阅读说明：本技术 正温度系数元件 (Positive temperature coefficient element ) 是由 曾郡腾 王绍裘 于 2019-01-21 设计创作，主要内容包括：一种正温度系数元件包括：电流及温度感测元件、第一绝缘层、第二绝缘层、第一电极层及第二电极层。该电流及温度感测元件为层叠结构,包含第一导电层、第二导电层及PTC材料层,该第一导电层设于该PTC材料层的第一表面,第二导电层设于该PTC材料层的第二表面,第二表面位于第一表面的相对侧。该第一绝缘层设置于该第一导电层表面,且第二绝缘层设置于该第二导电层表面。该第一电极层设置于该第一绝缘层表面,且电气连接该第一导电层。该第二电极层设置于该第二绝缘层表面,且电气连接该第二导电层。该第一电极层和第二电极层作为该正温度系数元件焊接于一电路板的爬锡面。(A positive temperature coefficient element comprising: the temperature sensing device comprises a current and temperature sensing element, a first insulating layer, a second insulating layer, a first electrode layer and a second electrode layer. The current and temperature sensing element is a laminated structure and comprises a first conducting layer, a second conducting layer and a PTC material layer, wherein the first conducting layer is arranged on the first surface of the PTC material layer, the second conducting layer is arranged on the second surface of the PTC material layer, and the second surface is positioned on the opposite side of the first surface. The first insulating layer is arranged on the surface of the first conductive layer, and the second insulating layer is arranged on the surface of the second conductive layer. The first electrode layer is arranged on the surface of the first insulating layer and is electrically connected with the first conducting layer. The second electrode layer is arranged on the surface of the second insulating layer and is electrically connected with the second conducting layer. The first electrode layer and the second electrode layer are used as the positive temperature coefficient element and are welded on a tin climbing surface of a circuit board.)

1. A positive temperature coefficient device, comprising:

The current and temperature sensing element is of a laminated structure and comprises a first conducting layer, a second conducting layer and a PTC material layer, wherein the first conducting layer is arranged on the first surface of the PTC material layer, the second conducting layer is arranged on the second surface of the PTC material layer, and the second surface is positioned on the opposite side of the first surface;

A first insulating layer disposed on the surface of the first conductive layer;

A second insulating layer arranged on the surface of the second conductive layer;

A first electrode layer disposed on the surface of the first insulating layer and electrically connected to the first conductive layer; and

The second electrode layer is arranged on the surface of the second insulating layer and is electrically connected with the second conducting layer;

The first electrode layer and the second electrode layer are used as the positive temperature coefficient element to be welded on a tin climbing surface of a circuit board.

2. The positive temperature coefficient device according to claim 1, wherein the first electrode layer, the first insulating layer, the first conductive layer, the PTC material layer, the second conductive layer, the second insulating layer and the second electrode layer are laminated in this order.

3. PTC-element according to claim 1, wherein the first electrode layer, the first insulating layer, the first conductive layer, the PTC-material layer, the second conductive layer, the second insulating layer and the second electrode layer form a bottom plane facing the circuit board as an interface for soldering to the circuit board.

4. PTC-element according to claim 1, further comprising:

a first conductive hole passing through the first insulating layer and connecting the first electrode layer and the first conductive layer; and

and a second conductive hole passing through the second insulating layer and connecting the second electrode layer and the second conductive layer.

5. PTC-element according to claim 4, wherein the first conductive via is located in the center, side or corner of the first insulating layer and the second conductive via is located in the center, side or corner of the second insulating layer.

6. PTC element according to claim 1, wherein the first insulating layer, the first conductive layer, the PTC material layer, the second conductive layer and the second insulating layer form a bottom plane facing the circuit board, the outer edge of the first electrode layer is recessed with respect to the first insulating layer to form a gap, and the outer edge of the second electrode layer is recessed with respect to the second insulating layer to form a gap.

7. PTC-element according to claim 6, wherein the outer edge of the first electrode layer comprises an extension block extending to the edge of the first insulating layer and the outer edge of the second electrode layer comprises an extension block extending to the edge of the second insulating layer.

Technical Field

The present invention relates to a thermistor, and more particularly to a Positive Temperature Coefficient (PTC) device.

Background

Ptc devices can be used to protect electrical circuits from damage due to overheating or excessive current flow. Ptc devices typically comprise two electrodes and a resistive material disposed between the two electrodes. The resistance material has the positive temperature coefficient characteristic, namely, the resistance value is low at room temperature, and when the temperature rises to a critical temperature or excessive current is generated on a circuit, the resistance value can jump hundreds or thousands of times at once, thereby inhibiting the excessive current from passing through and achieving the purpose of circuit protection; or the over-temperature detection circuit can detect the ambient temperature in advance to indicate the back-end circuit to start over-temperature protection actions, such as shutdown or power supply stopping actions. When the temperature is reduced to room temperature or no overcurrent is generated on the circuit, the PTC element can return to the low resistance state, so that the circuit can operate normally again. This re-usability advantage allows the ptc device to replace a fuse or other temperature sensing device, and be more widely used in high density electronic circuits.

The future electronic products will be developed to have the trend of being light, thin, short and small, so that the electronic products can be more miniaturized. For example, in a mobile phone, the PTC overcurrent protection device is disposed on a Protection Circuit Module (PCM), and an external electrode plate thereof occupies a certain space, so that the ultra-thin overcurrent protection device has a strong demand. In the application of Surface Mount Device (SMD) over-current protection, how to reduce the thickness of the protection device is a major challenge in the current technology.

For example, according to the specification of SMD0201, the length is 0.6 + -0.03 mm, the width is 0.3 + -0.03 mm, and the thickness is 0.25 + -0.03 mm. The manufacturing time and the width dimension are not problematic, but the thickness requirement is not easy to achieve. At present, the carbon black plate of the pressboard line can be pressed to be 0.20mm as thin as possible, but the carbon black plate of the pressboard line is 0.2-0.23 mm as thin as possible on a ceramic powder plate, if the design of pre-impregnated glass fiber material (pre; PP layer) and inner and outer layer circuits (see the US patent US6,377,467) is still adopted, the thickness is not satisfactory, and if the thickness is close to or even larger than the width, the problem of element overturning caused by over-thick thickness can occur during subsequent production, packaging and customer use. In addition, because the inner layer circuit and the outer layer circuit are included, when a small-sized product is manufactured, the problem of inaccurate alignment of the inner layer circuit and the outer layer circuit is easily caused, and the production yield is affected.

In order to solve the above problems, the U.S. Pat. No. 9,007,166 proposes an improvement, which is to directly design a PTC substrate without adding a PP layer and an outer electrode layer, and only etch or cut the isolation line on one side of the electrode surface to divide it into left and right electrodes, so as to control the thickness of the PTC overcurrent protection device to be less than or equal to 0.28 mm. However, since the electrode surfaces on both sides are not symmetrical and have front and back surfaces, it is troublesome to distinguish the front and back surfaces when performing subsequent electrical detection and packaging, and if the isolation line has a deviation due to the influence of expansion and contraction of the material during manufacturing, the left and right electrodes are large and small, which affects the electrical characteristics. In addition, the element has no PP structural support, and the element may have the problem of easy breakage due to insufficient strength in the manufacturing process.

Disclosure of Invention

The invention discloses a positive temperature coefficient element, which provides overcurrent protection and/or temperature sensing functions, has simple structure and process, and is particularly suitable for manufacturing small elements with specifications of 0402 or 0201. The inner layer of the positive temperature coefficient element is not provided with a circuit, the problems of expansion and contraction of materials and alignment of the inner layer circuit and the outer layer circuit are avoided, the two PP supporting structures of the plates are still maintained, and the manufacturing yield can be improved besides the product structure.

A ptc device according to an embodiment of the present invention comprises: the temperature sensing device comprises a current and temperature sensing element, a first insulating layer, a second insulating layer, a first electrode layer and a second electrode layer. The current and temperature sensing element is a laminated structure and comprises a first conducting layer, a second conducting layer and a PTC material layer, wherein the first conducting layer is arranged on the first surface of the PTC material layer, the second conducting layer is arranged on the second surface of the PTC material layer, and the second surface is positioned on the opposite side of the first surface. The first insulating layer is arranged on the surface of the first conductive layer, and the second insulating layer is arranged on the surface of the second conductive layer. The first electrode layer is arranged on the surface of the first insulating layer and is electrically connected with the first conducting layer. The second electrode layer is arranged on the surface of the second insulating layer and is electrically connected with the second conducting layer. The first electrode layer and the second electrode layer are used as the positive temperature coefficient element and are welded on a tin climbing surface of a circuit board.

In one embodiment, the first electrode layer, the first insulating layer, the first conductive layer, the PTC material layer, the second conductive layer, the second insulating layer, and the second electrode layer are sequentially stacked.

in one embodiment, the first electrode layer, the first insulating layer, the first conductive layer, the PTC material layer, the second conductive layer, the second insulating layer and the second electrode layer form a bottom plane facing the circuit board as an interface for soldering to the circuit board.

In one embodiment, the PTC element further comprises a first conductive via and a second conductive via. The first conductive hole passes through the first insulating layer and connects the first electrode layer and the first conductive layer. The second conductive hole passes through the second insulating layer and connects the second electrode layer and the second conductive layer.

in one embodiment, the first conductive via is located at the center, side or corner of the first insulating layer, and the second conductive via is located at the center, side or corner of the second insulating layer.

In one embodiment, the first insulating layer, the first conductive layer, the PTC material layer, the second conductive layer and the second insulating layer form a bottom plane facing the circuit board, the outer edge of the first electrode layer is recessed relative to the first insulating layer to form a notch, and the outer edge of the second electrode layer is recessed relative to the second insulating layer to form a notch.

In one embodiment, the outer edge of the first electrode layer includes an extension block extending to the edge of the first insulating layer, and the outer edge of the second electrode layer includes an extension block extending to the edge of the second insulating layer.

The positive temperature coefficient element of the invention does not need to manufacture a complex inner layer circuit, has no problems of expansion and shrinkage and inner and outer layer contraposition, can be manufactured by a simple pressing technology, and is particularly suitable for manufacturing small-sized elements such as 0402 or 0201 specifications and the like. In addition, the elements can be designed to have the same width and thickness dimensions, and are not affected by the overturning problem.

Drawings

Fig. 1 to 4 show a manufacturing process of a ptc device according to an embodiment of the present invention.

Fig. 5 is a schematic perspective view of a ptc device according to an embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view of an embodiment of a ptc device according to the present invention.

Fig. 7 is a schematic perspective view of a ptc device according to another embodiment of the present invention.

Fig. 8 shows a method for manufacturing a ptc device according to another embodiment of the present invention.

Fig. 9 is a schematic perspective view of a ptc device according to another embodiment of the present invention.

Fig. 10 shows a method for manufacturing a ptc device according to another embodiment of the present invention.

list of reference numerals

10. 70, 90 positive temperature coefficient element

11 Current and temperature sensing element

12 PTC material layer

13 first conductive layer

14 second conductive layer

15 first insulating layer

16 second insulating layer

17 first electrode layer

18 second electrode layer

20 holes

21 first conductive via

22 second conductive via

24 base plane

26 gap

27. 28 extension block

60 circuit board

61 solder

81. 91 groove

Detailed Description

In order to make the aforementioned and other technical matters, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 1, a first electrode layer 17, a first insulating layer 15, a first conductive layer 13, a PTC material layer 12, a second conductive layer 14, a second insulating layer 16, and a second electrode layer 18 are laminated to form a laminated structure. A first conductive layer 13 is provided on a first surface of the layer of PTC material 12 and a second conductive layer 14 is provided on a second surface of the layer of PTC material 12, the second surface being on the opposite side of the first surface. The first insulating layer 15 is disposed on the surface of the first conductive layer 13, and the second insulating layer 16 is disposed on the surface of the second conductive layer 14. The first electrode layer 17 is disposed on the surface of the first insulating layer 15, and the second electrode layer 18 is disposed on the surface of the second insulating layer 16. The first and second conductive layers 13 and 18 may be copper layers, the first and second insulating layers 15 and 16 may be pre-preg glass fiber materials (prepreg), and the first and second insulating layers may be copper electrodes. The PTC material layer 12 contains a crystalline polymer and a conductive filler dispersed in the crystalline polymer. The crystalline polymer material may include, for example, polyethylene, polypropylene, polyfluorene, and mixtures and copolymers thereof. The conductive filler may be carbon black, metal particles, metal carbides, metal borides, metal nitrides, and the like. For example: the metal powder in the conductive filler may be selected from nickel, cobalt, copper, iron, tin, lead, silver, gold, platinum or other metals and alloys thereof. The conductive ceramic powder in the conductive filler may be selected from metal carbides, such as: titanium carbide (TiC) and carbide(WC), Vanadium Carbide (VC), zirconium carbide (ZrC), niobium carbide (NbC), tantalum carbide (TaC), molybdenum carbide (MoC), and hafnium carbide (HfC); or from metal borides, such as: titanium boride (TiB)₂) Vanadium Boride (VB)₂) Zirconium boride (ZrB)₂) Niobium boride (NbB)₂) Molybdenum boride (MoB)₂) And hafnium boride (HfB)₂) (ii) a Or from metal nitrides, such as: zirconium nitride (ZrN). In other words, the electrically conductive filler may be selected from a mixture of the aforementioned metals or electrically conductive ceramics, an alloy, a cemented carbide, a solid solution (sol solution) or a core-shell.

Reference is made to fig. 2 and 3, wherein fig. 2 is a transverse view and fig. 3 is a top view. Holes 20 are formed in the upper and lower portions of the laminated substrate at equally spaced locations, the upper holes 20 extending through the first electrode layer 17 and the first insulating layer 15 to the surface of the first conductive layer 13, and the lower holes 20 extending through the second electrode layer 18 and the second insulating layer 16 to the surface of the second conductive layer 14. The hole 20 can be directly manufactured by laser drilling, is suitable for manufacturing small-size elements, and can accurately control the depth of the hole 20. The holes 20 may also be formed by etching the first electrode layer 17 and the second electrode layer 18, and then laser drilling the first insulating layer 15 and the second insulating layer 16. The holes 20 are not limited to laser drilling but may be drilled mechanically. It is possible to drill down to part of the first 13 or second 14 conductive layer, or through the first 13 or second 14 conductive layer, using mechanical drilling.

Referring to fig. 4, conductive materials are filled in the upper and lower holes 20, respectively, to form a first conductive via 21 and a second conductive via 22. In one embodiment, the first conductive via 21 and the second conductive via 22 can be formed by electroplating copper, which also increases the thickness of the first electrode layer 17 and the second electrode layer 18. If the hole 20 is large, the first conductive via 21 and the second conductive via 22 may not completely fill the hole 20, so that the corresponding portions of the first electrode layer 17 and the second electrode layer 18 are recessed. In one embodiment, the surfaces of the first electrode layer 17 and the second electrode layer 18 may be plated with tin to increase the soldering effect. Then, the PTC elements 10 are cut at regular intervals at the dotted line positions to form a perspective view of a single PTC element 10, as shown in FIG. 5. In one embodiment, the ptc device 10 is designed to have the same width and thickness dimensions, i.e. the first electrode layer 17 and the second electrode layer 18 are shown as squares on the side of fig. 5, so that it is not affected by the flip-over problem.

Fig. 6 shows a schematic diagram of the ptc device 10 soldered to a circuit board, and the ptc device 10 is soldered to the surface of the circuit board 60 by solder 61. Further, the ptc device 10 includes a current and temperature sensing device 11, a first insulating layer 15, a second insulating layer 16, a first electrode layer 17, a second electrode layer 18, a first conductive via 21 and a second conductive via 22. The current and temperature sensing element 11 has a laminated structure including a first conductive layer 13, a second conductive layer 14, and a PTC material layer 12 laminated therebetween. The first electrode layer 17 is disposed on the surface of the first insulating layer 15 and electrically connected to the first conductive layer 13. The second electrode layer 18 is disposed on the surface of the second insulating layer 16 and electrically connected to the second conductive layer 14. A first conductive via 21 passes through the first insulating layer 15 and connects the first electrode layer 17 and the first conductive layer 13. A second conductive via 22 passes through the second insulating layer 16 and connects the second electrode layer 18 and the second conductive layer 14. In this embodiment, the first electrode layer 17, the first insulating layer 15, the first conductive layer 13, the PTC material layer 12, the second conductive layer 14, the second insulating layer 16, and the second electrode layer 18 are sequentially stacked, and a bottom plane 24 is formed, the bottom plane 25 facing the circuit board 60 as an interface soldered to the circuit board 60. When soldering, the solder 61 climbs tin along the first electrode layer 17 and the second electrode layer 18, that is, the first electrode layer 17 and the second electrode layer 18 are soldered to the tin climbing surface of the circuit board 60 as the ptc element 10.

Referring to fig. 4, when the ptc device 10 is cut to form the ptc device, the second electrode layer 18 under the ptc device may be pulled down and extended due to the ductility of the metal, which may cause burrs. Referring to fig. 7, another embodiment of a ptc device 70 is shown, which differs from the ptc device 10 shown in fig. 5 in that the outer edge of the first electrode layer 17 is recessed relative to the first insulating layer 15 to form a gap 26, and the outer edge of the second electrode layer 18 is also recessed relative to the second insulating layer 16 to form a gap 26, forming a symmetrical structure. Fig. 8 shows a manufacturing method of the first electrode layer 17 and the second electrode layer 18 of the ptc device 70, wherein before cutting, a groove 81 is formed in the first electrode layer 17 and the second electrode layer 18, and the electrode layer in the groove 81 is removed. The groove 81 surrounds the hole 20 and corresponds to the location where the ptc element 70 is cut. The width of the channel 81 is greater than the cutting width and is approximately equal to twice the width of the notch 26 plus the width of the cutting tool. Therefore, the first electrode layer 17 and the second electrode layer 18 are not cut during cutting, and the retracted notch 26 is not generated, so that the problem of generating burrs during cutting the electrode layers is effectively avoided.

Fig. 9 shows a ptc element 90 according to yet another embodiment of the present invention. The ptc device 90 and the ptc device 70 also retract the first electrode layer 17 and the second electrode layer 18, with the difference that the outer edge of the first electrode layer 17 includes an extension block 27 extending to the edge of the first insulating layer 15, and the outer edge of the second electrode layer 18 includes an extension block 28 extending to the edge of the second insulating layer 16. In this way, the extending blocks 27 and 28 extend to the bottom plane of the component, which is equal to the solder-climbing pipe, and thus it is helpful to improve the solder-climbing effect during soldering when the gap 26 is too large. Fig. 10 shows a method for manufacturing the first electrode layer 17 and the second electrode layer 18 of the ptc element 90, wherein a groove 91 is formed in the first electrode layer 17 and the second electrode layer 18, and the electrode layer in the groove 91 is removed. The grooves 91 correspond to the locations where the ptc elements 90 are cut, but are not completely continuous so that the first electrode layer 17 and the second electrode layer 18 between the connected elements are still partially continuous, forming the extension blocks 27 and 28. Preferably, the width of the extension block 27 or 28 is about 20-60% of the width of the first insulating layer 15 or 16. The width of the groove 91 is greater than the cutting width and is approximately equal to twice the width of the notch 26 plus the width of the cutting tool. Although the extending blocks 27 and 28 are cut during the cutting process, the extending blocks 27 and 28 occupy a small proportion compared with the first electrode layer 17 and the second electrode layer 18, so that the burr problem generated during the cutting process of the first electrode layer 17 and the second electrode layer 18 can be effectively reduced, and the tin climbing effect is considered.

The first conductive via 21 or the second conductive via 22 of the above embodiments is located approximately at the center of the first insulating layer 15 or the second insulating layer 16, but not limited thereto. The positions of the first conductive via 21 and the second conductive via 22 can also be located at the side edges or corners of the first insulating layer 15 and the second insulating layer 16, so long as the first conductive layer 13 and the first electrode layer 17 can be electrically connected and the second conductive layer 14 and the second electrode layer 18 can be electrically connected, which are all covered by the present invention.

The positive temperature coefficient element of the invention can be used for temperature sensing besides overcurrent protection application, a laminated plate is manufactured by using a direct pressing mode, and the laminated surface is used as a bottom plane after cutting for welding, so that the structure and the process are simple, and the positive temperature coefficient element is very suitable for manufacturing small-sized elements, such as products with specifications of 0402 and 0201. In one embodiment, the PTC element has the same width and thickness dimensions and is not affected by flip-flop problems. In addition, the positive temperature coefficient element of the invention can provide the following advantages: (1) the inner layer is not provided with a circuit, so that the problems of expansion and contraction of materials and alignment of the inner and outer circuits are solved; (2) the supporting structures of the two PP insulating layers of the plates are still maintained, so that the product structure is improved, and the manufacturing yield can be improved; (3) when the voltage resistance is improved, the space for adjusting the thickness of the plate is more elastic; (4) the cutting groove is matched with the local circuit design, so that burrs can be avoided and the climbing welding effect can be improved. (5) The two side surfaces of the element are provided with electrode layers, so that the resistance can be directly measured in a clamping manner without distinguishing the front surface from the back surface.

While the technical content and the technical features of the invention have been disclosed, those skilled in the art can make various substitutions and modifications without departing from the spirit and the scope of the invention based on the teaching and the disclosure of the invention. Therefore, the scope of the present invention should not be limited to the embodiments disclosed, but includes various alternatives and modifications without departing from the present invention, which are encompassed by the following claims.