PURPOSE:To satisfactorily connect the end point of lead wire and chip by fixing a semiconductor chip at the lower part of vessel divided into upper and lower sections, allowing the lead wire to run through the specified position at the upper part of vessel and then fixing them and connecting the end point of lead wire to the electrode on the chip. CONSTITUTION:A chip 2 on the bottom plate 1 coupled to the side wall 5 by welding is easily brazed by the automatic furnace assembling with a carbon jig. Meanwhile, the upper cover 6 is made of an insulator to which a lead frame having a lead 4 is previously bonded or fixed by the brazing or molding. A solder plate 9, for example, is placed on the electrode of this chip 2, the upper cover 6 to which the lead 4 is fixed is placed and thereafter the end point of lead 4 is connected to the chip 2 and electrode by the method such as allowing it to run in the automatic furnace. In this case, the lead 4 is short within the vessel and therefore the end point of lead is less deviated. In case a ceramic upper case 6 is used, the contact area with the side wall 5 is metallized and the upper cover 6 and side wall 5 are brazed simultaneously.

Assembling of semiconductor device

PURPOSE:To execute exactly an arc re-ignition at the time of converting the polarity of one set of power source, and to improve the welding operability by executing the welding by using an AC square wave voltage which can adjust optionally a frequency and a time ratio of a positive electrode component and a negative electrode component, as a welding power source. CONSTITUTION:A square wave signal which has been obtained by an oscillating circuit 6 is set to a desired optional ratio by a straight polarity/opposite polarity time ratio adjusting circuit 5. This signal is amplified to a value which can drive an inverter, by a pre-amplifying circuit 4 for an inverter circuit 3, and applied to each transistor 11-14 in the circuit 3. In this state, when one pair 11, 14 or 12, 13 of them has been cut off, a current flows by a small charge which has remained in the transistors. A short circuit between each transistor at that time is prevented by a control circuit 7. Thereafter, the other pair of transistors are conducted electrically at the same time, cut off after a prescribed time, the electric conduction is repeated alternately without being short-circuited as mentioned above, and a DC which has been obtained from a transformer 1 having a high no-load voltage and a rectifying circuit 2 is outputted as an AC square wave. This square wave becomes a plasma arc flame between an electrode 8 in a nozzle 9 and a base material 10.

Gii Arunuu

Papers

Sealing box for power module of hybrid circuit