JPH06827Y2 - Small stud type insulated heat sink for semiconductors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a heat sink that absorbs heat of a small stud type semiconductor such as a thyristor and a diode and cools it to secure its function and prevent its deterioration.

(Prior Art and Problems) As a conventional example of this kind of small-sized semiconductor heat sink for semiconductors, for example, as shown in FIGS. 4 (a) and 4 (b),
A pair of copper plate members 102a and 102b are erected on the base 100 with the insulating plate 101 interposed therebetween,
The cooling water pipes 103 are fixedly arranged on the respective end faces of a and 102b by, for example, filtering, and copper plate materials 102a and 102b are provided.
The screw portion of the semiconductor S is screwed into the screw hole 104 formed on each surface. In this case, the semiconductor to be mounted is used, for example, with the − polarity on the copper plate 102a side and the + polarity on the 102b side. Therefore, since each of the copper plate members 102a and 102b is a member that also serves as an electrode and a heat sink and has the same potential as that of the case of the semiconductor S, it is essential to ensure reliable insulation between them by the insulating plate 101 as described above. is there.

In the above-mentioned conventional configuration, the electrodes / heat sink combined members 102 for mounting the semiconductors S having different polarities or phases are required, and not only the number of the electrode / heat sink combined members 102 increases, but also piping to the cooling water pipe 103 is required. However, the whole structure is three-dimensional and requires a large space.

A particularly problematic point is that an electric potential is applied to the cooling water pipe 103 attached to the electrode / heat sink / combined member 102 that has the same electric potential as the case of the semiconductor S, so that electrolytic corrosion occurs in the cooling water pipe 103. , For example, Jitsuko Sho 55-2876
The electrolytic water corrosion prevention device as disclosed in No. 3 is installed in the cooling water pipe 103.
It is necessary to take countermeasures such as mounting it on the.

There is also another conventional structure in which the heat sink and the case of the semiconductor S are insulated from each other in order to avoid the same potential as the case of the semiconductor S as described above. That is, as shown in FIG.
5 is provided with a fool hole 106 into which the threaded portion of the semiconductor S can be inserted, and is inserted and fixed in the fool hole 106 via mica or special insulation 107 between the case of the semiconductor S and the heat sink 105. It is as a configuration.

In this structure, there is a problem that the thermal conductivity of the insulating material 107 is poor and the semiconductor S cannot be cooled sufficiently, and the insulating strength of the insulating material 107 is low.

(Object of the Invention) The present invention has been made in order to solve the above-mentioned problems existing in the prior art. The heat transfer is good so that the semiconductor can be cooled sufficiently, and the potential of the heat sink itself is not applied. , It is an object of the present invention to provide a small stud type insulated heat sink for a semiconductor, which has sufficient electric insulation between the electrode and the heat sink, achieves further miniaturization and simplification, and has high strength.

(Structure of the Invention) The gist of the present invention is (1) a ceramic thin plate that has high electrical insulation and high thermal conductivity, and has a thin copper metallized finish in a predetermined area in the center of the surface and the entire back surface, (2) on the surface A copper electrode is provided with a screw hole into which a screw part of a small stud type semiconductor can be screwed, and the back surface is in contact with a predetermined area of the ceramic thin plate surface. (3) The copper plate is in contact with the back surface of the ceramic thin plate on the surface. (4) and a heat sink body provided with a cooling water passage inside as a constituent element, (5) the contact surface between the electrode and the ceramic thin plate and between the ceramic thin plate and the copper plate is soldered, and (6) The periphery of the joint portion including the bare portion outside the contact surface of the ceramic thin plate is covered with an electrically insulating molding agent and solidified to be integrated, and (7) the back surface of the copper plate is brought into contact with and fixed to the heat sink body. Naru small In stud-type semiconductor insulating heat sink.

(Effect of the Invention) The insulating heat sink according to the present invention has an effect that the high electrical insulation of the ceramic thin plate does not apply a potential to the heat sink, and accordingly, an effect that the semiconductors having different polarities or phases can be mixedly mounted on the heat sink body and cooling The action that does not cause electrolytic corrosion in the water pipe, the high thermal conductivity of the ceramic thin plate,
Highly efficient bonding of copper metallization and the high cooling capacity of the heat sink body with cooling water passages help to absorb the heat of the semiconductor with high efficiency. Since it is formed on the surface, it has the effect of increasing the strength of the device.

(Embodiment) The present invention will be described in detail below with reference to an embodiment shown in FIGS.

In FIG. 1, 1 is an electrode, 2 is a ceramic thin plate, 3
Is a copper plate.

The electrode 1 is a copper block material, and the surface thereof is provided with a predetermined number of screw holes 11 into which screw parts of a small stud type semiconductor can be screwed, and screw holes 12 for mounting a power supply terminal. ing.

The ceramic thin plate 2 is, for example, aluminum nitride.
A material such as ceramics having high electrical insulation and high thermal conductivity is used.
The horizontal direction is rather long and has a large area. Copper metallization is applied to a predetermined area indicated by A at the center of the front surface of the ceramic thin plate 2 and the entire back surface A ′. The predetermined range A is the same as the back surface of the electrode 1.

As shown, the copper plate 3 has a width slightly larger than the width of the ceramic thin plate 2, and the length thereof is longer than the length of the ceramic thin plate 2 so that there is room to form the screw holes 31. The central portion of the copper plate 3 is formed as a recess B having an extremely shallow range that matches the length of the ceramic thin plate 2. The recess B is sufficiently shallower than the thickness of the ceramic thin plate 2.

The electrode 1, the ceramic thin plate 2, and the copper plate 3
The three parts are the recess B of the copper plate 3 and the ceramic thin plate 2.
The copper metallized back surface A'of the above, and the back surface of the electrode 1 and the copper metallized portion A of the ceramic thin plate 2 are soldered and integrated. In the soldering, the copper metallization has a good wettability, so that a strong bond is obtained. However, it is an essential condition that the solder does not stick out from the respective joint surfaces in order not to impair the insulating property.

As described above, in the state where the electrode 1, the ceramic thin plate 2 and the copper plate 3 are integrated, the four sides on the front surface side of the ceramic thin plate 2 are barely exposed from the joint surface with the electrode 1, and the three members including the bare portion are joined together. The periphery of the part is covered with an electrically insulating molding agent and solidified to form a composite insulated electrode member.

2A to 2C show a state in which the semiconductor S is mounted on the composite insulated electrode member 10 integrated through the above steps. Reference numeral 4 in the figure indicates the molding agent.

FIG. 3 is a plan view of a part of the completed state of the present embodiment. In FIG. 3, 5 is a heat sink main body through which cooling water is conducted, and 10a and 10b are screw holes provided in the copper plate 3. A composite electrode member 7a and 7 fixedly arranged on the heat sink body 5 with a screw 32 using 31.
Each of b is a power supply terminal attached to a screw hole 12 formed in the electrode 1.

In the embodiment of the present invention, since the composite insulated electrode members 10a and 10b each securely insulate the heat sink body 5 and the electrode 1 by the ceramic thin plate 2 having high electric insulation, for example, the + polarity of the DC power supply (not shown) is used. Power supply terminal 7a
There is no problem even if the negative polarity is connected to the power supply terminal 7b.

Further, since the ceramic thin plate 2 in the composite insulated electrode member 10 also has high thermal conductivity, the heat generated by the semiconductor S is in good contact with the ceramic thin plate 2.
Since the heat sink body 5 is effectively conducted to the heat sink body 5 through the copper plate 3 and the cooling water flows through the heat sink body 5 and has a high cooling ability, the semiconductor S is cooled with high efficiency.

(Other Embodiments) In the above embodiments, the shallow recess B is formed on the surface of the copper plate 3, and the ceramic thin plate 2 is brought into contact with and soldered to the recess B. The ceramic thin plate 2 may be contacted and soldered without forming the. However, from the viewpoints of robustness of fixation, workability at the time of soldering, and the like, it is preferable to follow the example, which is preferable.

Further, in FIG. 3 showing the completed state of the embodiment, the composite insulated electrode members 10a and 10b having different polarities are shown together, but two or more composite insulated electrode members 10a to 10n having different phases or polarities are shown. Of course, it can be arranged on one heat sink body 5.

(Effect of the Invention) The insulating heat sink according to the present invention can cool the heat generation of the semiconductor with high efficiency and does not apply any electric potential to the heat sink body. Therefore, it is possible to dispose a plurality of electrodes having different polarities or phases close to each other on a single heat sink, thereby achieving miniaturization and simplification. Further, there is no fear of electrolytic corrosion of the cooling water pipe, and it is unnecessary to install an electrolytic corrosion preventing device or the like. In addition, the present invention is extremely effective in that it has a strong structure and bears no fear of the above-mentioned electrolytic corrosion, and withstands long-term use.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of the constituent elements in an embodiment of the present invention, and FIGS. 2 (a) to (c) are plan views, front views and side views showing the assembled state of the constituent elements shown in FIG. Figure,
FIG. 3 is a plan view of the completed embodiment of the present invention, and FIG. 4 (a).
And (b) are a front view and a side sectional view of a conventional example,
The figure is a front sectional view of another conventional example. 1 …………………… Electrode 11 ……………… Screw hole 2 …………………… Ceramics thin plate 3 …………………… Copper plate 4 ………………… Electrically insulating mold Agent 5 …………………… Heatsink body A, A ′ ………… Copper metallization processing range B …………………… Recess S ………………… Small stud type semiconductor

Claims (2)

[Scope of utility model registration request] 1. A ceramic thin plate having a high electrical insulation property and a high thermal conductivity, and a thin copper metallized metal in a predetermined area of the front surface and the entire back surface, and a threaded portion of a small stud type semiconductor can be screwed on the surface. An electrode made of a copper material having a screw hole, the back surface of which is in contact with the above-mentioned predetermined range on the surface of the ceramic thin plate,
A copper plate whose front surface is in contact with the back surface of the ceramic thin plate,
And a heat sink body with a cooling water passage inside is a component, and the contact surfaces between the electrodes and the ceramic thin plates and between the ceramic thin plates and the copper plates are soldered and bare outside the contact surfaces of the ceramic thin plates. The periphery of the joint part including the projecting part is covered with an electrically insulating molding agent,
A small stud type insulated heat sink for semiconductors, which is solidified and integrated, and the back surface of the copper plate is brought into contact with and fixed to the heat sink body. 2. A small stud type insulated heat sink for semiconductors according to claim 1, wherein a predetermined area on the surface of the copper plate with which the back surface of the ceramic thin plate contacts is a very shallow recess.