JPS6050339B2 - semiconductor element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor element that is used by directly brazing a conductive portion on the outer surface of a container to a circuit conductor on a substrate such as a printed circuit without using lead wires.

2. Description of the Related Art Connecting circuit components to printed circuits on insulating substrates to construct electronic circuits is widely practiced. Conventionally, to connect semiconductor devices in this manner, the lead wires of the devices were inserted into holes in the board and brazed to circuit conductors on the board.
However, with advances in mounting technology, especially automatic mounting technology, there has been a desire to develop so-called leadless semiconductor elements that can be directly brazed to circuit conductors without using lead wires. FIG. 1 shows an example of the structure of a leadless diode devised by the present inventors to meet this requirement.

This tie auto includes a semiconductor body 1, two electrode bodies 2 that are in contact with both sides of the body, and a glass tube body 3 that spans between the two electrode bodies 2. 2
1 and a small-diameter cylindrical part 22 are coaxially coupled together, and the end face of the small-diameter cylindrical part 22 contacts each surface of the semiconductor body 1, and the glass tube 3 is connected to both electrode bodies 2. The structure is such that the semiconductor element body 1 is hermetically sealed by being in close contact with the side surface of the small-diameter cylindrical portion 22 . This diode is characterized in that it can be directly connected to a circuit conductor through the cylindrical portion 21, and that its structure and assembly are extremely simple. However, in this case, the glass tube body 3
It has been found that the following problems will occur if attention is not paid to the dimensions of the That is, in order to seal a semiconductor element with this structure,
The semi-J conductor element 1, both electrode bodies 2, and the glass tube body 3 are combined, and the glass tube body 3 is fused to the small diameter cylindrical portion of the electrode body 2 by heating while applying force to press both electrode bodies 2 together. let

At this time, as shown in FIG. 1, if the end surface of the glass tube 3 comes into contact with the inner end surface of the large diameter part of the electrode body, the distance between the two electrode bodies 1 will depend on the length of the glass tube 3. As a result, the electrical contact between the semiconductor element body 2 and the electrode body 1 may become uncertain. Alternatively, the glass tube 3 may be compressed by the weight of the electrode body and the load applied to the electrode body by a weight, etc. and deformed during melting, impairing the external dimensional accuracy of the finished diode, or causing glass to form on the side wall of the assembly jig. It adheres and significantly reduces workability. An object of the present invention is to provide a leadless type semiconductor element which is free from such inconveniences, has high reliability, and has no problems in dimensional accuracy and workability during assembly.

This objective is achieved by providing a gap between the inner end surface of the large-diameter cylindrical portion of at least one electrode body and the end surface of the glass tube.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, in the leadless type diode according to the present invention, a gap A is provided between the inner end surface of the large diameter cylindrical portion 21 of the electrode body 2 and the end surface of the glass tube body 3.
FIG. 3 shows the state of assembly of this diode, in which one electrode body 2a is placed at the bottom of the cavity 5 of the assembly jig 4, and then the glass tube body 3 is attached to the small diameter cylinder of the electrode body 2a. The semiconductor body 1 is placed on the center of the end surface 23a of the cylindrical portion. Finally, the other electrode body 2b is inserted and its small diameter cylindrical portion is fitted into the glass tube body 3, and at the same time, the end surface 23b of the other electrode body 2b is brought into contact with the upper electrode 11 of the semiconductor body 1. In order to facilitate these operations, the inner diameter of the cavity 5 is the same as the electrode body 2a,
The outer diameter of the small-diameter cylindrical portions of the electrode bodies 2a and 2b is slightly smaller than the inner diameter of the glass tube 3. The length of the glass tube body 3 is determined by this arrangement 3. A gap of dimension A is provided upon completion. When the assembly jig 4 containing the components in this manner is heated, for example, in a furnace surrounded by an inert gas atmosphere, the glass tube body 3 is fused to the electrode bodies 2a and 2b, and the assembly and sealing is completed. The semiconductor element body 1 and both electrode bodies are pressed together by the weight of the upper electrode body 2b and the weight of a weight added if necessary. In this case, since the gap A exists, the glass tube body 3 does not interfere with the loading of these loads, so that the electrodes on both sides of the semiconductor element body 1 and the end faces 23 of the electrode bodies 2a and 2b
Good contact with a, 23b is ensured. Also, the electrode body 2
Since the large-diameter cylindrical part b does not come into contact with the glass tube 3 and pressurize it, the glass tube 3 does not touch the assembly jig 4 during heating.
It does not bulge toward the side wall of the cavity 5, and of course it does not adhere to the side wall. Since the gap A has such an effect, its size may be so small that it does not become zero due to thermal dimensional changes of each component. As described above, in the present invention, the gap A is intended to prevent the above-mentioned problems from occurring in the glass tube body 3, and therefore, it goes without saying that it is not necessarily limited to only one gap.

This improves the reliability, external dimensional accuracy, and assembly workability of leadless glass-encapsulated semiconductor devices that can be directly brazed to circuit conductors without having to insert lead wires into holes. improvement can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the structure of a leadless diode, FIG. 2 is a vertical cross-sectional view showing the structure of a leadless diode according to the present invention, and FIG. 3 is a side view of the assembly device showing the assembly operation state. There is a cross-sectional view. 1... Semiconductor element body, 2... Electrode body, 3...
...Glass tube body.

Claims (1)

[Claims] 1 comprising a semiconductor element, two electrode bodies in contact with both surfaces of the semiconductor body, and a glass tube spanning between the electrode bodies,
Each of the electrode bodies is made up of a large diameter cylindrical portion and a small diameter cylindrical portion coaxially coupled together, and the end face of the small diameter cylindrical portion is in contact with each surface of the semiconductor element. , the glass tubular body is in close contact with the side surface of the small-diameter cylindrical portion of the electrode body to hermetically seal the element body, and the glass tube body is in close contact with the inner end surface of the large-diameter cylindrical portion of at least one of the electrode bodies. A semiconductor device characterized in that a gap exists between the end face of the tube and the end face of the tube.