阅读说明：本技术 加热设备 (Heating device ) 是由 C.贝纳本 S.维塔利 于 2018-05-25 设计创作，主要内容包括：加热设备(10),其适合用于加热在包括至少第一接触片(8_1)的电子部件(8)和印刷电路板(4)之间的至少一个焊接接头,焊接接头一方面将电子部件(8)固连至印刷电路板(4),并且另一方面提供电连续性,电子部件(8)还具有电子部件宽度(l_8)和电子部件厚度(e_8),其特征在于,所述加热设备包括适合用于联接到电源的电连接装置(12)和适合用于达到至少等于焊料的熔点的温度的加热装置(14)。(Heating device (10) suitable for heating at least one solder joint between an electronic component (8) comprising at least a first contact pad (8 _ 1) and a printed circuit board (4), the solder joint on the one hand securing the electronic component (8) to the printed circuit board (4) and on the other hand providing electrical continuity, the electronic component (8) further having an electronic component width (l _ 8) and an electronic component thickness (e _ 8), characterized in that it comprises electrical connection means (12) suitable for coupling to a power source and heating means (14) suitable for reaching a temperature at least equal to the melting point of the solder.)

1. A heating device (10) suitable for heating at least one solder joint between an electronic component (8) comprising at least a first contact pad (8 _ 1) and a printed circuit board (4), the solder joint on the one hand securing the electronic component (8) to the printed circuit board (4) and on the other hand providing electrical continuity, the electronic component (8) further having an electronic component width (l _ 8) and an electronic component thickness (e _ 8), characterized in that the heating device comprises electrical connection means (12) suitable for coupling to a power source and heating means (14) suitable for reaching a temperature at least equal to the melting point of the solder.

2. The heating device (10) according to claim 1, characterized in that the heating means (14) have a cylindrical shape.

3. The heating device (10) according to claim 1, characterized in that said heating means (14) have a parallelepiped shape.

4. A heating device (10) according to any of claims 1 to 3, characterized in that the heating means thickness (e _ 14) of the heating means (14) is smaller than the space (es _8_ 4) separating the electronic component (8) from the printed circuit board (4).

5. Heating device (10) according to any of claims 1 to 4, characterized in that the heating device length (L _ 14) of the heating device (14) is larger than the electronic component width (L _ 8).

6. A heating device (10) according to any of claims 1 to 5, characterized in that the heating means (14) are adapted to reach a temperature at least equal to the melting point of the material from which the solder is made.

7. Heating method for heating at least one solder joint between an electronic component (8) and a printed circuit board (4) according to any one of claims 1 to 6, comprising the steps of:

coupling the heating device (10) to a power source,

-placing a heating device (10) between the electronic component (8) and the printed circuit board (4) at a space (es _8_ 4) separating said electronic component (8) from the printed circuit board (4),

starting the power supply, and

-moving the heating device (14) against the solder under the electronic component (8) at a determined speed when the temperature of the heating device (14) reaches the melting point of the material of which the solder is made.

Technical Field

The present invention generally relates to a heating apparatus for unsoldering an electronic component from a printed circuit board.

The invention is particularly applicable in the field of electronics.

Background

Electronic equipment, such as electronic computers arranged in motor vehicles for controlling engines, is subjected to a lot of stress. These stresses may be of mechanical, thermal, electrical nature and may sometimes lead to permanent or intermittent failure of the electronic computer used to control the engine.

These malfunctions or malfunctions of the computer for controlling the engine require the intervention of a technician to diagnose them. In order to carry out such failure analysis of the electronic computer for controlling the engine, it must generally be removed from the motor vehicle so that the cause of the failure can be checked.

The high integration density of electronic components means that some complex electronic components (e.g. microcontrollers) need to be removed in order to analyze the cause of the failure. For this purpose, it is known practice to use a bell jar to locally heat the electronic component to be unsoldered and the printed circuit board to melt the metal alloy of one or more solder joints. Before this step is carried out, it is necessary to bake the electronic board to be tested, which sometimes makes the observed failures (for example related to the presence of moisture in the printed circuit board and/or the electronic components) disappear.

Disclosure of Invention

The present invention proposes a heating device which offers a partial or complete solution to the technical drawbacks of the cited prior art.

To this end, a first aspect of the invention proposes a heating device suitable for heating at least one solder joint between an electronic component comprising at least a first contact pad and a printed circuit board, the solder joint on the one hand securing the electronic component to the printed circuit board and on the other hand providing electrical continuity, the electronic component also having an electronic component width, an electronic component thickness, characterized in that the heating device comprises electrical connection means suitable for coupling to a power source and heating means suitable for reaching a temperature at least equal to the melting point of the material from which the solder is made.

For example, the heating device has a cylindrical shape.

Alternatively, the heating device has a parallelepiped shape.

In order to increase the efficiency of the heating device, it is proposed, for example, that the heating device of the heating device has a thickness smaller than the space separating the electronic component from the printed circuit board.

In order to make the heating device easy to operate, the heating means have a heating means length, for example, which is greater than the width of the electronic component.

In order to unsolder electronic components from a printed circuit, for example, it is proposed: the heating means are adapted to reach a temperature at least equal to the melting point of the material of which the solder is made.

A second aspect of the invention proposes a method for heating at least one solder joint between an electronic component and a printed circuit board, the method comprising the steps of:

coupling the heating device to a power source,

placing a heating device between the electronic component and the printed circuit board, at a space separating said electronic component from the printed circuit board,

starting the power supply, and

moving the heating device under the electronic component against the solder at a determined speed when the temperature of the heating device reaches the melting point of the solder.

Drawings

Other features and advantages of the present invention will become apparent from a reading of the following description. This description is purely illustrative and should be read with reference to the accompanying drawings, in which:

figure 1 is a simplified diagram of an electronic board,

figure 2 is a cross-sectional view of the electronic board of figure 1,

FIG. 3 is a schematic view of the apparatus of the invention, an

Figure 4 is a schematic view of the apparatus of the invention according to another embodiment.

Detailed Description

Fig. 1 shows a schematic view of an electronic board 2, which electronic board 2 may be an electronic board of an electronic computer arranged in a motor vehicle for controlling an engine. The electronic board 2 comprises a printed circuit board 4, also called PCB, on which electronic components 6 are arranged. Depending on the complexity of the electronic board 2, the printed circuit board 4 may be a single-layer or a multilayer printed circuit board. The electronic component 6 may have various forms and have a variable number of pins.

In the examples used below to illustrate the invention, complex electronic components 8 are also soldered to the printed circuit board 4. The complex electronic component 8 is for example a microcontroller. Preferably, the complex electronic component 8 is provided with a ball grid array or BGA package. Furthermore, one of the advantages of such a component equipped with a BGA package is its compactness, which makes it possible to have a relatively high contact patch density, corresponding to the distance between the solder balls. For example, the distance between the solder balls is about 100 μm (1 μm = 1.10)^-6m）。

Fig. 2 schematically shows a cross-sectional view of a complex electronic component 8 soldered onto a printed circuit board 4. Thus, the complex electronic component 8 has a ball grid consisting of a first contact pad 8_1, a second contact pad 8_2, a third contact pad 8_3 and a fourth contact pad 8_4 in this example. The number of contact pads and the layout of the contact pads are given by way of example. Further, the complex electronic component 8 has a complex electronic component thickness e _8 and a complex electronic component width l _ 8.

The printed circuit board 4 includes a first socket 4_1, a second socket 4_2, a third socket 4_3 and finally a fourth socket 4_ 4. In one exemplary embodiment, the receptacles 4_1 to 4_4 have the same shape as the contact pads 8_1 to 8_ 4. Further, the receptacles 4_1 to 4_4 have the same spacing as the spacing of the contact pads 8_1 to 8_4 on the one hand, and the same layout as the layout of the contact pads 8_1 to 8_4 on the other hand.

In order to achieve contact and electrical continuity between the complex electronic component 8 and the printed circuit board 4, the solder joint 20 is made of a metal alloy. For example, a "wave" type weld, well known to those skilled in the art, is performed.

As mentioned earlier in this specification, sometimes a fault may occur in the electronic components 6 of the electronic computer for controlling the engine. In the case of our example, it will be that the complex electronic component 8 will exhibit a fault. For example, the fault may be a fault 20 on the analog input, which would require the removal of the complex electronic component 8.

In the example of fig. 2 and the subsequent figures, the second socket 4_2 of the printed circuit board 4 has been selected to be defective in order to illustrate the invention and the associated method. In order to identify and locate the fault, it is necessary to unsolder the complex electronic component 8 from the printed circuit board 4 in order to determine whether the fault originated from the printed circuit board 4 or from the complex electronic circuit 8.

To this end, the invention proposes a heating device 10, which heating device 10 is suitable for heating solder joints and for unsoldering complex electronic components 8 from the printed circuit board 4 without heating the printed circuit board 4 and without using a bell jar.

As shown in fig. 3, the heating apparatus 10 includes an electrical connection device 12 and a heating device 14. The heating device 14 takes the shape of, for example, a parallelepiped like a blade. The heating device 14 has a heating device length L _14, a heating device width L _14, and a heating device thickness e _ 14.

Advantageously, in order to make it easier for the heating device 14 to pass under the complex electronic component 8, it is proposed that the value of the heating device length L _14 is slightly greater than the value of the width e _8 of the complex electronic component. Thus, for example, for a complex electronic component width e _8 equal to 1.3cm, the heating device length L _14 is equal to 1.5 cm.

Furthermore, in order to allow the heating device 14 to pass under and between the complex electronic component 8 and the printed circuit board 4, the heating device thickness e _14 is smaller than the space es _8_4 separating the complex electronic component 8 from the printed circuit board 4. The spaces es _8_4 are equal and determined by the solder height 20_ h _ s. For example, in the case where the value of the solder height 20_ h _ s is equal to 100 μm, the heating device thickness e _14 takes a value of 80 μm.

In addition, in order to improve the efficiency of the heating apparatus 10, it is proposed that: the heating device 14 and more specifically the heating device width l _14 has a value greater than the solder width 20_1_ s.

The heating apparatus 10 also has a heating device first end 16 and a heating device second end 18. The heating device first end 16 and the heating device second end 18 are arranged on both sides of the heating device 14. In the exemplary embodiment shown here, they are arranged on both sides of the blade.

The two ends 16 and 18 are adapted to receive and/or couple to the electrical connection device 12. The electrical connection means 12 are for example two electrical wires coupled to a stable power supply.

In another exemplary embodiment of the present invention and as shown in fig. 4, the heating device 14 is U-shaped. For example, a first portion of U, called U _1, has a length at least equal to the width of the complex electronic component l _ 8. Furthermore, the two arms of U (called U _2 and U _ 3) have the same dimensions, which are at least equal to but preferably greater than the complex electronic component thickness e _ 8. In another exemplary embodiment, the two arms of U (referred to as U _2 and U _ 3) have a height at least equal to the sum of the complex electronic component thickness e _8 and the height of solder 20_ h _ s.

In another exemplary embodiment, the heating device 14 has a cylindrical shape, wherein the diameter of the cylinder is smaller than the height h _ s of the solder.

The heating device 10 is made of, for example, a metal or a metal alloy.

The invention also proposes a heating method which makes it possible to heat at least one solder joint of a ball grid array of electronic components 6, and more particularly at least one solder joint of a ball grid array of complex electronic components 8. In the remainder of the description, it will be considered that the electronic board 2 is outside the casing of the electronic computer for controlling the engine. Furthermore, possible faults will be considered and located in areas where complex electronic components 8 are present.

The method of the invention first proposes to couple the electrical connection device 12 to a power source in a first step e 1. In one exemplary embodiment, the power supply is a regulated power supply.

During the second step e2, the heating device 10 is brought closer to the complex electronic component 8 to be unsoldered. Preferably, the heating device 14 is positioned at a space es _8_4 separating the complex electronic component 8 from the printed circuit board 4. Further, the heating device 14 is positioned against one or more weld joints 20.

During a third step e3, the power supply is activated. The power source is adapted to generate sufficient voltage to bring the heating means 14 to a temperature at least equal to the melting point of the metal alloy of which the weld joint is made. In an exemplary embodiment, the temperature is 250 ℃.

During a fourth step e4, the heating device 10 is moved around so that it passes between the complex electronic component 8 and the printed circuit board 4. Advantageously, the speed of movement of the heating device 10 is related to the rate at which the metal alloy of the weld joint 20 melts when in contact with the heating means 14. In an exemplary embodiment, the heating device is moved over the entire width of the complex electronic component 8, which advantageously allows it to be unsoldered from the printed circuit board 4.

The present invention thus allows for the heating of one or more solder joints that attach electronic components to a printed circuit board without the use of a bell jar. Therefore, advantageously, only the electronic component to be unsoldered is subjected to an increase in temperature, thereby improving the reliability of detecting a failure. Thus, the electronic component can be unsoldered and removed from the printed circuit board without overheating nearby components.

The invention is of course not limited to the preferred embodiments described above and shown in the drawings and the variant embodiments mentioned, but extends to all variants within the capabilities of the person skilled in the art.