JPH034042Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mounting bracket for a resin-molded transistor. The present invention relates to an adapter for attaching a transistor so that it can be used as a replacement for a transistor in a resin molded package that has compatible characteristics.

[Prior Art] As is well known, low frequency power transistors are used not only for power amplification in audio equipment but also for motor control, DC power control of stabilized power supplies, and the like. Since this power transistor handles a large amount of electric power, it is generally designed to be installed in a heatsink, and in the past, a metal can-type package structure as shown in Figure 2 was the mainstream. Ta. In other words, the structure is such that the semiconductor chip is directly attached to the stem and sealed with a metal cap. Typically, the collector and stem are electrically connected so that heat generated by the collector can be effectively dissipated to the outside. Transistor 1 with such a package structure
5 has a structure in which it is fixed to the radiator 10 using a pair of attachment holes 16 formed at both ends of the stem. Therefore, most of the various electronic devices designed and manufactured in the past have a structure in which a transistor 15 in a metal can type package is attached to a heat sink 10 as shown in FIG. 2.

However, in recent years, with improvements in polymer materials,
Resin molded packages are rapidly becoming popular as power transistor package structures, even those that handle considerably large amounts of power. In response to this, various electronic devices that have been recently designed and manufactured generally use resin-molded power transistors.

[Problems to be solved by the invention] Due to the above-mentioned changes in semiconductor packaging methods, power transistors in metal can-type packages have already been discontinued by semiconductor manufacturers and become scrap products. In other cases, although they continue to exist as maintenance items, they are often quite difficult to obtain. However, for equipment manufacturers, if a problem is discovered in a power transistor during maintenance or repair, they must replace it, and if they continue to manufacture the equipment, they must use power transistors. A problem arises in that the design of the area around the part that is currently in use must be changed. Other resin-molded transistors are usually quite cheap, about 1/3 or less of the price of metal-can type transistors with the same electrical characteristics, so even if metal-can type transistors are not readily available. However, it is far more advantageous to replace it with a resin-molded transistor. However, even in that case, the heat radiator or its surrounding area must be redesigned as described above.

The present invention was developed in consideration of the above-mentioned state of the art, and its purpose is to:
In the part originally designed and manufactured to use a metal can type package transistor,
In terms of electrical characteristics, a transistor in a resin molded package that is compatible with this can be installed as is, and there is no need to change the design of the heatsink or its surroundings. An object of the present invention is to provide a transistor mounting fitting that can be easily replaced.

[Means for solving the problem] The present invention uses a metal can type TO-3 type transistor and a resin mold type TO-3P transistor.
type transistors, or metal can type TO-66 type transistors and resin mold type TO-220 type transistors.
This was done by focusing on the fact that the distance between the base lead and the emitter lead is the same. In other words, the present invention, which can solve the above-mentioned problems, is a heat sink for a metal can type transistor that is interposed between a resin molded transistor and a heat sink for a metal can type transistor that is compatible with the resin molded transistor in terms of electrical characteristics. It is a metal fitting. This metal fitting consists of a substantially flat metal base on which the main body of the resin-molded transistor is placed in close contact. This metal base has mounting holes formed at positions corresponding to the pair of mounting holes of the metal can type transistor, lead insertion holes formed at positions corresponding to the two leads of the metal can type transistor, and two mounting holes formed at positions corresponding to the two leads of the metal can type transistor. It has a convex connection portion for soldering located on a line connecting the holes. One of the mounting holes is used for fixing the resin-molded transistor and for mounting the metal base, and the other is used for mounting the metal base (used for electrical connection of the center lead). The two lead insertion holes pass through the resin-molded transistor with the leads at both ends bent at approximately right angles.
The convex solder connection part, which looks like a cutout, is for connecting the center lead of the resin-molded transistor.

This transistor mounting fitting is made of a thin metal plate such as a copper plate, and can be mass-produced at low cost by punching, press molding, or the like. The connection portion of the center lead may have a punched-out structure by press molding, and it is desirable that the center lead of the transistor be in a state that is easy to solder.

[Function] The transistor mounting fitting having such a structure is interposed between the resin molded transistor and the heat sink, and can be used in place of the resin molded transistor with a metal can type transistor. In other words, bend the leads on both sides of the transistor at approximately right angles, pass them through the lead insertion hole, connect the tip of the center lead to the connection part by soldering, and use one mounting hole to connect the transistor to the metal. The base and the heat sink are connected together, and the other mounting hole is used for attaching the metal base and the heat sink.

Therefore, it is possible to easily replace parts where metal can type transistors have been used in the past with resin mold type transistors without making any changes.

[Example] An example of the present invention will be described based on the drawings. FIG. 1 is an explanatory diagram showing an embodiment of a transistor mounting fitting according to the present invention and a resin-molded transistor placed thereon. As is clear from the figure, this transistor mounting bracket 1
It is composed of a substantially flat metal base 3 on which a resin-molded transistor 2 is placed in close contact with it. This metal base 3 may be, for example, a thin copper plate or aluminum plate with a thickness of about 1 mm,
When the plate thickness is thin, it is desirable to form raised portions 3a on both sides as shown in the figure to provide a certain degree of rigidity. A pair of mounting holes 4a and 4b for mounting to a heat sink are formed in such a metal base 3. The diameter and spacing of the pair of mounting holes 4a and 4b correspond to the diameter and spacing of the mounting holes formed in the stem of the corresponding metal can type transistor. One of the mounting holes 4a is also used for mounting the resin molded transistor 2. The metal base 3 has two penetrating leads (base lead and emitter lead) 5a and 5b located at both ends of the resin-molded transistor 2 bent at approximately right angles (indicated by imaginary lines). Lead insertion holes 6a and 6b are bored. The positions of these two lead insertion holes 6a and 6b are the protruding positions of the base lead and emitter lead of the corresponding metal can type transistor. In other words,
When this transistor mounting metal fitting 1 is placed on a corresponding heat sink, the holes formed therein are formed in precisely corresponding positions so that they just communicate with each other. Furthermore, a connecting portion 8 to which the center lead 7 of the resin-molded transistor 2 is connected is formed in the metal base 3 at an intermediate position between the lead insertion holes 6a, 6b and the other mounting hole 4b. The connecting portion 8 has a structure in which parallel slits are made and the connecting portion 8 is drawn out in the form of a band, and the tip of the central lead 7 is constructed such that it just passes through the center of the drawn out portion.

Next, the state of use of the transistor mounting bracket having such a structure will be explained with reference to FIGS. 3 and 4. As is clear from these figures, the transistor mounting fitting 1 according to the present invention is interposed between the resin-molded transistor 2 and the heat sink 10, and is located on the back side of the heat sink 10 in this embodiment. It is configured to be connected to a printed wiring board 11. As described above, the leads 5a and 5b at both ends of the resin-molded transistor 2 are each bent at a substantially right angle at a predetermined position, and pass through the lead insertion holes 6a and 6b and the hole in the heat sink 10 to reach the printed wiring board 11. It will be connected to the circuit pattern by soldering or the like. The center lead 7 of the resin-molded transistor 2 passes through the raised connecting portion 8, and electrical connection is made by soldering. The transistor 2 and the transistor mounting fitting 1 are attached to a heat sink 10 or a printed wiring board 11 with screws 12 and 13, respectively. Collector of transistor 2 (center lead 7)
is electrically connected to the printed wiring board 11 via the mounting fittings and screws 12 and 13.

By using such a transistor mounting fitting, a resin mold type transistor can be easily connected as is to the same heat sink used for a metal can type transistor. In other words, a resin molded TO-3P type transistor can be used instead of a metal can type TO-3 type transistor, and a resin molded TO-220 can be used instead of a metal can type TO-66 type transistor. It can be replaced with a type of transistor.

[Other Possible Aspects] Although a preferred embodiment of the present invention has been described in detail above, it goes without saying that the present invention is not limited to this configuration, and that various modifications are possible. For example, in this embodiment, a metal base having a shape with both sides bent is used, but it may be a metal base having a simple flat plate shape. Further, although an arched shape is adopted as the connecting portion, any structure may be used as long as it can easily electrically connect the center lead of the resin-molded transistor.

[Effects] Since the present invention is a transistor mounting fitting constructed as described above, the fitting itself can be manufactured inexpensively and in large quantities by stamping, etc., and by using this, Therefore, it is possible to easily replace devices that are originally designed and manufactured to use transistors in metal can-type packages with transistors in resin-molded packages without making any design changes to the heatsink or surrounding areas. Therefore, even if a metal can type transistor is no longer available, it can be easily repaired using a resin molded transistor, and even for products that are already on the production line, the metal can type transistor can be replaced with a resin molded transistor. By replacing it with , it can produce excellent practical effects such as a significant cost reduction.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an embodiment of the transistor mounting bracket according to the present invention, Fig. 2 is an explanatory diagram showing the mounting state when a conventional metal can type transistor is used, and Fig. 3 is an explanatory diagram showing the mounting state of the transistor according to the present invention. Plan view showing how the mounting bracket is used, No. 4
The figure is a sectional view thereof. 1... Transistor mounting bracket, 2... Resin molded transistor, 3... Metal base, 4
a, 4b...Mounting hole, 5a, 5b...Leads at both ends, 6a, 6b...Hole for lead insertion, 7...
Center lead, 8...Connection part, 10...Radiator,
11...Printed wiring board.

Claims (1)

[Scope of utility model registration request] A metal fitting interposed between a resin molded transistor and a heatsink for a metal can type transistor, which has a pair of mounting holes for a metal can type transistor in a substantially flat metal base on which the resin molded transistor is placed in close contact with each other. A mounting hole is formed at a position corresponding to the mounting hole, one of which is also used for fixing the resin-molded transistor, and a mounting hole is formed at a position corresponding to the two leads of the metal can-type transistor, so that the leads at both ends of the resin-molded transistor are at approximately right angles. A transistor mounting bracket having a lead insertion hole that passes through the hole in a bent state, and a convex connecting portion located on a line connecting the two mounting holes and to which the center lead of the resin-molded transistor is soldered. .