JP4477977B2 - Method for producing Au-Sn alloy clad material - Google Patents

Description

  The present invention relates to a method for producing a clad material used as a sealing material for sealing an electronic component protection package, and indirectly heats an Au—Sn alloy plate material and a composite plate material made of Au / Ni / Kovar / Ni / Au. The present invention relates to a method for manufacturing a clad material that is clad through an Au layer while being heated by heating.

As a manufacturing method of the clad material used for the sealing material 102 for sealing the electronic component protection package 101 as shown in FIGS. 5 and 6, for example, an Au-based plate material 103 such as Au—Sn is used as shown in FIG. The base material 104 such as the above is overlapped and pressed between the lower die 105 and the upper die 106 and fixed, and heated in an electric furnace in that state to fuse the above two materials into a clad material (for example, (See Patent Document 1 and Patent Document 2).
JP 2000-31313 A Japanese Patent No. 3462392

  However, in the above-described conventional technology, the Au-based plate material such as Au-Sn and the base material of the Kovar composite material are overlay type clad materials, and this clad material is an Au-Sn alloy plate material constituting the clad material. Since the expansion coefficient α1 and the expansion coefficient α2 of the Kovar composite material are α1> α2, the warpage in the width direction of the clad material is large as shown in FIG. 2 due to the expansion during the clad processing by indirect heating and the shrinkage after the clad processing. When this is used as a material and a sealing material is formed by die pressing with a press, there is a problem that warping is large and the sealing material has poor sealing properties. Therefore, it must be placed in the electric furnace while being pressed and fixed with the lower mold and the upper mold and heat-fused to reduce deformation, and it must be housed in the electric furnace in an abnormally large state. A large furnace was required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cladding means that reduces warpage during cladding processing.

In the manufacturing method of the clad material of the Au—Sn alloy plate material and the base material of the composite plate material made of Au / Ni / Kovar / Ni / Au, the Au / Ni / Kovar / Ni / The width W2 of the base material of the composite plate material made of Au satisfies W2 / W1 ≦ 1.2 and satisfies W2-W1 ≧ W2 × 0.1, and the Au—Sn alloy plate material is Au / Ni / Kovar / in the width direction. The clad process is performed by being positioned at the center of the Ni / Au base material .

The base material requires an Au layer on the clad surface with the Au—Sn alloy plate material, but the surface other than the clad surface may not have an Au layer, and Au / Ni / Kovar / Ni A composite plate material may be used.
Further, the both side portions sandwiching the Au—Sn alloy plate material may be a composite plate material made of Ni / Kovar / Ni.

As a result, the present invention can obtain an Au—Sn alloy clad material with less warpage and less influence of deformation on expansion and contraction after processing. Thus, when used as a sealing material for a semiconductor package obtained by die cutting from this clad material, it becomes a material that does not cause defects due to warpage.
This is because Au / Ni / Kovar / Ni / Au or Ni / Kovar / Ni having a lower expansion coefficient than the central Au—Sn alloy plate material is arranged on both sides in the plate width direction of the clad material. The inventors have found that the warpage of the alloy plate material is less than that of the plate material clad with the overlay, and actually obtained the effect.

  In addition, in the manufacturing process, when provided as a long material, both side portions can be used as a guide during press working for die-cutting the sealing material, and the product quality can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
A plate 1 having a plate width of 50 mm and a plate thickness of 0.05 mm is made as a plate made of 80% Au—Sn.
A substrate 2 made of Au / Ni / Kovar / Ni / Au and having a plate width of 60 mm and a plate thickness of 0.2 mm is produced.

As shown in FIG. 1, the 80% Au—Sn plate material 1 is overlapped as shown in FIG. 2 and rolled by indirect heating so as to pass through the center of the Au / Ni / Kovar / Ni / Au substrate 2. A clad material having an 80% Au—Sn width of 50 mm, a total plate width of 60 mm, and a plate thickness of 0.1 mm was obtained.
Note that the 80% Au—Sn plate material and the Au / Ni / Kovar / Ni / Au base material are not as thick as described above, but are thicker, and as shown in FIG. 3, Au / Ni / Kovar / When it is possible to form a groove in the Ni / Au base material, a groove having a predetermined depth is formed, and an 80% Au—Sn plate is fitted in the groove, and rolling is performed by indirect heating as described above. Then, clad processing may be performed, and thereby the dimensional accuracy of the clad can be increased. When importance is attached to the bonding strength, the overlapping method shown in FIG. 2 is preferable.

For comparison, a plate material 1 made of 80% Au—Sn with a plate width of 60 mm and a plate thickness of 0.05 mm and a composite substrate 2 made of Au / Ni / Kovar / Ni / Au with a plate width of 60 mm and a plate thickness of 0.2 mm. And overlaying to form an integral, and clad by indirect heating to obtain an overlay clad material having a total plate width of 60 mm and a plate thickness of 0.1 mm.
The product of the example obtained in this way was compared with the product of the comparative example of the prior art with the degree of warpage S.

  Furthermore, each of the example and the comparative example was subjected to press processing on the shape of the sealing material of the electronic component package, mounted on the electronic component package, and compared with the number of defective sealing properties. These results are shown in Table 1.

Explanatory drawing which shows an Example Explanatory drawing of the state where the plate and base material are stacked Explanatory drawing of the state where the plate and base material are stacked Explanatory drawing showing a conventional example as a comparative example Perspective view of electronic component package Cross-sectional explanatory drawing of electronic component package Explanatory drawing of manufacturing method of clad material showing conventional example

Explanation of symbols

1 Plate material made of 80% Au-Sn 2 Base material made of Au / Ni / Kovar / Ni / Au

Claims (2)

In a method for producing a clad material of an Au—Sn alloy plate material and a base material of a composite plate material made of Au / Ni / Kovar / Ni / Au,
The width W2 of the base material of the composite plate material made of Au / Ni / Kovar / Ni / Au is W2 / W1 ≦ 1.2 and W2−W1 ≧ W2 × 0. A method for producing an Au—Sn alloy clad material, characterized in that an Au—Sn alloy plate material is placed in the center of an Au / Ni / Kovar / Ni / Au base material in the width direction and is clad. 2. The method for producing an Au—Sn alloy clad material according to claim 1, wherein the base material is Au / Ni / Kovar / Ni.