskers causes reliability problems to the electronic terminal product, thereby causing abnormality of the electronic terminal product, such as device failure and even severe burnout.

In order to improve the effect of tin whisker on the product performance, most of the current technologies focus on how to avoid tin whisker in the manufacturing process of electronic end products, such as developing new tin-containing lead-free solder or improving surface treatment process.

In addition, currently, regarding the influence of tin whisker on the reliability of electronic terminal products, a common evaluation measure is to verify whether tin whisker is generated in a specified environmental condition and time period and whether the length of the tin whisker is within an acceptable range through tin whisker experiments. However, the evaluation measure may also be wrong, for example, even if some electronic terminal products can pass the tin whisker experimental verification, the terminal products still have the possibility of generating tin whiskers due to the difference between the terminal load and the application environment and the experimental conditions, and the existence of the tin whiskers may cause product abnormality. That is, tin whiskers may continue to grow during the use of the electronic terminal product, thereby causing product abnormalities.

Therefore, in addition to taking necessary measures to avoid the generation of tin whiskers as much as possible in the manufacturing process of the electronic terminal product, a solution is needed to solve the problem that the tin whiskers existing in the electronic terminal product which is shipped from the factory affect the normal use of the product.

Disclosure of Invention

The invention aims to provide a tin whisker removing circuit, an electronic terminal product and a tin whisker removing method, which can solve the problem that the normal use of the product is influenced by the tin whisker possibly existing in the electronic terminal product.

In order to solve the above technical problem, the present invention provides a tin whisker removing circuit for removing tin whiskers in a same circuit with a component to be protected in an electronic terminal product, the tin whisker removing circuit comprising: the energy storage device comprises a first power supply module, a first switch module, a second switch module, an energy storage module and a control module; the switch path of the first switch module is connected in a first branch circuit connected between the energy storage module and the first power supply module, the control end of the first switch module is connected with the control module, and the first switch module is used for switching on or off the first branch circuit under the control of the control module;

the switch path of the second switch module is connected to a second branch circuit of the first power supply module, which is sequentially connected with the component to be protected and the energy storage module, the control end of the second switch module is connected with the control module, and the second switch module is used for switching on or off the second branch circuit under the control of the control module;

the first power supply module is used for charging the energy storage module when the first branch circuit and/or the second branch circuit are/is conducted;

the first power module is further configured to puncture an air gap around the tin whisker and burn the tin whisker through the second branch, or the tin whisker removing circuit further includes a voltage generating module, where the voltage generating module is connected to two ends of the energy storage module and is configured to generate a voltage different from a voltage of the first power module, so as to puncture the air gap around the tin whisker and burn the tin whisker.

Optionally, the energy storage module is a storage battery or a capacitor.

Optionally, the component to be protected includes a fuse.

Optionally, the tin whisker removing circuit further includes a current limiting module, the current limiting module is disposed in a circuit in which the first power supply module is connected to the switch path of the first switch module, and the current limiting module is configured to limit a current magnitude charged to the energy storage module by the first power supply module when the switch path of the first switch module is turned on.

Optionally, the tin whisker removing circuit further comprises a third switch module and a fourth switch module; the switch path of the third switch module is connected with the switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected with two ends of the energy storage module, a control end of the third switch module and a control end of the fourth switch module are both connected with the control module, and the third switch module and the fourth switch module are used for conducting or stopping according to a set switch time sequence under the control of the control module.

Optionally, the first to fourth switch modules respectively include at least one electronic switch tube or electromagnetic relay, and the electronic switch tube is an MOS transistor, a triode, or an IGBT tube.

Optionally, the voltage generation module includes a boost module, and the boost module is connected in series in the third branch and is configured to generate a corresponding voltage spike when the third switch module and the fourth switch module are turned on or turned off according to a set switch timing sequence, so as to break down a corresponding air gap and burn the tin whiskers.

Optionally, the boost module comprises at least one inductor.

Optionally, the voltage generation module includes a second power module and a voltage transformation module, one end of the voltage transformation module is connected to one end of the energy storage module, the other end of the voltage transformation module is connected to the second power module, and the voltage transformation module is configured to perform reverse operation or forward operation under the control of the control module, so that the second power module can charge the energy storage module, and/or generate a corresponding voltage to break down a corresponding air gap and burn the tin whiskers.

Optionally, the first power module and the second power module are dc power supplies with different voltages, and the transformation module is a dc-to-dc step-down transformation module, a dc-to-dc step-up transformation module, or a dc-to-dc step-up and step-down transformation module.

The invention also provides an electronic terminal product which comprises at least one component to be protected and the tin whisker removing circuit connected with the component to be protected.

The invention also provides a tin whisker removing method for removing tin whiskers on the same circuit with a component to be protected in the electronic terminal product, which comprises the following steps:

the control module controls the switch path of the first switch module to be switched on and the switch path of the second switch module to be switched off, so that the first power supply module precharges the energy storage module until the voltage of the energy storage module is precharged to a first voltage set value;

breaking down an air gap near a tin whisker by the voltage of the first power supply module to burn the tin whisker;

and controlling the switch path of the second switch module to be conducted through the control module so that the electronic terminal product starts subsequent normal operation.

Optionally, the tin whisker removing circuit of the electronic terminal product further includes a third switch module and a fourth switch module; the switch path of the third switch module is connected with the switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected with two ends of the energy storage module, and the control end of the third switch module and the control end of the fourth switch module are both connected with the control module;

after the voltage of the energy storage module is precharged to the first voltage setting value and before the switch path of the second switch module is turned on, the tin whisker removal method further comprises the following steps: the control module controls the switch path of the third switch module and the switch path of the fourth switch module to be switched on and off according to a set switch time sequence, so that the air gap near the tin whisker is broken through by the voltage of the first power supply module to burn the tin whisker.

Optionally, the tin whisker removal method further comprises: setting the execution frequency of the tin whisker removal method.

The invention also provides a tin whisker removing method, which is used for removing the tin whiskers on the same loop with the component to be protected in the electronic terminal product, wherein the tin whisker removing circuit of the electronic terminal product also comprises a voltage generating module, and the voltage generating module is connected with two ends of the energy storage module; the tin whisker removing method comprises the following steps:

the control module controls the switch path of the first switch module to be switched on or switched off, so that the first power module or the voltage generation module pre-charges the energy storage module until the voltage of the energy storage module is pre-charged to a second voltage set value;

breaking down the air gap near the tin whisker by the voltage of the voltage generating module to burn the tin whisker;

and controlling the switch path of the second switch module to be conducted through the control module so that the electronic terminal product starts to operate normally subsequently.

Optionally, the voltage generating module comprises a second power module and a transforming module, one end of the transforming module is connected to one end of the energy storage module, and the other end of the transforming module is connected to the second power module;

the step of controlling the switching path of the first switching module to be switched on or off through the control module so that the first power module or the voltage generation module pre-charges the energy storage module comprises the following steps: the control module controls the switch paths of the first switch module and the second switch module to be cut off and controls the voltage transformation module to work reversely, so that the second power supply module pre-charges the energy storage module through the voltage transformation module until the voltage of the energy storage module is pre-charged to a second voltage set value;

or, the step of controlling the switching path of the first switching module to be turned on or off by the control module so that the first power module or the voltage generating module pre-charges the energy storage module includes: firstly, the control module controls the switch path of the first switch module to be conducted, and the switch path of the second switch module is cut off, so that the first power supply module precharges the energy storage module until the voltage of the energy storage module is precharged to a third voltage set value; and then, the control module controls the transformation module to work reversely, so that the second power supply module pre-charges the energy storage module through the transformation module until the voltage of the energy storage module is pre-charged to a second voltage set value.

Optionally, after the tin whiskers are burnt, the control module controls the switch path of the first switch module to be turned on first, and then controls the switch path of the second switch module to be turned on later.

Optionally, the tin whisker removing circuit of the electronic terminal product further includes a third switch module and a fourth switch module, a switch path of the third switch module is connected with a switch path of the fourth switch module to form a third branch, two ends of the third branch are respectively connected to two ends of the energy storage module, and a control end of the third switch module and a control end of the fourth switch module are both connected to the control module;

after the voltage of the energy storage module is precharged to the second voltage setting value and before the switch path of the second switch module is turned on, the tin whisker removal method further comprises the following steps: the control module controls the switch path of the third switch module and the switch path of the fourth switch module to be conducted and cut off according to a set switch time sequence, so that the voltage of the voltage generation module breaks through an air gap near the tin whisker to burn the tin whisker.

Optionally, in the method for removing tin whiskers, when the third switch module and the fourth switch module are turned on or turned off according to a set switch timing sequence, the boost module generates a corresponding voltage spike to break down a corresponding air gap and burn out the tin whiskers.

Optionally, the tin whisker removal method further comprises: setting the execution frequency of the tin whisker removal method.

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

1. the tin whisker removing circuit can remove the existing tin whisker when the electronic terminal product leaves the factory and the tin whisker which is newly generated and continuously grows in the use process of the electronic terminal product, can solve the problem that the tin whisker in the electronic terminal product leaving the factory influences the normal use of the product, and has low cost and high efficiency.

2. Because the tin whiskers in the electronic terminal product are removed, the reliability of the electronic terminal product can be improved, the failure probability of the electronic terminal product in the operation process is reduced, and the use safety of the electronic terminal product can be improved.

3. The tin whisker-containing material is suitable for any electronic terminal product which has tin whiskers when the product leaves a factory and/or can generate tin whiskers in the using process, and particularly when the tin whisker-containing material is applied to electronic terminal products such as automobiles, the failure probability of the whole automobile in the running process can be reduced, and the driving characteristics and the safety of the whole automobile are improved.

Drawings

FIG. 1 is a schematic structural diagram of a tin whisker produced on a printed circuit board under a scanning electron microscope.

Fig. 2 is a system block diagram of a tin whisker removal circuit according to an embodiment of the invention.

Fig. 3 is a specific circuit example of the tin whisker removal circuit shown in fig. 2.

Fig. 4 is a flow chart of a method for removing tin whiskers by using the tin whisker removal circuit shown in fig. 3.

Fig. 5 is a system block diagram of a tin whisker removal circuit according to another embodiment of the invention.

Fig. 6 is a specific circuit example of the tin whisker removal circuit shown in fig. 5.

Fig. 7 is a flow chart of an exemplary method for removing tin whiskers using the tin whisker removal circuit shown in fig. 6.

Fig. 8 is a flow chart of another exemplary method for removing tin whiskers using the tin whisker removal circuit shown in fig. 6.

Fig. 9 is another specific circuit example of the tin whisker removal circuit shown in fig. 5.

Fig. 10 to 11 are two specific circuit examples of further simplified circuits for the tin whisker removal circuit described in fig. 2 and 3 according to still another embodiment of the present invention.

Fig. 12-13 are two specific circuit examples of further simplified tin whisker removal circuits described in fig. 5 or 6 according to still another embodiment of the invention.

Detailed Description

The technical solution proposed by the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Referring to fig. 2, an embodiment of the invention provides a tin whisker removal circuit for removing a tin whisker 11 in an electronic terminal product in the same circuit as a component 12 to be protected, where the tin whisker 11 may cause damage to the component 12 to be protected. The tin whisker removing circuit comprises: the power supply device comprises a first power supply module 20, a first switch module 21, a second switch module 22, a third switch module 23, a fourth switch module 24, an energy storage module 25, a boost module 26 (i.e. a voltage generation module), a control module 27 and a current limiting module 28.

Referring to fig. 3, the first power module 20 may be a dry battery, a dc generator, or other dc power source. The first power module 20 is configured to pre-charge the energy storage module 25 when the switching path of the first switching module 21 is turned on. The first power module 20 may be a power source of the electronic terminal product itself, or may be another power source independent from the power source of the electronic terminal product itself.

The control terminal of the first switching module 21 is connected to a signal output terminal of the control module 27 (for example, the terminal Q1 of the control module 27 in fig. 3), the switching path of the first switching module 21 is connected to a first branch of the energy storage module 25 connected to the first power supply module 20, and the current limiting module 28 is connected in series to the first branch, that is, to the switching path of the first switching module 21. The first switch module 21 is configured to turn on or off the first branch under the control of the control module 27, and a switch path of the first switch module 21 can be turned on when the tin whisker 11 needs to be removed, so as to turn on the first branch, so that the first power module 20 precharges the energy storage module 25. The current limiting module 28 is configured to limit a current magnitude charged to the energy storage module 25 by the first power module 20 when the switching path of the first switching module 21 is turned on.

The control terminal of the second switch module 22 is connected to another signal output terminal of the control module 27 (for example, the terminal Q2 of the control module 27 in fig. 3), the switch path of the second switch module 22 is connected to the second branch of the first power module 20 and the component 12 to be protected connected to the energy storage module 25, the second switch module 22 may be a front-stage circuit of the component 12 to be protected, and is connected between the first power module 20 and the component 12 to be protected, or may be a rear-stage circuit of the component 12 to be protected, and is connected between the component 12 to be protected and the energy storage module 25, the second switch module 22 is configured to enable the second branch to be turned on or off under the control of the control module 27, so that the first power module 20 provides power to the energy storage module 25 when the electronic terminal product needs to be used normally, so that the energy storage module 25 operates normally.

As an example, referring to fig. 2, the current limiting module 28 is a preceding stage circuit of the first switching module 21, that is, one end of the current limiting module 28 is connected to the positive electrode (i.e., the power output end) of the first power module 20, the other end of the current limiting module 28 is connected to one end of a switch path of the first switching module 21, the other end of the switch path of the first switching module 21 is connected to the common connection end N of the energy storage module 25 and the component 12 to be protected, and the other end of the energy storage module 25 is connected to the negative electrode of the first power module 20. The second switch module 22 is used as a post-stage circuit of the component 12 to be protected, one end of a switch path of the second switch module 22 is connected to one end of the component 12 to be protected, and the other end of the switch path of the second switch module 22 is connected to the common connection end N of the energy storage module 25 and the component 12 to be protected.

As another example, referring to fig. 3, the current limiting module 28 is a post-stage circuit of the first switch module 21, one end of a switch path of the first switch module 21 is connected to a positive electrode of the first power module 20, the other end of the switch path of the first switch module 21 is connected to one end of the current limiting module 28, the other end of the current limiting module 28 is connected to the common connection end N of the energy storage module 25 and the component 12 to be protected, and the other end of the energy storage module 25 is connected to a negative electrode of the first power module 20. The second switch module 22 is used as a pre-stage circuit of the component 12 to be protected, one end of a switch path of the second switch module 22 is connected to one end of the first power module 20, and the other end of the switch path of the second switch module 22.

The switch path of the third switch module 23 is connected to the switch path of the fourth switch module 24 to form a third branch. The boost module 26 is connected in the third branch, in this example the boost module 26 is connected between the switch path of the third switch module 23 and the switch path of the fourth switch module 24. That is, the switching path of the third switching module 23 is connected to a circuit in which the common connection end N between the energy storage module 25 and the component 12 to be protected is connected to the boost module 26, the control end of the third switching module 23 is connected to another signal output end (e.g., the end Q3 of the control module 27 in fig. 3) of the control module 27, and the third switching module 23 is configured to turn on or off the circuit in which the energy storage module 25 is connected to the boost module 26 according to a set switching timing under the control of the control module 27. The switch path of the fourth switch module 24 is connected in the circuit that the boost module 26 is connected with the switch path of the third switch module 23, and the control terminal of the fourth switch module 24 is connected with a further signal output terminal of the control module 27 (e.g., the terminal Q4 of the control module 27 in fig. 3). The fourth switching module 24 is configured to be turned on or off according to a set switching timing sequence under the control of the control module 27. After the energy storage module 25 is precharged to the first voltage setting value, the third switching module 23 and the fourth switching module 24 are switched together according to the set switching timing sequence under the control of the control module 27, and the voltage boost module 26 (i.e., the voltage generation module) can generate a corresponding voltage spike to break down an air gap near the tin whisker 11 and burn out the tin whisker 11.

It should be noted that the voltage peak generated by the boost module 26 is higher than the voltage of the first power module 20, so as to ensure that the voltage peak can break down the air gap near the tin whisker 11 and burn the tin whisker 11.

The first switch module 21, the second switch module 22, the third switch module 23, and the fourth switch module 24 may be an electronic switch tube or an electromagnetic relay, where the electronic switch tube may be a MOS transistor, a triode, an IGBT, or the like, or at least one switch module may be a switch circuit formed by connecting a plurality of electronic switch tubes. The current limiting module 28 may be a resistor, a MOS transistor operating in a resistor region, or a circuit including elements such as a resistor and a MOS. The energy storage module 25 may be a capacitor or a battery, etc. The control module 27 may be a microcontroller, which may be integrated with the main controller in the electronic terminal product, or may be separately provided from the main controller in the electronic terminal product. The control module 27 may be provided with a storage medium to store a corresponding program to control and coordinate operations of the first switch module 21, the second switch module 22, the third switch module 23, and the fourth switch module 24, so as to remove tin whiskers from the electronic terminal product and prevent a tin whisker removal circuit from affecting normal operations of the electronic terminal product after the tin whiskers are removed.

Referring to fig. 2, the present embodiment further provides an electronic terminal product, which has at least one component 12 to be protected and the tin whisker removing circuit shown in fig. 2 disposed in one-to-one correspondence with the component 12 to be protected.

When the electronic terminal product has a plurality of components 12 to be protected, each tin whisker removing circuit can share the same control module 27, the first switch module 21 of each tin whisker removing circuit can be integrated into one multiplexer, the second switch module 22 of each tin whisker removing circuit can be integrated into another multiplexer, the third switch module 23 of each tin whisker removing circuit can be integrated into another multiplexer, and the fourth switch module 24 of each tin whisker removing circuit can be integrated into another multiplexer.

Referring to fig. 2, the present embodiment further provides a tin whisker removing method for removing a tin whisker 11 in the electronic terminal product of the present embodiment, the tin whisker 11 being in the same circuit as the component to be protected, and the tin whisker removing method includes:

firstly, the control module 27 controls the switch path of the first switch module 21 to be turned on, and the switch paths of the second to fourth switch modules 22 to 24 to be turned off, so that the first power module 20 precharges the energy storage module 25 until the voltage of the energy storage module 25 is precharged to a first voltage set value;

then, the control module 27 controls the switch path of the first switch module 21 to be continuously turned on, the switch path of the second switch module 22 to be continuously turned off, and controls the switch path of the third switch module 23 and the switch path of the fourth switch module 24 to be turned on and turned off at a set switch timing sequence, so that the voltage boost module 26 generates a corresponding voltage spike to break down an air gap near the tin whisker 11 to burn out the tin whisker 11;

after the tin whiskers 11 are burnt, the control module 27 controls the switching path of the second switching module 22 to be conducted, so that the electronic terminal product can be normally operated subsequently.

The connection relationship between the modules of the tin whisker removing circuit and the corresponding tin whisker removing method in the present embodiment are described in detail below with reference to the specific example of the tin whisker removing circuit shown in fig. 3 and the flow example of the tin whisker removing method shown in fig. 4.

Referring to fig. 3, in the circuit for removing tin whiskers of the present example, the first power module 20 is a storage battery, the first switch module 21 is an electromagnetic relay Q1, the current limiting module 28 is a current limiting resistor R, the device 12 to be protected is a fuse FU, the second switch module 22 is an electromagnetic relay Q2, the third switch module 23 is an electronic switch Q3, the fourth switch module 24 is an electronic switch Q4, the energy storage module 25 is a capacitor C, and the voltage boosting module 26 is an inductor L. When Q3 and Q4 are IGBT transistors, control terminals of Q1 to Q4 are respectively connected to corresponding signal output terminals of the control module 27, an input terminal of Q1 and an input terminal of Q2 are both connected to the positive electrode of the first power supply module 20, an output terminal of Q1 is connected to one end of a current-limiting resistor R, an output terminal of Q2 is connected to one end of a fuse FU, the other end of the current-limiting resistor R, the other end of the fuse FU, and one end of a capacitor C are all connected to a common connection terminal N, a collector of Q3 is connected to the common connection terminal N, an emitter of Q4 is connected to one end of an inductor L, the other end of the inductor L is connected to a collector of Q4, and an emitter of Q4 and the other end of the capacitor C are.

Referring to fig. 4, the present example provides a method for removing tin whiskers 11 in the same circuit with the device to be protected in the electronic terminal product having the tin whisker removing circuit shown in fig. 3, and the method specifically includes the following steps:

s101, the control module 27 firstly controls the Q1 to be switched on and the Q2 to the Q4 to be switched off, and the first power module 20 pre-charges the capacitor C with a small current under the current limiting action of the current limiting resistor R.

S102, the control module 27 determines whether the voltage value of the capacitor C and the Q1 conduction satisfy the requirement, that is, whether the voltage of the capacitor C is precharged to the first voltage setting value, if yes, S103 is executed, and if no, S101 is returned to.

S103, the control module 27 controls Q1 to be turned on, Q2 to be turned off, and Q3 and Q4 to be switched at a set switching timing and pulse width, so that the inductor L can generate a voltage spike higher than the positive voltage of the first power module 20, and at this time, if the tin whisker 11 in fig. 2 is long enough, the voltage spike generated by the inductor L can break down the surrounding air gap and burn the tin whisker 11. Meanwhile, since the Q2 is not turned on, the continuous arc discharge will not occur after the tin whisker 11 is burned out, and the fuse FU will not be burned out.

S104, after the tin whiskers 11 are burnt out, the control module 27 controls the Q2 to be switched on and the Q3-Q4 to be switched off, so that the electronic terminal product starts to operate normally and the fuse FU operates normally.

It should be noted that, in the circuit for removing tin whiskers and the electronic terminal product of the present embodiment, not only the circuit example shown in fig. 2 and fig. 3 is limited, but also in other examples of the present embodiment, the voltage boosting module 26 may be omitted on the basis of the circuits shown in fig. 2 and fig. 3, as shown in fig. 10, or the third switching module 23, the fourth switching module 24, and the voltage boosting module 26 may be omitted at the same time, as shown in fig. 11, so that the structure and the control strategy of the circuit for removing tin whiskers of the present embodiment may be further simplified. The method for removing the tin whisker by using the tin whisker removal circuit without the boost module 26 shown in fig. 10 can still execute steps S101 to S104 shown in fig. 4, where steps S101 to S102 and S104 are the same as those in the above embodiments and are not described again in detail, except that in step S103, the voltage generated by the first power module 20 can break through the surrounding air gap and burn the tin whisker 11 through the first branch, and at this time Q2 is not turned on, so that no continuous arc is generated after the tin whisker 11 is burned, and the fuse FU is not burned. However, the method for removing tin whiskers by using the tin whisker removing circuit shown in fig. 11 without the third switch module 23, the fourth switch module 24, and the boost module 26 is applied, please refer to fig. 4, steps S101 to S104 shown in fig. 4 can still be executed, and steps S101 to S102 and S104 are the same as those in the above embodiments and will not be described in detail again.

The tin whisker removing circuit, the electronic terminal product and the tin whisker removing method can remove existing tin whiskers of the electronic terminal product when the electronic terminal product leaves a factory and tin whiskers which are newly generated and continuously grow in the use process of the electronic terminal product, can solve the problem that the tin whiskers existing in the electronic terminal product which leaves the factory influence the normal use of the product, are low in cost and high in efficiency, can improve the reliability of the electronic terminal product, and reduce the failure probability of the electronic terminal product in the operation process. The technical scheme of the embodiment is suitable for any electronic terminal product with one power supply module, and the to-be-protected component can be an electrical structure which needs to be protected arbitrarily in the electronic terminal product so as to avoid being influenced by tin whiskers.

It should be further noted that, in the above embodiment, there is only one power module, but the technical solution of the present invention is not limited thereto, and in other embodiments of the present invention, there may be two power modules.

Specifically, referring to fig. 5, another embodiment of the invention provides a tin whisker removal circuit for removing a tin whisker 11 in an electronic terminal product, the tin whisker being in the same circuit as a component 12 to be protected. The tin whisker removing circuit comprises: the power supply system comprises a first power supply module 20, a first switch module 21, a second switch module 22, a third switch module 23, a fourth switch module 24, an energy storage module 25, a boost module 26, a control module 27, a current limiting module 28, a transformation module 29 and a second power supply module 30. The connection relationship among the first power module 20, the first switch module 21, the second switch module 22, the third switch module 23, the fourth switch module 24, the energy storage module 25, the boost module 26, the control module 27, and the current limiting module 28 is the same as that in the above embodiment, and is not described herein again. The boosting module 26, the transforming module 29 and the second power module 30 form a voltage generating module.

The second power module 30 may be a dry battery, a storage battery, a dc generator, or other dc power source. The second power module 30 may be a power source of the electronic terminal product itself, or may be another power source independent from the power source of the electronic terminal product itself. One end of the transformation module 29 is connected to the common connection end N of the energy storage module 25 and the device 12 to be protected, the other end of the transformation module 29 is connected to the second power module 30, and the transformation module 29 is configured to perform reverse operation or forward operation under the control of the control module 27, so that the second power module 30 can charge the energy storage module 25. When the electronic terminal product works normally, the voltage of the first power module 20 can be converted into the voltage of the second power module 30 through the voltage transformation module 29, and when the tin whiskers 11 of the electronic terminal product need to be removed, the second power module 30 can pre-charge the energy storage module 25.

Optionally, the first power module 20 and the second power module 30 are dc power supplies with different voltages, and the transformation module 29 is a DCDC buck transformation module (dc-to-dc step-down transformation module), a DCDC boost transformation module (dc-to-dc step-up transformation module), or a DCDC boost-buck transformation module (dc-to-dc step-up and step-down transformation module). The specific circuit design of the transformer module 29 can refer to the conventional design in the art, and is not illustrated and described herein. In this embodiment, the voltage spike generated by the boost module 26 is higher than the voltage of the first power module 20 and the voltage of the second power module 30, respectively.

Referring to fig. 5, the present embodiment further provides an electronic terminal product, which includes at least one device 12 to be protected, and the circuit for removing tin whiskers, as described in the present embodiment, connected to the device 12 to be protected.

Referring to fig. 5, the present embodiment further provides a tin whisker removing method for removing a tin whisker 11 in the electronic terminal product of the present embodiment, the tin whisker 11 being in the same loop as the component 12 to be protected, the tin whisker removing method includes:

first, the control module 27 controls the switching paths of the first to fourth switching modules 21 to 24 to be turned on or off, so as to pre-charge the energy storage module 25 through the first power module 20 and/or the second power module 30 until the voltage of the energy storage module 25 is pre-charged to a second voltage setting value, which may be the same as or different from the first voltage setting value of the previous embodiment.

Then, the control module 27 controls the switch paths of the first to second switch modules 21 to 22 to be turned off, and controls the switch path of the third switch module 23 and the switch path of the fourth switch module 24 to be turned on and off at a set switch timing, so that the voltage boost module 26 generates a corresponding voltage spike to break down an air gap near the tin whisker 11 to burn out the tin whisker 11.

After the tin whiskers 11 are burnt out, the control module 27 controls the switch path of the first switch module 21 and the switch path of the second switch module 22 to be sequentially conducted, so that the electronic terminal product can be normally operated subsequently.

The connection relationship between the modules of the tin whisker removing circuit and the corresponding tin whisker removing method in the present embodiment are described in detail below with reference to the specific example of the tin whisker removing circuit shown in fig. 6 and the flow examples of the tin whisker removing method shown in fig. 7 to 9.

Referring to fig. 6, in the circuit for removing tin whiskers of the embodiment, the first power module 20 and the second power module 30 are both storage batteries, and the voltage of the first power module 20 is higher than that of the second power module 30, the first switch module 21 is an electromagnetic relay Q1, the current limiting module 28 is a current limiting resistor R, the device 12 to be protected is a fuse FU, the second switch module 22 is an electromagnetic relay Q2, the third switch module 23 is an electronic switch Q3, the fourth switch module 24 is an electronic switch Q4, the energy storage module 25 is a capacitor C, the voltage boosting module 26 is an inductor L, and the voltage transforming module 29 is a DCDC buck transformation module.

Referring to fig. 7, an example of the method for removing tin whiskers in this embodiment can remove tin whiskers 11 in the same loop as a component 12 to be protected in an electronic terminal product having the tin whisker removal circuit shown in fig. 6, and the method includes the following specific processes:

s201, the control module 27 firstly controls Q1-Q4 to be disconnected, and controls the DCDC buck transformation module 29 to reversely work, so that the second power module 30 precharges the capacitor C through the DCDC buck transformation module 29.

S202, the control module 27 determines whether the voltage value of the capacitor C meets the requirement, i.e. whether the voltage of the capacitor C is precharged to the second voltage setting value, if yes, S203 is executed, otherwise, S201 is returned to.

S203, the control module 27 controls Q1-Q2 to be turned off, and Q3 and Q4 are switched at the set switching timing and pulse width, so that the inductor L can generate a voltage spike higher than the positive voltage of the first power module 20, and at this time, if the tin whisker 11 in fig. 6 is long enough, the voltage spike generated by the inductor L can break down the surrounding air gap and burn the tin whisker 11. Meanwhile, since the Q2 is not turned on, the continuous arc discharge will not occur after the tin whisker 11 is burned out, and the fuse FU will not be burned out.

S204, after the tin whiskers 11 are burnt out, the control module 27 controls the Q1 and the Q2 to be switched on in sequence, and the Q3-Q4 are switched off, so that the electronic terminal product starts to operate normally and the fuse FU operates normally. Specifically, the control module 27 first controls the Q1 to be turned on, and the first power module 20 pre-charges the capacitor C with a small current under the current limiting action of the current limiting resistor R, so as to avoid voltage spike when the electronic end product starts to operate normally.

The exemplary tin whisker removal method can initially pre-charge the capacitor C using the DCDC buck transformer module operating in reverse.

Referring to fig. 8, another example of the method for removing tin whiskers in this embodiment can remove tin whiskers 11 in the same circuit as a component 12 to be protected in an electronic terminal product having the tin whisker removal circuit shown in fig. 6, and the method includes the following specific processes:

s301, the control module 27 firstly controls the Q1 to be switched on and the Q2 to the Q4 to be switched off, and the first power module 20 pre-charges the capacitor C with a small current under the current limiting action of the current limiting resistor R.

S302, the control module 27 determines whether the voltage value of the capacitor C and the Q1 conduction satisfy the requirement, that is, determines whether the voltage of the capacitor C is precharged to a third voltage setting value, where the third voltage setting value is smaller than the second voltage setting value, if so, S303 is executed, and if not, S301 is returned to.

And S303, the control module 27 firstly controls Q1-Q4 to be disconnected, and controls the DCDC buck transformation module 29 to reversely work, so that the second power supply module 30 precharges the capacitor C through the DCDC buck transformation module 29.

S304, the control module 27 determines whether the voltage value of the capacitor C meets the requirement, i.e. whether the voltage of the capacitor C is precharged to the second voltage setting value, if so, S305 is executed, otherwise, S303 is returned to.

S305, the control module 27 controls Q1-Q2 to turn off, and Q3 and Q4 are switched at the set switching timing and pulse width, so that the inductor L can generate a voltage spike higher than the positive voltage of the first power module 20, and at this time, if the tin whisker 11 in fig. 6 is long enough, the voltage spike generated by the inductor L can break down the air gap around the tin whisker and burn the tin whisker. Meanwhile, since the Q2 is not turned on, the continuous arc discharge will not occur after the tin whisker 11 is burned out, and the fuse FU will not be burned out.

S306, after the tin whiskers 11 are burnt out, the control module 27 controls the Q1 and the Q2 to be switched on in sequence, and the Q3-Q4 are switched off, so that the electronic terminal product starts to operate normally and the fuse FU operates normally. Specifically, the control module 27 first controls the Q1 to be turned on, and the first power module 20 pre-charges the capacitor C with a small current under the current limiting action of the current limiting resistor R, so as to avoid voltage spike when the electronic end product starts to operate normally.

The tin whisker removal method of the present example can initially pre-charge the capacitor C in two stages, wherein the first power module 20 pre-charges a portion of the capacitor C by turning on the Q1, and then the DCDC buck transformation module works in reverse to pre-charge the capacitor C until the capacitor C is pre-charged to the second voltage setting. Therefore, compared with the tin whisker removing method shown in fig. 7, the performance requirement on the DCDC buck transformation module and the circuit design difficulty can be reduced, and the cost of the tin whisker removing circuit can be reduced.

It should be noted that, in the circuit for removing tin whiskers and the electronic terminal product of the present embodiment, the boost module 26 may be omitted on the basis of the circuits shown in fig. 5 and fig. 6, as shown in fig. 12, or the third switch module 23, the fourth switch module 24, and the boost module 26 may be omitted at the same time, as shown in fig. 13, so that the structure and the control strategy of the circuit for removing tin whiskers of the present embodiment may be further simplified. The method for removing tin whiskers by using the tin whisker removal circuit without the boost module 26 shown in fig. 12 can still execute the steps shown in fig. 7 or fig. 8, and details are not repeated, but the difference is that when step S203 or step S303 is executed, the voltage generated by the second power module 30 can be output through reverse transformation by the transformation module 29, and break through the surrounding air gap and burn out the tin whiskers 11, or the voltage generated by the first power module 20 can be output through the first branch and break through the surrounding air gap and burn out the tin whiskers 11, and at this time, Q2 is not turned on, and after the tin whiskers 11 are burned out, continuous arcing cannot be generated, and the fuse FU cannot be burned out. The method for removing tin whiskers by using the tin whisker removing circuit which is shown in fig. 13 and omits the third switch module 23, the fourth switch module 24 and the boost module 26 can still execute the steps shown in fig. 7 or fig. 8, and details are not repeated, but the differences are that, when step S203 or step S303 is executed, the control of Q3 and Q4 can be omitted, and the voltage generated by the second power module 30 can be output through the reverse transformation of the transformation module 29 to break through the surrounding air gap and burn off the tin whiskers 11, or the voltage generated by the first power module 20 is output through the first branch and break through the surrounding air gap and burn off the tin whiskers 11, and at this time, Q2 is not turned on, and no continuous arc-pulling occurs after the tin whiskers 11 are burned off, and the fuse FU cannot be burned off.

The technical scheme of the embodiment can also remove the existing tin whiskers of the electronic terminal product when the electronic terminal product leaves the factory and the tin whiskers which are newly generated and continuously grown in the use process of the electronic terminal product, can solve the problem that the tin whiskers existing in the electronic terminal product which leaves the factory influence the normal use of the product, and has low implementation cost and high efficiency. The technical scheme of the embodiment can be applied to electronic terminal products with dual power supply modules, such as electronic terminal products like automobiles, the failure probability of the whole automobile in the running process can be reduced, and the driving characteristics and the safety of the whole automobile are improved. In addition, referring to fig. 6 and fig. 9, in the technical solution of the present embodiment, the DCDC buck transformation module in fig. 6 may be replaced by a DCDC boost transformation module, where the voltage of the second power module 30 is higher than the voltage of the first power module 20. The method for removing the tin whisker 11 in the same circuit as the device 12 to be protected in the electronic terminal product based on the tin whisker removal circuit shown in fig. 9 may also adopt the method flow shown in fig. 7 or fig. 8, which is not described herein again.

It should be further noted that, when the method for removing tin whiskers in the electronic terminal product described in this embodiment is executed to remove tin whiskers in the same circuit with the component to be protected in the electronic terminal product described in this embodiment, the execution frequency may be further set, for example, the execution frequency is set to be executed once before the electronic terminal product leaves a factory, and then the execution frequency is set to be executed once when the electronic terminal product is started up each time, or executed once every certain number of days, so as to ensure that even if new tin whiskers are generated again in the use process of the electronic terminal product, the tin whiskers can be removed in time. When the tin whisker removing method of the embodiment is adopted to remove the tin whisker in the electronic terminal product, the tin whisker can be burnt as long as the tin whisker grows to be long enough, the influence of the tin whisker to the normal use of the electronic terminal product is relatively small for the tin whisker not to be long enough, even if the tin whisker is not removed in the process of removing the tin whisker at a certain time, the tin whisker can continue to grow as the service time of the electronic terminal product is prolonged, and the tin whisker can be removed in the process of removing the tin whisker at a certain time later.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art according to the above disclosure are within the scope of the present invention.