JPS5936937A - Forming apparatus for semiconductor device - Google Patents

Abstract

PURPOSE:To miniaturize the size of molding apparatus and enhance resin efficiency by forming a chamber to which resin is supplied at the area near the cavity of bottom force and by supplying resin in the chamber into the cavity by means of a plunger. CONSTITUTION:A plurality of top force cavities 10 are formed in the top force 8 and the end point of top force ejector pin 11 which moves vertically together with the top force ejector plate 12 reaches the top force cavity 10. The bottom force 25 provides both the bottom force cavity 26 and the bottom force ejector pin 29. The bottom force 25 provides a chamber 42 to which the resin is supplied and the plunger head 49 at the end point of plunger 48 is accommodated in the chamber 42. A semiconductor device 38 is loaded in the forces and the resin is supplied to the chamber 42. Thereafter, the lower plate 21 is moved upward for tightening the forces. Then, the plunger head 49 is also moved upward by the cylinder 43, thereby supplying the resin in the chamber 42 into the cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding apparatus for semiconductor devices.

In the manufacture of semiconductor devices, after a semiconductor element is electrically connected to a lead frame using wire bonding or die bonding, the outer periphery of the semiconductor element is sealed with a resin such as epoxy to protect it from external mechanical and physical pressure. Such methods are generally known. The present invention relates to a molding device used in this resin sealing process.

A conventional molding apparatus will be explained in detail with reference to FIGS. 1 and 2. First, the upper mold relationship will be explained.

In FIG. 1, 1 is an injection cylinder, and a plunger 2 and a plunger head 3 are provided at the tip of the cylinder.
The plunger 2 and plunger head 3 are connected to the upper platen 4.
．． It passes through the heat insulating plate 5 and enters a chamber 9 fixed to the upper surface plate 1 and upper die 8 held via the frame plate 6.

The upper mold 8 has an upper mold cavity 10 formed in a part thereof, and is fixed to an upper surface plate T. 11 is an upper ejector bin, and upper surface plate 1. Penetrate the upper mold 8 and press the upper mold tool 1
2 with a presser plate 13. Further, its tip reaches the upper mold cavity 10. The upper ejector bin 11 has a structure that allows it to move vertically together with the upper ejector plate 12. 14 is a guide bin.

One end is fixed to the upper surface plate 7, and the other end is fitted into a guide bush 15 provided in the upper mold ejector plate 12, and serves as a guide for vertical movement of the upper mold ejector plate 12. A spring 16 is provided as a VC between the cutting pA plate 5 and the upper mold ejector plate I/-) 120, and serves to push the upper mold ejector plate 12 downward.

At this time, the upper mold ejector plate 12 is stopped downward by a stopper 17. Also, the upper mold 8 attached to the upper surface plate 7. The upper ejector plate 12 and the like are fixed to the upper platen 4. 18 is a return pin.

Next, the relationship between the lower molds will be explained. 21 is the lower platen,
The lower leg #124 is held via the heat insulating plate 22 and the frame plate 23, and the lower die 25 is fixed 51 on the lower surface plate 24. The lower mold 25 has a lower mold cavity 26 in a part thereof. Bot27.
A runner 28 is formed. bong) 27 is provided directly below the chamber 9. 29 is a lower mold ejector pin, one end of which is connected to the lower mold 25. It passes through the lower surface plate 24 and is fixed to a part of the lower mold cavity 2 - 6 , and the other end is fixed to the lower mold ejector plate 30 by a presser plate 31 .

A spring 32 serves to push down the lower mold ejector spring 30, and is provided between the lower surface plate 24 and the holding plate 31. 33 is a stopper.

34 is a fixing plate of the molding press main body, 35 is a mold clamping cylinder which is a driving means for clamping the upper die 8 and the lower die 25, and is attached to the fixing plate 34, The rod 36 is fixed to the lower platen 21. In this state, the lower platen 21 moves in the vertical direction while being guided by the mold clamping cylinder 35 and the guide ball 31. 3
8 is a semiconductor device, and 39 is a gate (FIG. 2).

Next, the actual operation will be explained. A semiconductor device 38 is loaded on the upper surface of the lower mold 25, and the upper mold 8. The lower mold 25 is clamped by the mold clamping cylinder 31
Clamp the mold from C to the state shown in Figure 1. The tree j[n is introduced into the chamber s from the space W of the borrowed mold 8 (in this case, the plunger head 3 is raised upward). After injection, the injection cylinder 1 is operated to lower the plunger 2 and the resin contained in the chamber 9 is compressed by the plunger head 3, and the resin flows from the bot 27 to the runner 28. The space surrounded by the upper mold cavity 10 formed in the upper mold 8 and the lower mold cavity 26 formed in the lower mold 25 is filled through the gate 39 (FIG. 2) and a predetermined group is filled. ) The molding is completed. After hy shape, upper mold 8. The lower mold 25 is opened and the semiconductor device 38 is taken out. At this time, the upper mold ejector bin 11 and the lower mold ejector kubbin 29 are as follows.
Lower mold capacity 26. It plays the role of extruding the molded product in the upper mold cavity 10 (the details of this mold 11 will be omitted).

However, when using a molding apparatus configured in this manner, there are a number of drawbacks as described below.

0) It is very difficult to center the plunger head 3 and chamber 9. The difference between the outer diameter of the plunger head 3 and the inner diameter of the chamber 9 is generally narrow, about 0.1 mm, and it is necessary to perform center alignment each time the mold is removed from the press for mold repair, etc. , which is very inconvenient and requires a lot of effort and time.

- Since the upper mold 8 always requires a space W to store the resin, the entire device becomes large.

■ tg As shown in Figure 2, the resin is bot 27. Injected into each lower mold cavity 26 via the runner 28,
The lower mold cavity 26 can actually be used as a molded product.
There is only resin in the runner 2B part and pot 2.
The resin in section 7 is a senior resin. This indicates poor resin efficiency.

There were many problems with conventional molding equipment.

This invention has been made to eliminate the above-mentioned drawbacks. Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 3, the same reference numerals as in FIGS. 1 and 2 indicate the same components, and 40 is a guide pin, one end of which is connected to the lower surface plate
4, and the other end is fitted into a guide bush 41 provided through the lower mold ejector plate 30 and the presser plate 31, and serves as a guide for the vertical movement of the lower mold ejector plate 30. A plurality of upper mold cavities 10 are installed in the upper mold 8, and the tips of the upper mold ejector bins 11 reach each upper mold cavity 10, respectively.

The upper ejector bin 11 moves up and down together with the upper ejector plate 12. A lower mold cavity 26 is formed in the lower mold 25 to pair with each of the plurality of upper mold cavities 10 formed in the upper mold 8, and a required number of chambers 42 are formed.

Further, the lower mold ejector bin 29 is attached with the same structure as the upper mold 8. A cylinder 43 is attached to the heat insulating plate 22, and a rod 44 is attached to the pnd plate 45. The p-rad board 45 is guided by a guide rod 46 fixed to the heat insulating board 22 and a gripper 4T, and is moved up and down by a cylinder 43 connected to the p-rad 36. A plunger 48 is fixed to the ρ Rad plate 45, and a plunger head 49 is attached to the tip of the plunger 48. The plunger head 49 is always inside the chamber 42 and is always movable up and down within the chamber by the drive of the mold clamping cylinder 35.

Further, the p-rad plate 45 and the lower mold ejector plate 30 are configured to be movable individually.

Next, the operation will be explained. When the mold clamping cylinder 35 is operated and the lower platen 21 is moved downward, a gap S is created between the upper mold 8 and the lower mold 25. Using this interval S, the semiconductor device 3
8 is loaded into the mold. Further, resin is also loaded into the chamber 42 using this interval S. Note that the resin is placed in chamber 4.
2, the plunger head 49 is lowered.

After the above operations are completed, the lower platen 21 is raised and the upper mold 8. The lower mold 25 is clamped. When this mold clamping is completed, the p-rad plate 45 is raised by the cylinder 43. Along with this rise, the plunger head 49 also rises, and the chamber 4
The resin loaded in 2 is injected into each cavity 10.26 to complete the prescribed molding. After that, the molded product in the mold is opened and removed. At this time, each ejector bin 11.29 serves to extrude the molded product in each cavity 10.26 when the mold is opened, but the details thereof will be omitted. The chamber 42 is close to each cavity 10.26 731
It is equipped with iK.

Incidentally, in the upper example, the cylinder 43 is placed inside the device, but it may also be provided below the device (some ingenuity is required in this case). Further, in the drawing, the plungers 48 are driven in multiple numbers for 431 cylinders, but it goes without saying that the same effect can be obtained even if the plungers 48 are provided with individual cylinders 43.

As explained above, the present invention provides a plurality of cavities in the upper and lower molds, forms a required number of chambers near these cavities, and provides a plunger with a plunger head that is always fitted in the chambers. In addition, since the resin is loaded using the gap between the upper mold and the lower mold, which is always formed when a semiconductor device to be molded is loaded into the mold, the following effects can be obtained. .

That is, (1) Since the plunger head is always inside the chamber, it is not necessary to center the plunger and the chamber by moving the mold in and out, as long as the plunger head is aligned when assembling the mold.

(2) Since the injection of resin utilizes the space required for loading and unloading the semiconductor device, a special space for loading the resin is not required, making the entire device compact.

(3) Since the chamber can be set close to each cavity, there is no need for conventional pipes and large pots, resulting in good resin efficiency.

(4) The resin can be poured over the entire surface of the mold, and the positions are close to each other in terms of height, resulting in good workability. Therefore, automatic insertion of resin is easy.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a bag portion of a conventional molding apparatus for semiconductor devices, Fig. 2 is a plan view of the lower mold of Fig. 1, and Fig. 3 is a bag of a molding apparatus for semiconductor devices showing an embodiment of the present invention. FIG. In the figure, 4 is the upper platen, 6 is the frame plate, 1 is the upper surface plate, 8 is the upper mold, 10 is the upper mold cavity, 11 is the shed ejector pin, 12 is the upper mold ejector plate, 13 is the presser plate, 21
23 is a lower platen, 24 is a lower surface plate, 25 is a lower mold, 26 is a lower mold cavity, 29 is a lower mold ejector bin,
30 is a lower mold ejector plate, 31 is a holding plate, 32 is a spring, 34 is a fixing plate, 35 is a mold clamping cylinder, 36 is a rod, 37 is a guide bar, 38 is a semiconductor device, 41 is a guide gun, 42 is a chamber, 43 is a cylinder, 44 is a rod, 45 is a p-rad plate, 46 is a guide rod, 4T is a fish, 4B is a plunger, and 49 is a plunger head. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno (1 other person)

Claims (1)

[Claims] an upper mold in which a plurality of upper mold cavities are formed and identified on an upper surface plate identified through a frame plate on the upper platen; an upper mold ejector bin that moves up and down to reach each of the upper mold cavities; A lower mold cavity corresponding to each upper mold cavity is formed, and a required number of chambers into which resin is charged when the mold is opened are formed near a predetermined part of the lower mold cavity, and a required number of chambers are formed in the lower mold cavity through a frame plate. a lower die fixed to a fixed lower surface plate; a lower die ejector bin that moves up and down to reach each of the lower die cavities; a plunger each having a plunger head that moves up and down in each of the chambers; A molding apparatus for a semiconductor device, comprising a driving means for clamping the upper mold and the lower mold and driving each of the plungers.