JPH043767Y2 - - Google Patents

Description

[Detailed explanation of the idea] "Industrial application field" The present invention relates to a mold for transfer molding.

``Prior Art'' Generally, in a transfer molding machine, thermosetting resin is put into a heating chamber called a pot, softened, and then pushed into a mold cavity by a plunger. It is designed to be hardened, and is used, for example, when molding into lead frames and the like.

5 and 6 show a conventional example of a mold used in a transfer molding machine, and the mold includes a cavity 4A near the center of the upper mold 21,
A pot 3 communicating with 4B is provided, and
A resin inlet 22 is formed which communicates with the front and rear of the mold while the upper part of the pot 3 is open. That is, the base plate 2 attached to the molding machine is divided into left and right parts above the pot 3, and the distance between the divided ends 2a is wider than the inner diameter of the pot 3, and the base plate 2 and the cavity 4A are separated. , 4B, a plurality of cylindrical posts 23
are arranged, and a rectangular notch 25 communicating between the divided edges 2a of the base plate 2 is formed in the spacer block 24 arranged at the front and rear of the mold, so that these base plates 2, The post 23 and the spacer block 24 allow the spacer block 2
The resin inlet 22 is formed such that the notch 25 of No. 4 and the pot 3 communicate with each other through the post 23.

``Problem that the invention attempts to solve'' However, with a mold having such a structure, the post 2 is placed in a position that avoids the resin inlet 22.
3, the mating surface (parting line) of the mold near the lower position of the resin inlet 22
The mold clamping pressure acting on the upper mold 2 becomes lower than on other parts, and the resin injection pressure into the cavity 4A disposed below the resin inlet 22 causes the upper mold 2 to
1 tends to warp upward from the vicinity of the resin inlet 22. As a result, a gap is created between the mating surfaces of the molds, causing burrs on the product. Furthermore, if an ejector pin (not shown) is provided in the upper mold 21, the sliding of the ejector pin This tends to cause problems such as difficulty in releasing the product from the mold due to warping.

The present invention effectively solves the above problems.
The purpose is to equalize the mold clamping pressure and prevent the occurrence of burrs.

"Means for Solving the Problems" The present invention consists of a template connected to the back of the mold, a plurality of posts erected on the back of the template, and a resin molded plate provided on the back of the template. In a transfer molding mold comprising a charging pot and a resin charging port extending from the side of the template toward the pot, at least one of the plurality of posts is inserted into the resin charging port. The post is characterized in that it is disposed in a protruding state toward the pot, and that the post is formed with an inclined surface that becomes more distant from the axis of the pot as it moves away from the pot.

"Example" Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4.

1 and 2 show the first embodiment of the present invention. Also in the mold of the first embodiment, the base plate 2 of the upper mold 1 is divided into left and right parts above the pot 3 and separated. The upper part of the pot 3 is in an open state due to the fact that the base plate 2
It is similar to the conventional example in that a plurality of posts 7 and 8 are arranged between the base and the template 6 supporting the chase 5 for forming the cavities 4A and 4B. The difference is that the resin inlet 9 formed along the front-rear direction between the divided edges 2a of the plate 2 is shaped so that its opening width gradually decreases downward. . That is, the notches 11 of the spacer blocks 10 disposed at the front and rear parts of the mold are formed in an inverted trapezoidal shape communicating between the divided edges 2a of the base plate 2, and the notches 11 in the vicinity of the pots 3 A post 7 is formed in a prismatic shape and is disposed so as to protrude inward from the divided edge 2a of the base plate 2, and has a post 7 on the top thereof which is the same as the inclined surface 11a of the notch 11 of the spacer block 10. Parallel inclined surfaces 7a are formed within the plane, and these inclined surfaces 7a and 11a form side walls of the resin inlet 9, so that the opening width of the resin inlet 9 is gradually reduced downward. This is what is being done. Note that the reference numeral 12 in FIG. 1 is a plunger that is press-fitted into the pot 3.

In a mold having such a structure, when a so-called mold clamping pressure is applied in the mold clamping state shown in FIG. At the same time as the clamping pressure is applied, the mold clamping pressure applied to the upper surface of the post 7 generates a component force along the inclined surface 7a as shown by the arrow in FIG. The mold clamping pressure acts in a distributed manner on the contact surface with the mold, and is transmitted to the mating surface of the mold below the contact surface, that is, below the resin inlet 9.
Therefore, the clamping pressure on the mating surfaces of the molds can be made approximately equal as a whole.

FIG. 3 shows a second embodiment of the present invention, in which the post 13 and the notch 15 of the spacer block 14 have inclined surfaces 13a, 15a.
are arranged so as to form the lower side wall of the resin inlet 16, and the upper opening of the resin inlet 16 is connected to the base plate 2.
Workability during resin injection is improved by widening the width to the same width as the dividing edge 2a, and in this case, part of the mold clamping pressure is applied to the inclined surfaces 13a,
It can act on the mating surface of the mold below the resin inlet 16 along line 5a.

FIG. 4 shows a third embodiment of the present invention, in which the inclined surfaces 17a and 19a of the post 17 and the notch 19 of the spacer block 18 are curved into an arc shape.
The opening width of the resin inlet 20 is further increased.

In addition, in each of the above embodiments, the base plate 2 and the template 6
A plurality of posts are arranged between the base plate 2 and the mold plate 6 to apply clamping pressure to the mating surfaces of the mold through these posts, but the base plate 2 and the mold plate 6 are supported by an integral block. You may also do this as follows:
In this case, the block is formed with a groove-shaped resin inlet opening communicating the upper part of the pot 3 with the outside of the mold, and the side wall thereof is formed with an inclined surface.

"Effects of the Invention" As explained above, the transfer molding mold of the present invention includes a template connected to the back of the mold, a plurality of posts erected on the back of the template, and In a transfer molding mold comprising a resin injection pot provided on the back side of a template, and a resin injection port extending from a side of the template toward the pot, at least one of the plurality of posts is provided. The book is disposed in a protruding state inward of the resin inlet, and the post is formed with an inclined surface that is spaced apart from the axis of the pot as it moves away from the pot, so that mold clamping pressure is uniform. Since the part can also be applied below the resin inlet along the inclined surface, the mold clamping pressure as a whole can be equalized, preventing burrs from occurring on the product, and the ejector pin inside the mold can be When the ejector pin is provided, the ejector pin slides smoothly and the product can be easily taken out.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the first embodiment of the transfer molding mold of the present invention, and FIG.
3 and 4 are longitudinal cross-sectional views of essential parts showing the third and fourth embodiments of the present invention, respectively, and FIG. 5 is a transfer molding die. FIG. 6 is a vertical sectional view showing a conventional example of the present invention, and FIG. 6 is a view taken along the line - in FIG. 1...Top mold, 2...Base plate, 3...Pot,
4... Cavity, 5... Chase, 6... Template, 7, 8, 13, 17... Post, 7a, 13
a, 17a... Inclined surface, 9, 16, 20... Resin inlet, 10, 14, 18... Spacer block, 11, 15, 19... Notch, 11a, 15
a, 19a... Slanted surface.

Claims (1)

[Scope of utility model registration request] A mold plate connected to the back side of the mold, a plurality of posts erected on the back side of the mold plate, a resin injection pot provided on the back side of the mold plate, and a mold plate connected to the mold plate from the side of the mold plate. In a transfer molding mold including a resin inlet extending toward a pot, at least one of the plurality of posts is disposed in a protruding state inward of the resin inlet, and
A mold for transfer molding, characterized in that the post is formed with an inclined surface that is spaced apart from the axis of the pot as it moves away from the pot.