JP2895549B2 - Materials for electronic components with excellent solder adhesion - Google Patents

Description

The present invention relates to an electronic component material having excellent electrical conductivity and solder adhesion.

[Prior Art] In the assembly of electronic equipment, soldering in joining and assembling electronic components and electronic circuits is one of the important techniques. This is because the adhesiveness between the outer leads of ICs and transistors and the solder ultimately determines the quality of electronic products.

2. Description of the Related Art Conventionally, tin-deoxidized copper or the like has been used as a material for electronic components such as lead frames of ICs and transistors, since conductivity is required.

However, tin-deoxidized copper has a problem in solder adhesion that a void is generated between the base material and the alloy layer for more than 500 hours when heated at 150 ° C. and the solder is separated.

Therefore, it is desired to use a material which does not peel off the solder even when heated at 150 ° C. for up to 1000 hours and has excellent solder adhesion. Several materials with improved solder adhesion have been provided, but attempts to improve solder adhesion have resulted in a decrease in electrical conductivity, which is important for electronic component materials.
There is no Cu alloy-based electronic component material having a conductivity of not less than% IACS and also having excellent solder adhesion.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems of the conventionally used tin deoxidized copper, and has been made as a result of intensive studies and studies by the present inventors. The object of the present invention is to provide a material for electronic parts which does not peel off even after heating for 1000 hours and has excellent electrical conductivity of 85% IACS or more and excellent solder adhesion.

[Means for Solving the Problems] The electronic component material of the present invention contains Zn: 0.01 to 0.1 wt% (but not including 0.1 wt%) and P: 0.01 to 0.1 wt%. It is characterized by the balance consisting of Cu and unavoidable impurities.

The electronic component material of the present invention has a Zn content of 0.01 to 0.1 wt% (however,
0.1% by weight), P: 0.01 to 0.1% by weight, Sn: 0.01 to 0.20% by weight, Ag: 0.01 to 0.20% by weight, Cu: 0.01 to 0.20% by weight, or It is characterized in that it contains two or more kinds and the balance consists of Cu and unavoidable impurities.

[Operation] The operation of the electronic component material having excellent solder adhesion according to the present invention will be clarified by explaining the reasons for limiting the components.

Zn significantly improves solder adhesion. Its effect is 0.
Less than 01 wt% is not sufficient, and more than 0.1 wt% lowers the conductivity.

 P has a deoxidizing effect.

Sn, Ag and Cr improve the strength. One or more of these are contained.

Sn remarkably improves strength by forming a solid solution.
The effect is not sufficient when the content is less than 0.01 wt%, and when the content exceeds 0.20 wt%, the electric conductivity is reduced.

Ag improves the strength and heat resistance by forming a solid solution. The effect is not enough if less than 0.01wt%, 0.20wt%
If it is contained in excess of%, the cost will increase.

Cr improves strength and heat resistance, but its effect is 0.01%.
If the content is less than wt%, it is not sufficient. If the content exceeds 0.20 wt%, the conductivity will be reduced, and lumping in the air will not be possible.

EXAMPLES The present invention will be described in detail with reference to examples.

The copper alloys having the components and content ratios shown in Table 1 were melted under a charcoal coating in the air in a crypt furnace and cast to form an ingot having a thickness of 50 mm, a width of 80 mm and a length of 180 mm.

The surface and back of the ingot are chamfered and the thickness is 10mm at 880 ℃
It was hot rolled and cooled in water.

Next, after removing the oxide scale, cold rolling is performed to obtain a thickness.
After finishing to 0.5 mm, heat treatment was performed at a temperature of 500 ° C. for 2 hours.

Next, after pickling and polishing, cold-rolled, the final sheet thickness 0.25mm
Was made.

The following tests were performed using the above-mentioned plate materials as test materials.

(Electrical Conductivity) The electrical conductivity was measured using a test piece of 10 ^W × 300 ^L by a double bridge, and calculated by the average sectional area method.

(Solder Adhesion) The change over time in solder adhesion was evaluated by the following two methods.

Two specimens with a thickness of 0.25 mm as shown in Fig.
The solder was joined so that the thickness of the solder was 0.3 mm and the solder area was 10 mm × 10 mm.

Next, as shown in FIG. 2, a tensile test was performed using the test piece, and the work required for the peeling of the solder was calculated from a load (solder peeling strength) -displacement curve obtained thereby.

Next, the work required for peeling the solder per unit area was obtained by dividing the work by the solder bonding area.

The soldered test piece was bent at a constant bending radius of 180 degrees and then returned to its original state. Pass / fail was determined by observing the cross section.

(Tensile strength) A tensile test was performed based on JISZ 2241.

 The above results are shown in Tables 2, 3 and 3.

As is evident from Table 2, all of the alloys Nos. 1 to 13 of the present invention satisfy an electrical conductivity of 85% IACS or more and show excellent strength. In particular, No.2-4, No.8-1 containing Sn, Ag, Cr
3 was even stronger.

As is clear from Table 3 and FIG.
In Nos. 13 to 13, the work required for the peeling of the solder did not decrease even after heating at 150 ° C. for 1000 hours, and the peeling of the solder did not occur.

However, in Comparative Alloy No. 21, the work required for the peeling of the solder was 0, and the peeling of the solder occurred. Comparative alloys Nos. 22 to 27 having compositions outside the range of the present invention are inferior in any of solder adhesion, strength, and electrical conductivity.

[Effects of the Invention] As is clear from the above description, according to the present invention, 85
It has a high electrical conductivity of not less than% IACS, and is excellent in solder adhesion as compared with tin deoxidized copper, and can provide a highly reliable material for electronic components as a material for ICs and transistors. To play.

[Brief description of the drawings]

FIG. 1 is a measurement showing the shape of a test piece. FIG. 2 is a graph showing how to determine the amount of work required for solder peeling. Third
The figure is a graph showing the amount of work required for solder peeling per unit area.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-140343 (JP, A) JP-A-62-9630 (JP, A) JP-A-1-225781 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) C22C 9/00-9/10 H05K 1/09 H01L 23/48-23/50

Claims (2)

(57) [Claims] (1) Zn: 0.01 to 0.1 wt% (but not including 0.1 wt%), P: 0.01 to 0.1 wt%, the balance being Cu and unavoidable impurities; A material for electronic components with excellent solder adhesion of not less than% IACS. 2. Zn: 0.01 to 0.1 wt% (excluding 0.1 wt%), P: 0.01 to 0.1 wt%, Sn: 0.01 to 0.20 wt%, Ag: 0.01 to 0.20 wt% %, Cr: 0.01 to 0.20 wt%, and the balance is composed of Cu and inevitable impurities. The conductivity is 85% IACS or more. Materials for parts.