| 摘要 |
<p>PURPOSE:To make it possible to utilize flat surfaces of metal balls and a land surface for mutual fusion bonding of base members, secure the wide area for fusion bonding, and increase fusion bonding strength, by a method wherein piers are formed by shaping metal balls buried in machining holes so as to be flat along a land surface. CONSTITUTION:Machining holes 4a turning to piars are formed in a copper-clad laminated board 1. A wiring pattern 6 and a land (l) of each layer base member 3 are formed, by patterning and etching, and further, in case of need, by performing nonelectrolytic plating or electroplating. Metal balls 11 are buried in the machining holes 4a. In this case, a guide plate 20 provided with a drop ping holes 21 formed at positions corresponding with the positions of the holes 4a is arranged. A lot of balls 11 arranged on the guide plate 20 are rolled and inserted in the holes 4a. After that, the balls 11 are pressed vertically by using a compressing machine or the like, and flat planes having a suitable height are formed along the surface and the rear of the base member 3. Low melting point solder paste S like Au-Sn is spread on the upper and the lower surfaces of the balls 11. After the paste is once fused and hardened, each base member 3 is stuck by using a spacer.</p> |
