JPH10258441A - Resin molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding apparatus having simple constitution and almost not molding or generating a non-molded product part. SOLUTION: This resin molding apparatus is constituted of a freely up and down movable upper mold 5 having a shape of a molded product formed to the single surface thereof and provided with a part of one or a plurality of cavity parts, the lower mold 6 opposed to the upper mold and having the residual part constituting the cavity part 1 provided to the single surface thereof and having the small diameter 9 through the conical taper part 10 continuing to the large diameter part 3 becoming a charging part of a tablet-shaped molding resin 2 provided thereto so as to be connected to the bottom surface of the cavity part 1 and an up and down freely movable plunger 4 corresponding to and coinciding with the large diameter part 3 and pressing the molding resin 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding apparatus used for sealing small electronic components and semiconductor elements with a thermosetting resin material by transfer molding or the like.

[0002]

2. Description of the Related Art As a conventional resin molding apparatus, a resin molding apparatus for electronic parts by transfer molding will be described as an example with reference to the drawings.

FIG. 3 is a cross-sectional view of a main part of a conventional resin molding apparatus by transfer molding using a thermosetting resin, and FIG. 4 is a plan view of a main part of a lower mold of the same apparatus. , 15 are upper dies having an injection hole 13 in the center, and 12 is a molding resin, which is a tablet formed by pressing a required amount of a thermosetting resin in a cylindrical shape into a cylinder in advance. . Reference numeral 14 denotes a plunger made of a metal material such as a steel material, which slides in the charging hole 13 to press the molding resin 12.

Numeral 16 denotes a lower mold facing the upper mold 15, and a cull portion 17 serving as a melting portion of the molding resin 12 is provided on the upper surface thereof corresponding to the lower opening of the charging hole 13. 1
7 and a pair of runner portions 18 serving as a flow path of the molten molding resin 12 are provided in a pair. The other end of the runner portion 18 is connected to a gate portion 19 serving as an injection portion of the molten molding resin 12. A cavity 11 is formed at the tip of the gate portion 19 to form a molded product together with the upper die 15. The upper die 15 and the lower die 16 are heated to a predetermined temperature by a heating mechanism (not shown).

[0005] The outline of the resin molding process using the conventional resin molding apparatus configured as described above is as follows. After the molding resin 12 using a tablet is charged into the cull portion 17 through the charging hole 13, the plunger 14 is lowered. By pressing the molding resin 12, the molding resin 12 is melted by heating with a mold and pressurizing by the plunger 14 in the cull portion 17, and the molten molding resin 12 is applied by the plunger 14. The pressure is injected into the cavity 11 via the runner 18 and the gate 19 to form a desired molded product.

[0006]

However, in the resin molding apparatus having the above-mentioned conventional construction, a cull portion 17, a runner portion 18, and a gate portion 19, which are not molded products, occur after molding, and these must be disposed of. There was a problem that the material yield was poor because it was not necessary.

[0007] Further, in a molded product in which a side gate must be adopted, there is also a problem that the gate portion needs to be separately cut in a later process.

An object of the present invention is to provide a resin molding apparatus which does not require a non-molded part and which is excellent in cost and productivity. is there.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, a resin molding apparatus according to the present invention is a resin molding apparatus comprising a large-diameter hole connected from a small-diameter hole for resin inflow through a conical tapered portion. And a plunger for pressurizing the molding resin having a shape corresponding to the shape of the molding resin charging portion, and connecting the cavity to the cavity formed in the mold. The molding resin is charged into the portion, heated and melted, and is then pressure-fed into the cavity by a plunger.

According to the present invention, resin molding can be performed without providing a non-molded portion such as a cull portion, a runner portion, and a gate portion.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that at least one of an upper mold and a lower mold has a cavity formed with a cavity for molding a molded article having a desired shape; A resin molding die provided with a molding resin injection section connected to a large diameter hole via a conical tapered portion from a small diameter hole for resin inflow provided to communicate with the cavity portion, and a heating mechanism. A molding resin having a heating mechanism formed in a shape corresponding to the shape of a large-diameter hole connected via a conical tapered portion from the small-diameter hole serving as a resin inflow path provided in the resin molding die. It consists of a plunger for pressurization, and heats and melts the molding resin injected into the molding resin input section provided in the resin molding die, and is pressure-fed into the cavity by the plunger. Yes, non-molded parts It has the effect of not raised.

According to a second aspect of the present invention, in the first aspect of the present invention, a tablet is used in which a required amount of powdery thermosetting resin for a molded article is press-molded into a predetermined shape as a molding resin. The height of the conical tapered portion provided on the resin molding die is set to 0.5 to 1.0 times the height of the tablet, and the diameter of the small diameter is set to 0.3 to 0.8 of the tablet diameter.
The diameter of the large-diameter hole is twice or slightly larger than the diameter of the tablet, and has the effect of efficiently melting the molding resin and smoothly flowing into the cavity.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of a resin molding apparatus using a thermosetting resin in the embodiment, and FIG. 2 is a plan view of a main part of the lower mold. In FIGS. A cavity that forms the shape of the molded product,
The upper die 5 made of a super-steel material or the like and the lower die 6 are divided by an opposing portion of the upper surface of the lower die 6 with a parting surface interposed therebetween.

Reference numeral 3 denotes a large-diameter hole which is a resin injection portion for molding having a circular cross section with the lower surface of the lower mold 6 being an opening, a conical tapered portion 10 having a trapezoidal vertical cross section, and a small-diameter hole which is an injection tip hole. 9
Is connected to the lower surface of the cavity part 1 via 4
Is a vertically movable plunger made of a super-steel material or the like, having a tapered portion 10 at the tip and a small-diameter hole 9 as an injection tip hole.
And a conical tapered portion 7 and a distal end portion 8 corresponding to the above.

Reference numeral 2 denotes a molding resin, which is prepared by measuring a necessary amount of a solid powder resin such as a thermosetting resin in a molded product in advance, and pressing it into a cylindrical shape called a tablet.

The upper mold 5 and the lower mold 6 are heated to a predetermined temperature (the heating mechanism is not shown).
0 is 0.5 of the height of the tablet-like molding resin 2.
The diameter of the large-diameter hole 3 at the bottom is equal to or slightly larger than the diameter of the tablet molding resin 2, and the small-diameter hole 9 at the tip is 0.3 to 0.3 mm of the diameter of the tablet molding resin 2. 0.
It is eight times the diameter.

Next, the operation of the thus-configured resin molding apparatus of the present embodiment will be described. First, the molding resin 2 is charged into the large-diameter hole 3 forming the molding resin charging section (a transport charging mechanism is not shown), and the plunger 4 is raised (a driving mechanism is not shown). The resin for use 2 comes into contact with the inner surface of the charging portion 3 and the tapered portion 10 from the surface thereof and starts melting due to the temperature of the mold, but actually flows into the cavity portion 1 through the small-diameter hole 9 which is the injection tip hole. Not melted to possible viscosity.

Subsequently, when the plunger 4 is further raised, the molding resin 2 is pressed and passes while being compressed by the inclination of the tapered portion 10. At this time, the height of the molding resin 2 is increased by the structure of the tapered portion 10. Pressure is applied, and due to the shear heating effect, a low-viscosity molten state that can flow into the cavity portion 1 and can be formed is formed.

Then, the plunger 4 is further raised, and finally, the tip 8 of the plunger 4 enters the small-diameter hole 9 which is the injection tip hole, and the tapered portion 7 of the plunger 4 comes into contact with the tapered portion 10. By raising the plunger 4, the molten molding resin 2 is caused to flow into the cavity 1 to form a desired molded product.

Thereafter, the plunger 4 is lowered to return to the original position, and the upper mold 5 and the lower mold 6 are released from the mold clamping to take out the molded product, thereby completing the resin molding process.

The upper die 5 and the lower die 6 can be turned upside down by 180 degrees, and the plunger 4 can be set on the upper part of the die, or the whole can be rotated in either direction 90 degrees. It is.

In the present embodiment, the cavity 1 is divided into an upper mold and a lower mold. However, the cavity 1 may be arranged in only one of them.

[0023]

As described above, according to the present invention, a cull part, a runner part, and a gate part which are not molded articles are not required, the amount of molding resin used is reduced, the yield is improved, and the size of the mold is reduced. In addition, the molded article using the side gate has an advantageous effect that the gate cutting in a later step is not required.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a resin molding apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the lower mold.

FIG. 3 is a sectional view of a main part of a conventional resin molding apparatus.

FIG. 4 is a plan view of a main part of the lower mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cavity part 2 Molding resin 3 Large diameter hole 4 Plunger 5 Upper die 6 Lower die 7 Tapered part 8 Tip part 9 Small diameter hole 10 Tapered part

Claims (2)

[Claims] 1. A cavity having at least one of an upper mold and a lower mold having a cavity for molding a molded article having a desired shape, and a resin inflow provided to communicate with the cavity. A resin injection mold connected to the large-diameter hole through a conical tapered portion from the small-diameter hole, and a resin molding die having a heating mechanism, and a resin inflow path provided in the resin molding die. It is formed in a shape corresponding to the shape of the large-diameter hole connected from the small-diameter hole via a conical tapered portion and comprises a plunger for pressurizing a molding resin provided with a heating mechanism, and is provided in the resin molding die. A resin molding apparatus which heats and melts the molding resin charged into the molding resin charging section provided and feeds the resin into the cavity by a plunger. 2. Use of a tablet obtained by press-molding a required amount of a thermosetting resin in a predetermined shape as a molding resin into a predetermined shape as a molding resin, and forming a height of a conical tapered portion provided in a resin molding die. The height of the tablet is 0.5 to 1.0 times the height of the tablet, and the diameter of the small diameter is 0.3 to 0.8 of the diameter of the tablet.
2. The resin molding apparatus according to claim 1, wherein the diameter of the large-diameter hole is twice or slightly larger than the diameter of the tablet.