JPH02109357A - Manufacture of clad plate for plastic molding - Google Patents

Abstract

PURPOSE:To make it possible to manufacture clad plates cheaply and make it highly efficiently used for lead frame materials of desired alloys, by making groove parts in the longitudinal direction of the central parts of both surfaces of a base board, inserting materials to be attached into the groove parts, cold pressure-welding them, and further diffusion-annealing them. CONSTITUTION:First, groove parts with almost the same size as that of the cross section of materials to be attached are made through rolling with working rolls 2 in the central parts of both surfaces of an unwound Cu alloy band 1. Next, cleaning treatment of the alloy band surfaces is performed with a heat furnace 3, and besides the parts where the materials are intended to be attached to are cleaned with wire brushes 4. After that, the materials to be attached, Fe alloy plates 5 containing 30-50% Ni, are inserted into the grooves being unwound, and cold pressure-welded with pressure-welding rolls 6 to finish the joining. Then, diffusion-annealing is performed with a heat furnace 7 in a specified temperature range to make the joining of the Ni-Fe alloy plate perfect in the longitudinal direction of both surfaces' central parts of the Cu alloy band 1, and to obtain a stripelike clad plate 8. This method makes it possible to manufacture at low cost and highly efficiently clad plates used for lead frame materials with an Ni-Fe alloy used for Si chip mounting parts, and with a Cu alloy for parts other than the parts.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application This invention relates to a method for manufacturing a clad plate for a plastic mold. niN
The present invention relates to a method of manufacturing a clad plate for a plastic mold by covering an Fe alloy plate containing 30 to 50% i.

Background technology Sealing alloys for plastic molds generally contain 42%
A Ni-Fe alloy is used, and a Cu alloy plate is used for large capacity applications.

The 42% Ni-Fe alloy is often used because its coefficient of thermal expansion is similar to that of semiconductor Si chips, but it has a large difference in coefficient of thermal expansion from the plastic to which it is sealed, and also has poor thermal conductivity. However, there is a drawback that it is not very good.

Furthermore, although Cu or Cu alloy has the advantage of having a thermal expansion coefficient similar to that of plastic and excellent thermal conductivity, it has the problem of a large difference in thermal expansion coefficient from that of a Si chip.

Therefore, in order to solve this problem of thermal expansion difference, conventionally,
A clad plate has been proposed in which a 42% Ni-Fe alloy plate or a 36% Ni-Fe alloy is used as a core material, and Cu or a Cu alloy is coated on both sides of the core material.

Nowadays, there is a growing demand for lowering the cost of the clad plate, and recently, 42% Ni-Fe alloy,
As for lead frame 4 A, which has the characteristics and advantages of Cu or Cu alloy, a Ni-Fe alloy having a coefficient of thermal expansion similar to that of Si is used for the Si chip mounting part of the semiconductor, and the other parts are A lead frame material for plastic molds using Cu or Cu alloy was proposed (Japanese Patent Laid-Open No. 62-13
No. 6059). However, no manufacturing method for providing this lead frame material at low cost has been proposed.

Purpose of the Invention This invention provides a Si chip mounting portion with a Ni-Fe alloy τ,
It is an object of the present invention to provide a method for efficiently manufacturing a clad plate used in an old lead frame in which Cu or Cu alloy is used in other parts at a cost of 1 mil.

Summary of the Invention This invention provides a groove portion having a size approximately equal to the cross-sectional dimension of Fe plywood containing 30 to 50% Ni to be adhered, in the longitudinal direction of at least one main surface of a substrate made of Cu or a Cu alloy. is formed continuously or discontinuously by machining or roll processing, and then a Fe alloy plate containing 30 to 50% Ni as a deposit is inserted into the groove and cold welded.

Furthermore, the method for manufacturing a clad plate for a plastic mold is characterized in that diffusion annealing is performed by heating to 600°C to 1050°C.

The clad plate obtained by this invention can be punched or etched to a required size to obtain a lead frame material.

For example, in the case of a striped clad plate in which the adherend material is continuously disposed on the substrate, DIP (dual
1nline package) can be obtained.

In addition, from the island-shaped clad plate on which the adherend material is disposed discontinuously, a large number of adherends are formed in four directions perpendicular to the adherend material.
QFP (quad flatpackag) that takes dopin
Lead frame material for e) can be obtained.

Structure of the Invention In this invention, the reason why the bonding material is Fea gold containing 30 to 50% Ni is that if the Ni content is less than 30%, the coefficient of thermal expansion becomes large. This is because the difference with thermal expansion becomes larger.
A preferred Ni-Fe alloy is a 42% N1-Fe alloy.

Further, it is preferable that the dimension of the groove formed on the substrate surface is approximately equal to the cross-sectional dimension of the attached moon.

The rolling reduction during cold rolling is 30% to 70%, preferably 50%.
% to 60%.

In addition, the diffusion annealing conditions are preferably 1 minute to 60 minutes at 600"(,'~)050°C; below 600"C, bonding is insufficient;
If it exceeds 'C, Cu will melt, which is not preferable.

When the clad plate according to the present invention is punched to obtain a lead frame material, the material to be adhered to can be applied to both sides of the substrate in order to prevent the generation of punching distortion due to different materials adhering to the surface of the substrate. preferable.

Effects of the Invention By the manufacturing method of the present invention, it is possible to efficiently and inexpensively manufacture a striped clad plate that is most suitable for a leash frame material for DIP and QFP.

In addition, the clad plate according to the present invention has a smaller difference in coefficient of thermal expansion with the Cu or Cu bonded plate plastic of the substrate, compared to the conventionally used 42% Ni-Fe alloy, so there is less thermal distortion and It has the advantage that there is little change in adhesion with plastic, and it also has good thermal conductivity, so it has great heat dissipation properties.
Since the Fe alloy containing 30 to 50% i has a thermal expansion coefficient similar to that of the Si chip and has good plating properties, it is possible to obtain an ideal lead frame material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a process explanatory diagram in the longitudinal direction of an alloy strip showing the manufacturing method of the present invention. Here, the case of a striped clad plate in which the adherend material is continuously disposed on the substrate will be described.

In FIG. 1, first, a groove with dimensions almost the same as the cross section of the adherend material is formed in the center of both sides of the unwound Cu alloy strip (1) by rolling with a processing roll (2), or (not shown). is formed by machining.

Thereafter, the alloy strip is annealed in a reducing atmosphere in a heating furnace (3) to perform a cleaning treatment on the surface of the alloy strip.

Furthermore, the part to be coated with the old material to be cold-welded is cleaned by rubbing with a gloss brush (4).

After cleaning the groove, a 30-50% Ni-containing Fe alloy plate (5) to be bonded is inserted into the groove while being returned to the boat, and cold rolled with a pressure roll (6) to complete the bonding.

Then, heat the heating furnace (7) to 'C1600''C~1050.
Diffusion annealing is performed in a temperature range of C to completely bond the Ni-Fe alloy plate in one direction in the center of both sides of the Cu alloy strip (1) to obtain a striped clad plate (8). .

Furthermore, in order to adjust the obtained clad plate to the required shape and shape, cold rolling is performed at least once,
After that, in order to remove the internal strain unevenly remaining in the clad plate, heat treatment is performed at a temperature below 800°C, or while heating at a temperature below 800°C, tension is temporarily applied to the striped clad plate.
Corrections can also be made.

Example While unwinding a Cu alloy plate with a thickness of 0.8 mm and a width of 40 mm, the above C
Groove size 0.15 mm x 15, which approximates the cross-sectional dimension of the 42% Ni-Fe alloy plate as the adherend material, in the center of both sides of the u alloy plate.
．． A groove of 5 mm was formed.

Thereafter, the surface was cleaned after annealing in a reducing atmosphere.

Next, in the groove portion of the Cu alloy plate, a plate thickness of 0. ], 5mmX
A 42% Ni-Fe alloy with a width of 15 mrn was inserted while being unwound, and cold welding was performed using a pressure roll at a reduction rate of 60%.

Thereafter, diffusion annealing was performed at 1000° C. for 3 minutes in an atmosphere of H2 gas or a mixed gas of 20 Fr to obtain a striped clad plate.

The striped clad plate according to the present invention has a thickness of 42 mm on a Cu substrate-4L.
%Ni-Fe alloy is pressure welded, but the thermal expansion coefficient of the pressure welded part (N7.
1.0xlO-6, Cu group 4 is 16-18xl
It was O-6.

On the other hand, the thermal expansion coefficient of the Si chip is 9~l1xlO-6,
The coefficient of thermal expansion of plastic is 16 to 1.8xlO-6 (AF), and it is clear that by using the striped clad plate according to the manufacturing method of this invention, a lead frame material with excellent properties can be obtained. be.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram of the length T-j direction of the alloy strip showing the manufacturing method of the present invention. l...Cu alloy)ir, 2...processing roll, 3...
Heating furnace, 4... Y'Fragi, 5... 30-50%
Ni-containing Fe alloy plate, 6 ridge pressure welding roll, 7... heating furnace, 8 ridge clad plate. 1st piece

Claims (1)

[Claims] 1. In the longitudinal direction of at least one main surface of a substrate made of Cu or a Cu alloy, a groove portion approximately equal to the cross-sectional dimension of the Fe alloy plate containing 30 to 50% Ni, which is the adherend material, is formed continuously or A method of manufacturing a clad plate for a plastic mold, comprising discontinuously forming the clad plate, then inserting the adherend material into the groove, cold-pressing the material, and further diffusion annealing.