JPH01173586A - Continuous manufacture of conductive piece for electronic parts - Google Patents

Abstract

PURPOSE:To improve productivity by sequentially joining a punching process to punch pilot holes, a spot welding process, and a press formation process in accordance with operation timing of each process thereof. CONSTITUTION:Hoop materials 1, 2 consisting of different kinds of metals different in width are plated and overlapped each other after being positioned according to a datum plane parallel to the transfer direction, and a punching process I which punches pilot holes, a spot welding process II which forms, at a fixed curvature, the end pressing part of an electrode tip on one side of the different kinds of metals to be positioned by the pilot holes and spot-welds the top pressing part of an electrode tip on the other side and leaves the plated layer without damaging, on the side to be pressed with the plane pressing part of the electrode tip on the other side, and a press formation process III which transfers and supplies the hoop materials 1 and 2 being welded to a successively sending press equipment 60 so as to perform the specified dying, bending and cutting in order, are sequentially joined according to the operation timing of each process I, II and III. Hereby, productivity is improved.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a conductive piece for electronic parts, which is formed by applying solder or tin plating to at least one of hoop materials of different metals, joining them by spot welding, and press-forming them. Concerning integrated manufacturing method.

[Prior art and its problems] Soldering is generally used to join conductive pieces that electrically connect electronic components such as transistors and IC parts, and conductive pieces that electrically connect electronic components and circuits on boards. It is being Therefore, the quality of the joints made by soldering or the like is one of the factors that directly affects the quality and reliability of the product itself incorporating the electronic component. In addition, as the size of electronic components has become smaller, the conductive pieces have also become smaller, causing problems such as reduced joint strength and deterioration of joints such as soldered joints due to stress caused by mechanical vibrations or repeated thermal stress during cooling and heating cycles. It becomes. In particular, the soldering of electrically conductive pieces for electronic components with significantly different coefficients of linear expansion can be performed from -30℃ to 1
When placed under a cooling/heating cycle of 10° C., the bonding strength may deteriorate significantly.

For this reason, as a countermeasure against deterioration of joints of dissimilar metals, there is a method of ensuring a strong joint using silver brazing, but the brazing temperature is high at approximately 700°C, and the heating may affect electronic components, etc.
This is difficult to implement easily considering productivity and other factors.

Next, from the viewpoint of productivity and bonding strength, spot welding may be adopted as a method for joining electronic components made of dissimilar metals. Conditions for performing spot welding satisfactorily include the welding current 2 application time, the pressing force, and the material and shape of the electrode. In addition to the above conditions, the joining of dissimilar metals is affected by the material. In particular, conductive pieces with low electrical resistance or plated conductive pieces are directly joined to circuits, IC parts, etc. on the board by spot welding. It is not easy to find optimal conditions with high reliability for each material of the circuit, etc.

The reason why the joint strength of joints such as soldered joints deteriorates under the above-mentioned cooling and heating cycles is due to joining of dissimilar metals having significantly different coefficients of linear expansion. Therefore, in the parts to be joined by soldering etc., a member with a coefficient of linear expansion relatively close to the am tensile coefficient of the members to be joined is interposed and soldered, and the member and the conductive piece are firmly bonded by spot welding. By joining them to each other, it is possible to solve the problem of deterioration of joints such as soldering under thermal cycles. However, as mentioned above, conductive pieces for electronic components are to be joined to circuits, etc. on a board by soldering, etc., so in order to form a plating layer necessary for soldering etc. on the surface of the conductive material, If tin or solder plating is performed after spot welding, not only will it be deformed during the plating process, making it impossible to maintain accuracy in dimensions and shape, but the plating solution that has seeped into the gaps between welds will not be removed by washing, impairing the quality of the plating. Such inconveniences are expected to occur. For this reason, a method can be considered in which the materials are plated with solder, etc., then spot welded to join them, and then formed into a predetermined shape by press molding, etc. However, the size of the conductive pieces is extremely small. For,
In terms of productivity and cost, there were problems that needed to be solved, such as the desire to develop an automated mass production method.

"Means for Solving the Problems" The present invention aims to solve the above-mentioned problems, and has a specific configuration in which solder or tin is applied to at least one of the hoop materials of different metals having different widths. Plating is applied, and the dissimilar metals positioned by the reference plane parallel to the direction of conveyance and supply are superimposed, and the drilling process involves drilling a pilot hole using a press device, and dissimilar metals positioned by the pilot holes. A spot welding machine in which the tip pressure part of one electrode tip made of a high melting point material such as tungsten is formed with a constant curvature, and the tip pressure part of the other electrode tip made of a chromium copper alloy is formed into a flat shape. a spot welding process in which the plating layer of the plating is left undamaged on the side to be pressurized by the planar pressurizing part of the electrode tip on the other side; and a hoop material joined by the welding process. A press forming step in which the material is conveyed and supplied to a progressive press device by a conveying device and predetermined punching, bending, cutting, etc. It is something to do.

"Function" As clarified in the explanation of the above-mentioned specific structure, in the present invention, hole punching is performed in a hoop of dissimilar metals for punching, bending, cutting, etc. in a progressive press machine in a subsequent process. In addition to accurately positioning the materials, pilot holes are drilled for the spot welding process and press forming process. The electrode tip is made of a high melting point material such as tungsten with a constant curvature, and the electrode tip is made of a copper chromium alloy. When pressure is applied using an electrode tip with a planar pressure part and a large current is applied, a local temperature rise due to resistance heat generation in the intermediate plating layer melts and removes the plating layer and locally melts the dissimilar metal. On the other hand, the plating layer on the pressurizing side of the metal material that is pressurized by the planar electrode has a large pressurizing area, and the heat generated at the electrode is conducted to the electrode tip. Therefore, it remains without any mechanical or thermal damage, and is then conveyed and supplied to a progressive press device by a conveyance device, and is subjected to predetermined press molding in a press molding process to manufacture a conductive piece for electronic parts.

"Example" A schematic layout of each process constituting the method of the present invention will be explained in the order of conveyance of materials with reference to FIG.

The metal material of the conductive piece for electronic parts has a plate thickness of 0.15M1ll.
, hoop material 1 made of copper material with a board width of 10 cm and board thickness.

A hoop material 2 made of a 42 nickel alloy material of 0.25 mm and a plate width of 251 is pre-plated with 90% tin solder, and the thickness of the plating layer m is set to 51 JII (see Figure 2).
The hoop materials 1.2 made of both metal materials are wound into a coil, hung on an autoreel 3.4, and unwound once. They are passed through pilot stands 5 and 5.6, respectively, and guided by a guide 7. Holes are sequentially punched by a press device. The holes made by 10 are joined and integrated through step (1) and spot welding step (II) by the spot welding machine 21, and then conveyed to the reversing device 52 by the conveying and supplying device 50 to be turned over and placed on the pilot stand. 8 and conveyed to a progressive press device 60, a press molding process (I[[) by the device 60 is performed to produce a conductive piece of a predetermined shape, and the blank material is wound up by a winding reel 9. Each of the pilot stands 5, 6 and 8 is configured to detect slack in each of the hoop materials 1 and 2 and the hoop materials joined together by spot welding, and to transport and supply the hoop materials with a constant tension. .

Hereinafter, each of the steps (1), (TI), and (III) will be explained.

Drilling is step (1) For drilling, a guide 7 is placed on the front side of the press device 10, and the coiled hoop material hung on the autoreels 3 and 4 is unwound to form a guide groove on the upper side of the guide 7. After passing the hoop material 1 made of copper material and the hoop material 2 made of 42 nickel alloy through the lower guide groove, they are overlapped by a pair of guide rollers 7'.
Is the anamei pressed? ! Transport and supply to fio. The hole punching press device 10 is configured by a normal hole punching press, and an air cylinder 12 is fixed to the upper surface of a frame 11.
On a punch holder 14 attached to the lower end of the piston rod 13, punches 15 having an even number of holes with a fixed pitcher are arranged in two rows in the transport direction, and a die 17 is fixed to a bolster 16.

The die 17 is provided with a conveyance guide groove 18 for the hoop material 1 made of the copper material and a conveyance guide groove 19 for the hoop material 2 made of the 42 nickel alloy material so that the reference plane 20 on one side in the conveyance direction coincides with each other. This is because the hoop material is generally meandering in the length direction, so the pilot hole P is bored while the two metal materials are overlapped with the two metal materials precisely aligned in position.

Spot welding process (II) The spot welding machines 21 are two machines connected in the conveyance direction, and the six positioning devices 22, which have three positioning devices 22 arranged on both sides and in the middle of the spot welding machines 21 and 21, have the above-mentioned positioning devices 22. A guide 25 having a conveyance guide groove 23 for the hoop material 1 made of copper material and a conveyance guide lever 24 for the hoop material 2 made of 42 nickel alloy material is provided continuously except for the spot welding position, and the upper surface of the frame 26 is provided. This air cylinder 27 is fixed, and a positioning pin 29 is attached to the lower end of the piston rod 28.
The zero positioning pin 29 that fixes the hoop material 1.2 is fitted into a pilot hole P drilled in the hoop material 1.2 that is conveyed within the conveyance guide grooves 23 and 24 of the guide 25, and performs positioning during spot welding. It is.

Spot welding is performed inside the drilling position of the pilot hole P at the same pitch as the pitch p of the six P.

The spot welding machine 21 uses a capacitor type spot welding machine, and forms the tip pressurizing part of the upper electrode tip 31 driven by the air cylinder 30 with a curvature of 2.5 mm, and pressurizes the lower electrode tip 32. The part is planar.

The material of the upper electrode tip 31 is tungsten, but other materials such as silver tungsten and molybdenum have high thermal conductivity,
A material with high conductivity and high melting point can be used.

The material of the lower electrode tip 32 is a chromium steel alloy.

The lower electrode tip 32 has a rectangular bar shape with one end fixed to the slider 33 and supported in a cantilevered manner, and the tip thereof faces below the upper electrode tip 32. The slider 33 is the base 3
The hoop material 1, 2 can be slid by a guide 35 at a right angle to the transport direction of the hoop materials 1, 2, and a serrated rack 36 formed with a constant step is provided on the lower surface. 37 is the serrated rack 3
6 is a feed pawl that is engaged by the spring elasticity of a pressing spring 38, and is swingably supported by a pin 39 on a feed pawl support base 40. 41 is a solenoid disposed on the base 34, and the plunger 42 is connected to the feed claw support base 40.
Connect to. By driving the solenoid 41, the support base 4
o is moved by one pitch of the serrated rack 36, and the slider 33 is simultaneously moved forward by the pitch by the feed pawl 37. Therefore, the lower electrode tip 32 supported by the slider 33 moves by one pitch to change the corresponding position of the upper electrode tip 31. This is to be done every fixed number of spot welds, and the rear end of the step is detected by a limit switch 42 and the lower electrode tip 32 is replaced. It is an electrode.

When the hoop materials 1 and 2 described above are positioned by the positioning device 'R22 and spot welded by the spot welding machine 21, a local temperature rise occurs due to resistance heat generation in the solder plating waste m in the middle of the overlapping part of the picture materials. As a result, the plating Mm is melted and removed, and the copper and 42 nickel alloy are locally melted to form a nugget n, which is a cast structure of both metals, and are joined. On the other hand, the pressurized side of the 42 nickel alloy material that is pressurized by the lower electrode chip 32 has a large pressurized area and high thermal conductivity, so the solder plating layer m is not damaged mechanically or thermally. remains. In addition, the copper material on the side that is pressurized by the upper electrode tip 31 is
Since pressure is applied locally at the tip pressurizing portion formed with a constant curvature, an indentation 0 is formed in which the solder plating layer is destroyed.

The welding conditions for the spot welding described above are a current value of 4 KA and a pressing force of 10 k [r], but the f& suitable conditions for spot welding vary depending on the quality of the metal material, plate thickness, plating thickness, etc.

, 50 is a conveying device for the hoop material 1.2, and includes an air cylinder 5 that operates at a pitch twice the spot welding pitch p.
The conveyance device 50, which conveys in a stepwise manner by means of a gripping device 51a provided at the tip of the guide 7, repeats the forward movement of gripping and the release and backward movement, is comprised of a pair of guide rollers 7' of the guide 7 described above.
The hoop materials 1 and 2 are conveyed and supplied under tension to each process.

52 is a hoop material integrally joined by the spot welding process (II)], 2 is a reversing device, which includes a pair of feed rollers 53, a pair of twisting rollers 54 whose rotating support shaft is tilted at an angle of 90 degrees, and a feed roller. Consisting of 55 pairs. Conveying device 5
The hoop material 1.2 conveyed by the hoop material 1.2 is twisted by 90 degrees between a pair of feed rollers 53 and a pair of twisting rollers 54, and further twisted by 90 degrees between the pair of twisting rollers 54 and a pair of delivery rollers 55.
The hoop material 1.2 is twisted by 0° and turned over.

The hoop materials 1 and 2 that have passed through the reversing device 52 are conveyed and supplied to the press molding process (I[[) through the pilot stand 8.

Press molding process (III) The press molding process (lI[) is performed using a normal progressive press device 6.
1, the hoop materials 1 and 2 are inverted and supplied by the reversing device 52, and are positioned by their pilot holes P and transferred to the air cylinder 61. The molding is performed in the order shown in FIGS. 9(a) to 9(c) using a progressive press mold 62 that moves up and down.

By the punching and bending performed at the spot welding position S shown in FIGS. 9(a) and 9(b), sag is caused by punching on the end face of the 42 nickel alloy that has passed through the reversing device 50 and has been reversed and turned upward. Therefore, the soldering of the conductive piece 70 improves solder welding in the case of joining.

FIG. 9(c) shows cutting and forming, in which the cut and separated conductive pieces 70 fall below the progressive press die, and the continuous blank material is wound up by the take-up reel 9. Since each of the above-mentioned moldings is performed using a normal progressive press device, a detailed explanation will be omitted by showing the molded cross section of the conductive material 70 as well.

Each step (1), (n), (I[[
) is as explained above, and as shown in FIG.
, the air cylinder 30 of the Subo I/welding machine 21, and the air cylinder 61 and electromagnetic switching valve 12 of the press forming process (■)
pneumatic pressure control circuits 81, 82, 83 and 84 are respectively constructed by intervening the a, 27a, 30a and 61a, and a pneumatic control circuit 85 of the conveying device 50 is provided to synchronize the operation timing of each process. Continuous conveyance and supply of materials 1 and 2 degrees is controlled to perform integrated manufacturing of conductive pieces 70 for electronic components. In this case, hole-making is the process (1
) The operation of the air cylinder 12 depends on the relationship between the number of pilot holes P drilled in the - process and the welding machine, that is, since there are two welding machines in this example, (number of pilot holes P/2
) will operate intermittently.

Further, in this embodiment, solder plating was applied to the partners of the hoop materials of different metals to be joined by spot welding, but depending on the type of metals to be joined, only one of the hoop materials may be solder plated.

"Effects" As clarified in the explanation of the specific structure and operation described above, the present invention provides a method for punching different types of material for punching, bending, cutting, etc. in the progressive press machine in the subsequent process. In addition to accurately positioning the metal hoops relative to each other, pilot holes are drilled for the spot welding process and press forming process. The electrode tip is made of a high melting point material such as tungsten with a constant curvature, and the electrode tip is made of a copper chromium alloy. When pressure is applied using an electrode tip with a planar pressure part and a large current is applied, a local temperature rise due to resistance heat generation in the intermediate plating layer melts and removes the plating layer and locally melts the dissimilar metal. On the other hand, the plating layer on the pressure side of the metal material that is pressed against the planar electrode has a large pressurizing area, and the heat generated at the electrode part is transferred to the electrode tip. Because it is conductive, it remains without any mechanical or thermal damage, and is then conveyed and supplied to a progressive press device by a conveyance device, where it is press-formed in a predetermined manner in a press-forming process to manufacture conductive pieces for electronic components. Since each of the above steps is timed to the operating timing and connected continuously, the integrated manufacturing of conductive pieces for electronic components made by joining dissimilar metal materials such as hoop materials with solder plating etc. is possible at low cost and with high efficiency. There is an effect that can be achieved by

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate the method of the invention, and FIG. 1 shows hoop material 1.
2 is an enlarged cross-sectional view of No. 2, FIG. 2 is a schematic layout diagram of the steps constituting the method of the present invention, and FIG. Figure 4 is a plan view of the die 17, Figure 5 is Figure 4A.
-A line sectional view, Fig. 6 is an enlarged sectional view of Fig. 3 B-Bli, Fig. 7 is a partially cutaway enlarged front view of the main part of the spot welding machine 21, and Fig. 8 is a spot welding joint section. The enlarged sectional view, FIG. 9, shows the press forming process of the progressive press device 60.
10 is a pneumatic circuit diagram, which is an explanatory diagram shown together with a molded cross section of No. 0. 1.2. ,,Hoop material, 21,,Spot welding machine, 31,,,Upper electrode tip, 32. , Lower electrode chip 50 , Transport device 60 , Progressive press device 70 , Conductive piece (1) Hole drilling process (n) Spot welding process (I[[
),,, press molding process, Pll, pilot hole,
m31. Solder plating layer. Figure 1 Figure 4 -A Figure 5 Figure 6 Figure 8 Figure 9

Claims (1)

[Scope of Claims] At least one of hoop materials of different metals with different widths is soldered or tin-plated, positioned and overlapped by a reference plane parallel to the direction of conveyance and supply, and a pilot hole is formed using a punching press device. The dissimilar metal positioned by the pilot hole is formed with a constant curvature at the tip pressurized part of one electrode tip made of a high melting point material such as tungsten, and made of a chromium-copper alloy. The tip pressurizing part of the electrode tip on the other side is welded using a spot welding machine that is formed into a flat shape, and the plating layer of the plating is damaged on the side that is pressurized by the flat pressurizing part of the electrode tip on the other side. The hoop material joined by the welding process is conveyed and supplied to a progressive press device by a conveyance device, and is subjected to predetermined punching, bending, and
1. An integrated manufacturing method for a conductive piece for electronic components, characterized in that a press forming process in which cutting, etc. are sequentially performed is successively combined at the timing of the operation of each of the steps.