JPH09252013A - Die, apparatus and method for sealing semiconductor device with resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce voids, prevent blow holes, and improve the production efficiency by providing a movable center pressing part, a peripheral pressing part and a die clamp disposed to press from the central part of the peripheral part. SOLUTION: A die 7a has an upper and lower parts symmetric to a plane, a pressing face 8a of the die is concentricity square defined by a central part 9a and peripheral part 10a around which a die clamp 11a to group and fix a lead frame is disposed. The central part 9a protrudes to a chip housing side (pressing direction) from the part 10a. Both parts 9a and 10a are movable to the clamp 11a, thereby being able to reduce voids staying in a seal member and prevent blow holes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for a sealing device of a semiconductor device, a sealing device and a sealing method, and more particularly to improvement of a compression molding method for resin sealing of a semiconductor device.

[0002]

2. Description of the Related Art FIG. 6 is a plan view of a conventional mold for a semiconductor device sealing device, and FIG. 7 is a cross-sectional view of the semiconductor device sealing device taken along line 7-7 of FIG. . As shown in FIG.
The mold 1 of the sealing device is composed of a mold clamping portion 1a on the periphery and a mold 1b inside thereof. Air vents 2 are provided at four corners of the mold clamping portion 1a. Further, there is a push-cut surface 1c along the boundary of the inner portion of the pressing surface of the mold clamping portion 1a. Push cut surface 1c is 5
It is a thin thin elongated surface having a convex shape of about 0 μm.

As shown in FIG. 7, the mold 1 of the sealing device is plane-symmetrical in the vertical direction in the figure. This device has a structure in which a resin sheet (tablet) 3 which is a sealing member, a semiconductor chip 4, and a resin sheet 3 are stacked in this order, and a mold 1 is used to press the resin sheet from above and below in the figure to perform resin sealing. There is. The contact surface of the resin sheet 3 that contacts the semiconductor chip 4 is formed in a convex shape.

A lead frame (or TAB tape) 5 is connected to the semiconductor chip 4. Push cut surface 1
The mold clamping portion 1a including c is fixed by sandwiching the lead frame 5. Driving means 6a are attached to the upper and lower mold clamping portions 1a, respectively. Also, the upper and lower inner molds 1b
A drive means 6b is attached to each. The drive means 6a, 6b may be a known hydraulic mechanism, servo motor, or the like.

Next, the operation and sealing method of the sealing device using the mold 1 will be described. The resin sheet 3, the semiconductor chip 4, and the resin sheet 3 are stacked in this order from the top in the figure and housed in the mold 1. After that, the lead frame 5 is sandwiched and fixed by the mold clamping portion 1a. Then, the heated inner mold 1b is pressed against the resin sheet 3. The resin sheet 3 melts and is further pressed by the inner die 1b. At this time, the air entrained in the compression process of the inner mold 1b and the air bubbles contained in the resin escape from the air vent 2. Then, heating is continued, the resin is cured, and the semiconductor chip 4 is sealed.

[0006]

However, the above configuration has the following problems. At the time of pressure molding, the resin melted in the mold 1 receives a uniform pressure, so that the bubbles left behind remain in the melted resin. Since the resin is cured as it is, there is a problem that voids are generated by the bubbles.

To solve this problem, for example, in Japanese Patent Laid-Open No. 6-326143 (Japanese Patent Application No. 5-109381), the contact surface of the resin sheet 3 with the semiconductor chip 4 as shown in FIG. It is described to form. That is, the contact surface of the resin sheet 3 has a spherical shape in which the central portion is raised more than the periphery. When the resin sheet 3 having such a shape is used,
When pressure is applied, the pressure is sequentially transmitted from the center toward the outer circumference. As a result, the pressure in the periphery of the molten resin becomes lower than that in the central portion, and the bubbles are easily expelled.

However, also in this case, in order to adjust the shape of the resin sheet 3 to a convex shape (hereinafter referred to as a preform) before the above-mentioned sealing, a dedicated preform die or the like is provided for each package. You need to prepare. Further, there is a problem that the efficiency of resin production is lowered and the cost is significantly increased.

An object of the present invention is to provide a sealing device for a semiconductor device, which prevents generation of defects and has good manufacturing efficiency, a mold for the sealing device therefor, and a sealing method with low manufacturing cost.

[0010]

In order to solve the above problems and achieve the object, the following means are taken in the mold for a sealing device of a semiconductor device, the sealing device and the sealing method of the present invention. (1) A mold for a sealing device of a semiconductor device according to a first aspect of the present invention is provided so as to face an upper surface and a lower surface of a semiconductor chip to which a lead frame is connected, respectively. And a movable central pressing portion that presses with a central portion of a flat plate-shaped sealing member sandwiched therebetween, and an upper and a lower surface of the semiconductor chip, which face each other and are adjacent to the central pressing portion. A movable peripheral pressurizing portion that is provided to press the peripheral portion adjacent to the central portion of the sealing member, and at least adjacent to the peripheral pressurizing portion, and sandwich the lead frame. And a mold clamping part that is movable relative to each other for fixing. Further, it is arranged so as to sequentially apply pressure from the central pressurizing portion toward the peripheral pressurizing portion on the outer periphery.

In the mold for the sealing device of the semiconductor device according to the present invention, since the portions for pressing the central portion and the peripheral portion of the sealing member are separate and are movable with respect to each other, the pressure is applied. At this time, it becomes possible to decrease the magnitude of the pressure from the central portion of the sealing member toward the peripheral portion. Therefore, it becomes possible to reduce the air bubbles staying in the sealing member and prevent the occurrence of nest defects. (2) A semiconductor device encapsulation device according to a second aspect of the present invention is a semiconductor device on which a lead frame is connected,
Centrally movable parts that are provided to face each other and are movable on both sides of the semiconductor chip, sandwiching the central part of the sealing member arranged on the upper and lower surfaces of the semiconductor chip, and on the upper and lower surfaces of the semiconductor chip. Peripheral pressurizing portions, which are provided so as to face each other and are adjacent to the central pressurizing portion, and which pressurize while sandwiching a peripheral part adjacent to the central part of the sealing member, and at least the peripheral pressurizing portion. And a mold having a mold clamping part that is movable adjacent to each other and is fixed by sandwiching the lead frame. Further, a driving means for driving the sealing member by driving in order from the central pressing portion of the mold to the peripheral pressing portion is provided.

In the semiconductor device sealing device of the present invention described above, since the amount of pressure applied from the central portion to the peripheral portion of the sealing member decreases during sealing, Air bubbles that accumulate are reduced. Therefore, the occurrence of nest defects is prevented. In addition, the cost of the semiconductor device is reduced because there is no need to preform the sealing member.

Further, according to a third aspect of the present invention, the central pressurizing portion has a rectangular shape, and the peripheral pressurizing portion has a concentric one-step or multi-step rectangular shape surrounding the central pressurizing section. And the mold clamping portion is formed in a concentric square shape surrounding and adjoining the peripheral portion.

In the semiconductor device sealing device of the present invention, since the mold is square, the shape of the sealing member matches the shape of the semiconductor chip, and the sealing after sealing is performed. The shaping of the member is easy.

According to a fourth aspect of the present invention, the peripheral pressurizing portion is provided adjacent to the mold clamping portion via a first elastic member, and the tip portion thereof is the non-pressurizing portion. At a first position distant from the tip of the mold clamping portion, and in the state where the mold clamping portion holds the lead frame, the tip portion of the first elastic member resists the urging force of the first elastic member from the lead frame. It is moved to a second position that is a predetermined distance away. Further, the central pressurizing unit is movably provided inside the peripheral pressurizing unit with a second elastic member interposed, and when the peripheral pressurizing unit is at the first position of the mold clamping unit, The tip portion is projected from the tip portion of the peripheral pressure portion, and when the peripheral pressure portion moves to the second position, the tip abuts against the sealing member to press it, and the second elastic A structure in which the distal end portion is located at the same position as the distal end portion of the peripheral pressure portion when the peripheral pressure portion moves into the peripheral pressure portion against the biasing force of the member and the peripheral pressure portion is in the second position. It is said that.

In the above-described semiconductor device sealing device of the present invention, since the amount of pressure applied from the central portion of the melted resin to the peripheral portion thereof decreases, the amount of bubbles remaining in the cured resin decreases and The occurrence of defects is prevented. Further, since the driving means may be the same as the conventional one, the cost of the sealing device can be reduced.

According to a fifth aspect, the driving means comprises:
The mold clamping section, the central pressing section, and the peripheral pressing section are independently driven. In the above-described semiconductor device sealing device of the present invention, since the driving means is independently attached to the central pressing portion, the peripheral pressing portion, and the mold clamping portion, the driving force for pressing is dispersed. The driving means having a relatively weak driving force can be used. Therefore, the cost of the sealing device is reduced. (3) In the method for sealing a semiconductor device according to claim 6, the die clamping portion for sandwiching the lead frame and the periphery of the encapsulating member provided in the die clamping portion and provided on the upper surface side and the lower surface side of the semiconductor chip. A mold is used which includes a peripheral pressurizing part for pressurizing the peripheral part and a central pressurizing part provided in the peripheral pressurizing part for pressurizing the central part of the sealing member. Further, the central pressing portion heats and pressurizes the central portion of the sealing member while the lead frame is sandwiched by the mold clamping portion. Then, the periphery of the sealing member is pressed by the peripheral pressing unit.

In the method of sealing a semiconductor device according to the present invention, since the magnitude of the pressure applied from the central portion to the peripheral portion of the melted sealing member becomes smaller, air bubbles staying in the sealing member are reduced. Decrease. In addition, since the resin cures in a state where the bubbles of the sealing member are reduced, it is possible to prevent the occurrence of a defect in the sealed semiconductor device. Therefore, the manufacturing efficiency is improved. Further, the manufacturing cost is reduced, and eventually the cost of the semiconductor device is reduced.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The same parts as those in FIGS. 6 and 7 are designated by the same reference numerals. 1A is a plan view of an embodiment of the present invention, and FIG. 1B is a sectional view taken along line 1b-1b of FIG. 1A. Hereinafter, the part different from FIG. 7 will be mainly described.

As shown in FIG. 1 (a), the mold 7a has a quadrangular shape and comprises a central quadrangular pressing surface 8a and a mold clamping portion 11a around the pressing surface 8a. As shown in FIG. 1B, the mold 7a
Includes a semiconductor chip (not shown) and a resin sheet which are stacked on top of each other and are composed of an upper part and a lower part so that pressure is applied from the vertical direction in the figure. The upper part and the lower part of the mold 7a are plane-symmetric. The pressing surface 8a of the mold 7a is formed in a concentric square shape by the central pressing portion 9a and the peripheral pressing portion 10a around the central pressing portion 9a. That is, in this case, the pressing surface 8a has two steps. Around the peripheral pressure portion 10a, a mold clamping portion 11a for fixing the lead frame (not shown) is provided. The central pressing portion 9a projects from the peripheral pressing portion 10a on the side where the semiconductor chip is housed (hereinafter referred to as the pressing direction). The mold clamping portion 11a projects in the pressing direction more than the central pressing portion 9a. The central portion 9a and the peripheral pressure portion 10a are movable with respect to the mold clamping portion 11a, as described later.

FIG. 2 is a sectional view showing the construction of the embodiment including a hydraulic mechanism which is a driving means. As shown in FIG. 2, hydraulic mechanisms 6a and 6b are attached to the upper and lower peripheral pressing portions 14 and the mold clamping portions 15 in the drawing, respectively.
The structure of the semiconductor chip 4 and the upper portion of the lead frame 5 will be described below, but the same applies to the lower portion.

The central pressing portion 13 is arranged at the center of the pressing surface of the peripheral pressing portion 14. That is, a concave portion is provided at the center of the pressing surface of the peripheral pressing portion 14, and the central pressing portion 1 is provided in the concave portion.
3 is inserted. The central pressure member 13 is connected to the peripheral pressure member 14 via an elastic body 16.

A convex portion is provided on each of the four side surfaces of the peripheral pressing portion 14. Mold clamping part 1 corresponding to the convex part
A concave portion is provided at a position on the side surface of 5. The convex portion of the peripheral pressing portion 14 is fitted in the concave portion of the mold clamping portion 15. The difference d in the width between the convex portion of the peripheral pressing portion 14 and the concave portion of the mold clamping portion 15 in the pressing direction is sufficiently longer than the distance a1 described later.
That is, the elastic member 17 is inserted into the space between the combined convex portion and concave portion, and the peripheral pressing portion 14 and the mold clamping portion 15 are connected. That is, in the initial state, the elastic member 17 pushes up the peripheral pressure portion 14. In the case of the lower side in the figure,
The elastic member 17 pushes down the peripheral pressing portion 14.

When the semiconductor chip 4, the lead frame 5 and the flat resin sheet 18 are housed in the mold 12, the surface of the resin sheet 18 opposite to the surface in contact with the semiconductor chip 4 and the lead frame are included. The distance from the plane is a1, and the distance between the virtual plane including the pressure surface of the mold clamping portion 15 and the pressure surface of the central pressure portion 13 is b. In this case, the distance a1
Is shorter than the distance b. The distance c between the pressure surface of the peripheral pressure portion 14 and the pressure surface of the central pressure portion 13 is larger than 0. still,
In the case of the lower side in the figure, the distance a2 between the surface of the resin sheet 18 opposite to the surface in contact with the semiconductor chip 4 and the plane including the lead frame is approximately the thickness of the resin sheet 18. On the other hand, the distance a
1 is the sum of the thicknesses of the resin sheet 18 and the semiconductor chip 4. In addition, the central pressure part 13 and the peripheral pressure part 14, and
The sliding portions of the convex portion of the peripheral pressing portion 14 and the concave portion of the mold clamping portion 15 are designed to have a normal fitting tolerance.

It should be noted that the peripheral pressing portion 14 has a concave portion and a mold clamping portion 15
A convex portion may be provided at. In this case, in the initial state,
The elastic member 17 pushes up the peripheral pressure portion 14 on the upper side, and pushes it down on the lower side. In addition, although the convex portion and the concave portion are provided on the four side surfaces, respectively, the convex portion and the concave portion may be provided at one place or a plurality thereof. Further, the convex portion and the concave portion may be formed in a continuous band shape around the four side surfaces. When there are a plurality of protrusions and recesses, it is desirable that the positions where the protrusions and recesses are provided are symmetrical with respect to the center of the mold from the viewpoint of sliding balance.

Next, the operation of the embodiment of the present invention and the sealing method thereof will be described. FIG. 3 is a cross-sectional view for explaining the sealing method in the case of FIG. As shown in FIG. 3A, first, the mold clamping portion 11a is driven, the lead frame 5 is sandwiched by the mold clamping portion 11a, and the semiconductor chip 4 is positioned and fixed. After that, as shown in FIG. 3B, the heated central pressing portion 9a is driven to press and heat the vicinity of the central portion of the flat resin sheet 18. As shown in FIG. 3C, the resin sheet 18 is melted near the center and
The peripheral portion of the resin sheet 18 is pressed by driving the heated peripheral pressing portion 10a. At this point, a difference in pressure between the central portion and the peripheral portion of the melted resin (hereinafter, referred to as a differential pressure) occurs. Therefore, the bubbles inside the molten resin are sequentially pushed out to the outside. Finally, the bubbles escape from the air vent 2 to the outside of the mold 7a.

Further, the central pressing portion 9a and the peripheral pressing portion 10
The heating is continued by a to cure the resin. That is, the semiconductor chip 4 is sealed. The central pressing portion 9a and the peripheral pressing portion 10a on the lower side in the drawing are moved in time with the central pressing portion 9a and the peripheral pressing portion 10a on the upper side.

In the case of FIG. 2, the mold clamping section 15 and the peripheral pressing section 14 of the mold 12 are driven separately and simultaneously at the same speed by the hydraulic mechanisms 6a and 6b. That is, the mold clamping unit 15,
The central pressing portion 13 and the peripheral pressing portion 14 are pressed against the resin sheet 18, the semiconductor chip 4, and the lead frame 5 while maintaining the same positional relationship.

After the lead frame 5 is sandwiched and fixed by the mold clamping portion 15, the peripheral pressure portion 14 continues to be driven by the hydraulic mechanism 6b. The heated central pressing portion 13 presses the central portion of the resin sheet 18 via the elastic body 16. As in the case of FIG. 3, the bubbles inside the molten resin are pushed out to the periphery by the differential pressure. Further, heating is continued, and the resin is sequentially cured from its central portion.

Next, the periphery of the central portion of the resin sheet 18 is pressed by the heated peripheral pressing portion 14. That is,
The resin melts from the center to the periphery, and
Due to the pressure difference, the bubbles inside the resin are further pushed out from the central portion to the outer peripheral side. Thereafter, the semiconductor chip 4 and the lead frame 5 are resin-sealed as in the case of FIG.

In the above-mentioned embodiment, since the magnitude of the pressurization becomes smaller from the central portion of the melted resin toward the outer peripheral portion thereof, the bubbles effectively escape from the air vent 2 to the cured resin. Air bubbles that accumulate are reduced. Therefore,
The occurrence of nest defects is prevented. Further, since there is no need to preform the resin sheet, the manufacturing cost is reduced. In addition, since the mold has a square shape, the shape of the resin sheet matches the shape of the semiconductor chip. That is, it is easy to shape the sealing member after sealing. Further, since the hydraulic mechanisms 6a and 6b may be the same as the conventional ones, the cost of the sealing device does not increase.

In the sealing method of the above embodiment,
Since the amount of pressure applied from the center of the melted resin to the outer circumference decreases, the bubbles remaining in the melted resin decrease. Further, since the resin is sequentially cured from the central portion toward the outer periphery in the state where the bubbles are reduced, the occurrence of nest defects is prevented, the manufacturing efficiency is improved, and the manufacturing cost is reduced. (Modification) A modification will be described. FIG. 4A is a plan view when the pressing surface 8b of the mold 7b of FIG. 1 has three steps. FIG. 4B is a sectional view taken along line 4b-4b of FIG. As shown in FIG. 4A, similarly to the mold 7a, the central pressing portion 9b, the peripheral pressing portions 10b, 10c, and the mold clamping portion 11b are arranged in that order from the center of the mold 7b toward the outer periphery. , Are concentric squares. Further, the mold clamping part 11b, the central pressing part 9b, the peripheral pressing parts 10b, 10c.
Protrude in the pressing direction in that order. In addition, the central pressure unit,
The pressing surface composed of the peripheral pressing portion may have four or more steps. The central pressing portion 9a, the peripheral pressing portions 10b, 10c, and the mold clamping portion 11b are movable with respect to each other.

FIG. 5 is a sectional view showing another modification. FIG. 5 shows a state during operation. The pressing surface, basic structure, operation, and sealing method are the same as those in the above-described embodiment. That is, the pressing surface of the mold 20 is the same as the pressing surface 8a of the first embodiment. The different points will be described below.

As shown in FIG. 5, hydraulic mechanisms 19a, 1 which are respective driving means fixed to another base not shown.
9b and 19c are independently attached to the central pressure part 21, the peripheral pressure part 22 and the mold clamping part 23 of the mold 20, respectively. A servo motor may be used instead of the hydraulic mechanisms 19a, 19b, 19c.

In this case, the hydraulic mechanisms 19c, 19a, 19
b is operated independently. That is, the hydraulic mechanisms 19c, 19
The drive start timings, drive speeds, and pressures of a and 19b are set separately and adjusted to the optimum state. The hydraulic mechanism 19
The mold clamping portion 23, the central pressing portion 21, and the peripheral pressing portion 22 may be pressed against the resin sheet with the same driving start timing, the same driving speed, and the same pressure by c, 19a, and 19b. Therefore, the contact timing of each part is determined by the distance between the mold clamping part 23 and the lead frame 5, the central pressing part 21, the peripheral pressing part 22 and the resin sheet.

In this modification, since each pressurizing unit is driven by another hydraulic mechanism, the driving force for pressurizing is dispersed, and a hydraulic mechanism having a relatively weak driving force can be used.

The molds of the above-mentioned embodiments are rectangular and are arranged concentrically from the central pressing portion toward the outer periphery. However, the arrangement is not limited to this arrangement, and the peripheral pressing portion may be provided outward only on the left and right sides from the central pressing portion.

The vertical direction of the semiconductor chip 4 and the lead frame 5 of the above-described embodiment is in Japanese Patent Application No. 6-3261.
As shown in No. 42, it is preferable that the element surface is downward. That is, the resin sheet 1 is provided on the surface opposite to the element surface of the semiconductor chip 4, that is, the surface of the lead frame 5 that is not connected to the leads.
Equipped with 8. Then, another resin sheet is directly supplied to the lower mold, and at the same time as or immediately after this, the semiconductor chip 4 and the resin sheet 18 mounted thereon are put together on the element side (the resin sheet 18 is a semiconductor The upper side of the chip 4) is supplied to the inside of the mold, and the resin is sealed. In this case, it is possible to prevent problems such as the resin sheet dropping before mold clamping,
It is valid. In addition, at this time, since the resin sheet 18 is mounted on the non-connecting surface between the semiconductor chip 4 and the leads, the connection wire is less likely to be deformed by mounting the resin sheet.

The resin may be a thermoplastic resin which is cured by cooling. In this case, the central pressure unit,
The resin is melted and cured by the heating and cooling of the peripheral pressurizing portion, respectively.

[0040]

As described above, according to the present invention, a semiconductor device encapsulation device which prevents occurrence of defects and has high manufacturing efficiency, a metal mold for an encapsulation device therefor, and a low manufacturing cost encapsulation device. A method can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a mold according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a sealing device for a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a method for sealing a semiconductor device according to an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a mold according to an embodiment of the present invention.

FIG. 5 is a sectional view showing a sealing device for a semiconductor device according to an embodiment of the present invention.

FIG. 6 is a plan view showing a configuration of an example of a mold of a conventional semiconductor device sealing device.

FIG. 7 is a sectional view showing a configuration of an example of a conventional semiconductor device sealing device.

[Explanation of symbols]

 3, 18, 18a ... Resin sheet (or resin), 4 ... Semiconductor chip, 5 ... Lead frame, 1, 7a, 7b, 12, 20 ... Mold, 8a, 8b ... Pressing surface, 9a, 9b, 13, 21 ... central pressing part, 10a, 10b, 10c, 14, 22 ... peripheral pressing part, 11a, 11b, 15, 23 ... mold clamping part, 16, 17 ... elastic member, 6a, 6b, 19a, 19b, 19c ... Hydraulic mechanism.

Claims (6)

[Claims] 1. A semiconductor chip to which a lead frame is connected is provided on an upper surface and a lower surface of the semiconductor chip, respectively, and a flat plate-shaped sealing member disposed on the upper surface and the lower surface of the semiconductor chip is sandwiched by a central portion. A movable central pressing portion that is pressed against each other, and a peripheral portion that is provided adjacent to the central pressing portion facing the upper and lower surfaces of the semiconductor chip, respectively, and that is adjacent to the central portion of the sealing member. A centrally-pressurized portion, which includes a movable peripherally-pressurizing portion that pressurizes with each other, and a mutually movable mold-clamping portion that is provided adjacent to at least the peripherally-pressurized portion and that sandwiches and fixes the lead frame. A mold for a sealing device of a semiconductor device, wherein the mold is arranged so as to sequentially apply pressure to the peripheral pressure applying portion on the outer periphery. 2. A semiconductor chip to which a lead frame is connected is provided on the upper and lower surfaces of the semiconductor chip so as to face each other. A central pressing part, and a semiconductor chip that is provided adjacent to the central pressing part so as to face the upper and lower surfaces of the semiconductor chip, and presses each other while sandwiching a peripheral part of the sealing member adjacent to the central part. A mold having a movable peripheral pressing part, and a mold clamping part which is provided adjacent to at least the peripheral pressing part and which is fixed with the lead frame sandwiched therebetween, and a central pressing part of the mold. A sealing device for a semiconductor device, comprising: a driving unit that drives in order from a pressing unit to a peripheral pressing unit to press the sealing member. 3. The central pressing part has a quadrangular shape, and the peripheral pressing part is formed in a concentric one-step or multi-step quadrangular shape surrounding the central pressing part. 3. The semiconductor device encapsulation device according to claim 2, wherein is formed in a concentric square shape that is adjacent to and surrounds the peripheral portion. 4. The peripheral pressurizing part is provided adjacent to the mold clamping part via a first elastic member, and its tip is separated from the tip of the mold clamping part when no pressure is applied. In the first position, the tip of the second elastic member is separated from the lead frame by a predetermined distance against the urging force of the first elastic member in a state where the mold clamping portion holds the lead frame. To a position, the central pressurizing unit is movably provided in the peripheral pressurizing unit with a second elastic member interposed, and the peripheral pressurizing unit is located at the first position of the mold clamping unit. At a certain time, the tip portion thereof is projected from the tip portion of the peripheral pressure portion, and when the peripheral pressure portion moves to the second position, the tip end abuts against the sealing member to press it, The second elastic member moves into the peripheral pressure applying portion against the biasing force of the elastic member, and the peripheral pressure applying portion moves to the second pressure applying portion. The semiconductor device encapsulation device according to claim 2, wherein the tip portion of the semiconductor device is located at the same position as the tip portion of the peripheral pressurizing portion when in the position. 5. The semiconductor device according to claim 2, wherein the driving unit drives the mold clamping unit, the central pressing unit, and the peripheral pressing unit independently of each other. Sealing device. 6. A mold clamping part for sandwiching a lead frame, a peripheral pressing part for pressing the periphery of a sealing member provided in the mold clamping part on the upper surface side and the lower surface side of a semiconductor chip, and a peripheral pressing part. A mold provided with a central pressure part that is provided in a pressure part and presses the central part of the sealing member is used, and the mold is clamped by the central pressure part while sandwiching the lead frame. A method of encapsulating a semiconductor device, comprising heating and pressurizing a central part of a member, and thereafter applying pressure to the periphery of the encapsulating member by the peripheral pressurizing part.