JPS5911659A - Lead material for semiconductor - Google Patents

Abstract

PURPOSE:To provide a Cu alloy with all characteristics required for the lead material for the semiconductor: that is, excellent plating capability, press punchability, radiation, resistance to repeated bending and conductivity and heat resistance by imparting specific quantities of iron, phosphorus and zirconium. CONSTITUTION:The lead material contains 0.10-0.30% Fe, 0.03-0.08% P and 0.005-0.10% Zr, a Fe component improves the heat resistance and strength of the lead material, a P component forms an iron phosphate together with Fe and improves the heat resistance, conductivity and strength of the lead material, and Zr improves the heat resistance of the lead material. A content ratio of Fe%/P% is brought to 3.5-5.5 in order to ensure stably excellent conductivity. Ingots are hot-rolled at a temperature of 850 deg.C, annealing is repeated through a cold rolling process, these materials are held for sixty min at 410- 585 deg.C, cooled with air to execute the heat-treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead material for semiconductors that has excellent plating properties, press punching properties, heat dissipation properties, repeated bending resistance, and conductivity, and also has excellent heat resistance. .

In general, semiconductors such as l-landisk and IC are known, but for example, semiconductors such as IC are (a,)
First, the surface of the Cu alloy strip [Ni, Sn
.

A lead material made of A1 or its alloy with a plating layer formed thereon is prepared.

(b) Form a lead frame conforming to the shape of the semiconductor to be manufactured by press punching from the above lead mass.

(c) Next, high-purity S1 or Ge elements are sequentially placed at predetermined locations on the lead frame at approximately 350 to 500°C.
The above plating layer is bonded by thermocompression at a temperature of .

(d) Connecting the collector and emitter across the element and the lead frame, (θ) and then
The element, the wiring, and the part of the lead frame to which the element is attached are coated with resin. (f) Finally, the interconnected parts of the lead frame are cut out to obtain a semiconductor having an O alloy lead material 5 It is manufactured by the main steps (a) to (f) above.

Therefore, the above-mentioned lead material, which is used as a lead material for semiconductors, has good plating properties and press punching properties, heat resistance that does not cause thermal distortion and thermal softening when semiconductor elements are thermocompression bonded at about 350 to 500°C, and good heat resistance. Heat dissipation and conductivity, as well as repeated bending resistance to prevent damage when transporting semiconductors or incorporating them into electrical equipment, are required.

Conventionally, lead phases for semiconductors developed to meet these requirements include Ou-Sn alloys and C! u -Fe alloys have been proposed, but although these Cu alloys have excellent plating properties, press punching properties, heat dissipation properties, repeated bending resistance, and electrical conductivity, they are inferior in heat resistance, so the above ( c) During thermocompression bonding of semiconductor elements within a temperature range of 350 to 500° C., especially during thermocompression bonding at the high temperature side of the temperature range, thermal softening and thermal distortion noise were likely to occur.

Therefore, from the above-mentioned viewpoint, the present inventors conducted research in order to impart excellent heat resistance to the conventional lead phase without impairing its excellent properties, particularly conductivity, and found that Fe: 0.10-030%.

P: 0.03-0.08%, Zr: 0.00
A Cu alloy with a composition of 5 to 0.10% total content, with the remainder consisting of Cu and unavoidable impurities (the above weight percentages and the following weight percentages) has all the requirements for semiconductor lead stripping. characteristics, that is, excellent plating properties.

They found that it has press punching properties, heat dissipation properties, repeated bending resistance, and electrical conductivity, as well as excellent heat resistance.

This invention has been made based on the above knowledge, and the reason why the entire component composition range is limited to the above general range will be explained below.

(a) Fe The Fe component has the effect of improving the heat resistance and strength of the steel, but if its content is less than 0.10%, the desired effect cannot be obtained; on the other hand, if the content is less than 0.30% If the content exceeds 'z, the conductivity will deteriorate, so the content was determined to be 0.10-0.301'.

(b) p The P component has the effect of forming iron phosphide with Fe to improve the heat resistance, electrical conductivity, and strength of the lead material, but if its content is less than 0.03%, the relative The formation of iron phosphide is small, and the desired effect of improving the above action cannot be obtained. On the other hand, if the content exceeds 0.081 i, excess P will be generated in the relative content with Fe that forms iron phosphide. The content was determined to be 0.03 to 0.08% since Cu dissolves solidly in the base material and lowers the conductivity of the lead strip.

(c) Zr Zr is contained to improve the heat resistance of the lead material, but if the content is less than 0.0051, the desired effect of improving heat resistance cannot be obtained; on the other hand, if the content exceeds 0.10 If it is contained, the conductivity decreases, so the content was determined to be 1o, oos to 010.

Nao, in order to generate the maximum amount of iron phosphide and ensure stable and excellent conductivity in the semiconductor lead fabrication of this invention, the content ratio of Fe (@/P@) must be 35. It is desirable to set it to ~5.5.

This has a content ratio of Fe (%) / P (%) of 3.5
If it is less than 5.5 or more than 5.5, the relative balance between Fe and P will be disrupted when iron phosphide is formed, and the excess Fe or P will become solid solution in the Cu matrix, resulting in poor conductivity of the lead phase. This is because a downward trend appears in the market.

Next, lead removal for semiconductors according to the present invention will be explained using examples and comparing with comparative examples.

Example Using a low-frequency groove-type melting furnace, Cu alloys having the compositions shown in Table 1 were melted and cast by a semi-continuous casting method to a thickness of 150 mm x width of 400 w + 1 x length of 140 mm.
The ingot is made into an ingot with a dimension of 0 mm, and then this ingot is
After hot-rolling at a temperature of 0°C to obtain a hot-rolled plate with a thickness of 10+n+n, the hot-rolled plate was cooled with water, and the upper and lower surfaces of the hot-rolled plate were each coated with 0.2
The plate was side-faced by mm, followed by cold rolling, annealing and rolling were repeated to achieve a plate thickness of 0.25 tam at a finish rolling rate of 30 degrees, and finally after holding this at 410 to 585 °C for 60 minutes, Average grain size i0.010mm after air cooling heat treatment
Plate materials 1 to 5 for reeds of the present invention and comparative reed materials 1 to 3 were manufactured by adjusting the following. Note that Comparative Lead Material Plate Materials 1 to 3 have compositions in which the content of any one of the constituent components (those marked with * in Table 1) is outside the scope of the present invention.

Next, the resulting reed-using board materials 1 to 5 of the present invention
And for comparative lead utilization pseudophases 1 to 3, tensile strength,
The yield strength, elongation, conductivity, and softening temperature were measured. The measurement results are also shown in Table 1.

As shown in Table 1, plate materials 1 to 5 for lead materials of the present invention
All of these have the characteristics required for semiconductor lead stripping, and are particularly excellent in conductivity and heat resistance, but the P content is outside the scope of the present invention, and Comparative lead material 1, which does not contain lead material 1, has inferior conductivity and heat resistance, and also has a large content of P and Zr, which is out of the range of the present invention. Although No. 3 exhibits excellent surface J thermal properties, it has low conductivity and does not have a conductivity of 90% lAC3 or more required for this type of semiconductor lead material.

As mentioned above, the semiconductor lead material of the present invention has excellent conductivity with a conductivity of 90%lAC3 or more, and is completely free from thermal distortion and thermal softening during thermocompression bonding of semiconductor elements. It has excellent heat resistance and all other properties required of semiconductor lead materials.

Applicant 6. Tamagawa Machinery & Metals Co., Ltd.

Claims (1)

[Claims] Fe: 0.10~0.30%, P: 0.03~
0.08%. A lead material for a semiconductor, characterized in that it contains Zr: 0.005 to 0.10'Iy, and the remainder is Cu and unavoidable impurities, and has a composition C or higher (by weight).