JPH05345331A - Cylindrical resin tablet and molding machine for same - Google Patents

Abstract

PURPOSE:To melt resin tablets quickly by forming a cylindrical tablet, installing a tablet guide which can be inserted into a hole of a plunger and forms a ring- shaped space between a pot and the plunger, heating the external surface of the tablet by the pot, while heating the internal surface of the tablet by the tablet guide. CONSTITUTION:A resin tablet 65 of a hollowed cylindrical form is produced. A molding machine is equipped with a ring-shaped pot 44 which adjoins a cavity, a plunger which can slide on the pot 44 and moves vertically, and a tablet guide 61 which can be inserted into a hole 60 bored on the plunger and forms a ring-shaped space between the pot 44 and the plunger. The tablet guide 61 is energized by a spring 63 in the direction in which the tablet guide 61 is projected against the plunger. The external surface of tablet 65 is heated by the pot 44, and the internal surface of the tablet 65 is heated by the tablet guide 61 so that the tablet 65 is quickly melted. In this way, the resin tablets can be prompltly subjected to melt injection without installing a complex preheating means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin tablet which is a material for molding a semiconductor element or the like with a synthetic resin, and further, a mold for molding a semiconductor element or the like using the resin tablet. Regarding the device.

[0002]

2. Description of the Related Art In a molding apparatus having a single plunger, since only one resin tablet is used, preheating is generally performed before the resin tablet is put into a mold. However, in a molding apparatus having a plurality of plungers, that is, a so-called multi-plunger type molding apparatus, a large number of resin tablets must be processed at one time, so that the structure for preheating becomes complicated. Therefore, in the multi-plunger type molding apparatus, the resin tablet is put into the mold without being preheated.

As a result, in the multi-plunger type molding apparatus, the resin tablet is less likely to melt, and as the size of the resin tablet increases, unfilling in the mold and defective molding occur.

The present invention firstly solves the above problems by forming a resin tablet into a hollow cylindrical shape.

Secondly, the present invention relates to a molding device for using the resin tablet, which is a molding device for heating and injecting resin into a cavity between an upper mold and a lower mold. An adjacent annular pot, a plunger that is slidable with respect to the pot and that moves up and down, and a tablet guide that can be inserted into a hole formed in the plunger and forms an annular space between the pot and the pot. And a spring for urging the tablet guide in a protruding direction with respect to the plunger.

[0006]

According to the first aspect of the invention, the resin tablet has a larger specific surface area, that is, a heat transfer area per unit volume, than that of a solid resin tablet. Therefore, the molten state is achieved in a shorter time than the solid one.

According to the second invention, the cylindrical resin tablet is heated by the pot on the outer peripheral surface and by the tablet guide on the inner peripheral surface. As the resin tablet melts and then the plunger slides against the pot, the tablet guide immerses into the hole formed in the plunger.

By providing an air vent hole in this hole,
The air filled in the holes is discharged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 3 is a schematic elevational view showing a molding apparatus 10 according to the present invention. The upper mold part 13 is provided on the lower surface of the top platen 12 fixed to the upper ends of the pair of guide posts 11.
Lower mold parts 15 are fixed to the movable platen 14 so as to face each other. The movable platen 14 is moved up and down by a hydraulic cylinder (not shown) to open and close the upper mold 16 and the lower mold 17. Reference numerals 18 and 19 denote concavo-convex pins for engaging the concavities and convexities with each other just before the mold clamping to perform the mold matching.

4 to 6 show the lower mold part 15 in detail. However, FIG. 4 shows only the half of the lower mold part 15 with respect to the center plane XX. The lower die part 15 has a center plane XX on the base 20 fixed on the movable platen 14.
It has a groove 21 which is symmetrical with respect to and parallel to the center plane XX. In this groove 21, a movable plate 22 is arranged so as to be able to move up and down at a symmetrical position with respect to a Y-Y plane that is perpendicular to the center plane X-X. Therefore, four movable plates 22 are provided for convenience.

A main transfer hydraulic cylinder 23 having a small stroke is provided at the bottom of the groove 21 in which each movable plate 22 is installed.
A vertical hole 24 serving as a hydraulic chamber is formed. This vertical hole 2
The upper end of the rod 26 of the piston 25 fitted in 4 is screwed and fixed to the movable plate 22. 27 is a rod cover screwed onto the upper end of the vertical hole 24, and 28 is an oil seal. Vertical holes 29 are formed on both sides of each vertical hole 24, a guide lock 31 is fitted into a bush 30 inserted and fixed in the vertical hole 29, and an upper end of the guide lock 31 is attached to the movable plate 22 by a nut 32.
The movable plate 22 is guided so as to move up and down in a horizontal state.

The equal pressure cylinder device 33 fixed on the movable plate 22 is moved up and down integrally with the movable plate 22 by the hydraulic cylinder 23. In the vertical plane aa parallel to the XX plane, a large number (six in the present embodiment) of equal pressure hydraulic cylinders 34 arranged at predetermined intervals are provided. Each cylinder 3
The piston rod 35 of No. 4 is connected to the lower end of the plunger 37 by the connector 36. Isobaric hydraulic cylinder 34
A known pressure is applied to the.

A lower die support plate 40 is fixed on the base 20 via a heat insulating plate 39 having square holes 38 through which the isobaric cylinder device 33 can pass. A square hole 41 is provided to surround 33 ascending / descending passages. A block 42 is fitted in the square hole 41 so as to be flush with the lower die receiving plate 40, and a hole 43 concentric with the constant pressure hydraulic cylinder 34 is formed in the block 42. The connector 36 is guided up and down through the hole 43. In addition, the pot 44
The lower end of is inserted.

The pot 44 is provided so as to pass through a support block 45 fixed on the lower die receiving plate 40 and a lower die 17 fixed on the upper portion thereof. The pot 44 has an annular flange 46 in the middle thereof. Annular flange 46
Is fitted in an annular recess formed in the upper surface of the support block 45, and is pressed by the lower mold 17. As a result, the pot 44 is fixed. A lower end of the plunger 37 is fixed to the connector 36, and an intermediate portion of the plunger 37 is in sliding contact with the inner surface of the pot 44.

Chase blocks 49, which are long in the XX direction, are flushly embedded in the lower mold 17 on both sides of the pot 44, and a resin passage 50 is provided between a cavity provided in the chase block 49 and the outer surface of the upper end of the pot 44. Are formed. Upper mold 1
6 also has a chase block, and a resin passage 51 that connects the pot 44 and the resin passage 50 in the mold closed state is formed.

Immediately below the chase block 49, a lateral groove 52 in the XX direction is formed in the support block 45, and metal fittings 54 and 55 urged downward by disc springs 53 combined in series vertically are provided therein. Has been. The lower end heads of a pair of ejector pins 56 are sandwiched between the metal fittings 54 and 55 just below the cavity. The ejector pin 56 penetrates the hole of the lower mold 17 and is held so that its upper end is flush with the inner surface of the cavity 57. Reference numeral 58 is a support pillar.

FIG. 1 shows the upper portion of the plunger 37 in detail. A hole 60 is formed at the tip of the plunger 37. A tablet guide 61 that can appear and disappear is inserted into the hole 60. A spring 63 is fitted and inserted between the bottom of the hole 60 and the tablet guide 61, and the spring 63 normally biases the tablet guide in a protruding direction. Hole 60
An air vent hole 64 is formed at the bottom of the hole, and the air in the hole 60 is discharged when the tablet guide is submerged.

The resin tablet 65 has a hollow cylindrical shape, as shown in FIG. Its inner diameter is slightly larger than the outer diameter of the tablet guide 61. Resin tablet 65
Is inserted between the pot 44 and the tablet guide 61, as shown in FIG. The tablet guide 61 and the tip of the resin tablet 65 are set to be flush with each other.

FIG. 7 shows another embodiment. This embodiment is used for a so-called upper plunger type molding apparatus. 44 'is a pot and 37' is a plunger. A hole 60 'is formed in the lower mold 17', and a tablet guide 61 'which can be retracted and inserted is fitted in the hole 60'. A spring 63 'is inserted between the bottom of the hole 60' and the tablet guide 61 ', and the spring 63' biases the tablet guide 61 'in a protruding direction. Hole 6
An air vent hole 64 'is formed in the bottom of 0', and when the tablet guide 61 'is submerged, the air in the hole 60' is discharged.

The resin tablet 65 'is inserted between the pot 44' and the tablet guide 61 '. And
The tablet guide 61 'and the tip of the resin tablet 65' are set to be flush with each other.

[0021]

According to the first aspect of the present invention, by making the resin tablet into a hollow cylindrical shape, the specific surface area, that is, the surface area per unit volume is expanded as compared with the solid resin tablet, and The resin tablet can be brought into a molten state at an early stage by increasing the heat transfer area at. As a result, even in a multi-plunger type molding apparatus, it is possible to quickly melt and inject a resin tablet without providing a complicated preheating mechanism, shorten the molding time, and improve the production efficiency.

A second aspect of the present invention is a molding device for handling a hollow cylindrical resin tablet, wherein the resin tablet is put into an annular space defined by a pot and a tablet guide, so that the resin tablet can be immediately used. Moreover, since the plunger is immersed when the plunger slides on the pot, air is not mixed with the molten resin.

According to the third aspect of the present invention, since the air in the hole is discharged when the tablet guide is immersed in the hole formed in the plunger, an escape path for the air when the tablet guide is operated is secured. You can
It is possible to prevent air from being mixed into the molten resin.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an upper portion of a plunger of a molding apparatus according to the present invention.

FIG. 2 is a perspective view of a hollow cylindrical resin tablet according to the present invention.

FIG. 3 is an overall front view of the molding apparatus according to the present invention.

4 is a plan view showing a part of a lower die in the molding apparatus of FIG.

5 is a partial side view of the molding apparatus of FIG.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is a partially enlarged cross-sectional view of a molding device according to another embodiment.

[Explanation of symbols]

 10 Molding device 13 Upper mold part 15 Lower mold part 16 Upper mold 17,17 'Lower mold 37,37' Plunger 44,44 'Pot 60,60' Hole 61,61 'Tablet guide 63,63' Spring 64,64 'Air vent hole 65,65' Resin tablet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H01L 21/56 C 8617-4M T 8617-4M // B29L 31:34 4F

Claims (3)

[Claims] 1. A resin tablet used for molding a semiconductor element or the like, which has a hollow cylindrical shape. 2. A molding device for heating and injecting resin into a cavity between an upper mold and a lower mold, the annular pot being adjacent to the cavity and slidable with respect to the pot. A plunger that operates, a tablet guide that can be inserted into a hole formed in the plunger and forms an annular space between the pot, and a spring that biases the tablet guide in a protruding direction with respect to the plunger. A molding device comprising: 3. The molding apparatus according to claim 2, wherein the plunger has an air vent hole communicating with the hole.