Fill the hole with silver paste

- Oct 20, 2018-

For the through-hole of double-sided printed circuit board, the connection of two-sided circuit is realized without copper plating, but the method of filling the through-hole with silver paste can also reduce the cost of double-sided printed circuit board.The detailed process is shown in FIG. 4.88.This method is commonly used in common phenolic resin board with copper on both sides.The method firstly cleans the surface of the common phenolic resin board with copper on both sides, and then prints the corrosion resistant pattern on both sides with screen printing. After the corrosion, the conductor figure is formed. After removing the corrosion resistant layer, the hole is drilled through, and then the silver paste is filled into the hole.In order for the silver paste to be in good contact with the conductor figure on both sides, the silver paste should be pumped out of the through hole, and the diameter of the silver paste figure in the extruded part is larger than that of the through hole.In order to prevent the migration of silver ions, a covering layer is applied to the surface of the extruded part of the silver paste through screen printing.Then, on both sides of screen printing resistance welding graphics, isolation graphics, stamping or drilling fixed printed circuit board screw holes, processing shape.At last, the double-sided printed circuit board with silver paste filling through hole was finished.