A pin soldering needle and a soldering tool for interdigital electrode capacitive sensor

Abstract

The utility model discloses a pin soldering needle and welding frock for interdigital electrode capacitive sensor, relate to sensor technical field, and interdigital electrode capacitive sensor includes interdigital electrode plate, pin soldering needle and PCB detection board, and pin soldering needle includes soldering needle and sets up in the upper pin and lower pin of soldering needle one end, and the upper pin and lower pin are arranged along the extension direction of soldering needle, and the surface of the opposite setting of upper pin and lower pin is used for with the upper and lower surface of interdigital electrode plate respectively and through the soldering paste welding connection and is pasted together. The double -sided pasting of upper pin and lower pin and interdigital electrode plate forms the clamping, and the structure cooperation intensity and the contact area with soldering paste are increased, and then cooperate the low -temperature welding of soldering paste one -time melting forming. The welding frock includes the heat conduction block and the cushion block, and the heat conduction block is used for the heat conduction when pin soldering needle and interdigital electrode plate are welded through soldering paste, and the cushion block is used for guaranteeing the parallelism between interdigital electrode plate and PCB detection board when pin soldering needle and PCB detection board are welded.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to a pin for welding interdigital capacitive sensors and a welding fixture. Background Technology

[0002] Interdigitated electrodes, as a special type of sensing element, are widely used in the detection end of sensors. They are manufactured by depositing pure gold onto an alumina ceramic substrate to form an interdigitated electrode plate. The alumina ceramic substrate is brittle, and this brittleness becomes more pronounced under high temperatures. The connection between the interdigitated electrodes and the sensor is typically achieved by soldering circuit pins to the sensor detection plate. Traditionally, this involves directly soldering the pins to both the ceramic interdigitated electrode and the detection plate using an electroplating iron.

[0003] The aforementioned traditional electro-iron welding method has the following disadvantages during operation:

[0004] (1) Risk of embrittlement and scrapping: The working temperature of the soldering iron (300-400℃) combined with continuous thermal shock (locally reaching 600-700℃) causes the ceramic to crack due to repeated heating;

[0005] (2) Scratching of interdigitated electrodes: During manual welding, the welding torch of the electric arc welding iron is prone to scratching the interdigitated electrodes, which damages the electrode structure and affects the sensor performance.

[0006] (3) Poor consistency: Manual welding makes it difficult to accurately control the distance between the interdigital electrode plate and the PCB test board, resulting in uneven welding.

[0007] Existing technologies cannot solve the above problems, and there is an urgent need for an optimized solution that can achieve low-temperature welding and high positioning. Utility Model Content

[0008] The purpose of this invention is to provide a pin for an interdigital capacitive sensor and a welding fixture to solve the problems existing in the prior art and achieve low-temperature welding and high positioning.

[0009] To achieve the above objectives, this utility model provides the following solution:

[0010] A pin for an interdigital capacitive sensor, the interdigital capacitive sensor comprising an interdigital electrode plate, a pin, and a PCB detection board, wherein the two ends of the pin are respectively soldered to the interdigital electrode plate and the PCB detection board, the pin comprising a pin and an upper pin and a lower pin disposed at one end of the pin, the upper pin and the lower pin being arranged along the extension direction of the pin, and the surfaces of the upper pin and the lower pin being disposed opposite to each other being used to adhere to the upper and lower surfaces of the interdigital electrode plate and be soldered together by solder paste.

[0011] In an exemplary embodiment, the upper pin is disposed at the end of the welding pin, and the upper surface of the upper pin is flush with the upper end face of the welding pin.

[0012] In one exemplary embodiment, the number of upper pins is one, and it is centered and aligned with the side of the solder pin near the interdigital electrode plate.

[0013] In one exemplary embodiment, the number of lower pins is two, which are fixedly disposed on both sides of the welding pin.

[0014] In one exemplary embodiment, the lead solder pins and the interdigitated electrode plate are interference-fitted.

[0015] This utility model also provides a welding fixture for welding and assembling the above-mentioned interdigitated electrode capacitive sensor, comprising:

[0016] A heat-conducting block, the upper surface of which has a sixth groove for accommodating the lower pin of the pin soldering pin; the upper surface of the heat-conducting block is used to fit against the lower surface of the interdigital electrode plate, the lower surface of the heat-conducting block is used to fit against the upper surface of the heating stage, the heating stage is used to provide heat energy when the pin soldering pin and the interdigital electrode plate are soldered with solder paste.

[0017] A pad has a second groove on its upper surface for accommodating the lower pin of the pin soldering pin; the upper surface of the pad is used to fit against the lower surface of the interdigitated electrode plate, and the lower surface of the pad is used to fit against the upper surface of the PCB test board; the upper and lower surfaces of the pad are parallel to each other.

[0018] In an exemplary embodiment, the thickness of the heat-conducting block is greater than the distance between the upper surface of the lower pin and the lower end face of the solder pin.

[0019] In an exemplary embodiment, the thickness of the pad is less than the distance between the upper surface of the lower pin and the lower end face of the solder pin.

[0020] In an exemplary embodiment, the interdigitated electrode plate is connected to both sides of the PCB detection board via the pins, and the width of the heat-conducting block is smaller than the width of the interdigitated electrode plate.

[0021] In an exemplary embodiment, the interdigitated electrode plate is connected to both sides of the PCB detection board via the pins, and the width of the pad is smaller than the width of the interdigitated electrode plate.

[0022] The present invention achieves the following technical advantages over the prior art:

[0023] 1. By configuring the lead soldering pins to include the soldering pins and upper and lower pins located at one end of the soldering pins, and having the upper and lower pins adhere to both sides of the interdigital electrode plate to form a clamp, the structural fit strength between the lead soldering pins and the interdigital electrode plate is increased, as well as the contact area between the lead soldering pins and the solder paste is increased. Furthermore, with the low melting temperature of the solder paste (200-300℃), it is melted and fixed by the heating table, forming a single piece without the need for repeated operations. This avoids the high-temperature thermal shock of the soldering iron, significantly reduces the heating temperature of the ceramic, and significantly inhibits embrittlement and fracture.

[0024] Other technical solutions disclosed in this utility model also have the following technical advantages:

[0025] 2. By setting a heat-conducting block with a first groove, the first groove of the heat-conducting block accurately accommodates the pins, ensuring the assembly stability of the pin soldering pins and the interdigital electrode plate; the heat-conducting block serves as the heat conduction medium between the heating stage and the interdigital electrode plate and the pin soldering pins, avoiding direct contact between the interdigital electrode plate and the heating stage, achieving uniform low-temperature heat transfer at 200–300℃, and allowing the solder paste to melt and form in one go, avoiding ceramic thermal brittle fracture caused by local high temperature (600–700℃) of the soldering iron.

[0026] 3. By setting a pad with a second groove, the second groove of the pad accommodates the pins. The upper and lower surfaces of the pad are strictly parallel, so that the distance between the interdigital electrode plate and the PCB test board is constant and without deviation, completely eliminating the problem of uneven height in manual soldering and improving product consistency. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of an interdigital electrode capacitive sensor disclosed in a specific embodiment of the present invention.

[0029] Figure 2 for Figure 1 Schematic diagram of the structure of the middle pin soldering pin;

[0030] Figure 3 This is a schematic diagram illustrating the usage of the heat-conducting block of the welding fixture according to a specific embodiment of the present utility model.

[0031] Figure 4 for Figure 3 Schematic diagram of the structure of the central heat-conducting block;

[0032] Figure 5 for Figure 3 Assembly diagram of the heat-conducting block and the lead soldering pins;

[0033] Figure 6 This is a schematic diagram illustrating the usage of the pad block of the welding fixture according to a specific embodiment of this utility model.

[0034] Figure 7 for Figure 6 Schematic diagram of the structure of the intermediate pad block;

[0035] Figure 8 for Figure 6 Assembly diagram of the center pad and lead solder pins;

[0036] Among them, 1. interdigitated electrode plate; 2. lead soldering pin; 3. PCB test board; 4. soldering pin; 5. upper lead; 6. lower lead; 7. heat-conducting block; 8. first groove; 9. heating platform; 10. pad; 11. second groove. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0038] The purpose of this invention is to provide a pin for an interdigital capacitive sensor and a welding fixture to solve the problems existing in the prior art and achieve low-temperature welding and high positioning.

[0039] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] Please refer to Figure 1 and Figure 2 This embodiment provides a pin for an interdigital capacitive sensor. The interdigital capacitive sensor includes an interdigital electrode plate 1, a pin 2, and a PCB detection board 3. The two ends of the pin 2 are soldered to the interdigital electrode plate 1 and the PCB detection board 3, respectively.

[0042] The lead soldering pin 2 includes a soldering pin 4 and an upper pin 5 and a lower pin 6 disposed at one end of the soldering pin. The upper pin 5 and the lower pin 6 are arranged along the extension direction of the soldering pin 4. The surfaces of the upper pin 5 and the lower pin 6 disposed opposite to each other are used to be attached to the upper and lower surfaces of the interdigital electrode plate 1 and soldered together by solder paste.

[0043] By configuring the lead soldering pin to include the soldering pin and upper and lower pins located at one end of the soldering pin, and having the upper and lower pins adhere to both sides of the interdigital electrode plate to form a clamp, the structural fit strength between the lead soldering pin and the interdigital electrode plate is increased, as well as the contact area between the lead soldering pin and the solder paste is increased. Furthermore, combined with the low melting temperature of the solder paste (200-300℃) and the one-time soldering process of the heating table, the high-temperature thermal shock of the soldering iron is avoided, the heating temperature of the ceramic is significantly reduced, and embrittlement and fracture are significantly suppressed.

[0044] In this embodiment, the upper pin 5 is disposed at the end of the welding pin 4, and the upper surface of the upper pin 5 is flush with the upper end face of the welding pin 4. There is one upper pin 5, which is centered on the side of the welding pin 4 near the interdigital electrode plate 1. There are two lower pins 6, which are fixedly disposed on both sides of the welding pin 4.

[0045] By setting the upper pin 5 and lower pin 6 to be attached to the upper and lower surfaces of the interdigital electrode plate 1 respectively, the stability and contact area of ​​the welding can be effectively improved, thereby enhancing the overall electrical connection performance of the sensor. Simultaneously, the symmetrical arrangement of the lower pin 6 on both sides of the welding pin 4 enhances the mechanical strength and balance of the welded structure, preventing welding failure caused by uneven stress. In practical applications, this structural design also facilitates automated welding, improving production efficiency.

[0046] The lead pin 2 and the interdigital electrode plate 1 are interference-fitted, meaning the distance between the lower surface of the upper lead 5 and the upper surface of the lower lead 6 is slightly less than the thickness of the interdigital electrode plate 1. This interference fit design ensures a tight, gapless connection between the lead pin 2 and the interdigital electrode plate 1, further enhancing the stability and reliability of the electrical connection. During assembly, the lead pin 2 is slightly expanded or the interdigital electrode plate 1 is slightly contracted through appropriate pressure or temperature treatment, thus achieving a tight fit between the two. This fit not only improves the electrical performance of the sensor but also effectively prevents loosening of the connection due to vibration or external forces, extending the sensor's service life.

[0047] Furthermore, the welding pin 4 is made of a high-strength, highly conductive alloy material to ensure good electrical conductivity and mechanical strength. The upper pin 5 and lower pin 6 are made of a corrosion-resistant metal material to prevent oxidation from affecting the welding quality and electrical connection performance during welding and use.

[0048] Furthermore, the design of the lead solder pin 2 also takes into account the connection stability with the PCB inspection board 3. The other end of the solder pin 4 is provided with a soldering part adapted to the PCB inspection board 3. This soldering part has a shape and size that matches the soldering holes on the PCB inspection board 3 to ensure a firm connection between the lead solder pin 2 and the PCB inspection board 3.

[0049] Example 2

[0050] This embodiment provides a welding fixture for welding and assembling the interdigital electrode capacitive sensor described in Embodiment 1, including a heat-conducting block 7 and a pad block 10.

[0051] The upper surface of the heat-conducting block 7 is provided with a first groove 8 for accommodating the lower pin 6 of the pin 2; the upper surface of the heat-conducting block 7 is used to fit against the lower surface of the interdigital electrode plate 1, and the lower surface of the heat-conducting block 7 is used to fit against the upper surface of the heating stage 9, which provides heat energy when the pin 2 and the interdigital electrode plate 1 are soldered with solder paste.

[0052] By setting a heat-conducting block with a first groove, the first groove of the heat-conducting block accurately accommodates the pins, ensuring the assembly stability of the pins and the interdigital electrode plate; the heat-conducting block serves as the heat conduction medium between the heating platform and the interdigital electrode plate and the pins, avoiding direct contact between the interdigital electrode plate and the heating platform, achieving uniform low-temperature heat transfer at 200–300℃, and allowing the solder paste to melt and form in one go, avoiding ceramic thermal brittle fracture caused by local high temperature (600–700℃) of the soldering iron.

[0053] The upper surface of the pad 10 is provided with a second groove 11 for accommodating the lower pin 6 of the pin soldering pin 2; the upper surface of the pad 10 is used to fit against the lower surface of the interdigitated electrode plate 1, and the lower surface of the pad 10 is used to fit against the upper surface of the PCB test board 3. The upper and lower surfaces of the pad 10 are parallel to each other.

[0054] By setting a pad with a second groove, the second groove of the pad accommodates the pins. The upper and lower surfaces of the pad are strictly parallel, so that the distance between the interdigital electrode plate and the PCB test board is constant and without deviation, completely eliminating the problem of uneven height in manual soldering and improving product consistency.

[0055] The heat-conducting block 7 is made of aluminum alloy or other high thermal conductivity material, and its thickness is greater than the distance between the upper surface of the lower pin 6 and the lower end face of the solder pin 4.

[0056] The interdigitated electrode plate 1 and the PCB detection board 3 are connected on both sides by pin soldering pins 2, and the width of the heat-conducting block 7 is smaller than the width of the interdigitated electrode plate 1.

[0057] The thickness of the pad 10 is less than the distance between the upper surface of the lower pin 6 and the lower end face of the solder pin 4.

[0058] The interdigitated electrode plate 1 and the PCB detection board 3 are connected on both sides by pin soldering pins 2, and the width of the pad 10 is smaller than the width of the interdigitated electrode plate 1.

[0059] The welding steps using this embodiment are as follows:

[0060] 1. After assembling the interdigital electrode plate 1 and the lead solder pin 2, align the lower lead 6 with the first groove 8 of the heat-conducting block 7 and insert it, ensuring that the interdigital electrode plate 1 and the heat-conducting block 7 are in close contact. Then place it on the heating table and prepare for heating.

[0061] 2. Use a graduated syringe to apply a certain amount of solder paste.

[0062] 3. Adjust the temperature of the heating table to (200-300℃) and heat the pad 10 to melt the solder paste. Then cool it to room temperature to complete the welding of the interdigital electrode plate 1 and the lead solder pin 2.

[0063] 4. Separate the heat-conducting block 7 from the assembly of the interdigital electrode plate 1 and the pin 2, align the lower pin 6 with the second groove 11 of the pad 10 and insert it, ensuring that the interdigital electrode plate 1 and the pad 10 are in close contact. Then place the pad 10 and the assembly on the PCB test board 3, so that the pin 2 aligns with the soldering hole of the PCB test board, and ensure that the pad 10 is in close contact with both the interdigital electrode plate 1 and the PCB test board 3.

[0064] 5. Use a soldering iron to solder the solder joints between the solder pins and the PCB test board 3, thus completing the soldering of the PCB test board 3 and the lead solder pins 2.

[0065] 6. Remove pad 10; welding is now complete.

[0066] Furthermore, as a preferred embodiment, the welding fixture also includes a fixing member for securing the heat-conducting block 7 and the pad 10 to ensure their stability during the welding process. This welding fixture enables rapid, accurate, and high-quality welding assembly of the interdigitated electrode capacitive sensor.

[0067] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this utility model, and do not imply or require that the device or element referred to have a specific orientation or construction method, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish the objects of description and should not be construed as limiting importance or order, and the features defined by such terms may explicitly or implicitly include one or more of those features. Unless otherwise stated, "a plurality of" in the description of this utility model refers to two or more.

[0068] The terms "installation," "connection," and "joining" should be interpreted broadly, unless otherwise explicitly defined, to include, but are not limited to, fixed connections, detachable connections, or integrally formed connections; mechanical or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art can understand their meaning based on the specific technical solution. The fixed connections involved in this utility model, unless otherwise stated, include both detachable fixed connections (such as bolt and screw connections) and non-detachable fixed connections (such as riveting and welding), and may also include integral structures achieved through an integral forming process (such as casting) (except where integral forming is clearly impossible).

[0069] Unless otherwise stated, the terms used in any of the technical solutions disclosed in this utility model to indicate positional relationships or shapes cover states or shapes that are similar to, close to, or adjacent to them.

[0070] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0071] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0072] In the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0073] Any adaptive changes made according to actual needs are within the protection scope of this utility model.

[0074] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A lead soldering pin for an interdigital capacitive sensor, the interdigital capacitive sensor comprising an interdigital electrode plate (1), a lead soldering pin (2), and a PCB detection board (3), wherein the two ends of the lead soldering pin (2) are soldered to the interdigital electrode plate (1) and the PCB detection board (3) respectively, characterized in that: The pin (2) includes a pin (4) and an upper pin (5) and a lower pin (6) disposed at one end of the pin. The upper pin (5) and the lower pin (6) are arranged along the extension direction of the pin (4). The surfaces of the upper pin (5) and the lower pin (6) disposed opposite to each other are respectively used to be attached to the upper and lower surfaces of the interdigital electrode plate (1) and connected by solder paste.

2. The pin for an interdigital capacitive sensor according to claim 1, characterized in that: The upper pin (5) is disposed at the end of the welding needle (4), and the upper surface of the upper pin (5) is flush with the upper end face of the welding needle (4).

3. The pin for an interdigital capacitive sensor according to claim 1, characterized in that: The number of the upper pins (5) is one, and they are centered and aligned with the side of the welding pin (4) near the interdigital electrode plate (1).

4. The pin for an interdigital capacitive sensor according to claim 1, characterized in that: The number of the lower pins (6) is two, which are fixedly set on both sides of the welding pin (4).

5. The pin for an interdigital capacitive sensor according to claim 1, characterized in that: The pin (2) and the interdigitated electrode plate (1) are interference fit.

6. A welding fixture for welding and assembling the interdigital electrode capacitive sensor according to any one of claims 1-5, characterized in that, include: A heat-conducting block (7) has a first groove (8) on its upper surface for accommodating the lower pin (6) of the pin soldering pin (2); the upper surface of the heat-conducting block (7) is used to fit against the lower surface of the interdigital electrode plate (1), and the lower surface of the heat-conducting block (7) is used to fit against the upper surface of the heating platform (9); the heating platform (9) is used to provide heat energy when the pin soldering pin (2) and the interdigital electrode plate (1) are soldered with solder paste. A pad (10) has a second groove (11) on its upper surface for accommodating the lower pin (6) of the pin soldering pin (2); the upper surface of the pad (10) is used to fit against the lower surface of the interdigitated electrode plate (1), and the lower surface of the pad (10) is used to fit against the upper surface of the PCB test board (3); the upper and lower surfaces of the pad (10) are parallel to each other.

7. The welding fixture according to claim 6, characterized in that: The thickness of the heat-conducting block (7) is greater than the distance between the upper surface of the lower pin (6) and the lower end face of the solder pin (4).

8. The welding fixture according to claim 6, characterized in that: The thickness of the pad (10) is less than the distance between the upper surface of the lower pin (6) and the lower end face of the solder pin (4).

9. The welding fixture according to claim 6, characterized in that: The interdigitated electrode plate (1) is connected to both sides of the PCB detection board (3) via the pin soldering pins (2), and the width of the heat-conducting block (7) is smaller than the width of the interdigitated electrode plate (1).

10. The welding fixture according to claim 6, characterized in that: The interdigitated electrode plate (1) is connected to both sides of the PCB detection board (3) via the pin soldering pins (2), and the width of the pad (10) is smaller than the width of the interdigitated electrode plate (1).

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