Temperature and pressure sensors, their welding methods, and welding fixtures

Abstract

This application provides a temperature and pressure sensor, its welding method, and a welding fixture. The welding method for the temperature and pressure sensor includes: fixing multiple welding components onto the base of the welding fixture; each welding component includes a thermistor and a connector arranged opposite to each other, with the first pin of the thermistor and the second pin of the connector overlapping one-to-one; applying molten solder balls to the overlapping area of ​​the first and second pins in each welding component to form solder, such that a first portion of the solder contacts the bottom surface of the second pin through a through-hole, a second portion of the solder is located within the through-hole, and a third portion of the solder is located on the second pin, forming an integral welded layer after solidification. Compared to manual fixing, this application offers higher precision, improved fixing stability, increased production efficiency, lower cost, and improved connection stability between the first and second pins.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more specifically, to a temperature and pressure sensor, its welding method, and welding fixture. Background Technology

[0002] In recent years, temperature and pressure sensors have been widely used in the field of new energy vehicles, such as battery pack systems and thermal management circuits, and are core components of intelligent sensing terminals. Generally, temperature and pressure sensors are implemented by integrating a thermistor and a pressure sensor through a connector. In the production process, the connector and the thermistor need to be welded together first.

[0003] However, the leads of thermistors are mostly flexible, and they are fixed manually during soldering, which is difficult and results in low production efficiency.

[0004] Moreover, in related technologies, soldering is often used to solder the leads of the thermistor to the lead surface of the connector. The leads of the connector are usually relatively hard, and after soldering, a relatively soft solder layer is formed on the lead surface of the connector, which leads to an imbalance in hardness and stress concentration. This results in poor bonding between the connector and the solder layer, and the connection is prone to breakage. Summary of the Invention

[0005] This application addresses the shortcomings of existing methods by proposing a temperature and pressure sensor, its welding method, and welding fixture to solve technical problems such as difficulty in fixing during welding, poor efficiency, or poor bonding between the connector and the solder layer.

[0006] In a first aspect, embodiments of this application provide a welding method for a temperature and pressure sensor, comprising:

[0007] Multiple welding components are fixed on the base of the welding fixture based on the welding jig; each welding component includes a thermistor and a connector arranged opposite to each other, with the first pin of the thermistor and the second pin of the connector overlapping one-to-one; the second pin has a through hole; along the first direction, the size of the second pin and the size of the through hole are both larger than the size of the first pin, the first direction is parallel to the base and perpendicular to the arrangement direction of the thermistor and the connector; the bottom surface of the second pin has a gap with the base.

[0008] Molten solder balls are applied to the overlap area of ​​the first and second pins in each set of soldering components to form solder, such that a first portion of solder contacts the bottom surface of the second pin through a through-hole, a second portion of solder is located inside the through-hole, and a third portion of solder is located on the second pin, and after solidification, an integral solder layer is formed; the solder layer covers at least a portion of the overlap area of ​​the first and second pins.

[0009] In some embodiments, multiple welding components are fixed to the base of the welding fixture based on the welding fixture, including:

[0010] Multiple welding components are fixed on a base using a welding fixture, and the second pin and the first pin are sequentially overlapped in a direction away from the base; at least a portion of the opening area of ​​the through hole is exposed on the first pin.

[0011] And, molten solder balls are applied to the overlap area of ​​the first and second pins in each group of soldering components to form solder, such that a first portion of solder contacts the bottom surface of the second pin through a through-hole, a second portion of solder is located inside the through-hole, and a third portion of solder is located on the second pin, including:

[0012] Molten solder balls are applied to the overlap area of ​​the first and second pins in each set of soldering components to form solder, such that a first portion of solder leaks through a through-hole onto the receiving groove of the base and flows to contact the bottom surface of the second pin, a second portion of solder is located in the through-hole, and a third portion of solder is located on the second pin and covers at least a portion of the overlap area of ​​the first and second pins.

[0013] In some embodiments, in the overlap region of the first pin and the second pin, the surface of the first pin is coated with a gold layer.

[0014] On the base, the orthographic projection of the first pin passes through the orthographic projection range of the edge of the through hole.

[0015] In some embodiments, multiple welding components are fixed to the base of the welding fixture based on the welding fixture, including:

[0016] Multiple welding components are fixed on the base using a welding fixture, and the first and second pins are sequentially overlapped in the direction away from the base.

[0017] And, molten solder balls are applied to the overlap area of ​​the first and second pins in each group of soldering components to form solder, such that a first portion of solder contacts the bottom surface of the second pin through a through-hole, a second portion of solder is located inside the through-hole, and a third portion of solder is located on the second pin, including:

[0018] Molten solder balls are applied to the overlap area of ​​the first and second pins in each set of soldering components to form solder, such that a first portion of solder leaks through a through-hole onto the receiving groove of the base and flows, covering at least a portion of the overlap area of ​​the first and second pins, a second portion of solder is located in the through-hole, and a third portion of solder is located on the second pin.

[0019] In some embodiments, a first portion of solder leaks through a via into a receiving groove on the base and flows, covering at least a portion of the overlap area of ​​the first and second pins, including:

[0020] The first portion of solder leaks through the through-hole to the bottom of the receiving tank, and the fourth portion of solder leaks through the gap between the side wall of the second bearing tank of the base and the second pin to the bottom of the receiving tank, flowing and covering at least a portion of the overlapping area of ​​the first pin and the second pin.

[0021] In some embodiments, multiple welding components are fixed to the base of the welding fixture based on the welding fixture, including:

[0022] Multiple sets of welding components are arranged in multiple receiving areas of the base; in each set of welding components, the thermistor is arranged in the first bearing groove of the receiving area, the connector is arranged in the second bearing groove of the receiving area, the first pin and the second pin overlap in the overlapping area of ​​the first bearing groove and the second bearing groove, and the top of the first pin and the second pin that is far from the base is not lower than the surface of the base.

[0023] Rotate the pressure plate of the welding fixture so that the pressure plate presses down on both ends of the overlapping area of ​​the first and second pins, and the through hole is exposed in the cutout of the pressure plate.

[0024] In some embodiments, a receiving groove is provided in the overlapping area of ​​the first bearing groove and the second bearing groove.

[0025] The orthographic projection of the through hole onto the base falls within the range of the receiving groove.

[0026] The bottom of the first pin and the second pin closest to the base is spaced from the bottom of the receiving groove.

[0027] Secondly, embodiments of this application provide a welding fixture for use in any of the welding methods provided in the first aspect above, comprising:

[0028] The base has multiple accommodating areas for accommodating multiple sets of welding components one by one; each accommodating area has a first bearing groove and a second bearing groove arranged opposite to each other, and the opposite end areas of the first bearing groove and the second bearing groove overlap.

[0029] Multiple pressure plates, each corresponding to a different receiving area, are rotatably connected; the pressure plates have cutouts.

[0030] In a fixed state, the thermistor is at least partially disposed in the first bearing groove, the connector is at least partially disposed in the second bearing groove, and the first pin and the second pin overlap in the overlapping area of ​​the first bearing groove and the second bearing groove; the pressure plate presses down on both ends of the overlapping area of ​​the first pin and the second pin, and the hollow of the pressure plate exposes the through hole.

[0031] Thirdly, embodiments of this application provide a temperature and pressure sensor manufactured by any of the welding methods provided in the first aspect above, comprising:

[0032] A thermistor with a first pin.

[0033] A connector having a second pin; the second pin has a through hole and overlaps with the first pin.

[0034] The solder layer includes portions connecting both sides of the second pin and portions located within the through-hole.

[0035] The solder layer covers at least a portion of the overlap area of ​​the first and second pins.

[0036] In some embodiments, the solder layer includes: a first solder layer connected to one side of the second pin, a second solder layer connected to the other side of the second pin, and a third solder layer formed in the through-hole.

[0037] The first solder layer covers at least a portion of the overlap area between the first and second pins.

[0038] On a plane parallel to the second pin, the areas of the first and second solder layers are both larger than the area of ​​the third solder layer.

[0039] In some embodiments, in the overlap area of ​​the first pin and the second pin, the surface of the first pin is covered with a gold layer and passes through the opening area of ​​the via.

[0040] In some embodiments, the through hole is a round hole or an oblong hole, and the long axis direction of the oblong hole is consistent with the length direction of the second pin.

[0041] The beneficial effects of the technical solutions provided in this application include:

[0042] (1) In the embodiments of this application, multiple welding components are fixed at the same time by using welding fixtures. Compared with manual fixing, the accuracy is higher, the stability of fixing is improved, the production efficiency is improved, and the cost is lower.

[0043] (2) In this embodiment of the application, solder ball soldering is performed on the solder assembly fixed by the soldering fixture. Molten solder balls are applied to the overlapping area of ​​the first pin of the thermistor and the second pin of the connector. The second pin is flat and has a top surface and a bottom surface (the top surface is the side away from the base when soldering, and the bottom surface is the side facing the base when soldering). The molten solder balls are applied towards the top surface of the second pin and can leak through the through hole of the second pin. The molten solder balls form liquid solder, which has fluidity. The second pin has a certain adsorption property for the solder, so that the first part of the leaked solder can contact the bottom surface of the second pin. The second part of the solder is located in the through hole, and the third part of the solder is located on the top surface of the second pin. The solder layer formed after the solder balls are solidified covers the overlapping area of ​​the first pin and the second pin and has an "I" shaped structure that is wide at both ends and narrow in the middle.

[0044] (3) The embodiments of this application can increase the bonding area between the solder layer and the first pin and the second pin, thereby improving the bonding force between the first pin and the second pin and the solder layer. Moreover, compared with the related technology where solder is applied to only one surface of the second pin, the solder layer is attached to both sides of the second pin, which can form a stable frame structure, disperse stress, reduce the possibility of cracking due to stress concentration, and improve the connection stability between the first pin and the second pin.

[0045] (4) The embodiments of this application use solder ball soldering to perform soldering. The solder ball is in a molten state before reaching the through hole and has fluidity, which can ensure that some solder balls or a part of a single solder ball can pass through the through hole and contact the bottom surface of the second pin, thus ensuring the feasibility of the soldering method.

[0046] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic flowchart illustrating the welding method for a first type of temperature and pressure sensor provided in this application embodiment;

[0049] Figure 2 A schematic flowchart illustrating the welding method for a second type of temperature and pressure sensor provided in this application embodiment;

[0050] Figure 3 A schematic flowchart illustrating the welding method for a third type of temperature and pressure sensor provided in this application embodiment;

[0051] Figure 4 One of the structural schematic diagrams of the second type of temperature and pressure sensor welding method provided in the embodiments of this application, after fixing multiple sets of welding components on the base of the welding fixture;

[0052] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0053] Figure 6 The second schematic diagram of the structure after fixing multiple welding components onto the base of the welding fixture in the welding method of the second temperature and pressure sensor provided in the embodiments of this application;

[0054] Figure 7 This is a schematic diagram of the structure of a welding fixture provided in an embodiment of this application;

[0055] Figure 8 for Figure 7 A magnified view of a section at point B in the middle;

[0056] Figure 9 for Figure 7 A magnified view of a section at point C;

[0057] Figure 10 This is a schematic diagram of the structure after multiple welding components are fixed on the base of the welding fixture in the third welding method for the temperature and pressure sensor provided in the embodiments of this application.

[0058] Figure 11 This is a schematic diagram of the structure of a temperature and pressure sensor provided in an embodiment of this application;

[0059] Figure 12 for Figure 11 A schematic diagram of the structure viewed in cross section DD'.

[0060] Figure label:

[0061] 100-Welding fixture; 10-Base; 11-Accommodation area; 111-First bearing groove; 112-Second bearing groove; 113-Accommodation groove; 20-Pressure plate; 21-Hollowout;

[0062] 200 - Welding assembly; 210 - Thermistor; 211 - First pin; 212 - Gold layer; 220 - Connector; 221 - Second pin; 222 - Through hole;

[0063] 300 - Solder layer; 310 - First solder layer; 320 - Second solder layer; 330 - Third solder layer. Detailed Implementation

[0064] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0065] Those skilled in the art will understand that, unless specifically stated otherwise, the terms "described" and "the" as used herein may also include plural forms. It should be further understood that the term "comprising" as used in this application's specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by this art. It should be understood that when we say an element is "connected" to another element, the element may be directly connected to the other element, or it may mean that the element and the other element are connected through an intermediate element. The term "and / or" as used herein refers to at least one of the items defined by the term; for example, "A and / or B" can be implemented as "A," or as "B," or as "A and B."

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0067] This application provides a first method for welding a temperature and pressure sensor, the flowchart of which is shown below. Figure 1 As shown, the method includes steps S1-S2:

[0068] S1: Multiple welding components 200 are fixed on the base 10 of the welding fixture 100. Each welding component 200 includes a thermistor 210 and a connector 220 arranged opposite to each other. The first pin 211 of the thermistor 210 and the second pin 221 of the connector 220 are overlapped one-to-one. The second pin 221 has a through hole 222. Along a first direction, the size of the second pin 221 and the size of the through hole 222 are both larger than the size of the first pin 211. The first direction is parallel to the base 10 and perpendicular to the arrangement direction of the thermistor 210 and the connector 220. The bottom surface of the second pin 221 is spaced from the base 10.

[0069] S2: Molten solder balls are applied to the overlapping area of ​​the first pin 211 and the second pin 221 in each welding assembly 200 to form solder, such that a first portion of the solder contacts the bottom surface of the second pin 221 through the through-hole 222, a second portion of the solder is located inside the through-hole 222, and a third portion of the solder is located on the second pin 221. After solidification, an integral welding layer 300 is formed. The welding layer 300 covers at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221.

[0070] Please refer to Figure 4 , Figure 4 The thermistor 210 and connector 220 are shown fixed to the base 10 of the welding fixture 100. Figure 4 The welding fixture 100 in the middle simultaneously fixes multiple welding components 200. For ease of demonstration, Figure 4 The second pressure plate 20 in the first row is in the raised state, while the other pressure plates 20 are in the state of pressing and welding the assembly 200.

[0071] In this embodiment, by using a welding fixture 100 to simultaneously fix multiple welding components 200, the accuracy is higher and the stability of the fixation is improved compared to manual fixing, which can improve production efficiency and reduce costs.

[0072] In this embodiment, solder ball soldering is performed on the soldering assembly 200 fixed in the soldering fixture 100. Molten solder balls are applied to the overlapping area of ​​the first pin 211 of the thermistor 210 and the second pin 221 of the connector 220. The second pin 221 is flat and has opposing top and bottom surfaces (the top surface is the side away from the base 10 during soldering, and the bottom surface is the side facing the base 10 during soldering). The molten solder balls are applied towards the top surface of the second pin 221 and can pass through the second pin 221. The molten solder ball leaks through the through-hole 222, forming liquid solder. This liquid solder is fluid, and the second pin 221 has a certain adsorption capacity for the solder, allowing the first part of the leaked solder to contact the bottom surface of the second pin 221. The second part of the solder is located inside the through-hole 222, and the third part of the solder is located on the top surface of the second pin 221. After the solder solidifies, the weld layer 300 formed covers the overlapping area of ​​the first pin 211 and the second pin 221, forming an "I" shaped structure that is wide at both ends and narrow in the middle.

[0073] This embodiment increases the bonding area between the solder layer 300 and the first pin 211 and the second pin 221, thereby improving the bonding force between the first pin 211, the second pin 221, and the solder layer 300. Furthermore, compared to related technologies where solder is applied only to one surface of the second pin 221, the solder layer 300 is bonded to both sides of the second pin 221, forming a stable frame structure, dispersing stress, reducing the possibility of breakage due to stress concentration, and improving the connection stability between the first pin 211 and the second pin 221.

[0074] This embodiment uses a solder ball soldering method. When the size of the solder ball is larger than the size of the through hole 222, the solder ball is in a molten state before reaching the through hole 222, exhibiting fluidity. This ensures that at least a portion of a single solder ball can pass through the through hole 222 and contact the bottom surface of the second pin 221, guaranteeing the feasibility of the soldering method. For example, if the solder ball diameter is 1.2 mm and the opening diameter of the through hole 222 is 0.25 mm, the solder portion formed after the solder ball melts passes through the through hole 222 and contacts the bottom surface of the second pin 221, with some remaining inside the through hole 222 and some connected to the second pin 221.

[0075] When the size of the solder ball is no larger than the size of the through-hole 222, due to surface tension, a single molten solder ball can maintain a relatively consistent shape and size with its original size when it reaches the through-hole 222. This allows the single solder ball to pass through the through-hole 222 and contact the bottom surface of the second pin 221, ensuring the feasibility of the soldering method. For example, if the solder ball diameter is 1.2 mm and the opening diameter of the through-hole 222 is 0.25 mm, the solder portion formed after the solder ball melts will pass through the through-hole 222 and contact the bottom surface of the second pin 221, with some remaining inside the through-hole 222 and some connected to the second pin 221.

[0076] For example, the diameter of the solder ball is 0.2 mm, the opening diameter of the through hole 222 is 0.25 mm, some complete solder balls can pass through the through hole 222 and contact the bottom surface of the second pin 221, some solder balls remain in the through hole 222, and some solder balls are connected to the second pin 221.

[0077] Understandably, after the solder balls melt, they are in a liquid state. Multiple melted solder balls form at least one clump of liquid, fluid solder. The first portion of solder can be formed from a part of one solder ball or from multiple solder balls. Similarly, the second portion of solder can be formed from a part of one solder ball or from multiple solder balls. The third portion of solder can also be formed from a part of one solder ball or from multiple solder balls.

[0078] Please refer to Figures 4-5 , Figures 7-9 , Figure 4 This is a schematic diagram showing the structure after multiple welding components 200 are fixed on the base 10 of the welding fixture 100. Figure 5 for Figure 4 A magnified view of a portion of point A in the middle. Figure 7 This is a structural schematic diagram of welding fixture 100. Figure 8 for Figure 7 A magnified view of a section at point B. Figure 9 for Figure 7 A magnified view of a section at point C.

[0079] In some embodiments, the step S1 described above, which involves fixing multiple welding assemblies 200 onto the base 10 of the welding fixture 100, specifically includes:

[0080] Multiple sets of welding components 200 are disposed in multiple receiving areas 11 of the base 10; in each set of welding components 200, the thermistor 210 is disposed in the first bearing groove 111 of the receiving area 11, the connector 220 is disposed in the second bearing groove 112 of the receiving area 11, the first pin 211 and the second pin 221 overlap in the overlapping area of ​​the first bearing groove 111 and the second bearing groove 112, and the top of the one of the first pin 211 and the second pin 221 that is far from the base 10 is not lower than the surface of the base 10.

[0081] Rotate the pressure plate 20 of the welding fixture 100 so that the pressure plate 20 presses down on both ends of the overlapping area of ​​the first pin 211 and the second pin 221, and the through hole 222 is exposed in the hollow 21 of the pressure plate 20.

[0082] In this embodiment, as Figures 4-5 , Figures 7-9 As shown, the welding fixture 100 includes a base 10 and multiple pressure plates 20 rotatably connected to the base 10. The surface of the base 10 has multiple receiving areas 11. Each receiving area 11 has a first bearing groove 111 and a second bearing groove 112 arranged opposite to each other. The interior of the first bearing groove 111 has a structure that matches the shape of the thermistor 210, which can fix the thermistor 210 inside. The interior of the second bearing groove 112 has a structure that matches the shape of the connector 220, which can fix the connector 220 inside. The fixing method of this embodiment is simple to operate and has strong effectiveness.

[0083] In this embodiment, the overlapping area of ​​the first pin 211 and the second pin 221 is pressed by the pressure plate 20. This can further fix the overlapping area of ​​the first pin 211 and the second pin 221 on the basis that the thermistor 210 and the connector 220 are fixed by the base 10, ensuring the effective overlap of the first pin 211 and the second pin 221, thereby ensuring the yield of subsequent soldering. It can also keep the first pin 211 and the second pin 221 in the factory shape and reduce the possibility of deformation of the first pin 211 and the second pin 221 during the fixing process.

[0084] It is understandable that, such as Figure 5 As shown, there are two first pins 211 and two second pins 221. The first pins 211 and the second pins 221 are connected in a one-to-one correspondence. That is, when the thermistor 210 and the connector 220 are arranged opposite each other, one first pin 211 is connected to one second pin 221, and the other first pin 211 is connected to the other second pin 221. Moreover, when connected, the first pin 211 may be on top (i.e., away from the surface of the base 10), or the second pin 221 may be on top.

[0085] In this embodiment, the first pin 211 and the second pin 221 are respectively disposed in the first bearing groove 111 and the second bearing groove 112. When the first pin 211 and the second pin 221 overlap, the top of the one furthest from the base 10 is not lower than the surface of the base 10, ensuring that the pressure plate 20 can contact and abut with the one of the first pin 211 and the second pin 221 furthest from the base 10, thus ensuring the effectiveness of the pressure plate 20 pressing.

[0086] In some embodiments, after step S1 described above, the welding fixture 100 carrying the welding assembly 200 is placed entirely in a welding machine, and molten solder balls are applied to the overlapping area of ​​the first pin 211 and the second pin 221. Solder balls can be applied sequentially to each overlapping area, or solder balls can be applied to multiple overlapping areas simultaneously. The solder balls have high precision and small size, and there is a gap between the second pins 221 of each connector 220, which is much larger than the size of the solder balls, thereby reducing the risk of short circuits caused by soldering between the second pins 221 of the connectors 220.

[0087] For example, the size of the solder ball is between 0.1 mm and 1.2 mm, and the size between the second pin 221 is 2 mm, which is larger than the size of the solder ball, thus reducing the risk of short circuit.

[0088] In some embodiments, such as Figures 5-9 As shown, a receiving groove 113 is provided in the overlapping area of ​​the first bearing groove 111 and the second bearing groove 112; the orthographic projection of the through hole 222 on the base 10 falls within the range of the receiving groove 113. The bottom of the one of the first pin 211 and the second pin 221 closest to the base 10 is spaced from the bottom of the receiving groove 113.

[0089] In this embodiment, the end of the first support groove 111 facing the second support groove 112 is used to accommodate the first pin 211, and the end of the second support groove 112 facing the first support groove 111 is used to accommodate the second pin 221. The opposite ends of the first support groove 111 and the second support groove 112 overlap, and there is a receiving groove 113 in the overlapping area. The overlapping area of ​​the first pin 211 and the second pin 221 is located within the receiving groove 113. Compared with the area in the first support groove 111 where the first pin 211 is located (excluding the receiving groove 113), and also compared with the area in the second support groove 112 where the second pin 221 is located (excluding the receiving groove 113), the receiving groove 113 is deeper and closer to the pin (first pin 211 or second pin 221) of the base 10, and there is a gap between the pin and the bottom of the receiving groove 113 of the base 10.

[0090] Therefore, the orthogonal projection of the through hole 222 on the base 10 falls within the range of the receiving groove 113, allowing the solder ball to fall from the through hole 222 into the receiving groove 113 during the soldering process. The molten solder ball can cover the pins closer to the base 10, thereby ensuring that the molten solder ball can cover the surfaces of the first pin 211 and the second pin 221 facing the bottom of the receiving groove 113, further increasing the area of ​​the first pin 211 and the second pin 221 covered by the solder ball, thereby improving the reliability of the soldering of the first pin 211 and the second pin 221.

[0091] This application also provides a second method for welding a temperature and pressure sensor, the flowchart of which is shown below. Figure 2 As shown, the method includes the following steps S3-S4:

[0092] S3: Based on the welding fixture 100, fix multiple welding components 200 on the base 10 of the welding fixture 100, and in the direction away from the base 10, connect the second pin 221 and the first pin 211 in sequence; at least part of the opening area of ​​the through hole 222 is exposed on the first pin 211.

[0093] S4: Molten solder balls are applied to the overlapping area of ​​the first pin 211 and the second pin 221 in each welding assembly 200 to form solder, so that the first part of the solder leaks through the through hole 222 onto the receiving groove 113 of the base 10 and flows, contacting the bottom surface of the second pin 221. The second part of the solder is located in the through hole 222, and the third part of the solder is located on the second pin 221 and covers at least part of the overlapping area of ​​the first pin 211 and the second pin 221. After solidification, an integral welding layer 300 is formed.

[0094] In this embodiment, as Figures 4-5 As shown, when fixing the soldering assembly 200, the second pin 221 and the first pin 211 overlap sequentially in the direction away from the base 10. That is, the second pin 221 is closer to the base 10, and the first pin 211 is farther away from the base 10. In other words, when the soldering fixture 100 is upright, the first pin 211 is located above the second pin 221. The first pin 211 is thinner, and the second pin 221 is wider. The width of the first pin 211 is smaller than the diameter of the through hole 222, so that the first pin 211 does not completely cover the opening area of ​​the through hole 222, thereby ensuring that the solder ball can reach the opening of the through hole 222 and leak into the base 10.

[0095] Furthermore, the first portion of solder leaks onto and flows into the receiving tank 113, covering at least a portion of the bottom of the receiving tank 113 and contacting the bottom surface of the second pin 221. The second portion of solder remains within the through-hole 222, and the third portion of solder is located on the top surface of the second pin 221 and covers the first pin 211. After the solder solidifies, an integral solder layer 300 is formed. Therefore, the solder layer 300 can cover both the top and bottom surfaces of the second pin 221 and enclose the first pin 211, thereby improving the connection reliability of the first pin 211 and the second pin 221.

[0096] It is understood that the second pin 221 is flat, with one side being the bottom surface facing the base 10 and the other side being the top surface away from the base 10. Taking the top surface of the second pin 221 as an example, the dimension of the second pin 221 along the length direction is the length of the second pin 221, and the dimension of the second pin 221 along the width direction (i.e., the first direction) is the width of the second pin 221. The overlapping portions of the first pin 211 and the second pin 221 are parallel to each other, and the length and width directions of the first pin 211 are consistent with the length and width directions of the second pin 221.

[0097] It should be noted that in the second welding method of the temperature and pressure sensor in this embodiment, only the features that are different from the first welding method in the above embodiment are described. Other parts not described can be used interchangeably and will not be repeated here.

[0098] The research and development ideas of this application also include: the pins are generally made of copper or alloy, which are easily oxidized in the air. The oxide layer formed will hinder the wetting between the solder ball and the pin, making it difficult for the molten liquid solder to spread on the pin surface and hindering the soldering.

[0099] In some embodiments, such as Figure 6 As shown, in the overlapping area of ​​the first pin 211 and the second pin 221, the surface of the first pin 211 is covered with a gold layer 212.

[0100] On the base 10, the orthographic projection of the first pin 211 passes through the orthographic projection range of the edge of the through hole 222.

[0101] In this embodiment, the surface of the first pin 211 is coated with a gold layer 212. Gold is a very stable metal that hardly oxidizes in air. Therefore, the molten solder ball can easily spread on the metal surface and form an intermetallic compound, thereby completing the soldering.

[0102] Moreover, the gold layer 212 has a low surface energy, which helps to reduce the overall surface tension of the molten solder ball, has stronger fluidity, and is more easily drawn into the through hole 222 by capillary action, so that the solder ball can smoothly enter the through hole 222 and leak to contact the bottom surface of the second pin 221 to form an "I"-shaped solder layer 300.

[0103] This application also provides a third method for welding a temperature and pressure sensor, the flowchart of which is shown below. Figure 3 As shown, the method includes the following steps S5-S6:

[0104] S5: Fix multiple welding components 200 on the base 10 of the welding fixture 100, and connect the first pin 211 and the second pin 221 in sequence along the direction away from the base 10.

[0105] S6: Molten solder balls are applied to the overlapping area of ​​the first pin 211 and the second pin 221 in each group of soldering components 200 to form solder, so that a first part of the solder leaks through the through hole 222 onto the receiving groove 113 of the base 10 and flows, covering at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221, a second part of the solder is located in the through hole 222, and a third part of the solder is located on the second pin 221, and after solidification, an integral solder layer 300 is formed.

[0106] Unlike the previous embodiment, in this embodiment, when fixing the soldering assembly 200, the first pin 211 and the second pin 221 overlap sequentially in a direction away from the base 10, that is, the first pin 211 is closer to the base 10, and the second pin 221 is farther away from the base 10. In other words, when the soldering fixture 100 is upright, the second pin 221 is located above the first pin 211. The first pin 211 is thinner, and the second pin 221 is wider. The width of the first pin 211 is smaller than the diameter of the through hole 222, so that the first pin 211 does not completely cover the opening area of ​​the through hole 222, thereby ensuring that solder balls falling from the through hole 222 can pass through the first pin 211 and leak into the receiving groove 113 of the base 10.

[0107] Furthermore, the first portion of solder leaks onto and flows into the receiving tank 113, covering at least a portion of the bottom of the receiving tank 113 and contacting both the first pin 211 and the second pin 221, thus covering the overlapping area of ​​the first pin 211 and the second pin 221. The second portion of solder remains within the through-hole 222, and the third portion of solder is located on the top surface of the second pin 221. After the solder solidifies, an integral solder layer 300 is formed. Therefore, the solder layer 300 can cover both the top and bottom surfaces of the second pin 221 and enclose the first pin 211, thereby improving the connection reliability of the first pin 211 and the second pin 221.

[0108] It should be noted that in the third welding method of the temperature and pressure sensor in this embodiment, only the features that are different from the first welding method in the above embodiment are described. Other parts not described can be used interchangeably and will not be repeated here.

[0109] Alternatively, when using the third welding method, depending on the depth of the receiving groove 113, the bottom of the first pin 211 can either contact the bottom of the receiving groove 113 or have a gap between it and the bottom of the receiving groove 113. When the receiving groove 113 is deeper, the gap between the first pin 211 and the bottom of the receiving groove 113 allows the final weld layer 300 to completely cover the bottom of the first pin 211, thereby covering the entire circumference of the first pin 211 and improving the bonding force between the solder and the first pin 211.

[0110] Alternatively, when using the third welding method, the through hole 222 can be an oblong hole. A schematic diagram of the structure when the through hole 222 is an oblong hole is shown below. Figure 10 As shown. When using the third soldering method, since the overlapping area of ​​the first pin 211 and the second pin 221 is located on the bottom surface of the second pin 221, the use of an oblong hole allows more solder to leak to the bottom surface of the second pin 221, while covering the first pin 211 and the second pin 221.

[0111] In some embodiments, step S6 above, which involves causing the first portion of solder to leak through the through-hole 222 onto the receiving groove 113 of the base 10 and flow there, covering at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221, specifically includes:

[0112] The first portion of solder leaks through the through-hole 222 to the bottom of the receiving groove 113, and the fourth portion of solder leaks through the gap between the side wall of the second bearing groove 112 of the base 10 and the second pin 221 to the bottom of the receiving groove 113, flowing and covering at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221.

[0113] In this embodiment, there is a gap between the second pin 221 and the sidewall of the second carrier groove 112. When the solder ball applied towards the overlapping area of ​​the first pin 211 and the second pin 221 forms liquid solder, the solder can leak from the gap into the receiving groove 113 and flow to cover at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221, while also covering the side of the second pin 221 (i.e., the sidewall of the gap). This allows the solder layer 300 formed after the solder solidifies to cover the side of the second pin 221 on top of covering the overlapping area of ​​the first pin 211 and the second pin 221, further increasing the bonding area between the solder and the second pin 221, thereby improving the soldering reliability.

[0114] Based on the same inventive concept, this application also provides a welding fixture 100 used in any of the welding methods provided in the foregoing embodiments, and a schematic diagram of the structure of the welding fixture 100 is shown below. Figures 7-9 As shown, the welding fixture 100 includes a base 10 and a plurality of pressure plates 20.

[0115] The base 10 has multiple receiving areas 11 for accommodating multiple sets of welding components 200 in a one-to-one correspondence; each receiving area 11 has a first bearing groove 111 and a second bearing groove 112 arranged opposite to each other, and the opposite end regions of the first bearing groove 111 and the second bearing groove 112 overlap.

[0116] Multiple pressure plates 20 are rotatably connected to multiple receiving areas 11 in a one-to-one correspondence; the pressure plates 20 have hollowed-out sections 21.

[0117] In a fixed state, the thermistor 210 is at least partially disposed in the first bearing groove 111, the connector 220 is at least partially disposed in the second bearing groove 112, and the first pin 211 and the second pin 221 overlap in the overlapping area of ​​the first bearing groove 111 and the second bearing groove 112; the pressure plate 20 presses down on both ends of the overlapping area of ​​the first pin 211 and the second pin 221, and the cutout 21 of the pressure plate 20 exposes the through hole 222.

[0118] In this embodiment, the welding fixture 100 includes a base 10 and a plurality of pressure plates 20 rotatably connected to the base 10. The surface of the base 10 has a plurality of receiving areas 11, each receiving area 11 having a first bearing groove 111 and a second bearing groove 112 disposed opposite to each other. The interior of the first bearing groove 111 has a structure matching the shape of the thermistor 210, which can fix the thermistor 210 inside. The interior of the second bearing groove 112 has a structure matching the shape of the connector 220, which can fix the connector 220 inside. The fixing method of this embodiment is simple to operate and has strong effectiveness.

[0119] In this embodiment, the overlapping area of ​​the first pin 211 and the second pin 221 is pressed by the pressure plate 20. This can further fix the overlapping area of ​​the first pin 211 and the second pin 221 on the basis that the thermistor 210 and the connector 220 are fixed by the base 10, ensuring the effective overlap of the first pin 211 and the second pin 221, thereby ensuring the yield of subsequent soldering. It can also keep the first pin 211 and the second pin 221 in the factory shape and reduce the possibility of deformation of the first pin 211 and the second pin 221 during the fixing process.

[0120] Based on the same inventive concept, this application also provides a temperature and pressure sensor manufactured by any of the welding methods provided in the foregoing embodiments, such as... Figures 11-12 As shown, the temperature and pressure sensor includes: a thermistor 210, a connector 220, and a welding layer 300.

[0121] Thermistor 210 has a first pin 211.

[0122] The connector 220 has a second pin 221; the second pin 221 has a through hole 222, and the second pin 221 overlaps with the first pin 211.

[0123] The solder layer 300 includes a portion connected to both sides of the second pin 221 and a portion located within the through hole 222.

[0124] The solder layer 300 covers at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221.

[0125] In this embodiment, both sides of the second pin 221 are bonded with a welding layer 300, which can form a stable frame structure, disperse stress, reduce the possibility of cracking due to stress concentration, and improve the connection stability between the first pin 211 and the second pin 221.

[0126] In some embodiments, the thermistor is used to acquire temperature information; the temperature and pressure sensor also includes a pressure sensor connected to the connector 220 for acquiring pressure information.

[0127] In some embodiments, such as Figures 11-12 As shown, the solder layer 300 includes: a first solder layer 310 connected to one side of the second pin 221, a second solder layer 320 connected to the other side of the second pin 221, and a third solder layer 330 formed in the through hole 222; the first solder layer 310 covers at least a portion of the overlapping area of ​​the first pin 211 and the second pin 221; on a plane parallel to the second pin 221, the areas of the first solder layer 310 and the second solder layer 320 are both larger than the area of ​​the third solder layer 330.

[0128] In this embodiment, the first solder layer 310 covers the overlapping area of ​​the first pin 211 and the second pin 221. The first solder layer 310, the third solder layer 330, and the second solder layer 320 form an "I"-shaped structure that is wide at both ends and narrow in the middle. The "both ends" refer to the first solder layer 310 and the second solder layer 320, and the "middle" refers to the third solder layer 330. This structure can increase the bonding area between the solder layer 300 and the first pin 211 and the second pin 221, forming a stable frame structure, thereby improving the bonding force between the first pin 211 and the second pin 221 and the solder layer 300.

[0129] In some embodiments, in the overlapping area of ​​the first pin 211 and the second pin 221, the surface of the first pin 211 is covered with a gold layer 212, which passes through the opening area of ​​the through hole 222.

[0130] In this embodiment, the surface of the first pin 211 is covered with a gold layer 212, which easily forms an intermetallic compound with the solder, thereby improving the bonding force between the first pin 211 and the solder.

[0131] Moreover, the gold layer 212 has a low surface energy, which helps to reduce the overall surface tension of the molten solder ball and has stronger fluidity. The portion of the first pin 211 covered with the gold layer 212 passes through the opening area of ​​the through hole 222, making it easier for the solder to be drawn into the through hole 222 by capillary action. This allows the solder ball to smoothly enter the through hole 222 and leak out to contact the bottom surface of the second pin 221, forming an I-shaped solder layer 300.

[0132] In some embodiments, the through hole 222 is a circular hole.

[0133] In this embodiment, when the second welding method is used, the through hole 222 is a round hole, which can minimize the opening area of ​​the through hole 222 and ensure the strength of the second pin 221.

[0134] In some embodiments, such as Figure 5 As shown, the through hole 222 is an oblong hole, and the long axis of the oblong hole is consistent with the length direction of the second pin 221.

[0135] In this embodiment, as Figure 10 As shown, the through-hole 222 is an oblong hole, which allows more solder to leak into the receiving groove 113, ensuring that more solder adheres to the bottom surface of the second pin 221. The oblong hole has a major axis and a minor axis. The major axis of the oblong hole is aligned with the length direction of the second pin 221, and the minor axis is aligned with the width direction of the second pin 221. This design increases the opening area of ​​the through-hole 222 while maintaining the rigidity of the second pin 221.

[0136] By applying the embodiments of this application, at least the following beneficial effects can be achieved:

[0137] (1) In this embodiment of the application, multiple welding components 200 are fixed at the same time by using welding fixture 100. Compared with manual fixing, the accuracy is higher, the stability of fixing can be improved, the production efficiency can be improved, and the cost is lower.

[0138] (2) In this embodiment of the application, solder ball soldering is performed on the soldering assembly 200 fixed in the soldering fixture 100. Molten solder balls are applied to the overlapping area of ​​the first pin 211 of the thermistor 210 and the second pin 221 of the connector 220 to form solder. The second pin 221 is flat and has a top surface and a bottom surface (the top surface is the side away from the base 10 during soldering, and the bottom surface is the side facing the base 10 during soldering). The molten solder balls are applied towards the top surface of the second pin 221, which can pass through the first pin 211 to form solder. The molten solder ball leaks through the through-hole 222 of the second pin 221. It is in a liquid state and has fluidity. The second pin 221 has a certain adsorption to the solder ball, so that the first part of the leaked solder can contact the bottom surface of the second pin 221. The second part of the solder is located inside the through-hole 222, and the third part of the solder is located on the top surface of the second pin 221. The solder layer 300 formed after the solder ball solidifies covers the overlapping area of ​​the first pin 211 and the second pin 221, forming an "I" shaped structure that is wide at both ends and narrow in the middle.

[0139] (3) The embodiments of this application can increase the bonding area between the solder layer 300 and the first pin 211 and the second pin 221, thereby improving the bonding force between the first pin 211 and the second pin 221 and the solder layer 300. Moreover, compared with the related technology where solder is applied to only one surface of the second pin 221, the solder layer 300 is attached to both sides of the second pin 221, which can form a stable frame structure, disperse stress, reduce the possibility of cracking due to stress concentration, and improve the connection stability between the first pin 211 and the second pin 221.

[0140] (4) The embodiment of this application uses solder ball soldering. The solder ball is in a molten state before reaching the through hole 222 and has fluidity, which can ensure that part of the solder ball or part of a single solder ball can pass through the through hole 222 and contact the bottom surface of the second pin 221, thus ensuring the feasibility of the soldering method.

[0141] (5) The surface of the first pin 211 is covered with a gold layer 212. Gold is a very stable metal that hardly oxidizes in air. Therefore, the molten solder ball can easily spread on the metal surface and form an intermetallic compound, thereby completing the soldering. Moreover, the surface of the gold layer 212 has a low surface energy, which helps to reduce the overall surface tension of the molten solder ball, has stronger fluidity, and is more easily drawn into the through hole 222 by capillary action, thereby allowing the solder ball to smoothly enter the through hole 222 and leak to contact the bottom surface of the second pin 221, forming an "I"-shaped solder layer 300.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of welding a temperature and pressure sensor, characterized by, The method comprises: fixing multiple groups of welding components on a base of a welding fixture based on the welding fixture; each group of the welding components comprises a thermistor and a connecting piece arranged oppositely, a first pin of the thermistor and a second pin of the connecting piece are overlapped one by one; the second pin has a through hole; in a first direction, the size of the second pin and the size of the through hole are both larger than the size of the first pin, the first direction is parallel to the base and perpendicular to the arrangement direction of the thermistor and the connecting piece; the bottom surface of the second pin has a spacing from the base; applying molten tin balls to the overlapping area of the first pin and the second pin in each group of the welding components to form solder, so that a first part of the solder contacts the bottom surface of the second pin through the through hole, a second part of the solder is located in the through hole, and a third part of the solder is located on the second pin to form an integrated solder layer after solidification; the solder layer covers at least part of the overlapping area of the first pin and the second pin.

2. The welding method according to claim 1, characterized in that, The method comprises: fixing multiple groups of welding components on a base of a welding fixture based on the welding fixture, comprising: fixing multiple groups of the welding components on the base based on the welding fixture, sequentially overlapping the second pin and the first pin in a direction away from the base; at least part of the opening area of the through hole is exposed to the first pin; and applying molten tin balls to the overlapping area of the first pin and the second pin in each group of the welding components to form solder, so that a first part of the solder contacts the bottom surface of the second pin through the through hole, a second part of the solder is located in the through hole, and a third part of the solder is located on the second pin, comprising:

3. The welding method according to claim 2, characterized in that, applying molten tin balls to the overlapping area of the first pin and the second pin in each group of the welding components to form solder, so that a first part of the solder leaks onto a containing groove of the base through the through hole and flows to contact the bottom surface of the second pin, a second part of the solder is located in the through hole, and a third part of the solder is located on the second pin and covers at least part of the overlapping area of the first pin and the second pin. In the overlapping area of the first pin and the second pin, the surface of the first pin is covered with a gold layer; 4. The welding method of claim 1, wherein, On the base, the orthographic projection of the first pin passes through the orthographic projection range of the edge of the through hole. The method comprises: fixing multiple groups of welding components on a base of a welding fixture based on the welding fixture, comprising: fixing multiple groups of the welding components on the base based on the welding fixture, sequentially overlapping the first pin and the second pin in a direction away from the base; and applying molten tin balls to the overlapping area of the first pin and the second pin in each group of the welding components to form solder, so that a first part of the solder contacts the bottom surface of the second pin through the through hole, a second part of the solder is located in the through hole, and a third part of the solder is located on the second pin, comprising: Applying molten solder balls to the overlap region of the first pin and the second pin in each of the plurality of solder assemblies forms solder, such that a first portion of the solder leaks through the through hole onto the receiving groove of the base and flows to cover at least a portion of the overlap region of the first pin and the second pin, a second portion of the solder is located within the through hole, and a third portion of the solder is located on the second pin.

5. The welding method of claim 4, wherein, The first portion of the solder leaks through the through hole onto the receiving groove of the base and flows to cover at least a portion of the overlap region of the first pin and the second pin, including: The first portion of the solder leaks through the through hole onto the bottom of the receiving groove, and the fourth portion of the solder leaks through a gap between the sidewall of the second bearing groove of the base and the second pin onto the bottom of the receiving groove, and flows to cover at least a portion of the overlap region of the first pin and the second pin.

6. The welding method of claim 1, wherein, Fixing a plurality of solder assemblies to a base of a soldering jig based on a soldering jig, including: Placing the plurality of solder assemblies in a plurality of receiving areas of the base; in each of the plurality of solder assemblies, the thermistor is disposed in a first bearing groove of the receiving area, the connecting piece is disposed in a second bearing groove of the receiving area, the first pin and the second pin overlap in an overlapping region of the first bearing groove and the second bearing groove, and a top of a pin that is farther away from the base of the first pin and the second pin is not lower than a surface of the base; Rotating a pressing plate of the soldering jig such that the pressing plate presses both ends of the overlap region of the first pin and the second pin, and the hollow of the pressing plate exposes the through hole.

7. The welding method of claim 6, wherein, The overlapping region of the first bearing groove and the second bearing groove has a receiving groove; A range of a normal projection of the through hole on the base falls within a range of the receiving groove; A bottom of a pin that is closer to the base of the first pin and the second pin has a spacing from the bottom of the receiving groove.

8. A welding jig for use in a welding method as claimed in any one of claims 1 to 7, characterized in that Including: A base having a plurality of receiving areas for one-to-one receiving a plurality of solder assemblies; The receiving area has a first bearing groove and a second bearing groove arranged oppositely, and opposite end regions of the first bearing groove and the second bearing groove overlap; A plurality of pressing plates are one-to-one rotatably connected to the plurality of receiving areas; The pressing plate has a hollow; In a fixed state, the thermistor is at least partially disposed in the first bearing groove, the connecting piece is at least partially disposed in the second bearing groove, the first pin and the second pin overlap in the overlapping region of the first bearing groove and the second bearing groove, the pressing plate presses both ends of the overlap region of the first pin and the second pin, and the hollow of the pressing plate exposes the through hole.

9. A warm pressure sensor manufactured by the welding method according to any one of claims 1 to 7, characterized by Including: A thermistor having a first pin; A connecting piece having a second pin, the second pin having a through hole, and the second pin overlapping the first pin; A solder layer including a portion connected to both sides of the second pin and a portion located within the through hole; The solder layer covers at least a portion of the overlap region of the first pin and the second pin.

10. The temperature and pressure sensor of claim 9, wherein, The welding layer comprises a first solder layer connected to one side of the second pin, a second solder layer connected to the other side of the second pin, and a third solder layer formed in the through hole; The first solder layer covers at least part of the overlap area of the first pin and the second pin; In a plane parallel to the second pin, the area of the first solder layer and the area of the second solder layer are both greater than the area of the third solder layer.

11. The temperature and pressure sensor of claim 9, wherein, In the overlap area of the first pin and the second pin, the surface of the first pin is covered with a gold layer, and the opening area of the through hole is penetrated.

12. The temperature and pressure sensor of claim 9, wherein, The through hole is a circular hole or a waist-shaped hole, and the long diameter direction of the waist-shaped hole is consistent with the length direction of the second pin.

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