JPH02280980A - Manufacture of spotted partial cladding material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Field of Application The present invention relates to a method for manufacturing spot-shaped partial cladding materials by overlapping pressure welding and rolling, in which a metal foil fed to a fixed length is sandwiched and cut with a punch, and at the same time a base plate is fed to a fixed length. The present invention relates to a manufacturing method for obtaining a spot-shaped partial cladding material having a highly accurate pitch and dimension by spot welding and temporarily fixing a plate material using a welding current-carrying material incorporated in a punch, followed by pressure welding and rolling.

Background Art In recent years, there has been a strong demand for miniaturization of devices using integrated circuits, and flat packages have come to be frequently used.

A lead frame (3) as shown in FIG. 4 in which terminal portions are provided in the four circumferential directions for such a flat package is provided with a metal (AL Ag, etc.) adhered portion for good bonding in the portion where wire bonding is to be performed. There is a need, especially
Lead frames are formed by press processing or etching for mass production and miniaturization of patterns.
As shown in the figure, it is necessary to provide the deposited metal (2) portion on the lead frame material (1) with high precision in a spot shape.

Conventionally, methods for manufacturing such composite materials include a.
There are vapor deposition methods, plating methods, and C0 rolling pressure welding methods, but a method with better mass productivity has been desired.

In other words, (a) the vapor deposition method not only requires expensive equipment, but also requires masking of unnecessary areas, resulting in slow vapor deposition and low productivity; and (b) the plating method may not be able to plate some metals. There is also a limit to the thickness that can be plated efficiently, and in both cases, it is impossible to maintain a predetermined pitch and dimension of the spot-shaped partial cladding material with high accuracy and to realize this in mass production.

In addition, in the C6 rolling pressure welding method, after providing AI or Ag foil in stripes on the lead frame strip material, unnecessary parts are mechanically or chemically removed to form predetermined spot shapes. 1078), but the yield of the deposited metal is poor, the efficiency is poor as it involves masking the parts that need to be deposited and removing unnecessary parts, and it is also difficult to deposit the metal in spots at a predetermined pitch and size with high precision. That was difficult.

Furthermore, it is possible to manufacture a spot-shaped partial cladding material of a certain length by overlapping metal foil pieces of a certain length on a certain length of a substrate material at a certain position, that is, at a certain pitch, rolling, and pressure welding. Because it is not possible to continuously unwind the plate coil, cut the metal foil to be adhered to a predetermined size and length with high precision, align it with high precision, and temporarily fasten it continuously, it is difficult to do so industrially. Mass production was considered impossible.

In other words, a lead frame has been proposed (Japanese Patent Publication No. 60-227456) in which AI foil is spot-welded onto the lead frame material and then made into a cladding. No specific manufacturing method has been proposed for positioning and continuous temporary fixing, and it is difficult to put it into practical use.

Furthermore, simply spot welding causes problems in rollability, making it impossible to maintain predetermined pitches and dimensions with high precision.

Purpose of the Invention In view of the current situation, the present invention is to cut a metal foil to be adhered to a predetermined size and length with high precision, align it with a lead frame material with high precision, and continuously temporarily cut the metal foil to a predetermined length. The object of the present invention is to provide a method for producing spot-shaped partial cladding material that can be fixed and cladded.

Summary of the Invention This invention provides a method for manufacturing a spot-shaped partial cladding material in which metal foil pieces of a predetermined size are crimped onto a substrate strip material at predetermined intervals, including a material guide for feeding the metal foil by a fixed length on the substrate strip material. The metal foil is sandwiched and cut into a predetermined size by the die and a vertically moving punch that maintains a minimum clearance with the die end face provided at the end of the metal foil, and the metal foil piece is banded after being pinched and cut by the descending punch. The metal foil pieces are temporarily welded at one or more points in the width direction of the substrate material using an electrode that is pressed onto the material and brought into contact with the back side of the strip material.Then, the temporarily attached metal foil pieces and the substrate strip This is a method for producing a spot-shaped partial cladding material, which is characterized by press-welding and rolling materials.

To be more specific, this invention: ■ Feeds a metal foil strip of a predetermined width, a predetermined length into a pinch cutting mechanism, cuts it by pinching, and repeats this process to continuously obtain metal foil of a predetermined size with high precision. .

■Incorporating current-carrying material for series spot welding into the punch,
Series spot welding is performed immediately after cutting the metal foil.

■By such metal foil cutting and series spot welding, metal foils of a predetermined size are overlapped at a predetermined position, temporarily fixed to a substrate material, and then the substrate material is sent out by a predetermined length.

(2) By repeating this process, metal foil pieces of a predetermined size can be stacked continuously on the substrate material at a predetermined pitch.

(2) After this, the process consists of pressure welding and rolling to obtain a spot-shaped partial cladding material that is excellent in mass production.

Based on the Drawings <Disclosure of the Invention Figures 1a to 1e are schematic explanatory diagrams of an embodiment of a fixed-size feed and welding device showing the manufacturing process according to the present invention, and Figure a is an explanatory diagram as seen from the line direction. be.

FIG. 2 is a perspective explanatory view showing a pinch cutting mechanism according to the present invention.

The substrate material (10) unwound from the 4-kilometer coil is sent out to a series spot welding device in predetermined lengths by a constant feed device (not shown), and a metal foil (10) is placed near the welding device by a suction machine.
20) is equipped with an attachment/detachment mechanism to feed the metal foil in predetermined lengths at a time, as well as a pinch cutting device. Press and roll.

Here, the fixed size feeding device for metal foil (20) is such that a band-shaped metal foil (20) of a predetermined width is sucked by a suction device (31), and the metal foil (20) is provided on a material guide (30). It consists of a structure in which the suction device (31) is slid on the bottom surface of the four-part groove by one stroke of the suction device (31).

Although the fixed size feed device for the substrate material (10) is not shown, any known structure can be used as long as it can feed the substrate material by a predetermined length.

As shown in FIG. 2, the pinch cutting device uses the material guide (
The downstream end of 30) serves as a lower fixed die, and the punch (32) is driven vertically by a hydraulic cylinder or servo motor.
and the end face of the die.

In addition, the scissor cutting device uses a distance between the end face of the die (
Since the punch holder (34) is pressed by a spring or the like so that the clearance (clearance) becomes 0, clogging is less likely to occur.

The series spot welding device includes a roller electrode (33) that is placed in contact with the back side of the base material (10) at the position where the metal foil piece (11) is to be crimped, that is, the center of the lower surface, and the punch that is provided with the current-carrying material. (32), and when the punch (32) and the metal foil piece come into contact with the substrate material (10) after the above-mentioned sandwich cutting, electricity is applied and spot welding is performed.

Operation (2) A predetermined amount of metal foil (20) of a predetermined width is fed into the cutting device by a fixed size feeder having an attachment/detachment mechanism using suction. At this time, the predetermined feed amount needs to take into account the amount of deformation due to pressure welding, rolling, and finish rolling (see Figure 0).

(2) When a predetermined length of metal foil (20) overhangs the end face of the guide (30), lower the punch (32) to cut the metal foil (20) into metal foil pieces (11).

(See figure d) ■When the punch (32) presses the cut metal foil piece (11) against the substrate material (lO), the roller electrode (33) is energized with pressure, so that the metal foil piece (11) is pressed against the substrate material (lO). ) (see figure e).

At this time, it is desirable that the size of the metal molten part is such that it does not come out on the surface of the metal foil piece (11), and the welding parts are preferably arranged at one or more points in the width direction of the substrate material (10).

In particular, as shown in Figure 1a, it is best to weld two points at both ends of the metal foil piece (11) in the width direction of the substrate material (10), and only the tip side that will be caught in the roll during rolling in the subsequent process. By temporarily fixing and leaving the rear end free, pressure welding and rolling properties are improved.

(2) After the spot welding is completed, the substrate material (10) is sent by a predetermined amount using a sizing feeding device, that is, an amount that takes into account the amount of deformation due to pressure welding, rolling, and finish rolling.

Repeat the above process and cut the metal foil pieces to the specified size (1
1) are arranged at predetermined intervals on a substrate material (10) and spot welded.

For example, the cycle of carrying out the above-mentioned steps 1 and 2 at the same time and then performing the steps 1 and 2 is repeated.

Next, the substrate material (10) to which metal foil pieces (11) are continuously temporarily fixed at a predetermined pitch is pressed and rolled to obtain a spot-shaped partial cladding material.

Effects of the Invention The present invention has made it possible to manufacture spot-shaped partial cladding materials by rolling, which is superior in mass productivity compared to vapor deposition and plating methods.

The spot-shaped partial cladding material produced by the manufacturing method of the present invention has a metal part such as a brazing filler metal formed in a predetermined position with high precision and a predetermined size, so it has excellent shape accuracy and mass productivity when forming a lead frame. ing.

There is no waste in the metal foil pieces to be adhered, and for example, when Ag or the like is used as a metal that provides good bonding properties for lead frames, the yield is significantly improved.

In addition, since this invention employs pinch cutting to cut the metal foil, clogging is less likely to occur.For example, the conventional punching method that maintains a clearance of 2 to 3 pm is
It has the advantage that it is almost maintenance-free, whereas clogging occurs after about 00 cycles.

[Brief explanation of drawings]

1A to 1E are schematic explanatory diagrams of an embodiment of a sizing feed and welding device showing the manufacturing process according to the present invention, and FIG. 1A is an explanatory diagram as seen from the line direction. FIG. 2 is a perspective explanatory view showing a pinch cutting mechanism according to the present invention. FIG. 3 is a perspective explanatory view of a spot-shaped partial cladding material. FIG. 4 is an explanatory diagram showing an example of a lead frame.

Claims (1)

[Claims] 1. A method for manufacturing a spot-shaped partial cladding material in which pieces of metal foil of a predetermined size are crimped onto a substrate material at predetermined intervals, comprising: an edge of a material guide that feeds the metal foil by a fixed distance on the substrate material; The metal foil is sandwiched and cut into a predetermined size by the die and a vertically moving punch that maintains a minimum clearance with the end face of the die provided in the section, and after the metal foil is sandwiched and cut by the descending punch, the metal foil piece is placed on the strip material. The metal foil piece is temporarily fixed by spot welding at one or more points in the width direction of the substrate material using an electrode brought into contact with the back side of the strip material, and then the temporarily fixed metal foil piece and the substrate material are pressed together. A method for producing a spot-shaped partial cladding material, the method comprising rolling the spot-shaped partial cladding material.