JPS6214706Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a glass-sealed diode, particularly a DHD type diode for relatively low power use, in which a heat sink is provided on both sides of the pellet.

In general, DHD type diodes are constructed by welding external leads 3 and 4 that hold a diode pellet 2 (hereinafter simply referred to as pellet) to both ends of a cylindrical bulb 1, usually made of lead glass, as shown in Fig. 1. The heat sink electrodes 5 and 6 are inserted into a glass bulb 1 and sealed. This DHD
The type diode has excellent features such as sufficient heat dissipation from the pellet 2 through the electrodes 5 and 6, small size, low cost, and high reliability, and has been widely used. However, the following issues still remain. That is, since the external leads 3 and 4 extend in both directions from the electrodes 5 and 6,
As shown in FIG. 2, a diode preassembly 7,
7,... into lead insertion holes 8, 8,..., 9, 9,
When clamping with the carbon jigs 10, 11 provided with..., the leads 3, 3,..., 4, 4,... lead insertion holes 8, 8,..., 9, 9,... It is difficult to ensure that all the leads are inserted into the diode, and the leads are bent during the diode manufacturing process, making it impossible to omit the lead forming process. In addition, it is difficult to mark the polarity, that is, the direction in which forward current flows, that is, the anode side (or cathode side), which is a weak point of small diodes, and there is a high possibility that display defects will occur. Furthermore, even if the external dimensions of the valve, which can be called the diode body, could be made smaller, the space for housing the leads could not be reduced, and there was a limit to the reduction in product packaging volume during mass production.

This invention was proposed to solve the above-mentioned conventional drawbacks, and in a device where a pellet is sealed in a cylindrical glass bulb between a pair of lead conductors,
One of the outlet conductors is a heat radiator with lead-out leads, and the other is a heat radiator without lead-out leads. Examples of this invention will be described below.

Figure 3 shows a DHD showing the first embodiment of this invention.
In the longitudinal cross-sectional view of the type diode, reference numeral 12 denotes a glass bulb made of lead glass, which is set to be slightly shorter in length than the conventional glass bulb 1 shown in FIG. Numeral 13 is an outlet conductor to which an external lead 14 is welded in the same way as in the past, and which also serves as a heat sink and is inserted into one open end 15 of the glass bulb 12. Numeral 16 is an outlet conductor that protrudes to the other open end 17 of the glass bulb 12. Small diameter part 18
This is an outlet conductor having a T-shaped cross section, in which the large-diameter disk portion 19 is engaged with the other opening edge 20. A pellet 21 has a P ⁺ NN ⁺ layer structure and is held between the lead conductors 13 and 16.

In the DHD type diode configured as above, only one side of the external lead 14 is attached, so the fourth
As shown in the figure, preassembly bodies 22, 22,...
Temporarily fix the glass bulb 12 and the outlet conductor 1.
carbon jig 23 for sealing 3 and 16;
Of course, one of the 24 does not require a lead insertion hole,
Therefore, the external leads 14, 14, . . . are inserted into the lead insertion holes 25, 2 of the carbon jig 24, for example.
5. Insert the flat carbon jig 23 into...
It is only necessary to place the pre-assembly bodies 22, 22, . . . on top of the pre-assembly bodies 22, 22, . . . , and the sealing jig is extremely simple. Moreover, only the external lead-out leads 14, 14, . Significant improvement and no skill required. Further, since only one lead is led out to the outside, bending of the lead can be suppressed as much as possible during loading and unloading before and after transfer using a tray between manufacturing processes. Furthermore, the polarity of this diode can be determined simply by looking at it, eliminating the need for conventional polarity markings. Furthermore, the length of the conventional external lead for this diode is 1/2 that of the conventional one shown in Figure 1, so the product packaging volume can be reduced to approximately 1/2. .

The first embodiment described above is a case in which the outer surface of the outlet conductor 16 is flat, but as is clear from the above-mentioned gist, this invention is similar to the second embodiment shown in FIG. An exit conductor 2 having an axial protrusion 26 on its outer surface that fits into a mounting hole of a printed circuit board, etc.
7, and depending on convenience, glass bulb 1
The other open end edge 19' of the second embodiment may be formed into a knife-edge-like slope to reduce the contact surface of the outlet conductor 27 during the sealing operation and to facilitate the escape of the internally stored gas, and the same effect as in the first embodiment can be obtained. be.

According to this invention, even though the number of external lead points of component materials is reduced, lead bending can be suppressed and the lead forming process can be omitted. Furthermore, with this invention, even if the external dimensions of the diode are further reduced, there is no need for polarity indication, and the product packaging volume is more significantly reduced. Moreover, this idea improves the workability of sealing both ends of the glass bulb and simplifies the jig used.
It has an excellent practical effect of improving mass productivity more than ever before.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a DHD diode prior to this invention, Figure 2 is a side view of a jig in the sealing process, and Figure 3 is a DHD diode showing the first embodiment of this invention. 4 is a side view of a jig in the sealing process, and FIG. 5 is a longitudinal sectional view of a DHD type diode showing a second embodiment of this invention. 12... Cylindrical glass bulb, 13, 16, 27
... Output conductor, 14 ... Output lead, 21 ... Diode pellet.

Claims (1)

[Scope of utility model registration request] In a device in which a diode pellet is sandwiched between a pair of outlet conductors and sealed inside a cylindrical glass bulb,
A diode characterized in that one of the lead conductors is a heat radiator with lead-out leads, and the other is a heat radiator without lead-out leads.