RU1494376C - Method of diffusion welding of semiconductors or metals with alkaline glasses - Google Patents

Abstract

FIELD: pressure welding. SUBSTANCE: in order to make products, containing semiconductor or metallic plates, between which a layer of alkaline glass is arranged, the diffusion welding method is being performed by two stages. At the first stage layer of the alkaline glass is being welded with the first layer of the semiconductor or the metal by applying to the glass a negative electric potential and to the semiconductor a positive electric potential. A the second stage a layer, oversaturated by alkaline elements, is being removed off a free glass surface and a second layer of the semiconductor or the metal is being welded to it. EFFECT: enhanced quality of welded joint due to elimination of oxides on surface of the glass, being welded, upon making laminate products. 1 cl

Description

 The invention relates to pressure welding with heating, in particular to diffusion welding, and can be used in enterprises of electronic, aviation and other industries.

 The purpose of the invention is to improve the quality of the connection by eliminating oxides on the glass surface being welded in the manufacture of laminated products.

 The method is as follows.

 Semiconductor or metal parts are placed in contact with an alkaline glass part and placed in a welding chamber. Then, a positive electric potential is applied to the semiconductor or metal part, and negative to the alkaline glass part. The parts are heated to a welding temperature and isothermal exposure is carried out. After welding, the parts are cooled, a layer saturated with alkaline elements is removed from the free surface of the glass, a second part made of semiconductor or metal is placed in contact with it, and the negative electric potential is left on the glass, heated to the welding temperature and isothermal exposure is carried out. After welding, the resulting multilayer product is cooled and removed from the welding chamber. At the time of applying the electric potential due to migration polarization, a depleted Na layer is formed at the positive electrode. The field is concentrated on the boundary of the positive glass electrode. Positively charged Na ions exit to the negative electrode and neutralize on the glass surface, forming on it a layer of alkali metals and their oxides, a glass layer oversaturated with alkali metals. Removal of this layer helps to obtain a high-quality compound during further welding of the second layer of a semiconductor or metal.

 PRI me R. Diffusion welding is performed in the electrostatic field of single-crystal silicon disks with a thickness of 0.2 mm, a diameter of 8.0 mm, and Pyrex glass in the form of disks with a diameter of 8.0 mm and a thickness of 0.4 mm located between silicon disks. Silicon is treated in grade 14, glass in grade 12.

 Optimum mode: welding temperature T 680 K, voltage U 400 V.

 In the first stage, two discs are welded. A positive electric potential is applied to the silicon disk, and negative to the glass disk. Isothermal exposure is carried out for 10 minutes under pressure. After welding, a layer saturated with alkaline elements with a thickness of at least 2 μm is ground off from the free surface of the glass. Then a second semiconductor disk is placed on it and it is welded with glass similarly to the welding of the first disk. After welding, the resulting multilayer product is cooled and subjected to mechanical tests, which show an increase in bond strength.

Claims (1)

 METHOD FOR DIFFUSION WELDING OF SEMICONDUCTORS OR METALS WITH ALKALI GLASSES, in which the parts are squeezed, a positive electric potential is applied to the semiconductor or metal, and negative is applied to the glass and isothermal exposure is carried out, characterized in that, in order to improve the quality of compounds of alkali metals by eliminating the glass surface being welded in the manufacture of multilayer products, a layer saturated with alkaline elements is removed from the free surface of the glass.