JPH07205191A - Resin molding machine - Google Patents

Abstract

PURPOSE:To obtain a resin molding machine especially suitable for the molding of a thermosetting resin and having high reliability constituted so as to push up a thermosetting resin from the runner part provided to the lower part of a cavity to guide the same from the gate part of a vertical runner part to mold the resin. CONSTITUTION:A heated thermosetting resin tablet 16 is charged in a heated mold from a guide part 15 and pressure is applied to the tablet by pushing a plunger P in the mold to push up a molten thermosetting resin to introduce the same into a cavity 4 from a cull part 11 through a horizontal runner part 12 and the gate part 14 of a vertical runner part 13. After the thermosetting resin is held for a predetermined time, a movable template 8 is opened to cut off the runner resin from the molding resin of a product PAC 18 in the gate part 14. At this time, the horizontal runner part 12 is engaged with the engaging part 9a of a runner lock pin 9. Next, a fixed template 5 is operated to take out the product PAC 18. Further, a knock-out pin 10 is pushed out to apply rotatory power to the runner resin centering around the cull part and the engagement of the runner resin and the engaging part 9a of the runner lock pin 9 is released to take out the runner resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for resin molding, more specifically, by a pinpoint gate system.
The present invention relates to a resin molding device for molding a thermosetting resin.

[0002]

2. Description of the Related Art In recent years, with the high-density mounting of IC chips,
A resin-sealed semiconductor device having a large number of electrodes has been developed. A typical example thereof is PGA (pin grid array). PGA is an IC on one side of the circuit board
The chip is mounted and sealed with resin, and a plurality of pins connected to the IC chip are arranged on the other surface. P
The GA has an advantage that it can be attached to and detached from the motherboard, but it has a problem that it has a large size because it has a pin and it is difficult to reduce the size.

Therefore, as a small-sized resin-sealed semiconductor device that replaces the PGA, a pad array carrier (hereinafter abbreviated as PAC) in which pads are arranged instead of pins has been developed. Generally, there are a side gate method and a pinpoint gate method as a gate method of a resin molding die, and a pinpoint gate method in a thermoplastic resin molding,
The side gate method is relatively widely used in thermosetting resin molding.

Generally, thermosetting resin molding using the side gate method will be described. FIG. 6 and FIG. 7 are cross-sectional views for explaining a resin sealing method of an IC chip by transfer molding and an appearance of an IC module after molding. It is a perspective view. In FIG. 6, reference numeral 51 is a lower mold, and a circuit board 53 to which an IC chip 52 is bonded is arranged thereon. 54 is a cavity 5 together with the lower mold 51.
The upper mold 54 is formed with a gate groove 56 and a runner groove 57.

A runner 59 and a gate 60 for guiding the thermosetting resin 58 to the cavity 55 are formed on the mating surface of the upper die 54 and the lower die 51 and the mating surface of the upper die 54 and the circuit board 53. This is a so-called side gate type transfer molding method. The sealing portion 61 uses the plunger 62 to heat and melt the thermosetting resin 58.
9 is formed by filling the cavity 55 with the thermosetting resin 58 that has passed through the gate 60, and when the thermosetting resin 58 is further cured, the upper mold 54 is removed to form the sealing portion 61. The IC module 63 is taken out together with the runner resin.

However, the IC module 63 taken out
When the resin is separated from the runner resin, the remaining gate 64 communicating with the sealing portion 61 is formed as shown in FIG. 7, and when removing the remaining gate 64, the wiring pattern is destroyed or the sealing portion 61 is formed. There is a problem in that the resin that is used is cracked, and because the resin of the gate portion flows along the surface of the circuit board 53, the circuit board 53 is contaminated with the resin.

[0007] For resin encapsulation of semiconductors, the fluidity of the molten resin is poor, there is the risk of wire breakage, and thermoplastic resins with low encapsulation reliability after molding are unsuitable. Needless to say, a thermosetting resin that is good and has high shape accuracy and reliability after sealing is optimal.

Therefore, attention is paid to the pinpoint gate method which eliminates the problem of the side gate method, and this is adopted as the PAC.
Adopted for thermosetting resin molding. FIG. 8 is a cross-sectional view of a main part of a six-cavity mold for explaining resin molding for pinpoint gate type PAC sealing, and FIG. 9 is a cross-sectional view for explaining a runner lock releasing operation. In FIG. 8, the circuit board 53 to which the IC chip 52 is bonded is arranged on the movable side template 71, and the cavity 74 is formed by the fixed side template 73 aligned by the parting line 72. A stripper plate 75 includes the stripper plate 75 and the fixed-side mold plate 73, and includes a cull portion 76 and a lateral runner portion 7.
7 and a vertical runner portion 78 are formed as a resin transfer path, and a lower portion of the vertical runner portion 78 is connected to the cavity 74 by a gate portion 79.

A mounting plate 80 is placed on the stripper plate 75, and a plunger P for penetrating the mounting plate 80 and the stripper plate 75 and pressing the tablet 81 inserted into the cull portion 76 is provided. The guide portion 82 and the runner lock pin 83 are arranged corresponding to the vertical runner portion 78. The shape of the runner lock pin 83 is as shown in FIG.
An undercut m is applied to the end portion, and a locking portion 84 that locks with the runner resin is formed.

Next, a pinpoint gate type molding operation in PAC transfer molding will be described with reference to FIGS. 8 and 9. Upper mold (mounting plate 80, stripper plate 75, fixed side mold plate 73) and lower mold (movable side mold plate 71) heated to a predetermined temperature, for example, about 165 ° C.
The circuit board 53 to which the IC 52 is bonded is mounted between the two, and the thermosetting resin tablet 8 is heated to a predetermined temperature.
1 from the guide portion 82 of the plunger P to the cull portion 76
Then, the thermosetting resin is poured into the cavity 74 from the cull portion 76 through the lateral runner portion 77 and the gate portion 79 of the vertical runner portion 78 by pushing the plunger P and applying a pressure. The dissolution time of the resin is, for example, 8
It is about a second.

After the thermosetting resin is filled, it is held for a predetermined thermosetting time, for example, about 90 seconds, and then the mold is opened and the runner resin is unlocked. That is, as shown in FIG. 9, first, the stripper plate 75 and the fixed-side mold plate 73 are opened, and the runner resin around the locking portion 84 of the runner lock pin 83 is pulled up. Separate from the product PAC. Next, the stripper plate 75 is actuated in the direction of arrow F to remove the runner resin including the cull 86, the lateral runner 87, and the vertical runner 88 from the locking portion 84 of the runner lock pin 83 in the axial direction of the pin. In addition, 85 shows the resin residue which falls. Next, the mold is opened at the parting line 72, and the product PAC is taken out.

[0012]

However, the above-mentioned pinpoint gate type PAC thermosetting resin molding has the following problems. That is, especially in hard resin molding such as thermosetting resin, when the mold is opened, the effect of locking the runner resin by the runner lock pin becomes insufficient, so the vertical runner remains in the mold and separates from the product. Not so, so-called mold release failure easily occurs. In addition, if the amount of the undercut m of the runner lock pin is increased in order to achieve a sufficient locking effect, cracking or chipping of the runner resin in the locking portion will occur during stripper plate operation after mold release, When the resin residue is cleaned on the fixed-side mold plate surface, the gate part is clogged and the resin is not filled, or the hard resin residue enters the cavity, causing wire breakage, breakage and shoulder touch of the bonding wire.

Further, since the resin remains in the locking portion of the runner lock pin, the locking effect due to undercut is diminished, and in the next shot, defective release of the runner resin occurs. If the undercut amount of the runner lock pin is reduced, the locking effect becomes insufficient, which also causes a mold release defect, which leads to a vicious circle. Furthermore, when the upper mold and the lower mold are opened, since the circuit board is placed on the movable mold plate side, the resin sealing part of the PAC comes into close contact with the fixed cavity side, which is unnecessary for taking out the product. There are various problems that not only take time but also cause molding problems.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to solve the above problems in the pinpoint gate method, and is particularly suitable for thermosetting resin molding,
It is intended to provide a highly reliable resin molding device.

[0015]

In order to achieve the above object, in the resin molding apparatus of the present invention, a cavity is formed by a first mold and a second mold, and one of the molds is formed. The provided runner portion includes a horizontal runner portion and a vertical runner portion, and by filling the cavity with resin from the gate portion that is continuous with the vertical runner portion, the molding resin of the cavity and the runner resin of the runner portion are provided. Molded,
Further, in the resin molding device configured to separate the runner resin from the molding resin by a runner lock pin having a locking portion that locks to the runner resin, the cavity is formed above the vertical runner portion. It is what

Further, the runner lock pin is arranged such that a part of its outer periphery intersects the runner portion, and the engaging portion of the runner lock pin has a notch opening to the intersecting portion. The runner resin and the runner lock pin are unlocked by push-out means for pushing out the runner resin in the opening direction.

Further, the unlocking of the runner resin and the runner lock pin is performed by pushing out a knockout pin.

[0018]

Therefore, in the resin molding apparatus obtained according to the present invention, as described above, the thermosetting resin is guided from the gate portion above the vertical runner portion to the cavity so as to push it up from the runner portion below the cavity. By molding and pushing out the knockout pin, the runner resin is laterally moved to unlock the runner resin and the runner lock pin, and the runner resin can be easily taken out. Also, mounting of the circuit board with the IC chip bonded and removal of the product are easy by adsorbing the lower surface side of the flat circuit board, and even if the resin residue falls, it does not enter the cavity and reliability is improved. It is possible to manufacture a high PAC.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment will be described below with reference to the drawings. 1 is an embodiment of the present invention, which is a sectional view of a principal part showing a six-point resin molding apparatus for pinpoint gate type PAC sealing, and FIG. 2 shows a resin molding apparatus using the resin molding apparatus shown in FIG. FIG. 3 is a cross-sectional view for explaining the mold opening operation, FIG. 3 is a plan view for explaining the unlocking operation of the runner resin that gives a rotational force by the knockout pin, and FIG. 4 is a perspective view for the runner lock pin. First, in FIG. 1, an upper mold 1 which is a first mold includes a stationary mold plate 3, a stationary mounting plate 5 that forms a cavity 4 in combination with the stationary mold plate 3, and a plunger guide 15. The circuit board 6 having the IC chip bonded inside the cavity 4 formed in the fixed-side template 3 is arranged so that the IC chip is on the lower side.

The movable mold plate 8 of the lower mold 7 which is the second mold.
A runner lock pin 9 and a knockout pin 10, which will be described later, are arranged in this. With the fixed side mold plate 3 and the movable side mold plate 8,
A runner portion that is a resin transfer path including the cull portion 11, the horizontal runner portion 12, and the vertical runner portion 13 is formed. An upper portion of the vertical runner portion 13 is connected to the cavity 4 by a gate portion 14. The plunger P for pressing the resin tablet 16 put in the cull portion 11 is the upper mold 1
It is located in the upper center. The runner lock pin 9 is arranged so that a part of the outer periphery thereof intersects the lateral runner portion 12 at a right angle, and as shown in FIG. 4, the engaging portion 9a of the runner lock pin 9 is a notch opened at the intersection portion. A part of the outer circumference of the runner lock pin 9 including the engaging part 9a constitutes a part of the side wall of the runner part. The knockout pin 10 is also arranged so that the slope portion 10a contacts the runner portion and constitutes a part of the side wall of the runner portion.

Next, a pinpoint gate type molding operation in PAC transfer molding will be described with reference to FIGS. 1 and 2. Predetermined temperature, eg 165 ° C
A thermosetting resin tablet 16 heated to a predetermined temperature is attached to the plunger P heated to a certain degree.
Of the molten thermosetting resin from the cull part 11 to the lateral runner part 12 and the vertical runner part 13 by pushing in the plunger P and applying pressure.
It is pushed up into the cavity 4 through the gate portion 14 of.

After the thermosetting resin is filled, it is held for a predetermined thermosetting time, for example, about 90 seconds, and then the mold is opened and the runner lock pin and the runner resin are unlocked as shown in FIG. In FIG. 2A, first, the movable side mold plate 8 is opened from the fixed side mold plate 3 in the direction of arrow A, and the runner resin and the molding resin of the product-sealed product PAC 18 are separated at the gate portion 14. At that time, the lateral runner portion 12 is locked by the locking portion 9a of the runner lock pin 9, and the runner resin is reliably held on the movable side mold plate 8 side. Next, the fixed side mounting plate 5 is operated in the direction of the arrow B, and the product PA
Take out C18.

Next, as shown in FIGS. 2B and 3, a knockout pin 10 which is a means for pushing and removing the runner resin.
By pushing in the direction of arrow C, the slope portion 10a formed on the knockout pin 10 pushes the lateral runner 22 in the direction of arrow D, giving a rotational force in the direction of arrow E to the runner resin about the cull 21 and By releasing the lock between the resin and the locking portion 9a of the runner lock pin 9, the runner resin can be easily taken out of the mold by a take-out robot or the like. The PAC 18, which is a product, can be taken out easily by a suction means such as a general-purpose suction pad or by adding a light air blow since the flat lower surface side of the circuit board is located above. . Even if the runner resin is not pushed out by using a knockout pin, for example, the vertical runner of the runner resin may be sandwiched between the parallel rods of the take-out robot to give a rotational force to the runner resin. it can.

Furthermore, since the runner lock pin can be easily unlocked, the generation of the resin residue 19 is small, but even if the resin residue 19 falls, it does not face the gate portion 14, so that the resin residue 19 is removed. There is no invasion into the cavity 4, and filling failure due to clogging of the resin residue 19 and breakage of the bonding wire do not occur.

As described above, the resin molding apparatus shown in FIG. 1 is a so-called upper plunger system in which the plunger is arranged on the upper mold side, but FIG. 5 showing another embodiment is as follows. Figure 1
In the resin molding apparatus shown in FIG. 1, the plunger P is arranged on the upper mold 1 side, whereas the plunger P is arranged on the lower mold 7 side, which is a so-called lower plunger system. Therefore, the resin can be pressed from below the mold with a plunger (not shown). The other member arrangement is exactly the same as that shown in FIG.

[0026]

As described above, according to the present invention,
Particularly, when the mold is opened in hard resin molding such as thermosetting resin molding, it is easy to release the lock between the runner resin and the runner lock pin, eliminating the mold release defect of the runner resin, and cracking or chipping of the runner resin. No, by forming a cavity above the vertical runner part above all,
The resin unfilled due to the resin residue clogging the gate portion is also eliminated, and the hard resin residue does not enter the cavity, so that the bonding wire is not broken. Since the bottom surface of the circuit board is flat and the product is flat, the product can be taken out easily by a suction device such as a general-purpose suction pad. It is possible to provide a highly reliable resin molding device suitable for molding.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a resin molding device according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing a releasing operation after molding according to an embodiment of the present invention.

FIG. 3 is a plan view of relevant parts for explaining the unlocking operation of the runner resin according to the embodiment of the present invention.

FIG. 4 is a perspective view of a runner lock pin according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts showing a resin molding apparatus according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view of an essential part showing a conventional side gate semiconductor resin molding device.

FIG. 7: I molded by the side gate method of the prior art
It is an external appearance perspective view of a C module.

FIG. 8 is a cross-sectional view showing a conventional pinpoint gate type resin molding device.

FIG. 9 is a cross-sectional view showing a releasing operation after molding according to a conventional technique.

FIG. 10 is a front view showing the shape of a conventional runner lock pin.

[Explanation of symbols]

 1 Upper mold 4 Cavity 7 Lower mold 9 Runner lock pin 9a Locking part 10 Knockout pin 10a Slope part 12 Horizontal runner part 13 Vertical runner part 14 Gate part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Inoi 6-12 Hommachi Honmachi, Tanashi City, Tokyo Citizen Watch Co., Ltd. Tanashi Factory

Claims (3)

[Claims] 1. A cavity is formed by a first die and a second die, and a runner portion provided on the one die includes a horizontal runner portion and a vertical runner portion. By filling the cavity with a resin from the gate portion connected to the portion, the molding resin of the cavity and the runner resin of the runner portion are molded, and by a runner lock pin having a locking portion that is locked to the runner resin. A resin molding apparatus configured to separate the runner resin from a molding resin, wherein the cavity is disposed above the vertical runner portion. 2. The runner lock pin is arranged such that a part of the outer periphery thereof intersects with the runner portion, and the engaging portion of the runner lock pin has a notch opening to the intersecting portion. 2. The resin molding apparatus according to claim 1, wherein the runner resin and the runner lock pin are unlocked by push-out means for pushing out the runner resin in the opening direction. 3. The resin molding apparatus according to claim 2, wherein unlocking of the runner resin and the runner lock pin is performed by pushing out a knockout pin.