JPS605564A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the displacement of the positions between a semiconductor element and a contacting electrode plate by holding by a U-shaped clip a supporting plate of a semiconductor substrate, on which both gate and cathode electrodes are disposed without providing an irregular surface on a main surface, and a contacting electrode plate formed with an escape such as a through hole or a groove. CONSTITUTION:A stationary groove 22 for mounting a clamp to prevent the rotation is provided in the vicinity of the outer periphery of the surface of a contacting electrode plate. The contacting plate 6 and a semiconductor element formed of a silicon substrate 1 and a supporting plate 5 are secured with a U- shaped clamp 23 having a hook at the end formed of an insulating member such as rubber or Teflon. In this case, a groove 24 is formed similarly to the groove 22 of the plate 6 in the vicinity of the outer periphery of the surface of the plate 5. Thus, the clamp 23 is engaged with the stationary grooves 22, 24, thereby matching the plate 6 and the element at the relative positions to thereafter inhibit them to solely move.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to an assembly structure of a semiconductor device having a complex-shaped gate electrode, such as a high-speed thyristor.

[Prior art and its problems]

FIG. 1 is a plan view showing the surface shape of a high-speed silice element, and FIG. 2 is an enlarged cross-sectional view taken along the line AA in FIG. 1, in which main parts are shaded.

In FIGS. 1 and 2, a semiconductor substrate 1 has a complex-shaped gate electrode 2 and a cathode electrode 3 on its main surface.
In order to maintain normal operation of such a high-speed thyristor element, the gate electrode 2 and the cathode electrode 3 are generally arranged separately from each other so that the two electrodes are not permanently short-circuited. 4 is a first stage gate electrode.

A sectional view of a flat high speed thyristor device in which a semiconductor element having such a semiconductor substrate is sealed in a container is shown in FIG. 3, and the same reference numerals as in FIGS. 1 and 2 represent the same names.

As shown in FIG. 3, a semiconductor substrate 1 is fixed to a support plate 5 made of molybdenum or tungsten to constitute a semiconductor element, and a conductive layer with a smooth surface is placed on a cathode electrode 3 of the semiconductor substrate 1. A contact electrode plate 6 made of a metal 1 such as molybdenum is brought into contact. The means for arranging the gate electrode 2 and the cathode electrode 3 so that no electrical short circuit occurs is shown in FIGS. This is done by forming a step by etching using silicon substrate 1, and providing a gate electrode 2 made of an aluminum vapor deposited film in the recessed part of the silicon substrate 1 and a cathode electrode 3 also made of an aluminum vapor deposited film on the outermost main surface of the silicon substrate 1. be exposed. In this way, due to the height difference of the uneven surface provided on the main surface of the silicon substrate 1, p1
A space insulation portion is created between the gate electrode and the contact electrode plate 6, and the gate electrode &2 is kept electrically insulated from the cathode electrode 3 which is in contact with the contact electrode plate 6.

To explain the assembly procedure of the flat semiconductor device shown in FIG. 3, first, the electrodes 8 and the insulating ring 9 are passed through the container together with the spring member 10 and the insulating member 11, which are soldered via the flange 7. The gate lead wire 12 is placed on the silicon substrate 1 at a location where its tip is to be in contact with the first stage gate electrode 4, and the other end of the gate lead wire 12 is inserted into the hole 13 that passes through the insulating ring 9. , together with the tube 13, are crushed at the ends and sealed together. Next, a space ring 14 made of, for example, Teflon is inserted into the container, and a notch is cut into the space ring 14 at the point where it intersects with the lead wire m12.
2 so that it doesn't get in the way. Thereafter, a semiconductor element consisting of a contact electrode plate 6, a silicon substrate 1 whose main surface has been previously processed to have irregularities as shown in FIG. 2, and a support plate 5 is arranged as shown in FIG. An electrode 16 having a flange 15 as shown in FIG. .

However, due to the structure described above,
This flat semiconductor device inevitably has the following drawbacks.

One of them is that it is difficult to process because the depth dimension of the four parts formed on the main surface of the silicon base 17Rh must be controlled to 0102±001 mm. FIG. 4 is an enlarged sectional view showing the relationship between the gate electrode 2, the cathode electrode 3, and the contact electrode plate 6 of the silicon substrate 1 whose main surface is roughened according to the symbols in FIGS. 1 to 3. However, for example, if the processing depth of the recess on the main surface of the silicon substrate 1 is too shallow than the specified dimension, the gate electrode 2 may be damaged due to poor precision of the photomask, etc., as shown in FIG. If the protrusion 18 is generated, the protrusion 18 may come into contact with the contact electrode plate 6, resulting in an electrical short circuit between the gate electrode 2 and the cathode electrode 3. In addition, Fig. 5 shows a cross-sectional view similar to Fig. 4, but
In this case, for example, because foreign matter 19 such as metal particles has entered the concave portion provided on the main surface of the silicon substrate 1 during the manufacturing process, the conductive foreign matter 19 may be interposed between the gate electrode 2 and the contact electrode plate. By contacting 6, the gate
This indicates that there is a short circuit between the cathode and both electrodes.

The second drawback is that in the structure of the flat thyristor shown in FIG. 3, the contact electrode plate 6 is brought into contact with pressure only in the use state after the semiconductor element is housed in the container, and the semiconductor element also has a contact electrode plate 6. Since the plate 6 is not always restrained, the cathode electrode film 3 of such a flat thyristor may be scraped due to rotation of the semiconductor element sealed in the container or the contact electrode plate 6 during handling. Don't be afraid to damage it,
This may lead to a short circuit between the gate and cathode electrodes.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a semiconductor device in which the gate electrode and the cathode electrode are not short-circuited through the contact electrode plate, and the misalignment between the semiconductor element and the contact electrode plate is prevented. There is a particular thing.

[Key points of the invention]

The semiconductor device of the present invention has no irregularities on its main surface, and has a support plate for a semiconductor substrate having a gate, a cathode, and both electrodes, and a contact plate provided with relief parts such as through holes or grooves. By holding the electrode plate with a U-shaped clip,
The contact electrode plate and the semiconductor element are fixed by aligning their relative positions.

[Embodiments of the invention]

The present invention will be described below based on examples.The semiconductor device of the present invention and its assembly procedure are the same in principle as the one shown in FIG. Only the relevant parts will be described.The semiconductor device of the present invention is the third embodiment.
The difference from the figure is silicon substrate 1. These are various points regarding the shape of the contact electrode plate 6 and the fixing structure of the contact electrode plate 6 to the silicon substrate 1. These points are designated by the same symbols as in Figures 1 to 5.
Using the same name, as shown in the partially enlarged cross section of FIG. 6, in order to prevent short-circuiting between the gate and cathode electrodes without applying unevenness to the main surface of the silicon substrate 1, , a through hole 20 having the same contour shape and slightly larger than the electrode 2 is provided at a location where the gate of the contact electrode plate 6 that comes into contact with the cathode rod &3 faces the electrode 2; It is necessary to provide a groove 21 in the contact hole as shown in FIG.
In order to prevent the gate from contacting the electrode plate 6 with the electrode 2, a recess such as a through hole 20 or a groove 21 is provided on the side of the contact electrode plate 6, and a recess is provided on the main surface of the silicon substrate 1. It is no longer necessary to arrange one pole and two, and the depth of the relief parts such as through holes 20 and grooves 21 of the contact electrode plate made of molybdenum etc. can be set to 0.1 to 0.5 mm. , this value is much larger than the height difference of 0.02":061 between the unevenness provided on the main surface of the silicon substrate 1, which has been considered a drawback of the conventional method. Even if the protrusion shown in FIG. Even if the foreign matter 18 or the foreign matter 19 shown in FIG. Therefore, the phenomenon of short circuit between the gate electrode 2 and the cathode electrode 3 via the contact electrode plate 6 is eliminated.

However, this does not mean that the semiconductor substrate 1 and the contact electrode plate 6
are always kept in the correct position and aligned, but if the relative positions of the semiconductor substrate 1 and the contact electrode plate 6 are shifted due to their respective rotations, etc., as described above,
Due to rotation, abrasion of the cathode electrode may generate powder, which may cause a short circuit. Therefore, it is necessary to fix the semiconductor substrate 1 and the contact electrode plate 6 and provide a stop for both.

FIG. 8 is a plan view of the contact electrode plate 6 used in the present invention, and FIG. 9 is a sectional view taken along the line B-B in FIG. In case,
A fixing groove 22 is provided near the outer periphery of the surface of the contact electrode plate 6 to provide a fixing member for preventing rotation.

FIG. 10 shows the contact plate 6, the silicon substrate 1, and the support plate 5.
A semiconductor element made of A fixing groove 22 of the contact electrode plate 6 is provided near the outer periphery of the surface of the contact electrode plate 6.
Similarly, a groove 24 is provided. As shown in FIG. 10, by fitting the U-shaped fixture 23 into the fixing grooves 22 and 24, the relative positions of the contact electrode plate 6 and the semiconductor element are aligned, and they will not move independently thereafter. In FIG. 8, the fixing groove 22 is provided around the entire circumference of the contact electrode plate 6, but the groove may be provided partially, and the same applies to the fixing groove 24 of the support plate 5. In this case, the U-shaped fixture 23 may be provided in accordance with these fixing grooves. That is, the larger the area of the fixing point between the contact electrode plate 6 and the semiconductor element, the more effective it is in blocking rotational force, but it is not necessarily necessary to use the entire circumference, and it may be determined as appropriate depending on the actual situation.

〔Effect of the invention〕

As explained above, according to the present invention, it is no longer necessary to provide a recess on the main surface of a silicon substrate, which is extremely complicated and whose depth is difficult to control, and to arrange a gate electrode. The semiconductor device can be stably operated for a long period of time without shorting between the gate and cathode electrodes. This effect can be obtained by providing a relief part on the contact electrode plate to prevent short circuit between the gate and cathode electrodes at the position opposite to the contact electrode. This is because the positional relationship of the plates is correctly matched, but if this relative positional relationship cannot be maintained for some reason, the problem of short circuit will occur again. On the other hand, in the device of the present invention, the mounting is carried out by fitting a U-shaped insulator having a hook-shaped portion at the tip from the side surface of the grooved contact electrode plate and the support plate of the semiconductor substrate. The contact electrode plate and the semiconductor element are fixed as one body, preventing each from rotating independently. When assembling the semiconductor device of the present invention, this anti-rotation component is used after positioning the contact electrode plate and the semiconductor element by placing the through hole of the contact electrode on top of the gate electrode, and then using its elasticity. The assembly operation is extremely simple and workable, as all you have to do is fit it in.In addition to being able to reliably prevent the rotation of the contact electrode plate and semiconductor element, this rotation stopper also has the advantage of being able to prevent the contact electrode plate and semiconductor elements from rotating. This method has the advantage that there is no need to worry about the electrical performance of the semiconductor device at all, since the semiconductor substrate itself is not touched at all by simply holding down the board and the semiconductor element from the sides.

Figure 1 is a plan view showing the electrode arrangement of a high-speed thyristor element;
Fig. 2 is a partially enlarged sectional view, Fig. 3 is a sectional view of a conventional flat semiconductor device, Figs. 4 and 5 are partially enlarged sectional views showing the short-circuited state of the electrodes, @ Fig. 6, and Fig. 7. 8 is a partially enlarged sectional view showing the electrode structure of the present invention, and FIG. 8 is a plan view of the contact electrode plate according to the present invention.

FIG. 9 is a sectional view, and FIG. 10 is a partially enlarged sectional view showing how the contact electrode plate and semiconductor element of the present invention are identified.

DESCRIPTION OF SYMBOLS 1...Silicon substrate, 2...Gate electrode, 3...Cathode electrode, 5...Support plate, 6...Contact electrode plate , 20... through hole, 21... structure, 22.24... fixing groove, 23... U-shaped insulator.

Figure 71 2nd figure Figure 24 5th figure Figure 16 $7a f9 diagram age 10

Claims (1)

[Claims] 1) In a semiconductor substrate having a first electrode layer connected to the contact electrode plate and a second electrode layer not connected to the contact plate on the main surface of the semiconductor substrate, the contact electrode plate has a first electrode layer connected to the contact electrode plate. a contact surface in contact with the contact surface, a relief portion from the contact surface provided at a location facing the second electrode layer and having a slightly larger outline than the second electrode layer, and a relief portion on a surface opposite to the contact surface. The fixture mounting includes a groove, and the fixture is provided with a U-shaped insulator having a hook-shaped portion at its tip that hangs over the groove and the semiconductor support plate. semiconductor devices.