WO2015106555A1

WO2015106555A1 - Method for preparing conductive metal connecting piece connected to pcb and connecting piece

Info

Publication number: WO2015106555A1
Application number: PCT/CN2014/082933
Authority: WO
Inventors: 徐卓辉
Original assignee: 深圳市中金岭南科技有限公司
Priority date: 2014-01-14
Filing date: 2014-07-24
Publication date: 2015-07-23
Also published as: CN103715586A

Abstract

A method for preparing a conductive metal connecting piece connected to a PCB (3) and the connecting piece prepared by the method. The method comprises the steps of: embedding an embedding layer (2) in a groove of a metal substrate (1) and conducting rolling at the embedding position so as to form a composite metal strip, wherein the metal substrate (1) is made of copper or stainless steel, and the embedding layer (2) is a copper layer, a silver layer or a copper-silver composite layer with silver on the surface; conducting softening annealing and rolling on the composite metal strip after rolling for at least two times, wherein the rolling deformation rate between the two times of softening annealing is not lager than 60%; and stamping the composite metal strip to a thickness of required specifications so as to from the conductive metal connecting piece. By means of the preparation method, the processes are environmentally friendly, and the prepared conductive connecting piece has high electrical conductivity, high stability in bonding to the PCB (3), and good formability.

Description

Method and connector for preparing metal conductive connectors connected to PCB boards

[0001] The present invention relates to a method for preparing a metal conductive connector for connection to a PCB and a composite metal conductive connector prepared by the method, and belongs to the technical field of composite metal material preparation.

Background technique

[0002] The popularity and rapid development of mobile electronic products (such as smart phones and tablets) have made people put forward higher requirements on the performance of these products, and whether the conductive connectors for PCB circuit board connection can PCB circuits The reliable connection of the board has a great impact on the reliability and stability of the final product quality, especially the key factors affecting the important performance indicators such as internal resistance and temperature rise of the product.

[0003] At present, the conductive connecting members for PCB circuit board connection are mostly made of pure nickel material or stainless steel material with good corrosion resistance. For example, the PCB circuit board of the lithium battery power management system (BMS) is often made of pure nickel sheets. The conductive connector, the pure nickel piece is directly soldered to the button type battery case, and the substrate which is electrically connected with the PCB board is made of stainless steel. However, it is difficult to form a strong alloy layer with tin, whether it is pure nickel or stainless steel. Therefore, the connection between the connectors directly made of these materials and the solder paste on the PCB circuit board is not stable (for pure nickel) Word), either it is impossible to braze at all (for stainless steel).

[0004] US Pat. No. 4,729,925 provides a technical solution for improving the solderability of a conductive connector and a PCB circuit board by plating copper on a nickel substrate. However, the technical solution has the following problems: 1) When the plating method is thick, the bonding strength between the materials cannot be satisfied, because the electrochemical deposition process determines the chemical bonding between the gradually deposited materials, and the chemical bonding results in The density of the internal structure of the coating is poor, and the thicker the coating, the more severe the density decreases, and the poor density results in a decrease in the bonding stability between the coating and the substrate, which tends to cause peeling, which in turn affects the connection performance with the PCB circuit board. In addition, the waste liquid discharge problem caused by the plating process is difficult to avoid. 2) When the plating method is thin, it is not conducive to improve the electrical conductivity of the conductive connecting member, which is very disadvantageous for achieving the application performance index of some high-end products, for pure nickel (resistivity 8.3 μ Ω · cm or so) or Stainless steel (resistivity 50~80 μ Ω · cm) substrate, its conductivity is better than Poor, therefore, it is difficult to obtain a conductive connecting member having high conductivity by the existing plating method.

[0005] Chinese Patent Publication No. 200920130921.4 discloses a conductive connector for a PCB circuit board, including a connection

A pure nickel or nickel plated tab on the PCB circuit board, the tab having a copper layer on the surface in contact with the PCB circuit board. The copper layer and the nickel layer provided in the scheme are only combined by one side, and the bonding strength is low, and the bonding stability cannot be ensured; especially when the bending deformation is required later, the edge of the joint surface of the copper layer and the nickel layer is connected. The weak connection position between the chip and the PCB circuit board, in the process of stamping and bending, the vicinity of the edge of the copper-nickel joint surface of the bent outer edge becomes the stress concentration of the stamping deformation, and the copper layer is very easy to start from the stress concentration position, along the copper The nickel bond surface produces local delamination. Even if the delamination phenomenon does not occur during the stamping and bending process, this part will become a hidden trouble in the subsequent delamination process in the process of connecting with the PCB circuit board.

[0006] Based on the above analysis, how to provide a metal conductive connector for a PCB board that can be firmly combined with a PCB board, has good moldability and is environmentally friendly, and a preparation process thereof is a technical problem that has not been solved in the prior art. .

Summary of the invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the technical defects in the prior art in the preparation process of the conductive connecting member, such as the combination stability of the conductive connecting member and the PCB board, and the comprehensive performance of the formability. A preparation process of a conductive connecting member that makes a conductive connecting member and a PCB board firmly combined and has good moldability is provided.

[0008] A further technical problem to be solved by the present invention is a technical defect in the prior art in which the joint stability of the conductive connecting member and the PCB board is poor, and the comprehensive performance of the formability is poor, thereby providing a combination with the PCB board. A conductive connector with high stability and good formability.

To this end, the present invention provides a method of preparing a metal conductive connector for connection to a PCB board, comprising the steps of:

[0010] Step (1): fitting an inlay layer in the groove of the metal substrate with a groove, and rolling and compounding the fitting position of the metal substrate to form a composite metal strip ;

[0011] wherein, the metal substrate is a nickel material or a stainless steel material, the inlaid layer is a copper layer, a silver layer or a copper-silver composite layer having a silver surface; [0012] Step (2): performing at least two softening annealing and rolling treatment on the rolled composite metal strip to obtain a composite metal strip of a desired thickness, wherein the rolling between the two softening annealings The deformation rate is not more than 60%;

[0013] Step (3): The composite metal strip of the required gauge thickness is stamped to form a flat metal conductive joint.

[0014] Before the rolling in the step (1), the thickness of the inlaid layer accounts for 6% to 52% of the thickness of the ungrooved portion of the composite metal base tape.

[0015] the inlaid layer is a copper-silver composite layer having a surface of silver. Before the rolling in the step (1), the thickness of the silver layer in the copper-silver composite layer is not open to the metal substrate. The thickness of the groove portion is 2% to 7% of the thickness of the entire composite metal strip.

[0016] The total deformation rate of the metal substrate exceeds 80%, wherein the total deformation ratio = (thickness before deformation of the substrate - thickness of the finished metal conductive joint) / thickness before deformation of the substrate * 100%.

[0017] The softening annealing is a bright annealing.

[0018] The softening annealing temperature is 600 ° C to 950 ° C, preferably 700 ° C to 900 ° C.

[0019] The softening annealing speed is from 1.5 m / min to 5 m / min, preferably from 2 m / min to 4.5 m / min.

[0020] The softening annealing process in the step (2) is carried out under a protective atmosphere or a reducing atmosphere.

[0021] In the step (1), before the rolling of the step (1), the width of the inlaid layer is 90%-99% of the total width of the groove.

[0022] The step (1) The rolling deformation rate of the metal substrate of the rolling compounding process is 30% to 60%.

[0023] The present invention also provides a metal conductive connector prepared by the above method.

[0024] The thickness of the inlaid layer accounts for 5% to 50% of the thickness of the composite metal strip.

[0025] The inlaid layer is a copper-silver composite layer having a surface of silver, and the thickness of the silver layer in the copper-silver composite layer accounts for about 1% to 5% of the thickness of the entire composite metal strip.

The present invention also provides a method of fabricating a bent metal conductive connector for connection to a PCB board, comprising the steps of preparing the composite metal conductive connector described above, further comprising a bend after the step (3) Fold step (4).

[0027] in the bending step (4), bending one end of the composite metal strip without the mounting layer to shape A bent end that is substantially perpendicular to the surface of the metal substrate.

[0028] The present invention also provides a bent metal conductive connector for use in connection with a PCB board prepared by the above method.

[0029] The thickness of the inlaid layer accounts for 5% to 50% of the thickness of the composite metal strip.

[0030] The inlaid layer is a copper-silver composite layer having a surface of silver, and the thickness of the silver layer in the copper-silver composite layer accounts for about 1% to 5% of the thickness of the entire composite metal strip.

[0031] The present invention also provides a battery soldering foot of a button battery, comprising a PCB board, and a metal conductive connector prepared by the method for preparing any of the above metal conductive connectors, the inlay of the metal conductive connector The surface of the layer is attached to the PCB.

[0032] The present invention also provides a battery soldering foot of a button battery, comprising a PCB board, and a bent metal conductive connector prepared by the method for preparing any of the bent metal conductive connectors described above, the bending The surface of the inlaid layer of the metal conductive connector is attached to the PCB board. The method for preparing a metal conductive connector for mounting a PCB board, the metal conductive connector, the bent metal conductive connector, and the battery soldering foot of the button battery provided by the present invention have the following advantages:

[0033] 1. The method for preparing a metal conductive connector provided by the present invention firstly inserts an inlay layer in the groove of the metal substrate with a groove, and performs a fitting position of the composite metal strip. Rolling; then, the rolled composite metal strip is subjected to at least two softening annealing and rolling treatment to obtain a composite metal strip having a required thickness, wherein the rolling deformation ratio between the two softening annealings is not More than 60%, the composite metal strip of the required gauge thickness is finally stamped to form a flat or bent metal conductive joint. By using at least two softening annealings, the interdiffusion layer between the metal substrate and the inlay layer is successively thickened, and the firmness of the metal substrate and the inlaid layer is enhanced, so that the physical metallurgical bonding strength between the two is high. The subsequent processing property of the composite metal strip is good; and the rolling deformation rate between the two softening annealings is strictly controlled, which not only optimizes the bonding strength between the metal substrate and the inlay layer, but also optimizes the metal conductive connecting member. Formability, and improved process efficiency, reducing process costs.

[0034] In the method, the metal substrate is a nickel material or a stainless steel material, and the inlaid layer is a copper layer, a silver layer or a copper-silver composite layer having a silver surface. A copper layer, a silver layer or a copper-silver complex with a silver surface on a nickel or stainless steel metal substrate The layering can improve the brazing performance of the composite metal strip. Since the conductivity of the pure nickel of the substrate is only about 20% of that of copper or silver, the inlay of the copper layer or the silver layer in the composite metal strip makes the whole inlay. The electrical connection of the composite metal structure is significantly improved compared to the conductivity of the pure nickel material. In addition, a pure nickel substrate inlaid composite metal strip is taken as an example, wherein the unit price of copper is 1/3 of the unit price of nickel, and the unit price of nickel is 1/20 of the unit price of silver, so a copper layer or a silver layer is embedded in the composite metal strip. , which is beneficial to reduce costs, which is also applicable to stainless steel substrate inlaid composite metal strip.

[0035] 2. The method for preparing a metal conductive connector according to the present invention, the softening annealing is a bright annealing, and the softening annealing temperature is 600 ° C to 950 ° C, preferably 700 ° C to 900 ° C, The softening annealing speed is from 1.5 m/min to 5 m/min, preferably from 2 m/min to 4.5 m/min. The softening annealing process performed at the above temperature and speed unexpectedly has the highest bonding strength between the metal substrate and the inlaid layer, the metal conductive connecting member is less prone to delamination, and the metal conductive connector is most moldable. it is good.

[0036] 3. The method for preparing a metal conductive connector provided by the present invention, the thickness of the inlaid layer accounts for 6% of the thickness of the ungrooved portion of the metal substrate before the rolling in the step (1) ~52%. After long-term production practice, when the ratio of the inlaid composite metal inlaid layer to the composite metal strip is 6%~52%, the qualification rate of the material composite is relatively high; while the thickness ratio of the silver layer in the inlaid composite metal is only 2%. In the case of ~7%, two composite processes are needed to reduce the difficulty of the manufacturing process. That is, the first composite is first prepared with a copper-silver composite metal strip, and then the strip is rolled to a suitable thickness before being inlaid. The second composite into the substrate (Note: The second composite is inlaid and rolled composite). Moreover, since the conductivity of the substrate pure nickel is only about 20% of that of copper or silver, the relative thickness ratio of the copper layer or the silver layer in the entire inlaid composite metal strip is increased, so that the conductivity of the entire metal conductive joint is relative to Significantly improved in pure nickel. At the same time, a pure nickel substrate inlaid composite metal strip is taken as an example, wherein the unit price of copper is 1/3 of the unit price of nickel, and the unit price of nickel is 1/20 of the unit price of silver, so the proportion of the inlaid copper layer is higher or the thickness of the silver layer is minimized. The ratio is beneficial to material cost optimization.

4. The method for preparing a metal conductive connector provided by the present invention, before the rolling of the step (1), the width of the inlaid layer is 90%-99% of the total width of the groove. After the step (1), the deformation rate of the metal substrate is 30% to 60%. Controlling the composite metal by controlling the width of the mosaic layer to be 90% to 99% of the total width of the groove The rolling deformation rate of the strip, so that during the rolling deformation, the inlaid layer can be reasonably deformed in the groove as the rolling process progresses, and the edge of the inlaid layer can be made to be concave The grooves are in good contact, so that the process can be perfectly combined with subsequent softening annealing and rolling processes, ultimately resulting in a higher bond strength between the inlaid layer and the grooves.

[0038] 5. The method for preparing a metal conductive connector provided by the present invention, the total deformation rate of the metal substrate exceeds 80%, and the total rolling of the material from the in-situ rolling compounding process to the whole process of the finished product is greatly improved. The deformation rate increases the formation rate of the fresh surface of the mosaic layer, so that the area of the surface to be bonded between the heterogeneous metals is greatly enhanced, and the firmness of the metal substrate and the embedded layer is enhanced.

6. The present invention also provides a method of preparing a bent metal conductive connector, comprising the steps of preparing the composite metal conductive connector described above, and further comprising the bending step (4) after the step (3). In the bending step (4), one end of the composite metal strip on which the inlaid layer is not mounted is bent to form a bent end substantially perpendicular to the surface of the metal substrate. Since the step (1)-step (3) of the above-mentioned bent metal conductive connection is the same as the above-mentioned metal conductive connecting member, the method for preparing the bent metal conductive connecting member of the present invention has the above-mentioned metal conductive connecting member preparing method All the advantages you have. In addition, since the inlaid layer is located in the groove, at least the bottom surface and the side surface thereof are in contact with the metal substrate, and during the bending process, the delamination of the inlay layer and the groove is not easily caused, and the bending is ensured. The formability and bonding strength of the composite metal strip during the process; the solid bonding surface of the metal substrate and the insert material in the inlaid composite metal strip is more, and the formed "semi-wrapped" structure ensures the prepared conductive joints. The bending fracture resistance is remarkably improved, and the formability of the prepared conductive connector is enhanced. At the same time, by controlling the number of times of softening annealing to at least two times, the metal substrate and the interdiffusion layer on the adjacent side of the mosaic layer are successively thickened to enhance the firmness of the metal substrate and the embedded material.

[0040] 7. The method for preparing the bent metal conductive connector provided by the present invention has the following basic principles: 1) greatly improving the total rolling of the material from the in-situ rolling compounding process to the whole process of the finished product. The deformation rate, that is, increasing the formation rate of the fresh surface of the material, can also be understood as the area of the surface to be bonded (especially the side) between the heterogeneous metals is greatly enhanced, so that the fresh contact area between the sides is increased as much as possible to form a firm physical metallurgy. Bonding lays the foundation. 2) increase at the same time The number of softening annealing processes can be interpreted as the successive thickening of the interdiffusion layer of the substrate and the adjacent sides of the inlaid material until a strong physical metallurgical bond is formed between the sides. 3) The rolling process will simultaneously form two balance mechanisms of side composite strength failure and side composite strength enhancement. The deformation unevenness between the metal substrate and the embedded layer increases with the increase of the rolling deformation rate (Note: The work hardening rate of nickel and stainless steel substrates and copper or silver inserts differ greatly, the substrate Obviously higher), the tensile stress formed on the side of the metal substrate is more destructive to the bonding strength of the side surface between the heterogeneous materials; at the same time, the increase of the rolling deformation rate causes the surface of the fresh material adjacent to the adjacent side of the heterogeneous metal to increase. Conducive to the formation of a bond. Therefore, it is necessary to control the balance between the two mechanisms of bond strength failure and reinforcement, that is, it is necessary to control the rolling deformation ratio between the two softening annealings to a suitable range to ensure the side composite strength enhancement.

[0041] The preparation method proposed by the present invention comprehensively considers the above three mechanisms, thereby ensuring a firm physical metallurgical bond between the substrate and the side and bottom surfaces of the inlaid material. Compared with the existing single-sided structure of the coated structural substrate and the covering material, it is obvious that the "semi-wrapped" structure formed by the more solid bonding surface of the substrate and the embedded metal in the composite metal strip ensures the preparation. The flexural fracture resistance of the conductive connector is significantly improved, that is, the formability of the conductive connector is enhanced. The rolling compounding process belongs to the physical metallurgical bonding process between heterogeneous materials through large plastic deformation between different component materials and appropriate energy introduction. The green environmental protection of the production process has been recognized.

[0042] It can be seen from the above that compared with the existing pure nickel or stainless steel substrate surface plating technology and its material properties, the manufacturing method of the present invention has a curved shape prepared by the method in addition to obvious environmental advantages. The metal conductive connecting member has excellent comprehensive properties such as brazing property, moldability, and electrical conductivity, and has good stability and consistency.

DRAWINGS

[0043] In order to make the content of the present invention easier to understand, the present invention will be further described in detail below in accordance with the specific embodiments of the invention,

1 is a schematic structural view of a bent metal conductive connection member;

2 is a plan view of a metal conductive connector; [0045] FIG.

3 is a cross-sectional view of a metal conductive connector; [0047] FIG. 4 is a schematic structural view of a bent metal conductive connector and a PCB board

[0048] Reference numerals in the figures are indicated as follows: 1-metal substrate; 2-mount layer; 3-PCB board.

detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Embodiment 1

[0051] This embodiment provides a method of preparing a metal conductive connector for connection to a PCB board, the method uses a raw material: a nickel substrate including 30 mm (width) * 1.5 mm (thickness), 0.15 mm (thickness) ) *8mm (wide) pure copper tape.

[0052] The method comprises the following steps:

[0053] Step (1): continuously grooving a groove having a rectangular cross section on the surface of the pure nickel strip 1 with a groove width of 8.1 mm and a depth of 0.15 mm, and fitting the pure in the groove of the pure nickel substrate As a mosaic layer, the copper coiled tape was subjected to cold composite rolling at a corresponding fitting position by a rolling deformation rate of 60% to form a composite metal strip having a thickness of 0.6 mm. Wherein, the width of the inlaid layer-copper strip before rolling compounding is 98.77% of the total width of the groove;

[0054] Step (2): performing three times of softening annealing process on the composite metal strip after cold composite rolling, multi-pass rolling, strip cutting and the like in the annealing process, wherein the three-time soft-annealed strip The thickness and annealing speed are 0.6mm/1.8mpm, 0.3mm/3mpm, 0.13mm/5mpm, and the annealing temperature is 850°C, which is protected by reducing gas by ammonia decomposition gas. It can be seen from the above that the rolling deformation rate between the two softening annealing processes is 50% and 57%, respectively, and the total rolling deformation ratio of the inlaid composite metal substrate to the finished strip is 93%.

[0055] Step (3): stamping the composite metal strip of the required gauge thickness to form a flat metal conductive joint.

[0056] As shown in FIG. 2 and FIG. 3, a metal conductive connection member of 0.1 mm (thickness) * 25 mm (width) is prepared by the above-mentioned preparation method of the present embodiment, and the size of the copper layer of the mosaic layer 2 is 0.08 mm (thickness). ) *4mm (width). The bottom surface and the side surface of the inlaid layer 2 are physically metallurgically bonded to the pure nickel metal substrate 1. The thickness of the mosaic layer 2 is the metal conductive connector 8% of the total thickness.

[0057] As a modification to the preparation method of the present embodiment, the temperature of the softening annealing may also be selected within the range of 600 ° C to 950 ° C, preferably within the range of 700 ° C to 900 ° C, for example The softening annealing temperature can be selected from 600 ° C, 650 ° C, 700 ° C, 750 ° C, 800 ° C, 900 ° C, and the like.

[0058] As another variation of the preparation method of the present embodiment, the speed of the softening annealing may also be selected from the range of 1.5 m/min to 5 m/min, preferably from 2 m/min to 4.5 m/min. The selection is made within the range, for example, the softening annealing temperature may be 1.5 m / h, 1.8 m / h, 2 m / h, 2.5 m / h, 2.8 m / h, 3 m / h, 3.5 m / h, 4 m / bell and 4.5 m / bell.

[0059] As a further modification of the preparation method of the present embodiment, the deformation rate of the rolling compounding process in the step (1) may be in the range of 30% to 60% depending on the thickness relationship of the metal substrate and the inlaid layer. Make changes (Note: More than 50% are generally cold composite, 30% to 50% range is controlled by controlled atmosphere, and the atmosphere is ammonia decomposition gas or hydrogen). For example, the rolling deformation ratio of the composite metal strip is 30%, 35%, 40%, 45%, 48%, 50%, 52%, 58% and the like.

[0060] It should be noted that, before the cold composite rolling in the step (1), ensuring that the thickness of the inlaid layer accounts for 6% to 52% of the thickness of the ungrooved portion of the metal substrate, The composite metal strip has a thickness of 5-50% of the thickness of the entire metal substrate.

Example 2

[0062] This embodiment provides a method of preparing a metal conductive connector for connection to a PCB board. The raw material is a nickel substrate of 30 mm (width) * 1.5 mm (thickness), 0.3 mm (thickness) * 8 mm (width) The copper-silver layered composite material, wherein the copper-silver layered composite material has a total thickness of 10% and a copper layer of 90%, and the copper-silver layered composite material is composited by existing preparation techniques.

[0063] The method includes the following steps:

[0064] Step (1): continuously grooving a groove having a rectangular cross section on the surface of the pure nickel strip, the groove width is 8.2 mm, and the depth is 0.3 mm, and the copper is embedded in the groove of the pure nickel substrate. As a mosaic layer, the silver layered composite material was subjected to cold composite rolling at a corresponding fitting position by a rolling deformation rate of 60% to obtain a composite metal strip having a thickness of 0.6 mm. Wherein, the inlaid layer before rolling composite - The width of the copper strip is 97.56% of the total width of the groove, and the inlaid layer is deformed in the gap;

[0065] Step (2): performing three times of softening annealing process on the composite metal strip after cold composite rolling, and performing multi-pass rolling, strip cutting and the like in the heat treatment process, wherein the three-time soft-annealed strip The thickness and annealing speed are 0.6mm/1.5mpm, 0.4mm/2.5mpm, 0.18mm/5mpm, and the annealing temperature is 600°C, which is protected by reducing gas by ammonia decomposition gas. It can be seen from the above that the rolling deformation rate between the two softening annealing processes is 33% and 55%, respectively, and the total rolling deformation rate of the metal substrate before the inlaying to the finished strip is 90%.

[0066] Step (3): stamping the composite metal strip of the required gauge thickness to form a flat metal conductive joint.

[0067] As shown in FIG. 2 and FIG. 3, a metal conductive connecting member of 0.15 mm (thickness) * 25 mm (width) is prepared by the above-described preparation method of the present embodiment, and the size of the inlaid layer 2 is 0.025 mm (thickness) * 4mm (width). The bottom surface of the inlaid layer is physically metallurgically bonded to the pure nickel metal substrate. The thickness of the inlaid layer 2 is 16.7% of the total thickness of the metallic conductive connector.

[0068] before the cold composite rolling of the step (1), ensuring that the thickness of the silver layer in the copper-silver composite layer accounts for 2% to 7% of the thickness of the ungrooved portion of the entire metal substrate, the copper can be obtained. - A composite metal strip in which the thickness of the silver layer in the silver composite layer accounts for 1% to 5% of the thickness of the entire metal substrate.

Example 3

[0070] This embodiment is an improvement on the basis of Embodiment 1, and provides a method of bending a metal conductive connecting member. The method comprises the steps 1 to 3 of the preparation method described in the embodiment 1, and further comprising the step (4): bending the conductive connecting member obtained in the step (3).

[0071] According to the characteristics that the inlaid copper material is easily oxidized and discolored, the conductive connection member after the press forming is generally subjected to relevant surface treatment and protection to facilitate the subsequent brazing process.

[0072] After the SMT process, the outer surface of the damascene layer 2 is connected to the PCB 3 by soldering. After extensive testing, the peeling resistance between the metal conductive connector and the PCB 3 is above 1.6kgf, far exceeding the standard application requirements of 1.2kgf.

Example 4 [0074] This embodiment is an improvement on the basis of Embodiment 2, and provides a method of bending a metal conductive connecting member. The method comprises the steps 1 to 3 of the preparation method described in the embodiment 2, and further comprising the step (4): bending the metal conductive connecting member obtained in the step (3).

[0075] After the SMT process, the outer surface of the silver layer of the inlaid layer 2 copper-silver layer composite material is connected to the PCB 3 through solder. After extensive testing, the peeling resistance between the metal conductive connector and the PCB board is above 1.6kgf.

Example 5

[0077] This embodiment provides a method for preparing a battery soldering foot of a button battery and a battery soldering foot of the button battery.

[0078] The raw material used in the method: 60 mm (width) * 1.5 mm (thickness) of SUS430 ferritic stainless steel strip, 0.15 mm (deep) * 12 mm (width) of pure copper coil.

[0079] The method comprises the following steps:

[0080] Step (1): continuously grooving a groove having a rectangular cross section at a central symmetrical position of both surfaces of the stainless steel strip, the groove width being 12.3 mm and the depth being 0.15 mm; fitting in the groove of the stainless steel strip As a mosaic layer, the pure copper coil is subjected to a controlled atmosphere thermal compounding at a corresponding fitting position by a rolling deformation rate of 40%. The rolling composite temperature is 600 °C, and the protective gas is reduced by ammonia decomposition gas to obtain a thickness of 0.9 mm. Composite metal strip;

[0081] Step (2): performing a four-time softening annealing process on the composite metal strip after the controlled thermal composite rolling, and performing multi-pass rolling, strip cutting and the like in the heat treatment process, wherein four times of softening The annealed strip thickness and annealing speed were 0.9mm/1.5mpm, 0.45mm/2.5mpm, 0.25mm/3.5mpm, 0.15mm/4mpm, and the annealing temperature was 925°C, which was protected by reducing gas by ammonia decomposition gas. It can be seen from the above that the rolling deformation rate between the four softening annealing processes is 50%, 44%, 40%, respectively, and the total rolling deformation rate of the pre-composite composite substrate to the finished strip is 90%;

[0082] Step (3): The composite metal strip is punched to prepare a metal conductive joint having a required specification of 0.15 mm (thickness) * 56 mm (width).

[0083] Step (4): bending a 0.15 mm (thickness) * 56 mm (width) metal conductive connector to obtain a bent metal conductive connector; [0084] Step (5): brazing and bonding the bent metal conductive connector to the PCB board to obtain a button battery solder fillet.

[0085] In this embodiment, after step (3), a metal conductive connection member of 0.15 mm (thickness) * 56 mm (width) of a desired specification is obtained, and the bottom surface, the side surface of the mosaic layer and the metal substrate are obtained. The physical metallurgical bonding between them has a good bonding strength, and the subsequent formability of the metal conductive connecting member is good.

[0086] In the embodiment, after the step (5), the obtained battery soldering foot of the button battery, the PCB board and the copper material embedded on both sides of the 430 stainless steel substrate realize a firm soldering connection, and the conductive legs are electrically conductive. Compared with the original material (430 stainless steel nickel plated and then partially tinned), the processing parts are significantly improved.

[0087] It is to be understood that the above-described embodiments are merely illustrative and not restrictive. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Obvious changes or variations resulting therefrom are still within the scope of the invention.

Claims

Claim

A method of preparing a metal conductive connector for connection to a PCB board, comprising: the following steps: Step (1): fitting the inlay in the groove of the metal substrate with a groove a layer, and rolling and compounding the fitting position of the metal substrate to form a composite metal strip,

Wherein, the metal substrate is a nickel material or a stainless steel material, and the mosaic layer is a copper layer, a silver layer or a copper-silver composite layer having a silver surface;

Step (2): performing at least two softening annealing on the rolled composite metal strip and rolling treatment to obtain a composite metal strip having a required thickness, wherein the rolling deformation between the two softening annealings The rate is not more than 60%;

Step (3): Pressing a composite metal strip of a desired gauge thickness to form a flat metal conductive joint.

2. The method of manufacturing a metal conductive connector according to claim 1, wherein: before the rolling in the step (1), the thickness of the mosaic layer occupies an ungrooved portion of the metal substrate 6% to 52% of the thickness.

The method of manufacturing a metal conductive connector according to claim 1 or 2, wherein: the inlaid layer is a copper-silver composite layer having a surface of silver, before rolling in the step (1) The thickness of the silver layer in the copper-silver composite layer is 2% to 7% of the thickness of the ungrooved portion of the metal substrate.

The method of producing a metal conductive connector according to any one of claims 1 to 3, wherein the metal substrate has a total deformation ratio of more than 80%.

The method of producing a metal conductive connector according to any one of claims 1 to 4, wherein the softening annealing is a bright annealing.

The method of producing a metal conductive connector according to any one of claims 1 to 5, wherein the softening annealing temperature is 600 ° C to 950 ° C.

The method of producing a metal conductive connector according to claim 6, wherein the softening annealing temperature is 700 ° C to 900 ° C.

The method of producing a metal conductive connector according to any one of claims 1 to 7, wherein the speed of the softening annealing is from 1. 5 m / min to 5 m / min.

The method of producing a metal conductive connector according to claim 8, wherein the softening annealing has a speed of from 2 m/min to 4.5 m/min.

10. A method of preparing a metal conductive connector according to any of claims 1-9, characterized in that the softening annealing process in the step (2) is carried out under a protective atmosphere or a reducing atmosphere.

The method for preparing a metal conductive connector according to any one of claims 1 to 10, wherein: before the rolling of the step (1), the width of the inlaid layer material is the concave 90%-99% of the total width of the groove.

The method of manufacturing a metal conductive connector according to any one of claims 1 to 11, wherein: Step (1) The rolling deformation rate of the metal substrate in the rolling compounding process is 30% to 60%.

13. A method of preparing a bent metal conductive connector for connection to a PCB board, comprising: the step of preparing a metal conductive connector according to any one of claims 1 to 13, further comprising The bending step (4) after the step (3).

The method for preparing a bent metal conductive connector for connecting to a PCB board according to claim 13, wherein: in the bending step (4), the composite metal strip is not One end of the mounting layer is bent to form a bent end substantially perpendicular to the surface of the metal substrate.

A metal conductive connector for connection to a PCB, characterized in that it is produced by the production method according to any one of claims 1-12.

The metal conductive connector according to claim 15, wherein: the thickness of the inlaid layer accounts for 5% to 50% of the thickness of the composite metal strip.

The metal conductive connector according to claim 16, wherein: the inlaid layer is a copper-silver composite layer having a surface of silver, and the thickness of the silver layer in the copper-silver composite layer accounts for the composite metal strip 1% to 5% of thickness.

A bent metal conductive connector for connection to a PCB, characterized in that it is produced by the production method according to claim 13 or 14.

The bent metal conductive connector according to claim 18, wherein: the thickness of the inlaid layer accounts for 5% to 50% of the thickness of the composite metal strip.

The bent metal conductive connector according to claim 19, wherein: the inlaid layer is a copper-silver composite layer having a surface of silver, and the thickness of the silver layer in the copper-silver composite layer accounts for the entire composite metal strip The thickness of the material is 1% to 5%.

21. A battery solder fillet for a button cell, comprising a PCB board, characterized by: further comprising the surface of the inlaid layer of the metal conductive connector of the metal conductive connector of any one of claims 15-17 The PCB board is attached and connected.

22. A battery solder fillet for a button cell, comprising a PCB board, characterized by: further comprising the bent metal conductive connector according to any one of claims 18-20, wherein the bent metal conductive connector The surface of the inlay layer is attached to the PCB board.