Manufacturing method of semiconductor device
View Patent ↗A method of manufacturing a semiconductor device includes the steps of bonding a semiconductor chip to a first side of a circuit board, bonding a metal base for dissipating heat produced by the semiconductor chip to a second side of the circuit board, and forming a dam on the metal base by a dam material so as to restrict flow of a solder used in bonding a plurality of the circuit boards to the metal base.
1. A method of manufacturing a semiconductor device, comprising:
bonding a semiconductor chip to a first side of a circuit board;
forming, before or after the semiconductor chip is bonded to the first side of the circuit board, a dam made of a dam material on a metal base for dissipating heat produced by the semiconductor chip, said dam projecting upwardly from the metal base to define an area where the circuit board is placed; and
bonding a second side, opposite to the first side, of the circuit board on said area of the metal base by a solder so that the solder used in bonding the circuit board to the area of the metal base is blocked to flow beyond the dam.
2. A method according to claim 1 , wherein said dam material is painted on the metal base in a predetermined pattern.
3. A method according to claim 2 , further comprising disposing on the dam a carbon partition board for preventing outflow of the solder and confining the circuit boards to predetermined positions on the metal base.
4. A method according to claim 2 , wherein the dam material comprises as a main component an inorganic substance having a high solder heat resistance.
5. A method according to claim 4 , wherein the painted dam material is made by mixing particles of the inorganic substance with a volatile binder component, painting the mixture, and drying the binder component of the mixture.
6. A method according to claim 4 , wherein the inorganic substance is carbon or a ceramic.
7. A method according to claim 2 , wherein the dam is formed by painting the dam material in the predetermined pattern using a dispenser.
8. A method according to claim 2 , wherein a width of the predetermined pattern varies in accordance with an amount of the solder used for bonding.
9. A method according to claim 1 , wherein said dam is formed on the metal base by thermal spraying the dam material.
10. A method according to claim 9 , wherein the dam material is made of metal having a low solder wettability.
11. A method according to claim 9 , wherein the dam material is a ceramic.
12. A method according to claim 1 , wherein said dam is formed on the metal base by plating thereto the dam material.
13. A method according to claim 12 , wherein the dam material is chrome.
14. A method of manufacturing a semiconductor device, comprising:
bonding a semiconductor chip to a first side of a circuit board;
fitting, before or after the semiconductor chip is bonded to the first side of the circuit board, a carbon jig as a dam on a metal base for dissipating heat produced by the semiconductor chip, said carbon jig projecting upwardly from the metal base to define an area where the circuit board is placed; and
bonding a second side, opposite to the first side, of the circuit board on said area of the metal base by a solder so that the solder used in bonding the circuit board to the area of the metal base is blocked to flow beyond the dam.
15. A method according to claim 1 , wherein the dam is directly formed on the metal base.
16. A method according to claim 14 , wherein the carbon jig is directly fitted on the metal base.