JPH11340261A - Mold for resin encapsulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability and productivity in resin molding, as well as to simplify the process of automatic mold removal. SOLUTION: There is provided a knockout pin plate 3, having a knockout pin 4 provided reciprocatively on the opposite side of a cavity in a lower plate 2 for ejecting a package inside the cavity 55a on the movable side. The knockout pin 4 of the knockout pin plate 3 comprises an inner knockout pin 10 and an outer knockout pin 11 in axial alignment. The inner knockout pin 10 is axially movable reciprocatively inside the outer knockout pin 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealing mold suitable for use in molding a package of a semiconductor device.

[0002]

2. Description of the Related Art Generally, this type of resin sealing mold includes:
2. Description of the Related Art There are known two upper and lower mold plates each having a cavity for molding a package for sealing a semiconductor element, and a knockout pin that projects a package in a cavity of a lower mold plate.

In order to form a semiconductor element encapsulation package in such a resin encapsulation mold, the lead frame on which the semiconductor element is mounted is sandwiched between both mold plates in advance, and the mold is closed. A thermosetting resin is injected into the mold, the mold plates are separated from each other, the mold is opened, and then the package in the cavity is pushed out by a knockout pin.

Conventionally, this type of resin sealing mold is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-147633, and is configured as shown in FIG. The resin-sealing mold will be described with reference to the same figure. In the same figure, the resin-sealing mold indicated by reference numeral 51 is an upper mold plate (not shown) and a lower mold plate 5.
2, a knockout pin plate 53 and a knockout pin 54.

[0005] An upper mold plate (not shown) has a cavity block (not shown) and the like, and is fixed at a predetermined height position. In a cavity block (not shown) of the upper mold plate (not shown), a fixed side cavity (not shown) for opening a semiconductor sealing package is formed, which opens downward. The lower template 52 has a cavity block 55, a base plate 56, and a mounting plate 57, and is movably disposed below an upper template (not shown).

[0006] The cavity block 55 is fixed to the upper surface of the base plate 56. Cavity block 5
5 has an opening upward and a fixed side cavity (not shown)
Are formed on the movable side cavity 55a.
The cavity block 55 has a pin insertion hole 55 opened on the bottom surface of the cavity and the bottom surface of the cavity block.
b is provided.

[0007] The base plate 56 includes a mounting plate 5.
7 is fixed via a support block 58.
The base plate 56 is provided with a pin insertion hole 56a that opens in the same axial direction as the pin insertion hole 55b. Further, the base plate 56 is provided with a screw hole 56b that opens in an axial direction parallel to the axial direction of the pin insertion hole 56a and into which the mounting screw 59 is screwed.

The knockout pin plates 53 are composed of two main and sub knockout pin plates
0, 61, and is disposed between the base plate 56 and the mounting plate 57, and is disposed around the mounting screw 59 via a spacer 62 so as to be movable up and down. A return force toward the mounting plate 57 is applied to the knockout pin plate 53 by a spring 63. The downward movement of the knockout pin plate 53 is restricted by the head 59 a of the mounting screw 59.

The main knockout pin plate 60 is formed of a single knockout pin plate, and is disposed near the mounting plate 57. The auxiliary knockout pin plate 61 includes two upper and lower auxiliary knockout pin plates 6.
1a, 61b, the main knockout pin plate 6
0 is integrated with a mounting screw 64 and disposed near the base plate 56. The upper auxiliary knockout pin plate 61a has two pin insertion holes 55b,
A pin insertion hole 61A that opens in the same axial direction as the axial direction of 56a is provided.

The mounting plate 57 has a pin insertion hole 55
b, 56a, 61A open in a direction parallel to the axial direction,
Shaft insertion hole 57 through which plate push-up rod 65 is inserted
a is provided.

The knockout pin 54 is provided with a flange 54a interposed between the two auxiliary knockout plates 61a and 61b.
And a tip portion is formed by a knockout pin that protrudes a package (not shown) in the movable side cavity 55a. The knockout pin 54 is inserted into each of the pin insertion holes 55b, 56a, and 61A, and is fixed to the knockout pin plate 53.

In the resin sealing mold having the above-mentioned structure, a semiconductor device sealing package is formed and taken out as follows. First, a lead frame (not shown) on which a semiconductor element (not shown) is mounted in advance is placed on the lower template 52, and the lower template 52 is raised with respect to the upper template (not shown). And close the mold. At this time, a semiconductor element (not shown) is arranged in the fixed side cavity (not shown) and the movable side cavity 55a.

Next, a thermosetting resin is injected into the fixed side cavity (not shown) and the movable side cavity 55a. Thereafter, the lower mold plate 52 is lowered to open the mold.
At this time, the package P shown in FIG. 6 is disposed in the movable side cavity 55a with a part thereof being exposed to the outside.

Then, the knock-out pin plate 53 is raised by the plate push-up bar 65, the package P in the movable side cavity 55a is pushed up by the knock-out pin 54, and then the package P (package IC) is taken out from the lower mold plate 52. In this way, the package P for sealing the semiconductor element can be formed and taken out. In FIG. 6, the pin mark p of the knockout pin 54 is formed on the package P of the package IC indicated by the reference numeral 70.

[0015]

By the way, in this type of resin sealing mold, the pin diameter of the knockout pin 54 is set to a relatively small size. When the size of the package or the size of the semiconductor element (pellet) becomes large, the knockout pin 5 remains with a part of the package P adhered to the movable side cavity 55a during the forward movement of the pin (during knockout operation).
4 was pushed up.

As a result, a bending stress acts on a package or a pellet during a knockout operation, and a chip or a chip in a thin package and a large pellet in a TQFP or the like is generated, thereby lowering the reliability in resin molding. There was a problem.

Therefore, it is conceivable to set the pin diameter of the knockout pin to a size larger than the conventional pin diameter. In this case, however, a part of the molded product easily adheres to the tip surface of the knockout pin after the knockout operation. In addition to the simplification of automatic removal of molded products, there was a problem that productivity was reduced.

Although the prior art is disclosed in Japanese Unexamined Patent Publication No. 4-147633 as "mold for resin sealing", the above-mentioned problem has not been solved. That is, the resin sealing mold disclosed in the publication has a knockout pin serving as a bottom surface of the lower mold side cavity.

Therefore, in such a resin sealing mold, since a bending stress acts on the package and the pellet during the knockout operation, the occurrence of the chipping of the package and the chip cannot be prevented.

The present invention has been made in view of such circumstances, and it is possible to increase the reliability and productivity of resin molding and to simplify the automatic removal of molded products. The purpose is to provide a mold.

[0021]

According to a first aspect of the present invention, there is provided a resin sealing mold according to the first aspect of the present invention, which has a cavity for molding a semiconductor element sealing package. And a knockout pin plate having a knockout pin that is reciprocally disposed on the opposite side of the lower mold plate of the two mold plates and protrudes a package in the cavity, and includes a knockout pin of the knockout pin plate. , Formed by two inner and outer knockout pins located on the same axis, wherein the inner knockout pin is constituted by a knockout pin that can reciprocate along the axis with respect to the outer knockout pin. Therefore, when the knockout pin plate moves forward during the knockout operation, first, the package is pushed up by the two inner and outer knockout pins, and when the knockout pin plate moves forward in the same direction, the package is pushed up only by the inner knockout pin.

According to a second aspect of the present invention, in the resin sealing mold according to the first aspect, the upper mold plate of the two mold plates is a fixed mold plate, and the lower mold plate is a movable mold. . Therefore, when closing the mold, the lower template moves in a direction approaching the upper template, and when opening the mold, the lower template moves in a direction away from the upper template.

The invention according to claim 3 is the invention according to claim 1 or 2
In the resin molding die described above, the inner knockout pin has a configuration in which a return force is applied by a spring. Therefore, after the knockout operation, the inner knockout pin returns to the initial position before the knockout operation by the spring.

According to a fourth aspect of the present invention, in the resin sealing mold according to the first, second, or third aspect, the outer knockout pin comprises a knockout pin having a square cross section. Therefore, a shape close to the planar shape of the package can be obtained as the push-up surface shape of the knockout pin.

According to a fifth aspect of the present invention, in the resin sealing mold according to any one of the first to fourth aspects, a link mechanism for imparting a forward power to the inner knockout pin by the forward movement of the knockout pin plate is provided. It has a configuration to have.
Therefore, when the knockout pin plate moves forward,
The forward power is applied to the inner knockout pin by the link mechanism.

According to a sixth aspect of the present invention, in the resin sealing mold according to the fifth aspect, the link mechanism moves in the backward movement direction of the knockout pin by abutting against the cavity side due to the forward movement of the knockout pin plate. And a pin drive lever that applies forward power to the inner knockout pin toward the cavity by rotation of the lever drive shaft due to the movement of the lever drive shaft. Therefore, when the lever drive shaft comes into contact with the cavity side by the forward movement of the knockout pin plate, it moves in the backward movement direction of the knockout pin, and the rotation of the pin drive lever accompanying this movement causes the inner knockout pin to move toward the cavity side. Forward power is applied.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of a resin sealing mold according to a first embodiment of the present invention, and FIG.
FIGS. 3A and 3B are cross-sectional views showing a package being pushed up by inner and outer knockout pins and an inner knockout pin of the resin sealing mold according to the first embodiment of the present invention, and FIG. 3 is a resin according to the first embodiment of the present invention. 3 is a plan view showing an IC package formed by a sealing mold. In the drawings below, the same members (portions) as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, a resin sealing mold denoted by reference numeral 1 includes an upper mold plate (not shown), a lower mold plate 2, a knockout pin plate 3, a knockout pin 4, and a link mechanism 5.

The lower template 2 has a cavity block 6, a base plate 7, and a mounting plate 57, and is movably disposed below an upper template (not shown). The cavity block 6 is fixed on the upper surface of the base plate 7. The cavity block 6 is provided with a pin insertion hole 6a which is open on the bottom surface of the cavity and the bottom surface of the cavity block. The diameter of the pin insertion hole 6a is
The size is set to be larger than the hole diameter of the above-described conventional pin insertion hole 55b (shown in FIG. 5).

The base plate 7 includes a mounting plate 57.
It is fixed above via a support block 58. The base plate 7 is provided with a pin insertion hole 7a that opens in the same axial direction as the pin insertion hole 6a. The diameter of the pin insertion hole 7a is set to be substantially the same as the diameter of the pin insertion hole 6a.

The knockout pin plate 3 has a main knockout pin plate 8 and a sub knockout pin plate 9, is arranged between the base plate 7 and the mounting plate 57, and has a spacer 6 around the mounting screw 59.
2 so as to be able to move up and down freely. A return force to the mounting plate 57 is applied to the knockout pin plate 3 by a spring 63. The downward movement of the knockout pin plate 3 is restricted by the head 59a of the mounting screw 59.

The main knockout pin plate 8 is composed of a single knockout pin plate.
7 is arranged in the vicinity. The main knockout pin plate 8 has a lever storage space 8 opened on the upper and lower surfaces of the plate.
a is formed. Secondary knockout pin plate 9
Are the upper and lower two knockout pin plates 9a, 9b
The main knockout pin plate 8 has mounting screws 6
4 and is arranged near the base plate 7.

The upper auxiliary knockout pin plate 9a is provided with a pin insertion hole 9A that opens in the same axial direction as the axial direction of both pin insertion holes 6a and 7a.
The diameter of the pin insertion hole 9A is the same as that of the two pin insertion holes 6a and 7a.
The dimensions are set to be substantially the same as the hole diameters of. The lower auxiliary knockout pin plate 9b is opened in the same axial direction as the axial direction of the pin insertion hole 9A, and the lever storage space 8 is provided.
A through-hole 9B communicating with a is provided. The diameter of the through hole 9B is set to be larger than the diameter of the pin insertion hole 9A.

The knockout pins 4 are located on the same axis, and the two knockout pins 10 and 11 whose front ends can move up and down in the movable side cavity 55a.
Is formed by The inner knockout pin 10
A knockout pin having a circular cross section that can reciprocate along the axis with respect to the outer knockout pin 11 is provided on the opening edge of the lever storage space 8 a in the main knockout pin plate 8. And inside knockout pin 1
0 is set to a dimension whose axial length is greater than the axial length of the outer knockout pin 11, and the spring 1
2 gives a return behavior to the mounting plate 57 side. A flange 10a located in the through hole 9B of the lower auxiliary knockout pin plate 9b is provided at an end of the inner knockout pin 10 opposite to the cavity.

The outer knockout pin 11 is formed by a flange 11 interposed between the two auxiliary knockout pin plates 9a and 9b.
a, which is inserted into each of the pin insertion holes 6a, 7a, 9A and is fixed to the knockout pin plate 3.

The diameter of each of the knockout pins 10, 11 is determined according to the package size and the pellet size. For example, package size 14 × 14m
m TQFP, the inner knockout pin 10 has a pin diameter of 2-3 mm and the outer knockout pin 11
Is set to 10 to 12 mm.

If the gap in the radial direction between the knockout pins 10 and 11 is too large, the thermosetting resin enters between the knockout pins 10 and 11 during resin molding,
If the diameter is too small, the sliding resistance of the inner knockout pin 10 with respect to the outer knockout pin 11 becomes high.
It is set to 0 μm.

Further, in the mold closed state, the protrusion amount of the knockout pin 4 from the bottom surface of the movable side cavity 55a is set to 0 to 50 μm. In addition, the tip surfaces of both knockout pins 10 and 11 are located on the same surface, or the tip surface of inner knockout pin 10 is located at a position slightly lower than the tip surface of outer knockout pin 11. In this case, the pin mark p2 shown in FIG.
The position of the distal end surface of the inner knockout pin 10 is determined so that it does not protrude above the surface.

The link mechanism 5 has a lever drive shaft 13 and a pin drive lever 14, and is disposed on the knockout pin plate 3. The lever drive shaft 13 is inserted into the sub knockout pin plates 9a and 9b so as to be able to move up and down. On the opposite side of the cavity of the lever drive shaft 13 (on the side of the mounting plate), a hemispherical lever pressing portion 13a which is in contact with one end of the pin drive lever 14 in the lever storage space 8a of the main knockout pin plate 8 is formed. .

The pin drive lever 14 is a substantially L-shaped lever as a whole, and is disposed in the lever storage space 8a via a support shaft 15 so as to be rotatable in the directions of arrows a1 and a2 shown in FIG. . A hemispherical pin pressing portion 14a that contacts the flange 10a of the inner knockout pin 10 is formed at an end of the pin driving lever 14 opposite the lever driving shaft.

In the resin-sealing mold having the above-described structure, a semiconductor-sealing package P is formed and taken out as follows. First, a lead frame (not shown) on which a semiconductor element (not shown) is mounted in advance
Is placed on the lower template 2 and the lower template 2 is raised with respect to the upper template (not shown) to close the mold. At this time,
A semiconductor element (not shown) is arranged in the fixed side cavity (not shown) and the movable side cavity 55a.

Next, a thermosetting resin is injected into the fixed side cavity (not shown) and the movable side cavity 55a. Thereafter, the lower mold plate 2 is lowered to open the mold. At this time, the package P shown in FIG. 3 is arranged in the movable side cavity 55a with a part thereof being exposed outside the cavity.

Then, the knockout pin plate 3 is raised by the plate push-up bar 65, and the package P in the movable side cavity 55a is pushed out by the knockout pin 4.

At this time, when the knockout pin plate 3 moves toward the base plate (upward), the knockout pins 10 and 11 and the lever drive shaft 13 move in the same direction. Further, when the knockout pin plate 3 moves in the same direction, the lever drive shaft 13 comes into contact with the base plate 7, and the reaction force of this contact causes the lever drive shaft 13 to move forward.
Returns to the side opposite to the base plate (downward). When the lever drive shaft 13 is pressed, the pin drive lever 14 rotates in the direction of arrow a1 shown in FIG. 1, and this rotating force pushes the inner knockout pin 10 in the upward direction.

For this reason, FIG.
As shown in (a), the package P is pushed up by both knockout pins 10 and 11, and then the package IC 70 is pushed up only by the inner knockout pin 10 as shown in FIG. Thereafter, the package P (package IC) is taken out from the lower mold plate 2. In this way, the package P for sealing the semiconductor element can be formed and taken out.

Therefore, in the present embodiment, the tip surfaces of the knockout pins 10 and 11 come into contact with the package P during the knockout operation, so that bending stress does not act on the package or pellet as in the prior art, It is possible to prevent chipping or chipping of the pellet. Further, in the present embodiment, during the knockout operation, the tip surfaces of both knockout pins 10 and 11 are
The contact of only the inner knockout pin 10 with the package P after contact with the package P can prevent the knockout pin 4 from adhering to the package P after the knockout operation.

In this embodiment, the case where the outer knockout pin 11 is formed of a cylindrical knockout pin has been described. However, the present invention is not limited to this. No problem. In this case, a flat square pin mark p3 is formed on the package P as shown in FIG. Therefore, a shape similar to the planar shape of the package can be obtained as the push-up pin shape of the knockout pin, and the occurrence of chipping of the package or chipping can be more effectively prevented.

In this embodiment, the case where the upper mold plate and the lower mold plate are a fixed mold plate and a movable mold plate, respectively, has been described. However, the present invention is not limited to this. Of course, the plates may be a movable plate and a fixed plate, respectively.

[0048]

As described above, according to the present invention, the knockout pins of the knockout pin plate are formed by two inner and outer knockout pins located on the same axis, of which the inner knockout pin is the outer knockout pin. Since the knockout pin is reciprocable along the axis, the knockout pin plate moves forward during the knockout operation.First, the package is pushed up by the two inner and outer knockout pins, and when the knockout pin plate further moves in the same direction, The package is pushed up only by the internal knockout pins.

Therefore, the tip surfaces of both knockout pins come into contact with the package during the knockout operation, so that bending stress does not act on the package or pellet as in the prior art, and the occurrence of chipping of the package or chip is prevented. Reliability in resin molding can be improved.

Further, since only the inner knockout pins contact the package after the tip surfaces of both knockout pins contact the package during the knockout operation, it is possible to prevent the knockout pins from adhering to the package after the knockout operation. Therefore, productivity can be improved, and simplification of automatic removal of molded products can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of a resin sealing mold according to a first embodiment of the present invention.

FIGS. 2 (a) and (b) are cross-sectional views showing inner and outer knockout pins and a package pushed up state by inner knockout pins of a resin sealing mold according to a first embodiment of the present invention.

FIG. 3 is a plan view showing an IC package formed by a resin sealing mold according to the first embodiment of the present invention.

FIG. 4 is a plan view showing an IC package formed by a resin sealing mold according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a lower mold of a conventional resin sealing mold.

FIG. 6 is an IC formed by a conventional resin sealing mold.
It is a top view showing a package.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold for resin sealing 2 Lower mold plate 3 Knockout pin plate 4 Knockout pin 5 Link mechanism 6 Cavity block 55a Movable cavity 7 Base plate 8 Main knockout pin plate 9 Secondary knockout pin plate 9a Upper secondary knockout pin plate 9b Lower secondary knockout Pin plate 10 Inner knockout pin 11 Outer knockout pin 12, 63 Spring 13 Lever drive shaft 14 Pin drive lever 15 Support shaft 70 Package IC P Package

Claims (6)

[Claims] 1. An upper and lower mold plate having a cavity for molding a package for encapsulating a semiconductor element, and a reciprocatingly disposed one of the two mold plates on a side opposite to a cavity of a lower mold plate. And a knockout pin plate having a knockout pin that protrudes the package in the knockout pin plate.
A resin sealing mold formed by two inner and outer knockout pins located on the same axis, wherein the inner knockout pin comprises a knockout pin that can reciprocate along the axis with respect to the outer knockout pin. . 2. The resin sealing mold according to claim 1, wherein the upper mold plate is a fixed mold plate and the lower mold plate is a movable mold plate. 3. The resin sealing mold according to claim 1, wherein a return force is applied to the inner knockout pin by a spring. 4. The knockout pin according to claim 1, wherein the outer knockout pin comprises a knockout pin having a square cross section.
4. The resin sealing mold according to 2 or 3. 5. The resin sealing mold according to claim 1, further comprising a link mechanism for applying a forward power to the inner knockout pin by a forward movement of the knockout pin plate. 6. A lever drive shaft, wherein the link mechanism moves in the backward direction of the knockout pin by abutting against the cavity side due to the forward movement of the knockout pin plate, and the link mechanism is rotated by the movement of the lever drive shaft. 6. A pin driving lever for applying forward power to the cavity side to the inner knockout pin.
The resin sealing mold as described in the above.