JPH02134833A - Resin molder - Google Patents

Abstract

PURPOSE:To obtain the construction of an ejector which does not need delicate adjustment and whose ejector pins can be attached and detached easily with a simple structure by a method wherein the rear side end of each ejector pin is so constructed as to be attached to and detached from an ejector plate directly. CONSTITUTION:A plurality of cavities 17 are formed on parting planes of a pair of upper and lower dies 13 of a resin molder and resin is cast in the cavities 17 with a high pressure to form packages corresponding to the shapes of the cavities 17. An ejector pin 21 whose tip plane can protrude into the cavity 17 is provided for each cavity 17. The rear side end of the ejector pin 21 is fitted directly to an ejector plate 22 which is provided outside the dies 13 so as to be attached and detached easily. For instance, a fitting hole 23 having a key slot shape is provided on the ejector plate 22 and the large diameter pin head part 21a is fitted to the fitting hole 23 of the ejector plate 22 to fix the ejector pin 21 to the ejector plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device, and particularly to a technique that is effective when applied to a resin molding process in the manufacture of a resin-molded semiconductor device.

[Conventional technology]

An example of this type of technology described is Japanese Patent Laid-Open No. 52-95765.

The above-mentioned publication describes in detail the resin molding device used for forming a puff cage in the manufacturing process of a resin-sealed semiconductor device, and particularly the mold structure thereof.

Generally, in such resin molding equipment, a plurality of cavities are formed on each dividing plane of a pair of molds consisting of an upper mold and a lower mold, and a lead frame is placed between both molds. The package is formed by injecting molten resin into the cavity at high pressure and heating and hardening the resin in the shape of the cavity around the lead frame.

The outline of such a resin molding device will be explained using FIG. 6.

In the figure, a mold section 64 is fixed to a base unit 63 (substrate) supported by a platen 62. The core part 64 has a mold body 66 with a cavity 65 on its upper surface.
have. An ejector pin 67 is vertically provided on the mold body 66 for ejecting the package after molding. FIG. 7 shows such an ejector mechanism in more detail.

In the same figure, an ejector plate 68 and a presser plate 70 are fixed by bolts 72 at predetermined intervals via a collar 71, and a pin on the rear end side of the ejector pin 67 is located between the ejector plate 68 and the presser plate 70. It has a structure in which the head 67a is held in place.

An extrusion plate 74 equipped with an extrusion pin 73 is disposed on the side opposite to the cavity of the mold section 64, and the extrusion pin 73 penetrates the base unit 63 and presses the holding plate 70 of the ejector mechanism in the direction of the cavity. The structure is such that

Due to such an extrusion operation of the extrusion plate 74, the tip end surface of the ejector pin 67 held by the presser plate 70 and the ejector plate 68 moves in a direction in which it is protruded from the bottom surface of the cavity, and this ejection force causes the ejector pin 67 to be formed in the cavity. The structure is such that the package is detached and taken out from the mold body 66.

[Problem to be solved by the invention]

However, in the ejector structure shown in FIG. 7, firstly, it is necessary to finely adjust the axial length of each collar 71 in order to ensure that the amount of protrusion of the ejector pin 67 is a specified value.
Precise machining such as cutting the end face of the collar 71 was required, and the effort required for adjustment was excessive.

Second, in the above ejector structure, when replacing the ejector pin 67 due to damage or wear, the bolts 72 that fix each part such as the ejector plate 68, collar 71, and presser plate 70 are warmed, and each of these parts is heated. After separating into parts, the ejector pin 67 to be targeted is replaced, and the above-mentioned parts are fixed again with bolts 72, which is a complicated work. As a result, the efficiency of maintenance work has been greatly reduced.

Thirdly, as shown in FIG. 7, in addition to the ejector plate 68 to hold the ejector pin 67, a large number of components such as a presser plate 70 and a collar 7m bolt 72 are required, which makes the assembly work complicated. This also resulted in an increase in parts costs.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an ejector structure that does not require delicate adjustments such as machining of collars, has a simple structure, and allows easy attachment and detachment of ejector pins. The object of the present invention is to improve the workability of maintenance in a resin molding device.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

An overview of typical inventions disclosed in this application to the troops is as follows.

That is, the structure is such that the rear end side of the ejector pin is directly attached to the ejector plate in a removable manner.

[Effect]

According to the above-mentioned method, the ejector pin can be fixed to the ejector plate without using parts such as collars, pressers, or bolts to fix these, so fine adjustment of the protrusion amount can be done by processing only the ejector pin. In addition, when the ejector pin is damaged or worn out, it can be replaced by attaching and detaching only the target ejector pin, and furthermore, by reducing the number of parts, the ejector structure is easy to assemble and can be realized at low cost.

As a result, the workability of maintenance of the resin molding device can be greatly improved.

〔Example〕

FIG. 1 is a perspective view showing the structure of the ejector in the resin molding apparatus of this embodiment, FIG. 2(a) is a partially enlarged plan view showing the fitting hole in the ejector plate of this embodiment, and FIG. ) is an example of a partial sectional view showing the internal structure of the ejector plate of this embodiment, and FIGS. 3(a) to (6)
are front and bottom views showing the ejector pin, respectively;
FIG. 4 is an explanatory view of a main part showing the structure near the mold in the resin molding apparatus of this embodiment, and FIG. 5 is a schematic explanatory view showing the overall structure of the resin molding apparatus.

As shown in FIG. 5, the resin molding apparatus 1 used in this embodiment includes an upper mold part 3a held by an upper fixed platen 2, and a lower mold part 3b supported by a lower movable platen 4.
It has The detailed structure of the upper mold part 3a and the lower mold part 3b is as shown in FIG. 4, and the details will be described later.

The fixed platen 2 is supported above the stage by a column 9 hanging vertically from the apparatus base 5, and a transfer cylinder 7 into which the tablet 6 is inserted is attached to the upper part of the fixed platen 2. A platen driving cylinder 8 for moving the movable platen 4 up and down is provided at the bottom of the apparatus base 5, and the platen driving cylinder 8 is controlled by a control unit 10 disposed on the side of the stage.

Next, the structure of the upper mold part 3a and the lower mold part 3b will be explained based on FIG. 4. Note that the same members in the upper mold part 3a and the lower mold part 3b are given the same reference numerals to simplify the explanation.

A mold body 1 is mounted on the main surface of a base unit 12 supported by a plurality of support pillars 11 on a movable platen 4.
3 is fixed by a guide 14.

The mold body 13 is composed of a plurality of block unit structures, and FIG. 1 shows the structure of one of them.

The mold body 13 is made of a metal member such as die steel that can sufficiently withstand a mold temperature of about 180° C., and a runner 15, which is a passage for molten resin, is bored in its upper surface (dividing plane). The runner 15 is further branched into a plurality of branches and communicates with the cavity 17 via a gate 16 at its tip. The surface of the mold body 13 is chromium plated to improve the mold releasability from the package 18. In each of the cavities 17, an ejector hole 20 is perforated in the bottom surface 17a in the vertical direction, and the ejector hole 20 is configured to penetrate through the upper and lower surfaces of the mold body 13.

The ejector pin 21 of this embodiment is shown in FIG. 3(a), and has a bottle head 21a formed in a short shaft shape with a diameter of about 6 to 8 m1T1, and a long shaft shape with a diameter of 2 to 31TllTl. At least the tip and circumferential surfaces of the bottle shaft 21b are plated with chrome. Such an ejector pin 21 has its pin shaft portion 21b aligned with the ejector hole 2.
The tip of the bottle is exposed at the bottom of the cavity 17, and under normal conditions, the ejector pin 21
The distal end surface is on the same plane as the cavity bottom surface 17a, that is, it forms a part of the cavity bottom surface 17a.

As the ejector pin 21, in addition to the one shown in FIG. 3(a), those having structures shown in FIG. These can be replaced as appropriate depending on the product, that is, the shape and size of the cavity 17 formed in the mold body 13.

Therefore, when replacing the mold, these ejector pins 21 are also replaced as necessary.

An ejector plate 22 is arranged below the mold body 13. On the surface of this ejector plate 220, as shown in FIG.
As shown in a), a fitting hole 23 is opened. This fitting hole 23 is composed of an insertion portion 23a having a relatively large diameter and a fitting portion 23b having a relatively small diameter. and the fitting lI23b is the ejector pin 2
The first bottle shaft portion 21b is movable in the horizontal direction, and has a radial length that prevents the bottle head 21a inserted into the ejector plate 22 from falling off in the vertical direction. The cross-sectional structure of the ejector plate 22 at this fitting portion 23b is the second
As shown in FIG. is prevented.

The ejector pin 21 is positioned with respect to the mold body 13 while being attached to the ejector plate 22, and is supported on the base unit 12 by a guide 14. At this time, the ejector plate 22 has an elastic means 2 such as a tension spring.
5 in the direction opposite to the cavity 17.

Since the upper mold part 3a and the lower mold part 3b have the same structure, repeated explanation will be omitted.

Next, the operation of this embodiment will be explained together with the resin molding process realized by the resin molding apparatus 1 of this embodiment.

First, a heater (not shown) built into the base unit 12 is activated and the mold body 13 is heated to a predetermined temperature of about 180° C., and then a semi-molten tablet 6 made of epoxy resin is introduced into the transfer cylinder 7. be done.

Next, when the lead frame 19, which is the object to be molded, is positioned and placed between the upper mold part 3a and the lower mold part 3b, the platen driving cylinder 8 is operated under the control of the control part 10. , the movable platen 4 is raised, and the upper mold part 3a and the lower mold part 3b are in a closed state. In this way, both mold parts 3a.

When 3b is closed, the mold clamping force is, for example, 150
(T).

Next, the transfer cylinder 7 operates and the tablet 6
When a transfer pressure of about 75 (Kgf/cm2) is applied to the tablet 6, the synergistic effect with the heating causes the tablet 6 to turn into a molten resin, causing the runner 15 and gate 16 to melt.
is injected into the cavity 17 at high pressure.

By heating and hardening the resin injected under high pressure as described above, a package 18 corresponding to the shape of the cavity 17 is formed around the lead frame 19.

When taking out such a package 18, first, the platen driving cylinder 8 is operated to open the upper mold part 3a and the lower mold part 3b. At this time, the package 18 formed within the cavity 17 is in a state where it is attracted to either the upper mold part 3a or the lower mold part 3b.

When the ejector plate 22 is pressed in the direction of each cavity 17 in this state, the tip end surface of the ejector pin 21 moves in the direction of protruding from the cavity bottom surface 17a, and the package 18 that has been attracted by this protrusion force is moved into the mold. Main body 1
Will be withdrawn from 3rd.

The ejector pin 21 is damaged and worn out due to sliding with the ejector hole 20 while repeating the above ejecting operation. At this time, each ejector pin 21 may need to be replaced.

When replacing the ejector pin 21 in this manner, according to this embodiment, the mold body 13 and the ejector plate 22 are removed from the guide 14 as shown in FIG. 1, and the ejector pin 21 is replaced as shown in FIG. Once the ejector pin 21 is slid horizontally to move the pin head 21a to the insertion portion 23a of the fitting hole 23, the ejector pin 21 is pulled out from the ejector plate 22 in the vertical direction. When attaching a new ejector pin 21 to the ejector plate 22, after inserting the pin head 21a of the ejector pin 21 into the insertion part 23a of the fitting hole 23 of the ejector plate 22, Complete installation by sliding horizontally in the direction.

In this way, in this embodiment, the ejector pin 21 can be removed and attached extremely easily. Therefore, the work efficiency in replacing the ejector pin 21 can be greatly improved.

Further, as shown in FIG. 1, the ejector mechanism is composed of only the ejector plate 22 and the ejector pin 21, and the number of parts is extremely small, so that manufacturing costs can be reduced.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the mounting structure of the ejector pin on the ejector plate is that it fits into the fitting hole of the ejector plate, but it is not limited to this.The ejector pin itself has a screw structure and is fixed by screwing itself to the ejector plate. It may be something that does.

In the above explanation, the invention made by the present inventor was mainly applied to the field of application, which is package molding in a so-called resin mold type semiconductor device, but the present invention is not limited to this. It can be widely applied to other electronic devices and electronic components having the same structure.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, fine adjustment of the amount of protrusion by the ejector pin and replacement of the ejector pin become extremely easy.

Moreover, the ejector structure can be easily assembled and realized at low cost by reducing the number of parts.

As described above, the workability of maintenance in the resin molding device can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the ejector structure in the resin molding device of this embodiment, FIG. 2(a) is a partially enlarged plan view showing the fitting hole in the ejector plate of this embodiment, and FIG. 2(b) is a partial cross-sectional view showing the internal structure of the ejector plate of this embodiment, FIGS. 3(a) to (6) are front and bottom views showing the ejector pin, respectively, and FIG. 4 is the resin molding device of this embodiment. 5 is a schematic explanatory diagram showing the overall structure of a resin molding device. FIG. 6 is an explanatory diagram of essential parts showing a structure near a mold of a resin molding device in the prior art. FIG. 7 is a perspective view showing an ejector structure in the prior art. 1... Resin molding device, 2... Fixed platen, 3
a...Upper mold part, 3b...Lower mold part, 4...Movable platen, 5...Device base, 6...Tablet, 7...
・Transfer cylinder, 8...Platen drive cylinder, 9...Strut, lO...Control unit, ll...Support pillar, 12...Pace unit, 13...Mold body, 14...・・Guide, 15・・Runner, 16・
... Gate, 17... Cavity, 17a... Cavity bottom, 18... Package, 19... Lead frame, 20... Ejector hole, 21... Ejector pin, 21a... Pin head part, 21b...pin shaft part, 22...ejector plate, 23...fitting hole,
23a...insertion part, 23b...fitting part, 24a...
- Large space part, 24b... Small space part, 25... Elastic means, 61... Resin molding device, 62... Platen, 63... Base unit (substrate), 64... Mold part , 65... Cavity, 66... Mold body, 67...
...Ejector pin, 67a...Pin head, 68...
・Ejector plate, 70... Presser plate, 71... Blank,
72... Bolt, 73... Extrusion pin, 74... Extrusion plate. Runner gate cavity ejector hole Ejector pin Ejector plate fitting hole (b) (G) (b) (c) (d) Figure Figure 7

Claims (1)

[Scope of Claims] 1. A resin molding device that forms a package corresponding to the shape of the cavity by high-pressure injection of resin into a plurality of cavities formed on a dividing plane of a pair of upper and lower molds, The ejector pin is provided with an ejector pin capable of protruding its tip surface, and the ejector pin is removably attached at its rear end directly to an ejector plate provided outside the mold. Resin molding equipment. 2. A fitting groove is formed near the rear end of the ejector pin, the shaft diameter of which is smaller than that of other parts, and the ejector plate is provided with a corresponding keyhole-shaped fitting hole. 2. The resin molding device according to claim 1, wherein the ejector pin is fixed to the ejector plate by fitting a pin head formed with a large diameter into a fitting hole of the ejector plate.