JPS62149433A - Copper clad molybdenum plate and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a copper (Cu) clad molybdenum (Mo) board and a method for manufacturing the same, and more specifically, the present invention relates to a copper (Cu) clad molybdenum (Mo) board and a method for manufacturing the same. Moreover, the present invention relates to a Cu-clad Mo plate whose Cu has few surface defects such as "bulges" and a novel manufacturing method thereof.

[Technical Background of the Invention and Problems thereof] A Mo plate clad with Cu on one or both sides is used as a semiconductor substrate for manufacturing various types of filtering elements.

In this Cu-clad Mo board, a Cu plating film is formed with a predetermined thickness on one or both sides of a Mo board that is a substrate, for example.

However, in the case of this method, the plated plate obtained is M
The bonding strength at the interface between the o-plane and the Cu plane is not so great, and an unexpected external force may cause the two to peel off during handling or use. Furthermore, during the formation of the Cu plating film, oxides may be included between the MO surface and the Cu plating film depending on the applied electric IW conditions, and as a result, the Cu plating layer may have some "bulges". This may not only reduce the bonding strength but also cause surface defects in the Cu plating layer.

The above-mentioned problem also occurs when Cu foil is used in place of the Cu plating film, and a solution to this problem is strongly desired.

[Object of the invention] The present invention has been made in order to meet the above requirements, and
Cu-clad M has high bonding strength between Mo and Cu, and the Cu-clad film has few surface defects such as bulges.
The purpose is to provide an o-board and its manufacturing method.

[Summary of the Invention] In the course of intensive research to achieve the above object, the present inventors discovered that the bonding strength between MO and Cu is affected by the degree of mutual solid solution between them during hot press bonding. Furthermore, it was confirmed that the surface defects of the Cu clad film were caused by the dissociation of oxides during hot press bonding. Therefore, it is believed that the above problems can be solved by interposing an intermediate layer between MO and Cu that has excellent mutual solid solubility for both, and by performing hot pressing and mutual diffusion treatment in the absence of oxides. As a result of carrying out various experiments with the idea of We have developed a clad plate and its manufacturing method.

That is, the configuration of the Cu-clad Mo plate of the present invention is M
It is characterized in that the o'l board and Cu are bonded via a Ni layer, and the manufacturing method thereof is to laminate Cu on at least one or both sides of a Mo substrate via a Ni layer, and then laminate it in a non-oxidizing atmosphere. Step of hot-pressing to form a laminate; heat-treating the obtained laminate in a non-oxidizing atmosphere to obtain M.

It is characterized by comprising the following steps: performing a diffusion treatment on each interface between the substrate and the Ni layer, and between the Cu and Ni layers; and performing a rolling treatment on the obtained diffusion-treated laminate.

The clad plate of the present invention consists of a M o Q'^ plate, a Cu foil clad on one or both sides of the plate, and a Ni layer located between the two. 41 There is an interdiffused layer and at the same time the surface of the Cu foil! This is a laminate in which these mutual diffusion layers exist at the interface with the Ji layer.

This clad plate can be manufactured through the following steps.

The first step is to laminate a Mo substrate, a Ni intermediate layer, and a Cu foil (for example, oxygen-free Cu) in this order, and to integrate the resulting laminate by hot pressing in a reducing atmosphere.

In this case, the Cu foil to be applied to the Mo substrate is preferably composed of oxygen-free copper, since the presence of oxygen has an adverse effect on the clad plate as described above. Examples of the Ni intermediate layer interposed between the Mo substrate and the Cu foil include a Ni foil and a Ni plating film. The thickness of these layers is not particularly limited, but since this intermediate layer should function as a medium for bonding Mo and Cu, it is usually about 1 to 50% of the thickness of the Cu foil. Set.

Since the lamination operation of these three layers is carried out in the atmosphere, naturally air (oxygen) will be present between each layer, but this means that all the steps described below are carried out in a non-oxidizing atmosphere. This eliminates the disadvantages of air intervention.

The temperature during thermocompression bonding of the laminate needs to be lower than the melting temperature of Cu, but if the temperature is too low,
Each layer is rigid, and no temporary improvement in the bonding effect due to pressure bonding is observed. Usually the temperature is 350~toooo
Preferably, it is in the range of °C.

The atmosphere needs to be a non-oxidizing atmosphere in which each layer is not oxidized, and specifically, a hydrogen atmosphere is preferable.

The second step is a step of subjecting the laminate obtained in the first step to a diffusion treatment. The bonding between the interfaces of each layer in the first step is simple. This is a mechanical bonding process, but in this step it is transformed into a diffusion table.

That is, the contact interface between the Mo substrate and the Ni[] layer, the Ni
Diffusion bond the contact interface between the intermediate layer and Cum and these two interfaces. MO and Cu, which do not cause interdiffusion, are bonded through Ni 17, which interdiffuses with both Mo and Cu.

Specifically, the laminate may be held in a reducing atmosphere at a predetermined temperature. It is preferable that the atmosphere is, for example, a hydrogen atmosphere.If the temperature is too low, the diffusion reaction between each interface will not proceed effectively and the clay effect on the bonding strength will be small;
If the temperature exceeds 080°C, the Cu foil will melt. Usually 3
50~tooo℃, preferably 6 (l 0~950℃
It is.

Also, if the retention time is too long, the N
All i diffuses into Mo and Cu.

Even in such a state, diffusion bonding between MO and Cu is achieved and the bonding strength is high. However, if the N1 intermediate layer is left to some extent, the overall bonding strength will be stronger. When the temperature is constant, the shorter the retention time, the more the Ni intermediate layer remains (or, conversely, the diffusion of Ni). Therefore, by appropriately changing the holding time, the thickness of the remaining Ni intermediate layer can be changed. Normally, in the case of the above-mentioned temperature, holding time 1) may be 5 minutes or more.

The third step is a step of rolling the diffusion-treated laminate obtained in the second step to a desired thickness.

The rolling operation at this time is not particularly limited,
Common law may be applied as appropriate.

[Embodiments of the invention] Example N1 with a thickness of 0.3 mm on one side of a Mo plate with a thickness of 10 ma+
Foil, oxygen-free Cu foil with a thickness of 1.5 mm is layered one after another,
The whole was heat-pressed and integrated at a temperature of 800°C. The atmosphere was hydrogen. The total thickness was 8 mm.

The obtained laminate was left in a hydrogen furnace at 850°C for 30 minutes to undergo a diffusion treatment, and then rolled with normal rolls to a thickness of 0.
．． A 5 mm clad plate was obtained.

The degree of adhesion between the Mo plate and the surface Cu foil in the obtained clad plate was measured as the number of bends by the method shown in the figure. That is, two pedestals 1a whose corners are 4R,
The cladding plate 2 was sandwiched and crimped between the cladding plates 1 and lb as shown in the figure, and the operation of bending the cladding plate 2 by 90 degrees left and right was repeated, and the number of times of bending until the Cu of the cladding plate 2 peeled off was measured. The results were 3 to 6 times. In addition, the number of times of bending is counted as one bending back and forth.

Further, when the surface state of the surface Cu foil was closely observed, there was no "bulge" at all.

Comparative Example C with a thickness of ll-15Ji was applied to one side of the Mo plate used in the example.
A U-menki film was formed.

When a bending test was carried out on a Mo plate having a Cu coating film in the same manner as in the example, the number of bending errors was 1±0 to 1.6 [Effects of the Invention] As is clear from the above explanation, The Cu-clad Mo board manufactured by the invention method has a high bonding strength between Cu and Mo, and there are no defects such as swelling on the clad Cu surface, so it is easy to handle and use when used as a semiconductor substrate, for example. It has high reliability and is easy to perform, for example, when soldering other components to the Cu surface, and has great industrial value.

[Brief explanation of drawings]

The figure shows Mo in the clamp plate, (plate and clamp, de Cu)
It is a figure for explaining the evaluation method of the degree of adhesion with foil.

Claims (3)

[Claims] (1) A copper-clad molybdenum board characterized in that a molybdenum substrate and copper are bonded via a nickel layer. (2) The copper-clad molybdenum plate according to claim 1, wherein the copper is oxygen-free copper. (3) Step of providing copper via a nickel layer on at least one or both sides of a molybdenum substrate and then subjecting it to hot-pressing treatment in a non-oxidizing atmosphere to form a laminate; a step of performing a diffusion treatment on each interface between the molybdenum substrate and the nickel layer and a copper and nickel layer by heating in the wafer; a step of performing a rolling treatment on the obtained diffusion-treated laminate; Method for manufacturing copper-clad molybdenum plates.