JPH06270186A - Resin molding device - Google Patents

Abstract

PURPOSE:To prevent the warpage in the external cladding resin part of lead frame, the resin molding of which has been completed, from developing. CONSTITUTION:In a resin molding device for forming the external cladding resin part in the major portion of lead frame by pouring molten resin under the condition that the thin lead frame is clamped from its above and below by the upper and lower molds 25 and 28, the upper and lower molds 25 and 28 are made to be detachable from a device main body 21 and, in addition, a clamping mechanism for clamping the upper mold 25 and the lower mold 28 together is annexed to the upper and lower molds 25 and 28 themselves. Further, a constant-temperature oven 30, in which the upper and lower molds 25 and 28 under clamped together state separated from the device main body 21 after resin molding is housed for curing resin, is annexed to the device main body 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin mold device, which is used for manufacturing electronic parts such as a resin mold type semiconductor device. The lead frame is clamped from above and below to form an exterior resin portion by resin injection. The present invention relates to a resin molding device having upper and lower molds.

[0002]

2. Description of the Related Art A resin mold type semiconductor device such as a power IC is generally manufactured in a lump by using a thin lead frame. This semiconductor device is manufactured by a pellet mounting process for mounting a semiconductor pellet on a lead frame, a wire bonding process for electrically connecting the semiconductor pellet and the lead with a fine metal wire, and an epoxy resin material for the main part including the semiconductor pellet. There is a resin molding process for molding.

A conventional example of a resin molding apparatus used in this resin molding process will be described with reference to FIG.

Device body (1) of this resin molding device
Consists of a fixed base (3) attached to the upper end of a column (2) held upright as shown in FIG. 5, and a movable base (4) slidably mounted on the column (2). The movable base (4) moves close to and away from the fixed base (3) by a drive mechanism (not shown). The upper and lower molds (5, 6) are fixed to the upper and lower facing surfaces of the fixed base (3) and the movable base (4) by screwing or the like, and are arranged so as to face each other. The fixed base (3) is provided with a plunger (8) to be inserted into the pot (7) of the upper mold (5) and a drive mechanism (9) thereof.

FIG. 6 shows upper and lower molds (5) and (6) fixed to the apparatus main body (1). The upper and lower molds (5) and (6) have a cavity (10) formed between the abutting surfaces at a portion corresponding to the resin molding planned portion (exterior resin portion) of the lead frame (a) due to the abutting. A large number of cavities (10) communicate with each other through a gate (11) by a runner (12), and a cull (13) is formed at the base end of the runner (12). Further, a pot (7) is formed through the portion of the upper die (5) corresponding to the cull (13).

In this resin molding apparatus, when the lead frame (a) which has been wire-bonded is placed at a predetermined position of the lower mold (6), the upper and lower molds (5) (6) which are separated from each other are placed. ) Are brought closer to each other by raising the movable base (4), and finally the upper and lower molds (5) and (6) are abutted to each other to clamp the lead frame (a) as shown in FIG. In this state, the upper and lower molds (5) (6) are heated by a heating means (not shown), and the resin tablets previously supplied to the pot (7) of the upper mold (5) as shown in FIG. Melt (14) and pressurize it with a plunger (8), and melt the molten resin (13).
Pump to the runner (12). As a result, the molten resin is injected into the cavity (10) through the gate (11) and the resin is filled to form the exterior resin portion on the lead frame (a).

When the exterior resin part formed by this resin mold is cured to some extent, the lower mold (6) is separated from the upper mold (5) by the lowering of the movable base (4), and the lead frame (a) is moved up and down. Release from the mold (5) (6). The released lead frame (a) is supplied to the subsequent process and divided into individual semiconductor devices to be commercialized.

[0008]

By the way, when the lead frame (a) having the exterior resin portion manufactured by the above resin molding apparatus is cut and separated into individual semiconductor devices in a later step, among the semiconductor devices, There was a warp in the exterior resin part. That is, in the lead frame (a) separated from the upper and lower molds (5) and (6) of the resin molding apparatus, the exterior resin portion is still in the process of curing, and the exterior resin portion of the lead frame (a) remains as it is. When the resin was finally cured, a slight warp might occur in the exterior resin portion in its thickness direction.

When the exterior resin portion is warped in this manner, the semiconductor device (15) is mounted on the printed circuit board (16) as shown in FIG.
When mounted on, etc., the tip of the exterior resin part (17)
Although it comes into close contact with the printed circuit board (16) by the mounting screw (18), the rear end portion of the exterior resin part (17) does not come into close contact with the printed circuit board (16) and is in a slightly floating state. When mounted in such a state, the semiconductor pellet (not shown) is located at the rear end portion of the exterior resin part (17), so that heat from the semiconductor pellet escapes to the printed circuit board (16). It becomes difficult and the heat dissipation is greatly reduced, and the semiconductor device (1
5) It reduces the characteristics and shortens the service life.

Therefore, the present invention has been proposed in view of the above problems, and it is an object of the present invention to prevent the occurrence of warpage in the exterior resin portion of the lead frame that has been resin-molded. It is to provide a resin molding device.

[0011]

As a technical means for achieving the above object, the present invention provides a lead by injecting a molten resin in a state in which a thin lead frame is clamped from above and below by upper and lower molds. In a resin molding device that forms an exterior resin portion on a main part of a frame, the upper and lower molds can be freely attached to and detached from a fixed base and a movable base, and the upper and lower molds themselves are fastened to each other by the upper and lower molds. It is characterized in that a fastening mechanism for wearing is attached.

Further, it is desirable that a constant temperature oven for accommodating the upper and lower molds, which are separated from the respective bases after the resin molding and is housed therein, to cure the resin is provided in close proximity to the respective bases.

The tightening mechanism has a structure in which a fastening screw is screwed into a screw hole provided in a predetermined portion of the upper and lower molds, and a fixing means for fastening the fastening screw is provided on either one of the bases. It is possible to

[0014]

In the resin molding apparatus according to the present invention, after the resin molding by the upper and lower molds, the lead frame having the exterior resin portion which is being cured is taken out from the main body of the apparatus without being separated from the upper and lower molds. That is, while the lead frame after resin molding is clamped, the upper and lower molds are removed from the apparatus main body,
The outer resin portion of the lead frame is finally cured while it is left as it is. As a result, the exterior resin portion is resin-cured while being restricted by the upper and lower molds, so that even if the lead frame is released from the upper and lower molds thereafter, the exterior resin portion does not warp. .

[0015]

EXAMPLE An example of a resin molding apparatus according to the present invention will be described with reference to FIGS.

The device body (2 of the resin molding device of the present invention
1) consists of a fixed base (23) attached to the upper end of a column (22) which is held upright as shown in FIG. 1, and a movable base (24) slidably mounted on the column (22). Then, the movable base (24) moves close to and away from the fixed base (23) by a drive mechanism (not shown).
The fixed base (23) is provided with a plunger (26) to be inserted into the pot of the upper mold (25) and a drive mechanism (27) therefor. In addition, a constant temperature oven (30) for accommodating the upper and lower molds (25, 28) in a tight state, which are close to the apparatus body (21) and separated from the apparatus body (21) after resin molding, to cure the resin. Attach.

On the other hand, the upper and lower molds (25) (28) of the present invention for clamping the lead frame (a) are detachable from the apparatus body (21) and have a structure as shown in FIG. That is, the cavity (31) is formed between the abutting surfaces by the abutment of the upper and lower molds (25) and (28) at a portion corresponding to the resin molding planned portion (exterior resin portion) of the lead frame (a). A large number of cavities (31) communicate with each other through a gate (32) by a runner (33), a cull (34) is formed at the base end of the runner (33), and a cull ( A pot (35) is formed so as to penetrate the portion corresponding to 34).

Further, the upper and lower molds (25) (28) themselves are provided with a tightening mechanism (40) for mutually tightening and integrating the upper mold (25) and the lower mold (28). This tightening mechanism (40)
The upper and lower molds (25) (28) are provided with screw holes (37) into which the fastening screws (36) are screwed, and the screw holes (3
A recessed hole (38) is formed on the upper surface of the upper mold (25) so as to communicate with the upper mold (25), and the fastening screw (3) is inserted in the recessed hole (38).
The head of 6) is stored. On the other hand, in the device body (21),
An electric driver (29) as a fixing means for tightening the fastening screw (36) is provided at a portion of the fixed base (23) corresponding to the fastening screw structure of the upper and lower molds (25) (28).

Next, the operation of the resin molding apparatus having the above structure will be described.

First, the lower die (28) is placed on the movable base (24).
The lead frame (a) for which wire bonding has been completed is positioned and placed on a predetermined portion of the lower mold (28), and then the upper mold (25) is moved to the lower mold (28).
Abut. At this time, the fastening screw (36) is inserted and arranged in the recess hole (38) of the upper mold (25). Also, the resin tablet (39) is stored in the pot (35) of the upper mold (25).

Then, as shown in FIG. 3, the movable base (24) on which the upper and lower molds (25, 28) in an abutting state are placed.
Is raised by a drive mechanism (not shown) to approach the fixed base (23), and finally the upper and lower molds (25) (28) are sandwiched between the movable base (24) and the fixed base (23). Clamp the lead frame (a) with the upper and lower molds (25) (28). At this time, the fastening screw (36) inserted into the concave hole (38) of the upper mold (25) is tightened by the electric screwdriver (29) of the fixed base (23), and the upper mold (25) and the lower mold. Tighten the mold (28) and unite.

From this state, the upper and lower molds (25) (28) are heated by a heating means (not shown), and the resin tablets (39) previously supplied to the pot (35) of the upper mold (25). Is melted and pressurized by a plunger (26), and the molten resin is pressure-fed from the cull (34) to the runner (33). This allows
Molten resin is injected into the cavity (31) through the gate (32), and the lead frame (a) is filled with this resin.
The exterior resin portion is formed on the.

In curing the exterior resin portion, according to the present invention, the upper and lower molds (25) and (28) are fastened to each other with the fastening screws (25) while the movable base (24) is lowered and separated from the fixed base (23). 36) is firmly tightened and integrated. As shown in FIG. 4, this integrated upper and lower mold (25)
(28) is removed from the movable base (24), and the main unit (2
Transfer and store in a constant temperature oven (30) located close to 1). In this constant temperature oven (30), the upper and lower molds (25) (28) and the lead frame (a) are exposed to a constant temperature for a certain period of time, and the exterior resin part in the middle of curing is fixed to the upper and lower molds (25) (28). )
Curing proceeds in a state of being regulated by the above, and the curing is finally completed, so that the exterior resin portion does not warp.

Then, the upper and lower molds (25) are moved from the constant temperature oven (30).
After taking out (28), the fastening screw (36) is loosened to release the abutting state of the upper and lower molds (25) (28), and the lead frame (a) after the resin curing is released. The released lead frame (a) is supplied to the subsequent process and divided into individual semiconductor devices to be commercialized.

[0025]

According to the resin molding apparatus of the present invention, the upper and lower molds are removed from the main body of the apparatus after the resin-molded lead frame is clamped, and the outer resin portion of the lead frame is finally cured. Therefore, since the outer resin part is resin-cured while being restricted by the upper and lower molds, even if the lead frame is released from the upper and lower molds thereafter, the outer resin part does not warp. A good-quality semiconductor device can be provided, and when the semiconductor device is mounted, the entire exterior resin portion is in close contact with the mounting surface, so that a good mounting state can be obtained.

[Brief description of drawings]

FIG. 1 is a front view including a partial cross section showing an embodiment of a resin molding device according to the present invention.

2 is a cross-sectional view showing a state where upper and lower molds used in the resin molding apparatus of FIG. 1 are clamped with a lead frame and abutted against each other.

FIG. 3 is a front view showing a state in which the upper and lower molds are pressed by the resin molding apparatus of FIG.

FIG. 4 is a front view showing a state where upper and lower molds are taken out from the resin molding apparatus of FIG. 1 and housed in a constant temperature oven.

FIG. 5 is a front view including a partial cross section showing a conventional resin molding apparatus.

6 is a cross-sectional view showing upper and lower molds of the resin molding device of FIG.

7 is a front view showing a state in which the upper and lower molds are abutted with each other by the resin molding device of FIG.

FIG. 8 is a diagram showing a mounted state of a semiconductor device manufactured by a conventional resin molding device.

[Explanation of symbols]

 21 Device body 25 Upper mold 28 Lower mold 29 Fixing means (electric screwdriver) 30 Constant temperature oven 36 Fastening screw 37 Screw hole 40 Tightening mechanism a Lead frame

Claims (3)

[Claims] 1. A resin molding apparatus for forming an exterior resin portion on a main portion of a lead frame by injecting a molten resin in a state in which a thin lead frame is clamped from above and below with an upper and lower dies, A resin molding device characterized in that it is detachably attached to a fixed base and a movable base, and a clamping mechanism for clamping the upper mold and the lower mold to each other is attached to the upper and lower molds themselves. 2. A constant-temperature furnace for accommodating the upper and lower molds, which are separated from the respective bases after the resin molding and is housed therein, and which cures the resin, is provided in close proximity to the respective bases. The resin molding device described. 3. The tightening mechanism has a structure in which a tightening screw is screwed into a screw hole provided at a predetermined portion of the upper and lower molds,
The resin molding apparatus according to claim 1 or 2, wherein a fixing means for tightening the fastening screw is provided on either one of the bases.