JP2614395B2 - Method for producing thin sheet of Fe-Ni-based electronic material having excellent shrink resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thin Fe-Ni-based electronic material sheet having excellent shrinkage resistance, shape characteristics, hardness characteristics and the like, which is useful as an electronic material, especially as a lead frame material for semiconductor devices. .

[0002]

2. Description of the Related Art In recent years, with the development of the electronics industry, IC, L
Demand for semiconductor integrated circuits such as SI has increased significantly,
Therefore, stable supply of a high-quality lead frame, which is an element such as an IC or an LSI, is desired. For example,
In response to multi-pin, fine pitch, flat plastic package (FPP) with outer leads coming out from four directions, especially QFP type lead frames, the shape and dimensional accuracy are becoming more severe. is there.

Under such circumstances, a general method of manufacturing a lead frame includes a method of repeating processing and heat treatment. However, in this method, there is a problem that dimensional change (shrinkage) occurs during heat treatment. Was. On the other hand, under such circumstances, a technique for performing fine processing on a thin electronic material sheet such as a lead frame has been developed, but there is a limit. Accordingly, research and development for further improving the requirements for material properties, thinning, and low heat shrinkage properties have recently been active.

[0004]

In view of the above situation,
The inventors have also found that mainly from the aspect of improving material properties,
We attempted to develop Fe-Ni-based electronic materials that are well suited for lead frame materials. In such research, regarding the problem of "shrinkage" at the time of heat treatment, which was pointed out as a manufacturing problem, the residual strain of the thin plate was reduced by raising the strain relief annealing temperature or taking time. It has been found that reduction can be prevented. However, in this case, there is a new problem that a decrease in the hardness of the material cannot be avoided. Further, the above problem can be solved by increasing the C content of the material, but in this case, there is a problem that ductility is reduced.

[0005] It is an object of the present invention to maintain the basic characteristics of electronic materials, particularly thin plate materials for lead frames,
In particular, Fe- is excellent in shrinkage resistance, shape, and hardness.
It is to establish a new manufacturing technology for Ni-based electronic material thin plates.

[0006]

The above object can be attained by adopting a method of manufacturing a thin sheet of an Fe-Ni-based electronic material as described below. That is, according to the present invention, C: 0.001 to 0.03 wt%, N: 0.01 wt% or less, Si: 0.
01-2.0 wt%, Mn: 0.01-3.0 wt%, Ni: 30-50 wt%,
Electronic material thin plate containing Cr: 0.01 to 1.0 wt% or less, S: 0.01 wt% or less, and the balance being Fe and unavoidable impurities (No. 1
Invention), or B: 0.0005
Electronic material thin plate containing ~ 0.02wt% (third invention)
Is recrystallized and annealed at 720 to 950 ° C, and cold rolled to a rolling reduction of 20 wt% or more to a thickness of 0.3 mm or less.
This is a method for producing a thin Fe—Ni-based electronic material sheet having excellent shrink resistance, which is characterized by performing tension annealing performed at 650 to 800 ° C. for 10 seconds or more under a tension of 8.0 kgf / mm ² .

Further, the present invention relates to an alloy having the above component composition, wherein Nb ≦ 2.0 wt%, Zr ≦ 0.4 wt%, and Co ≦ 4.0 wt%.
wt%, Cu ≦ 4.0 wt%, Ti ≦ 1.0 wt%, Al ≦ 1.0 wt%, Be
≦ 0.5 wt%, V ≦ 4.0 wt%, Ta ≦ 2.0 wt% and Hf ≦ 2.
An electronic material thin plate containing at least one element selected from 0 wt% or two or more elements in a total amount of ≦ 4.0 wt% is subject to the present invention even if the above-described treatment is performed. It is effective in suppressing heat shrinkage (shrinkage) (second and fourth inventions).

[0008]

The reasons for limiting the component composition of the electronic material according to the present invention and the reasons for specifying the manufacturing conditions will be described below. (1) The reasons for limiting the composition of each component are as follows. C: 0.001 to 0.03 wt%; C is an element that suppresses thermal shrinkage of the material by fixing dislocations and contributes to strengthening the material by solid solution and work hardening. In particular, to ensure a heat shrinkage of 20 µm / 100 mm or less and a hardness of 190 Hv or more, 0.001 wt
%. On the other hand, too much Fe-Ni
The upper limit is limited to less than 0.03% by weight, since the low thermal expansion characteristic of the base alloy is impaired, and the ductility is lowered to significantly deteriorate the coining workability required for the lead frame.

N: 0.01 wt% or less; N has the same function and effect as C, but in an alloy based on B addition (third and fourth invention examples), it easily bonds with B to form BN. Therefore, the effective B amount decreases. Also, if this BN is contained in a large amount in the alloy, it has an adverse effect. Further, if this N is too large, a large amount of nitride precipitates, and the toughness and the punching property deteriorate. Therefore, considering such effects, this N is
It contains 0.01wt% as the upper limit.

Si: 0.01 to 2.0 wt%; Si is an element added as a deoxidizing agent at the time of alloy refining, and 0.01 wt% or more is necessary. However, if the content exceeds 2.0 wt%, the hot workability deteriorates, so the content is limited to 0.01 to 2.0 wt%.

Mn: 0.01 to 3.0 wt%; Mn is used as a deoxidizing agent in refining and 0.01% as a solid solution strengthening component.
It is necessary to add more than wt%. On the other hand, if the content exceeds 3.0 wt%, the deoxidizing effect is saturated and the cost is disadvantageous. On the other hand, if this Mn is increased, there is also a manufacturing problem that the hot workability at the time of manufacturing is essentially lowered. Therefore, the content is limited to 0.01 to 3.0 wt%.

[0012] Ni: 30 ~50wt%; Ni is martensite is formed in annealed condition and less than 30 wt%, magnetic properties, thermal expansion, strength, since undesirable since other physical properties are impaired, 30 wt % Or more is required. However, if this Ni content exceeds 50 wt%, the toughness is deteriorated, the saturation magnetic flux density is reduced, the electric resistance is reduced, the thermal expansion is increased, and the square characteristic of hysteresis loss is unfavorably deteriorated. Since it is disadvantageous in terms of cost, the upper limit is set to 50 wt%.

Cr: 0.01 to 1.0 wt%; Cr is effective to reduce the 0.2 wt% proof stress to improve press formability, and also has the effect of suppressing heat shrinkage. Let it. However, if the amount exceeds 1 wt%, the coefficient of thermal expansion becomes too large, so the amount is limited to 0.01 to 1.0 wt%.

B: 0.0005 to 0.02 wt%; B is an element effective for improving hot workability, and therefore, it is necessary to add 0.0005 wt% for this purpose. On the other hand, if it exceeds 0.02 wt%, a large amount of boron compound will precipitate, and the hot workability and the toughness of the material will deteriorate.
Limited to ~ 0.02 wt%.

S: 0.01 wt% or less; If S exceeds 0.01 wt%, hot workability is impaired, so the upper limit was made 0.01 wt%.

In addition to the basic component composition described above, the present invention further comprises Nb ≦ 2.0 wt%, Zr ≦ 0.4 wt%, Co ≦ 4.0 wt%
%, Cu ≦ 4.0 wt%, Ti ≦ 1.0 wt%, Al ≦ 1.0 wt%, Be ≦
At least one or two or more elements selected from 0.5 wt% are added in a total amount of 4.0 wt% or less.

These elements have a common effect of improving the strength further by the solid solution strengthening action and the aging effect, and suppressing the heat shrinkage of the material by fixing the dislocations. On the other hand, if the amounts of these elements are too large, not only will the cost rise, but also the toughness and weldability will decrease.

(2) Next, the manufacturing conditions according to the method of the present invention will be described below. a. Recrystallization annealing (720 to 950 ° C.); In the present invention, the thin material of the electronic material according to the above-mentioned composition is recrystallized and annealed at 720 to 950 ° C. to recrystallize the material, thereby obtaining a crystal grain size of 9 The above fine particles are obtained. The refinement of the crystal grain size improves the toughness and strength of the material. In this process, recrystallization does not take place at temperatures below 720 ° C. On the other hand, 950 ℃
If it exceeds 70, it will be difficult to obtain uniform fine particles.
Limit to 0-950 ° C.

B. Cold working (reduction rate: 20% or more); By performing cold working with a reduction rate of 20% or more in cold working,
The result is that the hardness does not decrease even after the strain relief annealing.

C. Strain relief annealing (tension annealing) This is performed at 650 to 800 ° C. for 10 seconds or more and 0.3 to 8.0 kgf / m
This is a heat treatment performed under a tension of m ² . In the present invention, the above material is heated at 650-800 ° C. for 10 seconds or more and 0.3-8.0 kgf / m
When the strain relief annealing is performed under the tension of m ² , the residual strain generated during the cold rolling can be reduced, and at the same time, the shape of the sheet can be corrected. Therefore, "shrinkage" of the material can be effectively suppressed through reduction of the residual compressive stress in the rolling direction, which is the main cause of the heat shrinkage of the material. In addition, the spring limit value (K
Effective improvement of toughness can be obtained together with b).
By the way, since such effects cannot be sufficiently recovered at an annealing temperature of less than 650 ° C., there is no effect in suppressing shrinkage. On the other hand, if the annealing temperature exceeds 800 ° C., the hardness of the material is significantly reduced. If the tension is less than 0.3 kgf / mm ² , the plate shape cannot be corrected and the residual compressive stress in the rolling direction cannot be sufficiently reduced. On the other hand, this tension is 8.0k
If it exceeds gf / mm ² , large plastic deformation occurs, making stable operation difficult. If the heating time is less than 10 seconds, the material does not recover sufficiently, so that there is no effect in suppressing "shrinkage".

[0021]

EXAMPLES Ingots were prepared by melting materials having the component compositions shown in Table 1 in an air induction furnace. Next, the ingot is hot forged at 1000 to 1280 ° C., heated to 720 to 950 ° C., and then air-cooled for recrystallization annealing.
% Cold rolling was repeated 1 to several times. Table 2 shows the manufacturing conditions at this time. Thus, a thin plate having a thickness of 0.15 mm was obtained. The shape of this plate and the change in the material length before and after heating at 650 ° C. for 10 minutes were measured. Table 2 also shows the results. Table 1 shows examples of chemical components compatible with the material of the present invention and scientific components of comparative materials. Table 2
Table 1 shows the examples of the material of the present invention listed in Table 1 and the heat shrinkage. As can be seen from Table 2, it can be seen that the heat shrinkage was sufficiently suppressed in the example of the present invention.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

As described above, after recrystallization annealing at 720 to 950 ° C., cold rolling is performed at a rolling reduction of 20% by weight or more.
0.3 mm or less, at 650-800 ° C for 10 seconds or more
By performing the strain relief annealing with a tension of 0.3 to 8.0 kgf / mm ^2, a thin plate for electronic materials having improved hardness and excellent punching characteristics can be obtained. In particular, it has become possible to realize a low heat shrinkage material necessary for maintaining the plate shape and coining workability. Therefore, according to the method of the present invention, it is possible to manufacture a thin plate for an electronic material that is always suitable as a lead frame material with high dimensional accuracy.

Continuation of the front page (72) Inventor Saito Fujiwara 4-2 Kojima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Pref. Nippon Yakin Kogyo Co., Ltd. Research and Development Division Technology Research Laboratory (56) References A) JP-A-62-290828 (JP, A)

Claims (4)

(57) [Claims] C: 0.001 to 0.03 wt%, N: 0.01 wt% or less, Si: 0.01 to 2.0 wt%, Mn: 0.01 to 3.0 wt%, N
i: 30-50 wt%, Cr: 0.01-1.0 wt%, S: 0.0
A thin plate containing 1 wt% or less and composed of the balance of Fe and unavoidable impurities is subjected to recrystallization annealing at a temperature of 720 to 950 ° C, and cold-rolled at a rolling reduction of 20 wt% or more to 0.3 m
the following thickness m, then the tension of a 0.3 ~8.0kgf / mm ^2, and performs a stress relief annealing of 650 to 800 ° C. -10 seconds or more conditions, excellent耐縮viewed properties such as Fe −Ni
Method of manufacturing electronic material thin plate. 2. C: 0.001 to 0.03 wt%, N: 0.01 wt% or less, Si: 0.01 to 2.0 wt%, Mn: 0.01 to 3.0 wt%, N
i: 30-50 wt%, Cr: 0.01-1.0 wt%, S: 0.0
1 wt% or less, Nb ≦ 2.0 wt%, Zr ≦ 0.4 w
t%, Co ≦ 4.0 wt%, Cu ≦ 4.0 wt%, Ti ≦ 1.0 wt
%, Al ≦ 1.0 wt%, Be ≦ 0.5 wt%, V ≦ 4.0 wt%,
A sheet containing at least 4.0 wt% of one or more elements selected from Ta ≦ 2.0 wt% and Hf ≦ 2.0 wt%, and a balance of Fe and unavoidable impurities,
Perform recrystallization annealing at a temperature of 720 to 950 ° C, cold-roll at a rolling reduction of 20 wt% or more to a sheet thickness of 0.3 mm or less,
Thereafter, the tension of a 0.3 ~8.0kgf / mm ^2, 650 ~80
A method for producing a Fe—Ni-based electronic material thin plate having excellent shrinkage resistance characteristics, wherein the strain relief annealing is performed at 0 ° C. for 10 seconds or more. 3. C: 0.001 to 0.03 wt%, N: 0.01 wt% or less, Si: 0.01 to 2.0 wt%, Mn: 0.01 to 3.0 wt%, N
i: 30 to 50 wt%, Cr: 0.01 to 1.0 wt%, B: 0.0
005-0.02wt%, S: 0.01wt% or less, balance Fe
And a thin plate composed of unavoidable impurities
Recrystallization annealing at a temperature of 0 ° C, cold rolling at a rolling reduction of 20 wt% or more to a thickness of 0.3 mm or less,
In the tension of a ^{0.3 ~8.0kgf / mm 2, 650 ~800} ℃ -10
A method for producing a thin Fe-Ni-based electronic material sheet having excellent shrinkage resistance characteristics, wherein the strain relief annealing is performed for a period of at least one second. 4. C: 0.001 to 0.03 wt%, N: 0.01 wt% or less, Si: 0.01 to 2.0 wt%, Mn: 0.01 to 3.0 wt%, N
i: 30 to 50 wt%, Cr: 0.01 to 1.0 wt%, B: 0.0
005-0.02wt%, S: 0.01wt% or less
b ≦ 2.0 wt%, Zr ≦ 0.4 wt%, Co ≦ 4.0 wt%, Cu ≦
4.0 wt%, Ti ≦ 1.0 wt%, Al ≦ 1.0 wt% Be ≦ 0.5 wt
%, V ≤ 4.0 wt%, Ta ≤ 2.0 wt% and Hf ≤ 2.0 wt%
A sheet containing at least one element selected from the group consisting of at least one element selected from the group consisting of 4.0 wt% or less, and the balance of Fe and unavoidable impurities, is subjected to recrystallization annealing at a temperature of 720 to 950 ° C. Cold rolling at a rolling reduction of 20 wt% or more
The following thickness 3 mm, then the tension of a 0.3 ~8.0kgf / mm ^2, and performs a stress relief annealing conditions above 650 to 800 ° C. -10 seconds, excellent耐縮viewed properties such as Fe −
Manufacturing method of Ni-based electronic material thin plate.