JPH08153741A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE: To prevent unevenness of the finish of a package or nonconformity of its outer appearance regardless of the diameter of a needle by contacting the edge surface of an auxiliary board with the edge surface of a wiring board closely so that the upper surface of a resin applying auxiliary board is in parallel with the major surface of the wiring board. CONSTITUTION: Bump electrodes 2a of a chip 2 are arranged so that those electrodes face with the corresponding connecting pads of the board 1 and the tips of the bump electrodes 2a are pressed into the connecting pads to be embedded and the silver paste on the connecting pads is cured thermally to bond the two. An auxiliary board 11 that is for the help of applying the resin is provided and the edge surface of the auxiliary board 11 is touched with the edge surface of the board 1 closely so that the upper surface of the auxiliary board 11 is in parallel with the major surface of the board 1. The resin 5a is applied on the surface that includes the part the auxiliary board 11 contacts the board 1 and the opening part between the chip 2 and the board 1 is filled with the resin 5a. Then the auxiliary board 11 is removed from the board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly to a semiconductor device having a single-sided resin-sealed package structure and a method for forming a resin layer for chip sealing.

[0002]

2. Description of the Related Art For semiconductor devices used in, for example, integrated circuit cards, mask ROM cards for games, small mobile phones, etc., there is a strong demand for miniaturization and thinning of packages. In order to meet such demands, mounting technology of bare semiconductor chips (bare chips) has been developed,
Chip-on-board (COB) mounting, flip-chip mounting, etc. are known.

In the flip chip mounting, the metal bump electrodes on the element forming surface of the bare chip are pressed against the electrode pads formed on one main surface of the wiring board to connect (flip chip bonding). This has a higher mounting density than the COB mounting which requires wire bonding, but has a problem that stress due to thermal expansion of the substrate is applied to the connecting portion between the substrate and the chip to impair the reliability of the connection.

As an improved example of the flip chip mounting,
A single-sided resin-sealed package structure in which a resin is interposed between a bare chip and a substrate to mechanically fix the substrate and the chip together is known, for example, from Japanese Patent Publication No. 2-7180.

Further, as an improved example of the single-sided resin-encapsulated package structure and a manufacturing method thereof, Japanese Patent Application Nos. Hei 6-32296 and Hei 6-5075, filed by the applicant of the present application, are disclosed.
Various proposals have been made in Japanese Patent No. 7 and Japanese Patent Application No. 6-60493.

[0006] FIG. 5 is a Japanese Patent Application No. 6-507 related to the above proposal.
57 shows an example of a single-sided resin-sealed package structure disclosed in No. 57. This package structure has a wiring board 1 having a wiring 1a including a connected portion (for example, a connection pad 1b) on one main surface, a semiconductor chip 2 mounted face down on the one main surface of the board, and the chip described above. And a wiring layer, and a resin layer 5 filled between the wiring board and the wiring board, and an external connection terminal 4 which is led out and exposed on the other main surface side of the board and electrically connected to the chip. In FIG. 5, 2a is a bump electrode and 3 is a through hole wiring.

FIG. 6 shows a Japanese Patent Application No. 6-604 relating to the above proposal.
An example of a single-sided resin-sealed package structure disclosed in No. 93 is shown. This package structure is an improved example of the package structure shown in FIG. 5, and the wiring 1a is formed by embedding so as to form substantially the same plane (planarity is about ± 10 μm) with respect to one main surface of the substrate 1. . Note that FIG.
5, the same parts as those in FIG. 5 are designated by the same reference numerals.

According to this package structure, when the resin is poured between the chip and the substrate by utilizing the capillary phenomenon,
The flatness between the chip and substrate is good, and the resin easily flows in, so a dense resin layer without voids can be formed.
The reliability of fixation between substrates can be improved.

When forming the resin layer 5 in FIGS. 5 and 6, as shown in FIG. 7, the resin 5a is applied to one side of the substrate 1 from the nozzle (needle) 71 of the resin supply device (dispenser). The resin is supplied and the resin is poured between the chip and the substrate by utilizing the so-called capillary phenomenon to fill the resin and then cured. The exposed upper surface of the chip 2 is made of a dense and robust material (for example, silicon), and there is little problem in reliability without resin sealing.

In the semiconductor device having the package structure according to the above proposal, since the burn-in test for applying the temperature stress and / or the electric field stress can be performed after the resin sealing, the resin sealing is not performed. Better than flip chip mounting.

By the way, in the resin filling method as described above, as shown in FIG. 7, the resin (the surface shape of which is called a fillet) is extruded on one side of the substrate opposite to the resin supply side. The resin protrusion amount S2 at one side of the substrate on the resin supply side is much larger than the amount (about 0.25 mm) S1. By the way, the protrusion amount on one side of the resin supply side is 0.83m at maximum when the resin supply amount is twice as large as the volume between the chip and the substrate.
m was 3.15 times, the maximum was 1.15 mm, and 4 times was the maximum 2.12 mm.

On the side opposite to the resin supply side, the resin protrusion amount S1 is substantially determined by the physical properties of the resin, but on the side of the resin supply side, the needle 71 is placed so as not to touch the tip. Since the resin is supplied in close proximity, the amount of resin squeeze out S2 is the size of the needle (the standard type currently used is 0.82 mm in outer diameter, 1.25 mm
mm).

Further, in the resin filling method as described above,
Distance between chip outer edge and substrate outer edge (resin supply space)
When trying to reduce S3, it is restricted by the outer diameter of the needle 71, and when trying to reduce the outer diameter of the needle 71, it becomes difficult to normally supply the resin to the side portion of the chip on the substrate. In other words, the resin discharged from the needle may run onto the top surface of the chip or hang down from the board end surface, resulting in variations in the finished dimensions of the package and appearance problems. It will be impossible.

As a countermeasure against this, if the outer diameter of the needle can be made smaller than the space for supplying the resin, if the outer diameter of the needle is made smaller, the inner diameter of the needle currently used (0.6 to 0.7 mm). ) Also needs to be small, and when a resin having a high viscosity is used, the resin that is about to be discharged from the needle is clogged, which makes it difficult to discharge from the needle. In addition, the amount of resin discharged at one time (supply amount) is reduced, and it is necessary to increase the number of times the resin is discharged from the dispenser in order to secure the amount of resin required to fill the space between the chip and the substrate. There is a problem that it becomes difficult.

On the other hand, further miniaturization of the single-sided resin-sealed package structure is required, and after flip chip bonding a chip and a substrate having a chip size close to each other, between the chip outer edge and the substrate outer edge on each side of the substrate. The distance S3 has been required to be, for example, 1 mm to 0.5 mm or less, but the above resin filling method cannot meet the above requirement.

[0016]

As described above, the method of filling the resin between the chip and the substrate when manufacturing the semiconductor device having the single-sided resin-sealed package structure according to the conventional proposal is as follows. If the distance is small, there is a problem that variations in the finished dimensions of the package and defects in appearance may occur.

The present invention has been made to solve the above problems, and when a resin is filled between a chip and a substrate to manufacture a semiconductor device having a single-sided resin-sealed package structure, the outer edge of the chip is sealed.・ Even when the distance between the outer edges of the substrate is small, the same dispenser and needle with a diameter that matches the properties of the resin used can be used, resulting in variations in the finished dimensions of the package and defects in the appearance It is an object of the present invention to provide a method for manufacturing a semiconductor device which can be suppressed regardless of the above, and can further reduce the size of the single-sided resin-sealed package structure.

[0018]

A method of manufacturing a semiconductor device according to the present invention is directed to a wiring board in which a wiring including a connected portion is provided on one main surface and external connection terminals are led out / exposed on the other main surface. The step of arranging the semiconductor chip so that the position of the connected part and the corresponding electrode terminal part of the semiconductor chip face each other, and the connected part of the wiring board and the electrode terminal part of the corresponding semiconductor chip are fixedly connected. And a step of subsequently filling a sealing resin between the semiconductor chip and the wiring board, and a step of curing the filled sealing resin, and filling the sealing resin In this case, an auxiliary plate for resin supply is used, and the end face of the auxiliary plate is in close contact with at least one end face of the wiring board so that the upper surface thereof is substantially horizontal to one main surface of the wiring board. The step of abutting, and then the auxiliary plate A step of supplying the resin to the opening between the chip and the board by supplying the resin on the surface including the contact portion of the board; and thereafter, a step of separating the auxiliary plate from the wiring board. It is characterized by

[0019]

When a semiconductor device having a single-sided resin-sealed package structure is manufactured, when a resin is filled between the chip and the substrate, an auxiliary plate for assisting the resin supply is used, and the upper surface of the auxiliary plate is the wiring board. The end surface of the auxiliary plate is brought into close contact with at least one end surface of the wiring board so as to be substantially horizontal to the one main surface. After that, the resin is supplied to the surface including the abutting portion of the auxiliary plate / wiring substrate to supply the resin to the opening between the chip and the substrate. As a result, the resin can be poured and filled between the chip and the substrate by utilizing the capillary phenomenon of the resin between the chip and the substrate. When the resin is supplied, it is desirable that the resin is supplied so as to adhere to the side surface of the chip so that the capillary action of the resin immediately starts. Then, the auxiliary plate is separated from the wiring board.

According to such a method, even when the distance between the outer edge of the chip and the outer edge of the substrate is small, a dispenser similar to the conventional one and a needle having a diameter suitable for the properties of the resin used can be used. Regardless of the reason, it is possible to stably and reliably supply an almost constant amount of resin between the chip and substrate,
The resin does not run onto the upper surface of the chip and the resin does not hang down from the end surface of the substrate, which makes it possible to prevent variations in the finished dimensions of the package and occurrence of defects in the appearance.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1A and 1B schematically show an example of a manufacturing process of a semiconductor device having a single-sided resin-sealed package structure according to an embodiment of the present invention, particularly a resin sealing process.

2A and 2B are a perspective view and a sectional view showing the semiconductor device after completion. This semiconductor device includes a wiring board 1 having a wiring 1a including a connected portion 1b on one main surface, a semiconductor chip 2 mounted face down on the one main surface of the board, and a chip between the chip and the board. A resin layer 5 which is filled with a resin and hardened, and an external connection terminal 4 which is led out / exposed to the other main surface side of the substrate and electrically connected to the chip.

Next, an example of steps up to the bonding of the wiring board 1 and the semiconductor chip 2 will be briefly described. As the chip 2, a chip having a bump electrode (for example, a diameter of 100 μm and a height of 30 μm) 2a made of a conductive substance, such as a metal, is prepared on the pad for external connection on the element formation surface. The bump electrodes 2a are, for example, gold bumps formed by electroplating or gold ball bumps formed by ball bonding.

The wiring board 1 has a wiring 1a including a connected portion 1b on one main surface, and is led out and exposed from the connected portion 1b to the other main surface side through the through-hole wiring 3.
For example, one having flat type external connection terminals 4 arranged in a grid pattern is prepared.

In this example, the substrate 1 is formed by embedding the wiring 1a so as to form substantially the same plane (planarity is about ± 10 μm) with respect to one main surface. The substrate 1
When forming the connected portion 1b on one main surface, the substrate 1 having the wiring 1a on one main surface is fixed on, for example, the stage of a screen printing machine with a vacuum suction mechanism, and on the substrate 1 the metal of the chip is attached. A flat type connection pad (for example, diameter 150 μm, height 80 μm) 1b is formed in a portion corresponding to the bump electrode 2a. At this time, a conductive paste, for example, a silver paste (silver particle size 1 μm, viscosity 100 ps) is formed on the wiring formation surface of the substrate using a metal mask having openings (for example, 150 μm × 150 μm) corresponding to the bump electrodes 2a of the chip. The connection pad 1b is formed by screen printing.

Next, flip chip bonding is carried out to mount the chip 2 on the substrate 1 in a face-down type by using a bonding apparatus having a mechanism capable of vacuum chucking the chip 2. In this case, the bump electrodes 2a corresponding to the chip are arranged so as to face the connection pads 1b on the substrate, and the bonding head is pressed down to press-fit the connection pads so that at least the tip portions of the bump electrodes are embedded. Are fixed, and in this state, the silver paste for the connection pad 1b is thermally cured to bond them.

Next, in the state where the chip is flip-chip bonded on the substrate as described above, the resin layer 5 is formed.
To form. The resin layer 5 includes a portion filled between the chip and the substrate (30 to 40 μm in this example), and a portion that covers the outer peripheral side surface portion of the chip and has a substantially uniform fillet on each outer peripheral side surface portion. Have.

If the size of the substrate 1 is, for example, 15 mm in length and width and 0.2 mm in thickness, and the size of the chip 2 is, for example, 13 mm in length and width and 0.25 mm in thickness, each side of the substrate 1 is assumed. The distance S3 between the outer edge of the chip and the outer edge of the substrate is extremely small (1 mm or less), and when the resin is supplied onto the end of one side of the substrate 1, the resin supply space is narrow, so the resin runs on the top surface of the chip. It is necessary to devise it so that it does not hang down from the substrate end face.

Therefore, in this embodiment, the resin 5 is used.
When filling a, as shown in FIG. 1, an auxiliary plate 11 for assisting the resin supply is used, and the end face of the auxiliary plate is attached to one end face of the substrate so that the upper surface thereof is substantially horizontal to one main surface of the substrate 1. The step of bringing them into contact with each other in close contact with each other, and thereafter the step of supplying the resin to the opening between the chip and the substrate by supplying the resin 5a onto the surface including the contact portion of the auxiliary plate / the substrate. After this,
And a step of separating the auxiliary plate from the substrate.

The steps of this embodiment are automatically carried out by using an existing automatic assembly apparatus for semiconductor devices and a newly produced special apparatus. When the resin is supplied onto the surface including the contact portion of the auxiliary plate / substrate, the resin is linearly aligned from the needle 10 using, for example, a dispenser similar to the conventional one along the contact portion of the auxiliary plate / substrate. It is possible to stably supply an almost constant amount of resin by supplying only once. In this case, it is desirable to supply the resin so that the resin adheres to the opening between the chip and the substrate on one side of the auxiliary plate contacting side on the substrate, and the opening is substantially evenly provided between the chip and the substrate. As a result, the capillarity phenomenon of the resin starts, and the resin can be poured and evenly filled between the chip and the substrate. At this time, if a temperature of, for example, about 60 ° C. is applied to the resin-filled portion in order to promote the capillary phenomenon, the viscosity of the resin is lowered and the pouring speed of the resin is improved.

As the material of the auxiliary plate 11, the auxiliary plate
Use a material that is more elastic than the board and has good adhesion to the board so that the resin does not flow into the contact area of the wiring board due to the capillary phenomenon and the resin does not hang down on the board end surface of the contact area. It is desirable to do.

When the end face of the auxiliary plate is brought into close contact with the one end face of the substrate, pressure is applied continuously from the lateral direction as indicated by an arrow in FIG. 1A to maintain the close contact state. Is desirable.

As the material of the auxiliary plate, it is desirable to use a material having a property of repelling the resin (lyophobic property) so that the resin on the auxiliary plate can be easily transferred onto the substrate. Also,
When the auxiliary plate is separated from the substrate, it is desirable that the auxiliary plate 11 and / or the substrate 1 be slid horizontally along the abutting end face thereof and separated as indicated by the arrow in FIG. Accordingly, even if the resin is attached to the end surface of the wiring board, the resin can be wiped off.

Incidentally, when the auxiliary plate is separated from the substrate, as shown in FIG.
Auxiliary plate 11 and / or substrate 1 as indicated by the arrow therein
May be slid vertically along the abutting end face and separated.

As described above, the preferable material for the auxiliary plate 11 is one that is more elastic than the substrate, has good adhesion to the substrate, and is lyophobic to the resin (the insulating base material of the substrate is ceramic-based or If it is a resin type,
It is desirable to use, for example, silicone rubber.

Further, when the end surface of the auxiliary plate is brought into close contact with one end surface of the substrate so that the upper surface of the auxiliary plate is substantially horizontal to the main surface of the substrate, the auxiliary plate is supported on the pedestal having the same horizontal plane. In order to improve workability by arranging the plate and the substrate side by side, it is desirable to use the auxiliary plate having the same thickness as that of the substrate.

After the resin filling is completed as described above and the auxiliary plate is separated from the substrate, the filled resin is cured by heat or the like to form a resin layer between the chip and the substrate. A semiconductor device having a resin-sealed package structure is completed.

When supplying the resin as described above,
In order to secure the stability of the work, it is desirable to use the auxiliary plate having a width (for example, 25 mm) wider than one side of the substrate on the auxiliary plate contact side.

When the resin is supplied as described above,
The resin is set to a condition that exhibits appropriate fluidity, or a liquid resin is used. In addition, the resin has a property of alleviating deterioration of the connecting portion between the chip and the substrate due to internal stress caused by the difference in the material of the chip and the substrate (Young's modulus, coefficient of thermal expansion, etc.) when formed as the resin layer. Holds the chip when filling between the chip and substrate
It is desirable to select a material containing a filler having a diameter (for example, 25 μm or less) that can enter between the substrates.

That is, in the method of the above embodiment, when the resin is filled between the chip and the substrate, the auxiliary plate for assisting the resin supply is used, and the upper surface of the auxiliary plate is substantially horizontal to the main surface of the substrate. So that the end face of the auxiliary plate is brought into close contact with at least one end face of the substrate. Then, after supplying the resin on the surface including the contact portion between the auxiliary plate and the substrate, the auxiliary plate is separated from the substrate.

As a result, even if the distance S3 between the outer edge of the chip and the outer edge of the substrate is small and the resin supply space on the end is narrow, the resin on the auxiliary plate is transferred onto the end of the substrate and the resin is transferred to the chip. -It can be attached to the side surface of the chip near the center of the opening between the substrates. When the resin adheres to the side surface of the chip in this way, the capillary action of the resin starts, and it becomes possible to flow and fill the resin between the chip and the substrate by utilizing the capillary action of the resin between the chip and the substrate.

Therefore, according to the method of the above-mentioned embodiment, even when the distance S3 between the outer edge of the chip and the outer edge of the substrate is small, the same dispenser as in the conventional case and the needle having the diameter corresponding to the property of the resin used can be used. Regardless of the diameter of the needle, a stable and reliable supply of a fixed amount of resin between the chip and the substrate is possible, and the resin does not run onto the top surface of the chip and the resin does not hang down from the end surface of the substrate. It is possible to suppress the occurrence of defects in appearance and appearance. This makes it possible to improve the yield of semiconductor devices and reduce the cost.

Instead of the auxiliary plate as shown in the above embodiment, an auxiliary plate 12 having a strip-shaped thin protruding piece 12a formed on one end surface is used as shown in FIG. The resin may be supplied onto the projecting piece and the surface of the substrate adjacent to the projecting piece while being mounted on the upper surface of one end of the substrate.

Further, in the above embodiment, when the resin is supplied, one auxiliary plate is brought into close contact with the end face of one side of the substrate and supplied only on one side, but two auxiliary plates are supplied. The plates may be brought into close contact with the end faces of the two orthogonal sides of the substrate so as to be supplied onto the two sides, respectively. Further, four auxiliary plates may be provided on each of the four sides of the substrate. You may make it contact | abut in contact with each end face, respectively, and may make it respectively supply on four sides.

Further, when the resin filled between the chip and the substrate is cured, it is desirable to apply a load to the chip and the substrate to cure the resin while preventing the displacement between the bump electrodes of the chip and the connection pads of the substrate. .

If a substrate having a solid wiring pattern formed on the outer peripheral edge of one main surface is prepared as a substrate, it is reinforced by the solid wiring pattern when performing the flip chip bonding. By the action, the generation of cracks or warpage of the wiring board is suppressed, the yield of the finished product is improved, and the noise resistance is also improved when the finished product is incorporated into a memory card or the like. Further, the bump electrodes may be formed on the substrate side instead of the chip side.

The substrate and the chips are not limited to have a square outer shape, but may have a rectangular outer shape. Also,
The substrate is not limited to an alumina-based or aluminum nitride-based substrate, and a resin-based substrate (BT resin substrate or the like) may be used. In addition, as shown in FIG. 6, the substrate is one in which wiring and external connection terminals are embedded so as to be substantially flush with the substrate (for example, a green sheet method is applied to an alumina-based insulating base material). Or a resin-based insulating base material formed by the prepreg method)
However, as shown in FIG. 5, the wiring and the external connection terminal may be formed so as to project from the substrate. Further, the substrate may have a structure in which the upper and lower surfaces are electrically connected via a blind via hole or a multilayer structure.

Further, when the chip is flip-chip bonded on the substrate, the method is not limited to the method of press-fitting so that at least the tip end of the bump electrode is embedded in the connection pad as in the above-mentioned embodiment, but the above-mentioned Japanese Patent Application No. 6-50757. As described in detail in Section 1), for example, solid phase diffusion may occur between the gold connection pad and the gold bump electrode so as to be joined.

[0049]

As described above, according to the method of manufacturing the semiconductor device of the present invention, when the resin is filled between the chip and the substrate to manufacture the semiconductor device having the single-sided resin-sealed package structure, Even if the distance between the outer edge of the chip and the outer edge of the substrate is very small, you can use the same dispenser as the conventional one and a needle with a diameter that matches the properties of the resin used. Can be suppressed regardless of the diameter, and the single-sided resin-sealed package structure can be further downsized.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a part of an example of a manufacturing process of a semiconductor device having a single-sided resin-encapsulated package structure according to an embodiment of the method for manufacturing a semiconductor device of the present invention, particularly an example of a resin-encapsulating process.

2A and 2B are a perspective view and a cross-sectional view showing an example of a semiconductor device formed through the resin sealing process of FIG.

FIG. 3 is a diagram showing a modified example of the process of FIG.

FIG. 4 is a diagram showing a modified example of the process of FIG.

FIG. 5 is a sectional view showing an example of a single-sided resin-sealed package structure according to the prior application.

FIG. 6 is a sectional view showing an example of a single-sided resin-sealed package structure according to another prior application.

FIG. 7 is a diagram showing a process of forming the resin layer of FIGS. 5 and 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wiring board, 1a ... Wiring, 1b ... Connected part (connection pad), 2 ... Semiconductor chip, 2a ... Bump electrode, 3 ... Through hole wiring, 4 ... External connection terminal, 5 ... Resin layer, 5a
... Resin, S3 ... Distance between chip outer edge and substrate outer edge, 11,
12 ... Auxiliary plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Iwasaki 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture

Claims (5)

[Claims] 1. A connected portion of a wiring board having wirings including a connected portion on one main surface, and external connection terminals led out and exposed on the other main surface, and an electrode terminal portion of a semiconductor chip corresponding to the connected portion. The step of arranging the semiconductor chip so that the positions of the semiconductor chips face each other, the step of fixedly connecting the connected part of the wiring board and the electrode terminal part of the semiconductor chip corresponding thereto, and then the semiconductor chip and the wiring board Between the step of filling a sealing resin, and a step of curing the filled sealing resin, when filling the sealing resin, using an auxiliary plate for resin supply assistance, A step of bringing the end surface of the auxiliary plate into close contact with at least one end surface of the wiring board so that its upper surface is substantially horizontal to one main surface of the wiring board;
After that, a step of supplying the resin to the opening between the chip and the substrate by supplying the resin on the surface including the contact portion of the auxiliary plate and the wiring board, and thereafter, the auxiliary plate is connected to the wiring board. And a step of separating the substrate from the substrate. 2. The method of manufacturing a semiconductor device according to claim 1, wherein when the resin is supplied onto a surface including a contact portion of the auxiliary plate / wiring board, the resin adheres to a side surface of the chip. A method for manufacturing a semiconductor device, characterized by supplying the same. 3. The method of manufacturing a semiconductor device according to claim 1, wherein when the auxiliary plate is separated from the wiring board, the auxiliary plate or the wiring board is horizontally or vertically oriented along an abutting end surface thereof. A method of manufacturing a semiconductor device, which comprises sliding the substrate to separate it. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the auxiliary plate is made of a material that is more elastic than the wiring board and has good adhesion to the wiring board. A method of manufacturing a semiconductor device, characterized by using a material having good lyophobic property to the resin. 5. The method of manufacturing a semiconductor device according to claim 4, wherein the insulating base material of the wiring board is a ceramic type or a resin type, and silicone rubber is used as the auxiliary plate. Production method.