Conductive terminal and method for manufacturing the same

Abstract

A conductive terminal and a manufacturing method thereof, the conductive terminal is formed by copper material electroplating and stamping, and has a nickel layer on the surface; the conductive terminal comprises a cylindrical area and a wire clamping area located behind the cylindrical area, the cylindrical area has opposite inner and outer sides and sequentially comprises a guide area, a contact area and a positioning area from front to back, the inner side of the contact area is provided with a contact point, and the guide area is only partially connected with the contact area. The thickness of the nickel layer on the outer surface of the guide area is less than the thickness of the nickel layer on other parts of the conductive terminal. The conductive terminal adopts a segmented immersion plating and inclined immersion plating electroplating mode, so that the thickness of the nickel layer of the guide area of the conductive terminal is less than the thickness of the nickel layer of other parts. In this way, when the copper sheet with a planar structure is bent to form the conductive terminal, the cracking phenomenon of the outer surface of the guide area is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a conductive terminal and a manufacturing method thereof, and more particularly to a conductive terminal with improved surface cracks. BACKGROUND

[0002] The crimp terminal is the main terminal structure used in the vehicle wire harness connector. With the development of the market, the performance requirements for the signal transmission of this section are getting higher and higher, especially the requirements for environmental resistance and reliability. The plating layer of the contact position is currently mainly pre-plated nickel / nickel undercoat / tin undercoat gold plating. Gold plating layer is more popular in the market due to its stability and high conductivity. However, the surrounding structure of the crimp terminal causes the electroplating solution inside the terminal to be unable to reach, thereby causing the problem of insufficient film thickness. Currently, the problem of insufficient film thickness on the inside can be solved by using a secondary stamping method. However, it has been confirmed that due to the influence of the plating layer, a large number of cracks appear on the outside of the contact end of the nickel undercoat gold-plated sheet after secondary stamping, which seriously affects the reliability and strength of the product.

[0003] Taiwanese invention patent TW202038517A discloses a metal terminal including a terminal body, a first plating layer, a second plating layer, and a third plating layer. The terminal body has a contact portion, a bending portion, and a welding portion, wherein both ends of the bending portion are connected to the contact portion and the welding portion, respectively. The first plating layer is disposed on the terminal body, wherein the thickness of the first plating layer on the bending portion is 0.3 to 1.75 um, and the thickness of the rest is 2 to 10 um. The second plating layer is disposed on part of the first plating layer, and the second plating layer corresponds to the contact portion, and the thickness of the second plating layer is 0.5 to 2 um. The third plating layer is disposed on another part of the first plating layer, and the third plating layer corresponds to the welding portion, and the thickness of the third plating layer is 0.01 to 0.1 um. By reducing the thickness of the first plating layer on the bending portion, the phenomenon of oxidation or corrosion caused by the falling off of the first plating layer on the bending portion can be avoided, and the stability of the electrical properties of the metal terminal can be maintained. However, this application cannot solve the influence of bending forming on the cracks of the terminal plating layer.

[0004] Therefore, it is necessary to provide an improved conductive terminal and a manufacturing method thereof to overcome the above-mentioned defects. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a conductive terminal and a manufacturing method thereof, which can effectively improve the surface cracks.

[0006] The present application is implemented by the following technical scheme: a manufacturing method of a conductive terminal, the base material of the conductive terminal being a copper material: the manufacturing method at least includes the following steps:

[0007] Step (1): providing a copper sheet formed by punching a copper material, the copper sheet having opposite front and back surfaces, vertically inserting the copper sheet into a nickel plating solution for first plating, the copper sheet including an immersion area immersed in the nickel plating solution and an exposed area exposed outside the nickel plating solution, the exposed area including a contact area and a guide area in front of the contact area, the contact area being provided with a contact point at the front surface thereof;

[0008] Step (2): placing the copper sheet after the step (1) plating in the nickel plating solution at an angle for second plating, wherein the direction of the angle is set such that the front surface of the copper sheet is closer to the nickel plating solution than the back surface;

[0009] Step (3): placing the copper sheet after the step (2) vertically for third plating.

[0010] Further, in the step (2), the angle is 45 degrees.

[0011] Further, the plating solution surface of the nickel plating solution is controlled to be 3 mm.

[0012] Further, step (4) is provided: the contact point is further plated with a gold layer on the basis of the nickel layer.

[0013] Further, step (5) is provided: the copper sheet after the step (4) is bent to form a three-dimensional structure of the conductive terminal.

[0014] The application can also be realized by the following technical solutions: a conductive terminal formed by copper plating and punching, the surface of which has a nickel layer; the conductive terminal includes a cylindrical area and a wire clamping area behind the cylindrical area, the cylindrical area has opposite inner and outer sides and sequentially includes a guide area, a contact area and a positioning area from front to back, the inner side of the contact area is provided with a contact point, and the guide area is only partially connected with the contact area; the nickel layer thickness of the outer surface of the guide area is less than the nickel layer thickness of other parts of the conductive terminal.

[0015] Further, the nickel layer thickness of the outer surface of the guide area is in the range of 20-40 micro inches.

[0016] Further, the nickel layer thickness of the inner surface of the contact area of the conductive terminal is 50 micro inches; the contact point further has a gold plating layer outside the nickel layer, and the gold plating layer has a minimum thickness of 30 micro inches.

[0017] Further, the cylindrical area comprises an upper wall, a lower wall and two side walls, the upper wall is formed with a joint seam after the copper material is bent close to each other; the side wall is provided with an L-shaped slot, so that the side wall is spaced apart from the lower wall and connected with the upper wall only, the part of the cylindrical area in front of the slot forms the guide area, the part between the slot and the upper wall forms the contact area, the inner wall surface of the contact area is provided with a convex point to form the contact point.

[0018] Further, the side wall of the cylindrical area is provided with a wing part behind the contact area, and the wing part is inclined outwardly.

[0019] Compared with the prior art, the conductive terminal has the following beneficial effects: the conductive terminal adopts the segmented immersion plating and inclined immersion plating mode, so that the thickness of the nickel layer of the guide area of the conductive terminal is smaller than that of other parts, and thus when the copper sheet with a planar structure is bent to form the conductive terminal, the phenomenon of cracking on the outer surface of the guide area is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a perspective view of the conductive terminal of the present application.

[0021] Figure 2 is another perspective view of the conductive terminal shown in Figure 1 .

[0022] Figure 3 is a perspective view of the conductive terminal shown in Figure 1 .

[0023] Figure 4 is a top view of the conductive terminal shown in Figure 1 .

[0024] Figure 5 is a side view of the conductive terminal shown in Figure 1 .

[0025] Figure 6 is an expanded view of the conductive terminal shown in Figure 1 .

[0026] Figure 7 is a schematic view of the electroplating process of the conductive terminal of the present application.

[0027] MAIN ELEMENT SYMBOL EXPLANATION

[0028] Conductive terminal 1000 Guide area 10, A

[0029] Cylindrical area 100 Outer surface 10a

[0030] Bending part 101 Contact area 20, B

[0031] Joint seam 102 Contact point 201, B1

[0032] upper wall 103 wing 30

[0033] lower wall 104 positioning area 40

[0034] side wall 105 wire clamping area 50

[0035] slot 106 copper sheet 200

[0036] front surface 210

[0037] immersion area C exposure area D

[0038] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings.

DETAILED DESCRIPTION

[0039] Please refer to Figures 1 to 7 As shown in the figure, a conductive terminal 1000, mainly used for vehicle wire harness connector (not shown), is formed by copper material through one-time stamping, electroplating and second bending. The hardness of the copper sheet after electroplating increases, and cracks are prone to occur at the bending part after the second bending, especially at the frame opening (guide area 10). The improvement point of the present application is that the copper material electroplating includes segmented immersion plating and inclined immersion plating, so that the thickness of the nickel layer of the guide area 10 of the conductive terminal 1000 is less than that of other parts. In this way, when the copper sheet 200 with a flat structure is bent to form a conductive terminal, the cracking phenomenon of the outer surface 10a of the guide area is improved, especially at the bending corner. Referring to Figures 6-7 As shown in the figure, the actual manufacturing method of the conductive terminal 1000 includes the following steps:

[0040] Step (1): providing a copper sheet 200 formed by one-time stamping of copper material (see Figure 6 ), the copper sheet has opposite front surface 210 and back surface 220, the copper sheet 200 is vertically inserted into nickel medicine for the first time electroplating, the copper sheet 200 includes immersion area C immersed in nickel medicine and exposure area D exposed outside the nickel medicine, wherein the electroplating liquid level of the nickel medicine is controlled at 3mm, the exposure area D includes contact area B and guide area A in front of the contact area B, the contact area B is provided with contact point B1 at the front surface thereof;

[0041] Step (2): placing the copper sheet 200 after step (1) electroplating in the nickel medicine for the second time electroplating, wherein the direction of the inclination is set such that the front surface 210 of the copper sheet is closer to the nickel medicine than the back surface 220; in the best embodiment, the direction of the inclination is set to 45 degrees;

[0042] Step (3): placing the copper sheet after step (2) vertically to continue the third time electroplating;

[0043] Step (4): continuing to electroplate a gold layer on the basis of the nickel layer at the contact point B1;

[0044] Step (5): The copper sheet after step (4) is bent to form a three-dimensional structure of the conductive terminal 1000 (see Figures 1-3 ).

[0045] The immersion area C realizes the same thickness of the nickel layer by conventional electroplating by directly immersing in the nickel plating solution, while the exposure area D realizes different thicknesses of the nickel layer of the copper sheet electroplated in different areas due to the different distances from the liquid surface caused by the wave effect of the liquid surface of the nickel plating solution. The electroplating liquid surface is controlled at 3 mm, and the front surface 210 of the copper sheet is closer to the nickel plating solution than the back surface 220. Obviously, the back surface of the guide area A is farthest from the liquid surface, so the nickel layer thickness of the back surface is thinnest, and the nickel layer thickness of the front surface is relatively thick because the front surface is closer to the liquid surface. The specific nickel layer thickness is described below.

[0046] Please refer to Figures 1 to 5 The conductive terminal 1000 is a three-dimensional structure formed by stamping and bending the copper sheet 200 after electroplating, so as to form a plurality of bending parts 101, and the inner side and the outer side of the conductive terminal correspond to the front surface 210 and the back surface 220 of the copper sheet, respectively. The conductive terminal 1000 includes a cylindrical area 100 and a wire clamping area 50 located behind the cylindrical area. The cylindrical area 100 sequentially includes a guide area 10 (i.e., the guide area A of the copper sheet), a contact area 20 (i.e., the contact area B of the copper sheet) from front to back, and the inner side of the contact area is provided with a contact point 201 (i.e., the contact point B1 of the copper sheet). The guide area 10 is only partially connected with the contact area 20. As analyzed above, the nickel layer thickness of the outer side surface 10a of the guide area 10 is smaller than that of other parts of the conductive terminal 1000. Specifically, the nickel layer thickness of the outer side surface of the guide area 10 ranges from 20 to 40 micro inches, and the nickel layer thickness of the inner side surface is 50 micro inches (1 micrometer is approximately equal to 39.37 micro inches). In this way, when the conductive terminal 1000 is connected, on the one hand, the contact performance and the friction resistance performance of the inner side surface of the guide area 10 are satisfied, and on the other hand, the outer side surface is ensured to have no cracking phenomenon. The nickel layer thickness of the inner side surface of the contact area 20 is 50 micro inches, and the contact point 201 has a gold plating layer outside the nickel layer, and the gold plating layer has a thickness of at least 30 micro inches to satisfy the contact performance. The nickel layer thickness of the bending part 101 of the outer side surface of the contact area 20 ranges from 20 to 40 micro inches to prevent cracks from occurring in the bending part 101.

[0047] The cylindrical area 100 comprises an upper wall 103, a lower wall 104 and two side walls 105, the upper wall 103 is formed with a joint 102 of copper material after being bent close to each other. The side wall 105 is provided with an L-shaped slot 106, so that the side wall 105 is spaced apart from the lower wall 104 and connected with the upper wall 103 only, the part of the cylindrical area 100 in front of the slot 106 forms a guide area 10, the part between the slot 106 and the upper wall 103 forms a contact area 20, the inner wall surface of the contact area 20 is provided with a convex point to form a contact point 201. The side wall 105 of the cylindrical area is provided with a wing part 30 and a positioning area 40 behind the contact area 20, the wing part 30 is outwardly inclined and opened, and the positioning area 40 is used to fix and stop the conductive terminal 1000 in the vehicle-mounted connector (not shown).

[0048] The above only describes some embodiments of the present application, not all embodiments, any equivalent changes made by those skilled in the art to the technical solutions of the present application by reading the specification of the present application are covered by the claims of the present application.

Claims

1. A method for manufacturing a conductive terminal, wherein the substrate of the conductive terminal is copper, characterized in that: The manufacturing method includes at least the following steps: Step (1): Provide a copper sheet formed by stamping copper material, the copper sheet having a front and a back side, and vertically insert the copper sheet into the nickel solution for the first electroplating. The copper sheet includes an immersion area immersed in the nickel solution and an exposure area exposed outside the nickel solution. The exposure area includes a contact area and a guide area located in front of the contact area. The contact area has a contact point on its front side. Step (2): The copper sheet after electroplating in step (1) is placed at an angle in the nickel solution for a second electroplating, wherein the angle is set such that the front side of the copper sheet is closer to the nickel solution than the back side. Step (3): After step (2), place the copper sheet back vertically and continue the third electroplating.

2. The method for manufacturing a conductive terminal as described in claim 1, characterized in that: In step (2), the tilt angle is 45 degrees.

3. The method for manufacturing a conductive terminal as described in claim 1, characterized in that: The electroplating solution level of the nickel plating solution is controlled at 3 mm.

4. The method for manufacturing a conductive terminal as described in claim 1, characterized in that: Step (4): The contact point is further electroplated with a gold layer on the basis of the nickel layer.

5. The method for manufacturing a conductive terminal as described in claim 4, characterized in that: Step (5): Bending the copper sheet after step (4) to form the conductive terminal with a three-dimensional structure.

6. A conductive terminal formed by electroplating and stamping copper, having a nickel layer on its surface; the conductive terminal includes a cylindrical region and a clamping region located behind the cylindrical region, the cylindrical region having opposing inner and outer sides and, from front to back, a guiding region, a contact region, and a positioning region, the inner side of the contact region having a contact point, the guiding region and the contact region being only partially connected, characterized in that: The thickness of the nickel layer on the outer surface of the guide area is less than the thickness of the nickel layer on other parts of the conductive terminal.

7. The conductive terminal as described in claim 6, characterized in that: The nickel layer thickness on the outer surface of the guide area ranges from 20 to 40 microinches.

8. The conductive terminal as described in claim 7, characterized in that: The nickel layer on the inner surface of the contact area of ​​the conductive terminal is 50 microinches thick; the contact point also has a gold plating layer outside the nickel layer, and the gold plating layer is at least 30 microinches thick.

9. The conductive terminal as described in claim 6, characterized in that: The cylindrical region includes an upper wall, a lower wall, and two side walls. The upper wall has a joint seam formed where the copper material is bent and brought close together. The side walls have L-shaped slots, which separate the side walls from the lower wall and connect only to the upper wall. The portion of the cylindrical region in front of the slots forms the guide area, and the portion between the slots and the upper wall forms the contact area. The inner wall surface of the contact area has protrusions to form the contact points.

10. The conductive terminal as described in claim 6, characterized in that: The sidewall of the cylindrical region is provided with a wing behind the contact area, and the wing is tilted outward and opens.

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