JPH0638256U - Structure of glass-sealed leadless diode - Google Patents

Abstract

(57) [Abstract] [Purpose] In a leadless diode formed by inserting a pair of electrode bodies 1 and 2 into a glass tube 3 with a diode chip 4 sandwiched between its tip surfaces 1a and 2a, both electrodes The accuracy of the axes of the bodies 1 and 2 is improved, and the contact failure of the diode chip 4 with the two electrode bodies 1 and 2 is reduced. [Structure] Recesses 7 and 8 into which the diode chip 4 is fitted are formed on the tip surfaces 1a and 2a of either or both of the two electrode bodies 1 and 2, respectively, on the axes 1b and 2b of the electrode bodies 1 and 2. Provide in the part.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the present invention, a diode chip sandwiched between the tips of a pair of electrode bodies (Dumet) is sealed with a glass tube fitted over both electrode bodies, while The present invention relates to a so-called glass-sealed leadless diode structure in which a large-diameter head is integrally formed on the protruding portion of the above.

[0002]

[Prior art]

 Generally, in this type of glass-sealed leadless diode, as shown in FIG. 4, first, one electrode body 1'of both electrode bodies 1 ', 2'is directed upward, and a glass tube is attached to this. After fitting 3 ', a diode chip 4'is loaded into the glass tube 3', and then the other electrode body 2'is turned downward into the glass tube 3'as shown in FIG. After the insertion, the entire glass tube 3'is melted by heating the glass tube 3 ', so that the glass tube 3'is fused to the outer peripheral surfaces of both electrode bodies 1', 2 '.

[0003]

[Problems to be solved by the device]

 By the way, the conventional glass-sealed leadless diode is disclosed in, for example, Japanese Unexamined Patent Publication No. 56-120149 and Japanese Utility Model Unexamined Publication No. 60-71148, the tips of both electrode bodies 1'and 2 '. Are formed on the planes 1a 'and 2a', and the diode chip 4'is sandwiched between the planes 1a 'and 2a'.

Therefore, in the state shown in FIG. 5, when the diode chip 4'is loaded in the glass tube 3 ', the diode chip 4'is formed because the tip of one electrode body 1'is a plane 1a'. , It cannot be mounted on the axial parts of both electrode bodies 1 ', 2', and as shown in FIG. 6, it will be mounted on the parts deviated from the axial lines of both electrode bodies 1 ', 2'. Therefore, when the glass tube 3'is subsequently heated and melted, the other electrode body 2'is inclined with respect to the one electrode body 1'as shown by the chain double-dashed line in FIG.

As a result, there is a problem that the accuracy of the axes of the two electrode bodies 1'and 2'decreases, and the contact failure of the diode chip 4'to the two electrode bodies 1'and 2'occurs frequently. The present invention has a technical object to provide a glass-sealed leadless diode which does not cause these problems.

[0006]

[Means for Solving the Problems]

 In order to achieve this technical problem, the present invention inserts a pair of electrode bodies into a glass tube with a diode chip sandwiched between the tip surfaces of the electrode bodies, and at the same time, to the protruding portions of the two electrode bodies from the glass tube. In a leadless diode formed by integrally molding a large-diameter head, a recess in which the diode chip is fitted is formed in the tip surface of either or both of the electrode bodies in the electrode body. The structure is provided at the axial portion.

[0007]

[Work]

 In this configuration, when the diode chip is loaded into the glass tube, the diode chip fits into the recess provided in the axial portion of the electrode body, so that it does not deviate from the axial line of the electrode body and stays on the axial line of the electrode body. Therefore, when the glass tube is melted, it is possible to significantly reduce the inclination of the other electrode body with respect to the one axis line.

[0008]

[Effect of device]

 Therefore, according to the present invention, it is possible to significantly improve the accuracy of the axis line in both electrode bodies, reduce the occurrence of defective contact of the diode chip with both electrode bodies, and reliably improve the yield rate. .

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings of FIGS. In this figure, reference numerals 1 and 2 denote electrode bodies (dumets) having heads 5 and 6 having large diameters at the other ends, reference numeral 3 denotes a glass tube, and reference numeral 4 denotes a diode chip. Show.

Recesses 7 and 8 into which the diode chip 4 is fitted are formed in the tip surfaces 1a and 2a of the two electrode bodies 1 and 2 at the positions on the axes 1b and 2b of the two electrode bodies 1 and 2, respectively. Form. A plurality of radially extending projections 9 and 10 are integrally formed on the end surfaces 5a and 6a of the heads 5 and 6, and the ridge lines of the projections 9 and 10 are the projections 9 and 10 respectively. Is inclined with respect to the end faces 5a, 6a of the heads 5, 6 so that the height from the end faces 5a, 6a at the inner side in the radial direction becomes lower on the outer side of the polygon.

Then, as shown in FIG. 2, one electrode body 1 of the two electrode bodies 1 and 2 is faced upward, and a glass tube 3 is fitted into the electrode body 1, and then, inside the glass tube 3, The diode chip 4 is loaded and vibration is applied. Then, the diode chip 4 is located in a portion on the axis 1b of the one electrode body 1 by being fitted in the recess 7 in the tip surface 1a of the one electrode body 1.

Therefore, as shown in FIG. 3, by inserting the other electrode body 2 downward into the glass tube 3, the position of the tip surface 2a of the other electrode body 2 on the axis 2b is adjusted. Will contact the diode chip 4, so that when the glass tube 3 is melted by heating the whole, the other electrode body 2 tilts with respect to the axis 1b of the one electrode body 1. Can be significantly reduced.

In the above embodiment, the recesses 7 and 8 are provided on both the tip surfaces 1a and 2a of both electrode bodies 1 and 2, but the present invention is directed to the tip surface of one electrode body 1. It goes without saying that the recess 7 may be provided only in 1a and the recess 8 may be omitted in the tip surface 2a of the other electrode body 2.

[Brief description of drawings]

FIG. 1 is an exploded view of a leadless diode according to an embodiment of the present invention.

FIG. 2 is a view showing an assembled state of a leadless diode according to an embodiment of the present invention.

FIG. 3 is a vertical sectional front view of a leadless diode according to an embodiment of the present invention.

FIG. 4 is a diagram showing an assembled state of a conventional leadless diode.

FIG. 5 is a vertical sectional front view of a conventional leadless diode.

FIG. 6 is a vertical sectional front view showing a problem of a conventional leadless diode.

[Explanation of symbols]

 1, 2 electrode body 1a, 2a tip surface of the electrode body 1b, 2b axis line of the electrode body 3 glass tube 4 diode chip 5,6 head portion 7,8 recess

Claims (1)

[Scope of utility model registration request] 1. A pair of electrode bodies are inserted into a glass tube with a diode chip sandwiched between their tip surfaces, and a large-diameter head is integrally formed on the protruding portions of the two electrode bodies from the glass tube. In the leadless diode formed in the above, a concave portion into which the diode chip is fitted is provided at a tip end surface of one or both of the two electrode bodies at an axial portion of the electrode body. Structure of glass-sealed leadless diode.