JPS6236834A - Resin sealing device and method - Google Patents

Abstract

PURPOSE:To automatically remove resin burrs produced when plastic IC packages or the like are produced, by providing means for supplying a resin burrs removing tape, which supplies a resin burrs removing tape having adhesive material layers formed on both surfaces thereof between the top force and the bottom force in synchronism with the operation of them. CONSTITUTION:Adhesive material layers 17a are provided on both surfaces of a resin burrs removing tape 17, and for the adhesive material layers 17a, melamine resin or the like is used for instance. After the completion of removal of the lead frame having completed in sealing, when the removing tape 17 is located between the top force 16 and the bottom force 11 with the top force 16 and the bottom force 11 being spaced apart, and the top force 16 and the bottom force 11 being spaced apart, and the top force 16 and the bottom force 11 are contacted with each other by clamping, then the adhesive material layers 17a of the removing tape are brought into strong contact with the resin burrs. Then, the mold opening is performed to separate the top force 16 and the bottom force 11. That is, the resin burrs 24 separate from the top and bottom forces, adhere to the adhesive material layers of the removing tape, and are implanted to the tape side. Moreover, if the rotation of a roller 18 is synchronized with the motions of the top and bottom forces using means 19 for supplying the removing tape, the work for removing resin burrs can be automated along with the operation of the resin sealing apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION (Requires $11) A resin sealing device and method that automatically removes resin burrs generated during resin molding using plastic tape or aluminum (A7 foil, etc.).

[Industrial application field]

The present invention relates to a resin sealing device and method, and more specifically, the present invention relates to a resin sealing device and method, and more specifically, a means for automatically removing resin burrs attached to the upper and lower molds of the resin sealing device after the resin sealing process of a lead frame, and its method. It is about the method.

[Conventional technology]

The following steps are used to manufacture a plastic IC package in which a semiconductor chip on which an integrated circuit is formed is sealed with resin.

A semiconductor chip with an IC formed thereon is bonded to the lead frame's lead stage, which consists of a lead stage, inner leads, and outer leads, and the electrodes of the semiconductor chip and inner leads are connected by wire bonding (wire attachment), and the wire attachment is completed. Place the lead frame in the resin sealing device as shown in FIG.

FIG. 4 is a plan view of the lower mold 11 of the resin sealing device. In the figure, 12 is a cull, 13 is a runner, 14 is a gate, and 15
indicates a cavity, and 20 indicates a lead frame. The first step is completed by arranging the lead frame 20 so that the guide stage is located inside the cavity 15 and setting the lead frame 2o.

In the second step, as shown in the sectional view of FIG. 5, mold clamping and resin injection are performed. In the figure, 16 is the upper mold, 21
22 represents the aforementioned semiconductor chip, 22 represents a wire, and 23 represents a sealing resin. The resin is injected into the cavity 15 through the runner 13 and gate 14, and then hardened. The air vent 25 is an escape port for letting air out of the cavity 15 during resin injection.

In the third step, open the upper and lower molds as shown in Figure 6 (
(open the mold) and take out the sealed lead frame 20. The above molding cycle is performed at a temperature of about 170° C. and is completed within 2 to 3 minutes.

(Problems to be Solved by the Invention) After opening the mold and removing the sealed lead frame, resin burr 24, also called resin flash (IIlli), appears on the top as shown by the thick black line in FIG. Resin burrs may adhere to the surfaces of the mold and lower mold, and such resin burrs also adhere to the surface of the lead frame.The reason for this is that the gap t1 to t1 shown in FIG. 5 between the upper mold and the lower mold is due to the thickness of the lead frame. However, lead frames vary in their thickness and do not necessarily match the standard thickness mentioned above, resulting in a small gap between the upper and lower molds and the lead frame. It is from.

Conventionally, such resin burrs have been removed by cleaning using melamine resin, but this requires 3 to 6 hours. Alternatively, resin burrs were removed by blowing cold air or brushing with plant hair, but it is difficult to completely remove resin burrs, and the removed resin burrs are charged with static electricity, so they adhere to lead frames and molds. There's a problem. Therefore, when directly operating the resin sealing apparatus by automation, there is a problem that becomes an obstacle to automation.

On the other hand, regarding resin burrs attached to the lead frame,
There is a problem that must be removed before Me.7. Nowadays, the common process for lead frames is to plate the guide stage and inner leads in advance, and then plate only the outer leads after resin sealing, but the resin burrs must be removed before this plating. However, it is a task that requires considerable time and effort.

The present invention was created in light of these points, and it is an object of the present invention to provide an apparatus and method for automatically removing resin burrs generated during molding of plastic IC pancakes and the like.

c. Means for Solving Problems] FIGS. 1 and 2 are cross-sectional views of an embodiment of the present invention, and FIG. 3 is a cross-sectional view of another embodiment of the present invention.

In Figures 1 and 2, a lead frame 20 on which an electronic device such as a semiconductor chip is mounted is inserted into the lower mold II of the resin sealing machine, the mold is clamped, resin is injected, the mold is opened, and the sealing is completed. After removing the completed lead frame 20, a resin burr removal tape is inserted, the mold is clamped again, and the mold is opened afterward to remove the resin burr 24 attached to the surfaces of the upper mold 16 and the lower mold 11. It belongs to
To this end, a means 19 consisting of a roll 18 or the like for supplying the resin burr removing tape 17 is provided to automatically feed the resin burr removing tape 17, and the tape 17 has adhesive material layers on both sides thereof. 17a and, in some cases, through holes 17b are formed to form the adhesive material layer 17a.
and the tape 17 is improved.

[Effect]

In the above-mentioned embodiment, the adhesive material layer 17a is selected to have a higher degree of adhesion with the resin burr than the degree of adhesion between the resin burr and the upper mold and the lower mold, so that the adhesive material layer 17a is not adhered to the upper mold and the lower mold. The tape 17 is used to efficiently remove resin burrs that have been removed, and to increase the degree of adhesion between the tape 17 and the adhesive material layer.
A through hole 17b is formed in the tape to prevent the adhesive material layer from peeling off from the tape.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 1, in the present invention, a resin burr removal tape 17 (hereinafter simply referred to as removal tape) shown in FIG. The removal tape is made of a resin material, such as heat-resistant polyester, strong paper, or aluminum foil, and the adhesive material layer 17a is made of, for example, melamine resin.

Referring to FIG. 1 (bl), after the third step of the conventional example, that is, mold opening, sealing, and removal of the lead frame, the removal tape 17 is applied while the upper mold 16 and the lower mold 11 remain separated. Place it between the upper and lower molds.

Next, as shown in FIG. 1 (C1), the upper mold 16 and the lower mold 11 are brought into contact with each other by clamping. At this time, the adhesive material layer 17a of the removal tape firmly contacts the resin burr.

Next, as shown in FIG. 1 (dl), the mold is opened and the upper mold 16 and the lower mold 11 are separated. Since the degree of adhesion between the lower mold and the resin burr 24 is selected to be greater than that between the lower mold and the resin burr 24, when the mold is opened, the resin burr 24 separates from the upper mold and the lower mold and adheres to the adhesive material layer of the removal tape. in a state,
That is, the resin burr 24 is transplanted to the removal tape side. Next, the removal tape 17 is removed from between the upper mold and the lower mold, and the resin sealing process described above is restarted.

In order to feed the removal tape 17 between the upper mold 16 and the lower mold 11, a removal tape supply means 19 consisting of a roller 18 shown in FIG. By synchronizing the movement, the resin burr removal work can be automated along with the operation of the resin sealing device.

Alternatively, instead of the roller means, means for automatically supplying a sheet-like removal tape may be provided. Furthermore, the second
In the figure, 10 indicates a press.

In another embodiment of the present invention, the adhesion between the removal tape 17 and the adhesive material 1i17a is increased, and the adhesive material layer 17a is
For example, in order to prevent the film from peeling off,
When through holes 17b with a diameter of several hundred μm are provided, even if the adhesive material layer between adjacent through holes 17b begins to peel off, this tendency is interrupted by the through hole, and the adhesive material layer is integrated with the removal tape. It is guaranteed that

Furthermore, as another embodiment, it is also effective to use a removal tape 17 whose base material is a heat-resistant plastic film or strong paper, with aluminum foil adhered to both sides with an adhesive. In this case, the plasticity of aluminum foil is utilized, and the problem of adhesive adhering to the mold does not occur. In this case as well, through holes may be provided in the removal tape.

In one example of use, conventional 3 to 6
Compared to the conventional method, it only takes a few seconds to several tens of seconds to insert and remove the removal tape after each cycle of the 2-3 minute resin sealing process, and the removal of resin burrs using the removal tape is much easier. It could be completely automated in synchronization with the operation of the resin sealing device.

〔Effect of the invention〕

As described above, according to the present invention, resin burrs in the resin sealing device are automatically and reliably removed from the upper and lower molds, and as a result, resin burrs are prevented from adhering to the lead frame. This is highly effective in improving the manufacturing yield of plastic IC packages. Note that the scope of application of the present invention is not limited to the above case (it also extends to the case of transfer molding equipment).

[Brief explanation of drawings]

Figure 1 (al to Tdl is a sectional view of the embodiment of the present invention, Figure 2 is a sectional view of a removal tape supply device, Figure 3 is a sectional view of a modified example of the removal tape, and Figure 4 is a sectional view of a resin sealing device. FIG. 5 is a sectional view of the conventional example, and FIG. 6 is a sectional view showing the problems of the conventional example. In FIGS. 1 to 6, 10 is a press. , 11 is the lower mold, 12 is the cull, 13 is the runner, 14 is the gate, 15 is the cavity, 16 is the upper mold, 17 is the removal tape, 17a is the adhesive material layer, 17b is the through hole, 17c is the window opening part , 18 is a roller, 19 is a removal tape supply means, 20 is a lead frame, 21 is a semiconductor chip, 22 is a wire, 23 is a sealing resin, and 24 is a resin burr.・: No. 6 tsurikou, -f hokooizu

Claims (2)

[Claims] (1) A device that includes an upper mold (16), a lower mold (11), and a press (10), and resin-seals a lead frame (20) on which an electronic device is mounted between the upper mold (16) and the lower mold. In this step, a resin burr removal tape (17) having an adhesive material layer (17a) formed on both sides is automatically fed between the upper mold (16) and the lower mold (11) in synchronization with the operation thereof. A resin sealing device comprising a resin burr removal tape supply means (19). (2) Lead frame (20
) on the lower mold (11) of the resin sealing device, a step of tightening the upper mold (16) and the lower mold (11) and injecting the resin (23), the upper mold (16), the lower mold Step (11) of opening the mold and removing the sealed lead frame (20), placing the resin burr removal tape (17) between the upper mold (16) and the lower mold (11), the upper mold A resin sealing method characterized by repeating a cycle consisting of a step of clamping (16) and a lower mold (11), and a step of opening the upper mold (16) and the lower mold (11).