Low stress hybrid integrated circuit interconnect and its forming jig and method of manufacture

Abstract

The present application relates to a kind of low stress hybrid integrated circuit connecting piece and its forming clamp and manufacturing method, connecting piece includes first welding section, stress relief section and second welding section;The one end of stress relief section is connected with first welding section, the other end is connected with second welding section, for reducing its internal stress welding when connecting piece occurs deformation;All or part of stress relief section is wrapped with solder resist layer.The present application, by setting stress relief section on connecting piece, can absorb the stress generated due to the mismatch of the welding surface CTE of first welding section and second welding section during the wide range of temperature cycle changes in space environment, so that the welding interconnection of connecting piece meets the high temperature cycle requirement of high reliability hybrid integrated circuit in space environment.

Description

Technical Field

[0001] This invention belongs to the field of hybrid integrated circuit technology, and relates to a low-stress hybrid integrated circuit connector, its molding fixture, and its manufacturing method. Background Technology

[0002] In the design of internal interconnect structures for hybrid integrated circuits, L-shaped connectors are typically used to achieve grounding electrical connections between the circuit board and the casing. The L-shaped grounding connector is made of copper and measures 1.5mm in length, 1.5mm in height, and 1mm in width. The connector is solderable, with its length and height directions respectively soldered to the circuit board and the casing. This L-shaped connector features low impedance and small size. However, aerospace high-reliability hybrid integrated circuits require high resistance to temperature cycling stress. When L-shaped connectors are used in aerospace high-reliability hybrid integrated circuits, a CTE (coefficient of thermal expansion) mismatch exists between the connector and the solder interface material. Since the connector itself lacks a stress-relief structure design, the thermal stress generated by temperature cycling directly acts on the connector solder joints. This leads to cracking of the solder joints after rigorous temperature cycling tests, affecting electrical parameters and circuit reliability. This fails to meet the high-reliability application requirements of the aerospace environment and represents a weak link in the interconnect structure of aerospace high-reliability hybrid integrated circuits. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a low-stress hybrid integrated circuit interconnect, its molding fixture and manufacturing method.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A low-stress hybrid integrated circuit connector includes a first welding section, a stress-relief section, and a second welding section. The first welding section is used for welding to a circuit board inside the hybrid integrated circuit, and the second welding section is used for welding to the casing of the hybrid integrated circuit. One end of the stress-relief section is connected to the first welding section, and the other end is connected to the second welding section, which is used to reduce the internal stress during welding when the connector is deformed. The stress-relief section is wholly or partially covered with a solder resist layer.

[0005] Furthermore, the first welding section, the stress-relieving section, and the second welding section are formed by bending the same flat copper wire.

[0006] Furthermore, the stress-relieving section includes a horizontal section, a first bent section, and a second bent section. One end of the horizontal section is connected to the first welded section through the first bent section, and the other end of the horizontal section is connected to the second welded section through the second bent section.

[0007] Furthermore, the angle between the first welding segment and the second welding segment is 90°, and the first bending part is a first arc-shaped part with a 90° arc shape, the radius of the first arc-shaped part being more than twice the thickness of the flat copper wire.

[0008] Furthermore, the second bending portion includes a second arc-shaped portion connected to the horizontal portion and a third arc-shaped portion connected between the second arc-shaped portion and the second welding segment; both the second arc-shaped portion and the third arc-shaped portion are 90° arcs, and the radii of the second arc-shaped portion and the third arc-shaped portion are greater than twice the thickness of the flat copper wire.

[0009] Furthermore, the thickness of the flat copper wire is 0.15mm to 0.25mm, and the width is 0.5mm to 1mm; and / or At both ends of the stress-relief section, there is a section of flat copper wire that is not covered with enamel film, thus forming a transition section. The flat copper wire between the two transition sections is covered with enamel film, thus forming a solder resist layer.

[0010] A low-stress hybrid integrated circuit connector forming fixture is disclosed for forming low-stress hybrid integrated circuit connectors. The forming fixture includes a base and a pressure block. A limiting structure is provided on the base to define a placement area for the pressure block. At least one side of the pressure block is curved. A first groove is vertically formed on the upper surface of the base and is located within the placement area of ​​the pressure block. The width of the first groove is adapted to the thickness of the flat copper wire. A second groove is also horizontally provided on the base and connected to the first groove. The depth of the second groove is adapted to the thickness of the flat copper wire. A first arc-shaped chamfer structure is provided at the connection between the first groove and the second groove.

[0011] Furthermore, the limiting structure includes two first limiting blocks arranged sequentially on one side of the upper surface of the base and two second limiting blocks arranged sequentially on the other side of the upper surface of the base. The distance between the two first limiting blocks and the distance between the two second limiting blocks are both adapted to the width of the pressure block. The curved surface includes a second arc-shaped chamfer structure connected to the lower surface of the pressure block and a third arc-shaped chamfer structure connected to the upper surface of the pressure block. The radii of the first arc-shaped chamfer structure, the second arc-shaped chamfer structure and the third arc-shaped chamfer structure are all greater than twice the thickness of the flat copper wire.

[0012] A method for fabricating a low-stress hybrid integrated circuit interconnect includes the following steps: S100. Take a piece of enameled flat copper wire with a varnish film covering its surface, and remove a section of the varnish film from each end of the enameled flat copper wire to expose the copper surface. S200, Take a low-stress hybrid integrated circuit connector forming fixture; S300, the first end of the enameled flat copper wire is vertically inserted into the first groove, and the part of the enameled flat copper wire protruding from the first groove is bent to fit against the bottom of the first arc-shaped chamfer structure and the second groove respectively; S400. Place the pressure block in the placement area and fold back the portion of the enameled flat copper wire that extends beyond the lower end face of the pressure block until it is in contact with the curved surface and the upper end face of the pressure block, respectively. S500, remove the pressure block and enameled flat copper wire from the base in sequence.

[0013] Furthermore, the portion of the enameled flat copper wire with the enamel film removed is tinned; and the tinned enameled flat copper wire is then cleaned and dried.

[0014] In this invention, the structure of the grounding connector is optimized while maintaining the electrical connection lines and overall installation space largely unchanged. By incorporating a stress-relief section consisting of a first arc-shaped portion, a horizontal portion, a second arc-shaped portion, and a third arc-shaped portion, the stress generated by the CTE mismatch between the welding surfaces of the first and second welding sections during large-scale temperature cycling in aerospace environments can be absorbed. This ensures that the interconnection of the connector meets the high-temperature cycling requirements of high-reliability hybrid integrated circuits in aerospace environments. Furthermore, the first arc-shaped portion, the horizontal portion, the second arc-shaped portion, and the third arc-shaped portion can be easily formed by bending, facilitating the fabrication of the connector. By providing transition sections at both ends of the stress-relief section, precise control of the length of the enamel film removed from both ends of the enameled flat copper wire is eliminated, simplifying the manufacturing process. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of a preferred embodiment of the low-stress hybrid integrated circuit interconnect of the present invention.

[0016] Figure 2 This is a schematic diagram showing the two ends of the connector soldered to the circuit board and the casing inside the hybrid integrated circuit, respectively.

[0017] Figure 3 This is a schematic diagram of a preferred embodiment of the low-stress hybrid integrated circuit connector forming fixture of the present invention.

[0018] Figure 4 for Figure 3 A cross-sectional schematic diagram.

[0019] Figure 5 This is a flowchart of a preferred embodiment of the low-stress hybrid integrated circuit interconnect fabrication method of the present invention.

[0020] Figure 6 A schematic diagram of the structure of an enameled flat copper wire after the enamel coating at both ends has been removed.

[0021] Figure 7 This is a diagram showing the pressure block after it has been removed from the base.

[0022] The meanings of the labels in the attached diagram are as follows: First welding section - 110; Second welding section - 120; Stress relief section - 130; Transition sections - 130a, 130b; First arc-shaped section - 131; Second arc-shaped section - 132; Third arc-shaped section - 133; Horizontal section - 134; Connecting section - 135; Paint film - 140; Base - 200; First limiting block - 201; Second limiting block - 202; First groove - 211; Second groove - 212; First arc-shaped chamfer structure - 213; Pressure block - 220; Vertical section - 221; Second arc-shaped chamfer structure - 222; Third arc-shaped chamfer structure - 223; Enameled flat copper wire - 300; First solderable section - 301; Second solderable section - 302; Circuit board - 400; casing - 500. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. The illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] Please see Figure 1 This invention discloses a low-stress hybrid integrated circuit connector. A preferred embodiment of the low-stress hybrid integrated circuit connector includes a first soldering section 110, a stress-relieving section 130, and a second soldering section 120. Please refer to [link / reference]. Figure 2The first welding segment 110 is used for welding to the circuit board 400 inside the hybrid integrated circuit, and the second welding segment 120 is used for welding to the casing 500 of the hybrid integrated circuit. The stress-relieving segment 130 is curved, with one end connected to the first welding segment 110 and the other end connected to the second welding segment 120, used to reduce the internal stress of the connecting piece when it deforms due to temperature changes. Because the size of the hybrid integrated circuit is very small, the size of the connecting piece is also very small. During the welding process, the stress-relieving segment 130 is prone to mis-welding, causing it to also be welded and fixed to components such as the casing 500, thus losing its stress-relieving function. To avoid this, the stress-relieving segment 130 can be wholly or partially covered with a solder resist layer. The solder resist layer has high-temperature resistance and will not be damaged in the high-temperature environment of connecting piece welding, thereby preventing mis-welding of the stress-relieving segment 130.

[0025] Please continue reading. Figure 1 To facilitate the fabrication of the connecting piece, the first welding section 110, the stress-relieving section 130, and the second welding section 120 can be formed by bending the same flat copper wire. The thickness d of the flat copper wire is 0.15mm to 0.25mm, preferably d=0.2mm; the width L is 0.5mm to 1mm, preferably L=1mm. The stress-relieving section 130 can be completely covered with the enamel film 140 to form a solder resist layer, or it can be partially covered with the enamel film 140 to form a solder resist layer. In this embodiment, a small section of flat copper wire is left uncovered with the enamel film 140 (i.e., the solder resist layer) at the positions of the stress-relieving section 130 adjacent to the first welding section 110 and the second welding section 120. The portion of the stress-relieving section 130 not covered with the enamel film 140 forms transition sections 130a and 130b. Transition sections 130a and 130b are transition areas between the welded and non-welded areas. When transition sections 130a and 130b are not welded, it will not affect the weld strength of the first welded section 110 and the second welded section 120. When transition sections 130a and 130b are welded, it will not significantly affect the stress-reducing effect of the stress-relieving section 130. In other words, transition sections 130a and 130b are areas that can be welded or not. This reduces the precision requirement for the length of the paint film 140; the length of the paint film 140 can be slightly shorter than the length of the stress-relieving section 130. This allows a small section at both ends of the stress-relieving section 130 to remain uncovered by the paint film 140, rather than the paint film 140 needing to be exactly equal to and completely cover the stress-relieving section 130. This reduces the manufacturing difficulty of the connecting piece.

[0026] Specifically, the stress-relieving section 130 includes a horizontal section 134, a first bent section, and a second bent section. One end of the horizontal section 134 is connected to the first welding section 110 via the first bent section, and the other end of the horizontal section 134 is connected to the second welding section 120 via the second bent section. In this embodiment, the angle between the first welding section 110 and the second welding section 120 is 90°, and the first bent section is a first arc-shaped section 131 with a 90° arc shape. The radius of the first arc-shaped section 131 is greater than twice the thickness of the flat copper wire.

[0027] The second bending portion includes a second arc-shaped portion 132 connected to the horizontal portion 134 and a third arc-shaped portion 133 connected between the second arc-shaped portion 132 and the second welding section 120. Both the second arc-shaped portion 132 and the third arc-shaped portion 133 are 90° arcs. The radii of the second arc-shaped portion 132 and the third arc-shaped portion 133 are generally larger than the radius of the first arc-shaped portion 131, and the radii of the second arc-shaped portion 132 and the third arc-shaped portion 133 are equal. The second arc-shaped portion 132 and the third arc-shaped portion 133 can be directly combined to form a semi-circular arc, or a connecting portion 135 can be vertically provided between the second arc-shaped portion 132 and the third arc-shaped portion 133. By providing the connecting portion 135, the overall height of the stress-relieving section 130 can be adjusted to adapt to different connection requirements.

[0028] In this embodiment, the first arcuate portion 131 and a small portion of the horizontal portion 134 are not covered with the paint film 140, thus forming a transition section 130a; the third arcuate portion 133 is mostly not covered with the paint film 140, thus forming a transition section 130b. Most of the horizontal portion 134, the entire second arcuate portion 132, and a small portion of the third arcuate portion 133 are covered with the paint film 140, thus forming a solder resist layer. Of course, in other embodiments, the transition section 130a may only include a portion of the second arcuate portion 132, and the transition section 130b may only include a small portion of the third arcuate portion 133.

[0029] In this embodiment, by providing a stress-relieving section 130 composed of a first arc-shaped portion 131, a horizontal portion 134, a second arc-shaped portion 132, and a third arc-shaped portion 133, the stress generated by the CTE mismatch between the welding surfaces of the first welding section 110 and the second welding section 120 during large-scale temperature cycling in aerospace environments can be absorbed, ensuring that the interconnection of the connecting pieces meets the high-temperature cycling requirements of high-reliability hybrid integrated circuits in aerospace environments. Furthermore, the first arc-shaped portion 131, the horizontal portion 134, the second arc-shaped portion 132, and the third arc-shaped portion 133 can be easily formed by bending, facilitating the fabrication of the connecting pieces.

[0030] Please see Figure 3 and Figure 4The present invention also discloses a low-stress hybrid integrated circuit connector forming fixture for forming low-stress hybrid integrated circuit connectors. A preferred embodiment of the low-stress hybrid integrated circuit connector forming fixture of the present invention includes a base 200 and a pressure block 220. A limiting structure is provided on the base 200 to define a placement area for the pressure block 220. Specifically, the limiting structure may include two first limiting blocks 201 sequentially arranged on one side of the upper surface of the base 200 and two second limiting blocks 202 sequentially arranged on the other side of the upper surface of the base 200. The spacing between the two first limiting blocks 201 and the spacing between the two second limiting blocks 202 are adapted to the width of the pressure block 220. The two first limiting blocks 201 are used to limit one end of the pressure block 220, and the two second limiting blocks 202 are used to limit the other end of the pressure block 220.

[0031] The upper surface of the base 200 has a vertically formed first groove 211, which is located within the placement area of ​​the pressure block 220. The width of the first groove 211 (i.e., its dimension in the x-axis direction) can be equal to the thickness of the flat copper wire, and the depth of the first groove 211 (i.e., its dimension in the z-axis direction) is equal to the length of the first welding segment 110 of the connecting piece. The first groove 211 can be a through slot that penetrates the base 200 in its length direction (i.e., in the y-axis direction), so that the position of the flat copper wire extending into the first groove 211 can be observed from the opening of the first groove 211 on the side of the base 200.

[0032] A second groove 212 is horizontally provided on the base 200. The first end of the second groove 212 penetrates the groove wall of the first groove 211 and communicates with the first groove 211. The second end of the second groove 212 penetrates the side of the base 200; of course, the second end of the second groove 212 may not penetrate the side of the base 200. The depth of the second groove 212 (i.e., the dimension in the z-axis direction) is adapted to the thickness of the flat copper wire, and the width of the second groove 212 (i.e., the dimension in the y-axis direction) is adapted to the width of the flat copper wire. A first arc-shaped chamfer structure 213 is provided at the connection between the first groove 211 and the second groove 212. The shape of the first arc-shaped chamfer structure 213 is adapted to the shape of the first arc-shaped portion 131 (first bending portion).

[0033] Both sides of the pressure block 220 are curved surfaces. Of course, the pressure block 220 may also have only one curved surface. The shape of the curved surface is adapted to the shape of the second bend of the connecting piece. For example, when the second bend includes a second arcuate portion 132 and a third arcuate portion 133, the curved surface includes a second arcuate chamfer structure 222 connected to the lower end face of the pressure block 220 and a third arcuate chamfer structure 223 connected to the upper end face of the pressure block 220. The shape of the second arcuate chamfer structure 222 is adapted to the shape of the second arcuate portion 132 of the connecting piece, and the shape of the third arcuate chamfer structure 223 is adapted to the shape of the third arcuate portion 133 of the connecting piece. Of course, when a connecting portion 135 is provided between the second arcuate portion 132 and the third arcuate portion 133, the curved surface may also include a vertical segment 221 formed between the second arcuate chamfer structure 222 and the third arcuate chamfer structure 223.

[0034] In this embodiment, by designing the shapes of the base 200 and the pressure block 220, the flat copper wire can be easily bent to form the first welding section 110, the first arc-shaped part 131, the horizontal part 134, the second arc-shaped part 132, the third arc-shaped part 133 and the second welding section 120, which can quickly complete the production of the connecting piece.

[0035] Please see Figure 5 The present invention also discloses a method for fabricating a low-stress hybrid integrated circuit interconnect. A preferred embodiment of the method for fabricating a low-stress hybrid integrated circuit interconnect includes the following steps: S100, please refer to Figure 6 Take an enameled flat copper wire 300 with a varnish film 140 covering its surface. Remove a section of the varnish film 140 from each end of the enameled flat copper wire 300 to expose the copper surface, while retaining the varnish film 140 in the middle region of the enameled flat copper wire 300. Specifically, removing a section of the varnish film 140 from the first end of the enameled flat copper wire 300 forms a first solderable section 301, and removing a section of the varnish film 140 from the second end forms a second solderable section 302; the remaining varnish film 140 on the enameled flat copper wire 300 forms a solder resist layer. The length of the first solderable section 301 is greater than the length of the first welding section 110 of the connecting piece; the length of the first solderable section 301 can be slightly greater than the sum of the lengths of the first welding section 110 and the first arc-shaped portion 131, or it can be less than or equal to the sum of the lengths of the first welding section 110 and the first arc-shaped portion 131. The length of the second weldable section 302 is greater than the length of the second weldable section 120 of the connecting piece, but less than the sum of the lengths of the second weldable section 120 and the third arc-shaped portion 133.

[0036] The length of the enameled flat copper wire 300 is equal to the length of the low-stress hybrid integrated circuit connector. The enameled flat copper wire 300 can be obtained by cutting a section of the required length from a long enameled flat copper wire 300. The thickness of the enameled flat copper wire 300 is 0.15mm to 0.25mm, preferably 0.2mm; the width is 0.5mm to 1mm, preferably 1mm. For example, the enameled flat copper wire 300 can be a QY-2 type enameled flat copper wire 300, whose enamel film 140 can withstand a high temperature of 220℃ and is resistant to immersion in organic solvents.

[0037] The method for removing the enamel film 140 from the enameled flat copper wire 300 is as follows: Place the enameled flat copper wire 300 flat on the workbench, hold and fix the enameled flat copper wire 300 in your hand, and use a metal knife to scrape off the enamel film 140 horizontally on the enameled flat copper wire 300. Apply gentle and even force when scraping to remove the enamel film 140 without damaging the copper wire. Rotate the enameled flat copper wire 300 during the scraping process so that the enamel film 140 on the entire annular surface of the enameled flat copper wire 300 is completely removed, exposing the copper wire.

[0038] After removing the enamel film 140 from both ends of the enameled flat copper wire 300, the first solderable section 301 and the second solderable section 302 can be tinned; and the tinned enameled flat copper wire 300 is then cleaned and dried. The tinning process is as follows: First, place the SnPbAg solder bar into the solder melting furnace, turn it on, and set the temperature to 260℃. Once the furnace temperature reaches the set value and stabilizes, the solder bar will melt. Next, immerse the area at the first end of the enameled flat copper wire 300 (with the enamel film 140 removed) in rosin and quickly remove it. Then, vertically immerse the first end of the enameled flat copper wire 300 (with the rosin applied) into the solder in the melting furnace, hold for 1-3 seconds, and remove it. Repeat the same process for the second end of the enameled flat copper wire 300 (with the enamel film 140 removed).

[0039] The method for cleaning and drying the 300 enameled flat copper wire after tinning is as follows: Place the enameled flat copper wire 300 in a polytetrafluoroethylene basket and clean it with MOS grade ethanol. After cleaning, place the enameled flat copper wire 300 in a hot air oven and bake it at 150℃ for 10 minutes to dry it.

[0040] S200. Take a low-stress hybrid integrated circuit connector forming fixture; the low-stress hybrid integrated circuit connector forming fixture can be any of the low-stress hybrid integrated circuit connector forming fixtures described above.

[0041] S300, please continue reading Figure 3 and Figure 4The first solderable section 301 of the enameled flat copper wire 300 is vertically inserted downwards into the first groove 211, so that the first solderable section 301 abuts against the bottom of the first groove 211; and the portion of the enameled flat copper wire 300 protruding from the first groove 211 is bent to fit against the bottom of the first arc-shaped chamfer structure 213 and the second groove 212, respectively. Thus, the portion of the enameled flat copper wire 300 located in the first groove 211 forms the first solderable section 110, and the portion of the enameled flat copper wire 300 that fits against the first arc-shaped chamfer structure 213 forms the first arc-shaped portion 131.

[0042] S400, please continue reading Figure 3 and Figure 4 The pressure block 220 is placed in the placement area. At this time, one end of the pressure block 220 is located in the gap between the two first limiting blocks 201, and the other end of the pressure block 220 is located in the gap between the two second limiting blocks 202. The portion of the enameled flat copper wire 300 extending from the lower end face of the pressure block 220 is folded back to fit against the curved surface and the upper end face of the pressure block 220, thereby bending the enameled flat copper wire 300 to obtain a low-stress hybrid integrated circuit connector. At this time, the section of the enameled flat copper wire 300 located directly below the pressure block 220, after fitting against the lower end face of the pressure block 220, is not folded back and remains in the second groove 212, thereby forming a horizontal portion 134. The portion of the enameled flat copper wire 300 extending beyond the lower end face of the pressure block 220, after being folded back, forms a second arc-shaped portion 132 when it fits against the second arc-shaped chamfer structure 222 of the curved surface. The portion that fits against the third arc-shaped chamfer structure 223 of the curved surface forms a third arc-shaped portion 133, and the portion that fits against the upper end face of the pressure block 220 forms a second welding segment 120. Specifically, the portion of the first arc-shaped portion 131 and the horizontal portion 134 where the enamel film 140 has been removed forms a transition segment 130a, and the portion of the third arc-shaped portion 133 where the enamel film 140 has been removed forms a transition segment 130b. Of course, when the curved surface includes a vertical segment 221, the portion of the enameled flat copper wire 300 that fits against the vertical segment 221 forms a connecting portion 135.

[0043] S500, please refer to Figure 7 The pressure block 220 can be horizontally pulled out along its axial direction (i.e., the y-axis direction) to remove it from the base 200. Then, the enameled flat copper wire 300, which has been formed into a low-stress hybrid integrated circuit connector, can be taken out from the first groove 211.

[0044] Using the method of this embodiment, the first welding section 110, the first arc-shaped portion 131, the horizontal portion 134, the second arc-shaped portion 132, the third arc-shaped portion 133, and the second welding section 120 can be quickly formed on the enameled flat copper wire 300 through the cooperation of the pressure block 220 and the base 200, thereby completing the fabrication of the low-stress hybrid integrated circuit interconnect. The fabrication method is simple and fast. Moreover, the enameled flat copper wire 300 is a common material and is easy to obtain; the fabrication process does not involve complex processes and the fabrication cost is low. In addition, by setting transition sections 130a and transition sections 130b at both ends of the stress-relieving section 130, it is not necessary to precisely control the length of the removed enamel film 140 when removing the enamel film 140 at both ends of the enameled flat copper wire 300, further simplifying the process.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A low-stress hybrid integrated circuit connector forming fixture, characterized in that: For forming low-stress hybrid integrated circuit connectors, the connector includes a first welding section, a stress-relief section, and a second welding section. The first welding section is used for welding to the circuit board inside the hybrid integrated circuit, and the second welding section is used for welding to the casing of the hybrid integrated circuit. One end of the stress-relief section is connected to the first welding section, and the other end is connected to the second welding section, which is used to reduce the internal stress during welding when the connector is deformed. The stress-relief section is wholly or partially covered with a solder resist layer. The forming fixture includes a base and a pressure block. The base is provided with a limiting structure, which is used to define the placement area of ​​the pressure block. At least one side of the pressure block is curved. A first groove is vertically formed on the upper surface of the base. The first groove is located within the placement area of ​​the pressure block, and the width of the first groove is adapted to the thickness of the flat copper wire. A second groove is also horizontally provided on the base and connected to the first groove. The depth of the second groove is adapted to the thickness of the flat copper wire, and a first arc-shaped chamfer structure is provided at the connection between the first groove and the second groove. The limiting structure includes two first limiting blocks arranged sequentially on one side of the upper surface of the base and two second limiting blocks arranged sequentially on the other side of the upper surface of the base. The distance between the two first limiting blocks and the distance between the two second limiting blocks are adapted to the width of the pressure block. The curved surface includes a second arc-shaped chamfer structure connected to the lower surface of the pressure block and a third arc-shaped chamfer structure connected to the upper surface of the pressure block. The radii of the first arc-shaped chamfer structure, the second arc-shaped chamfer structure and the third arc-shaped chamfer structure are all greater than twice the thickness of the flat copper wire.

2. The low-stress hybrid integrated circuit connector forming fixture according to claim 1, characterized in that: The first welding section, the stress-relieving section, and the second welding section are formed by bending the same flat copper wire.

3. The low-stress hybrid integrated circuit connector forming fixture according to claim 2, characterized in that: The stress-relieving section includes a horizontal section, a first bending section, and a second bending section. One end of the horizontal section is connected to the first welding section through the first bending section, and the other end of the horizontal section is connected to the second welding section through the second bending section.

4. The low-stress hybrid integrated circuit connector forming fixture according to claim 3, characterized in that: The angle between the first welding segment and the second welding segment is 90°, and the first bending part is a first arc-shaped part with a 90° arc shape. The radius of the first arc-shaped part is greater than twice the thickness of the flat copper wire.

5. The low-stress hybrid integrated circuit connector forming fixture according to claim 4, characterized in that: The second bending portion includes a second arc-shaped portion connected to the horizontal portion and a third arc-shaped portion connected between the second arc-shaped portion and the second welding segment; both the second arc-shaped portion and the third arc-shaped portion are 90° arcs, and the radii of the second arc-shaped portion and the third arc-shaped portion are greater than twice the thickness of the flat copper wire.

6. The low-stress hybrid integrated circuit connector forming fixture according to any one of claims 2 to 5, characterized in that: The thickness of the flat copper wire is 0.15mm to 0.25mm, and the width is 0.5mm to 1mm; and / or At both ends of the stress-relief section, there is a section of flat copper wire that is not covered with enamel film, thus forming a transition section. The flat copper wire between the two transition sections is covered with enamel film, thus forming a solder resist layer.

7. A method for fabricating a low-stress hybrid integrated circuit interconnect, characterized in that, Includes the following steps: S100. Take a piece of enameled flat copper wire with a varnish film covering its surface, and remove a section of the varnish film from each end of the enameled flat copper wire to expose the copper surface. S200, Take a low-stress hybrid integrated circuit connector forming fixture as described in any one of claims 1 to 6; S300, the first end of the enameled flat copper wire is vertically inserted into the first groove, and the part of the enameled flat copper wire protruding from the first groove is bent to fit against the bottom of the first arc-shaped chamfer structure and the second groove respectively; S400. Place the pressure block in the placement area and fold back the portion of the enameled flat copper wire that extends beyond the lower end face of the pressure block until it is in contact with the curved surface and the upper end face of the pressure block, respectively. S500, remove the pressure block and enameled flat copper wire from the base in sequence.

8. The method for fabricating a low-stress hybrid integrated circuit interconnect according to claim 7, characterized in that: The enamel-coated flat copper wire is then tinned after the enamel film has been removed; and the tinned flat copper wire is then cleaned and dried.

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