JPH09205176A - Apparatus for adhering film to lead frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhering failure of an insulating film to a lead frame immediately after the operation is started by providing a heater at a punch used also for punching and adhering the film with adhesive. SOLUTION: A sheet-like heater 21 is connected to the surface of a punch 7. The heater 21 has higher thermal inertia efficiency when the position of the heater 21 is near the end of the punch 7, but there is the fear of engaging the punch 7 with the inner wall of the die 6 when the die 6 is passed vertically. Then, to prevent it, the end of the punch 7 is adhered so as to be above the upper surface of the die 6 when it is disposed in a standby state. The heater 21 is energized to prevent the drop of the temperature of the punch 7. Thus, the heater 21 is provided at the punch 7 to make it possible to reduce the adhering failure immediately after the operation is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame film sticking device for sticking an insulating film to the inner leads of a lead frame.

[0002]

2. Description of the Related Art Electronic component materials, particularly integrated circuits (hereinafter referred to as "I")
In the field of “C”), for example, a large size I
When manufacturing C (for example, a multi-pin IC having 42 pins or more), a large lead frame is required. Since a large lead frame has elongated inner leads and a large number of leads, it is easy to be exposed or deformed, and its handling is difficult. For this reason, conventionally, in order to eliminate the deformation of the tip of the internal lead, a strip-shaped insulating film with an adhesive has been attached near the tip of the internal lead.

As a device for sticking a deformation preventing film to this kind of lead frame, a film sticking device to a lead frame (Japanese Patent Laid-Open No. 4-196576) has been proposed.

Further, there is a LOC (Lead-On-Chip) type semiconductor device in which an insulative film is attached to the inner lead of the lead frame and the IC is fixed through this insulative film. An insulating film with an adhesive cut into strips is attached to the inner leads of the frame.

FIG. 3 is a partial sectional view of a conventional film sticking device for a lead frame, FIG. 4 is a partial plan view of a lead frame before sticking a film, and FIG. 5 is a partial plan view of a lead frame after sticking a film. It is a figure.

The film sticking apparatus 1 shown in FIG. 3 punches the adhesive-attached film feeding mechanism (not shown) and the fed adhesive-attached film 2 into a predetermined shape (for example, “=” shape) and punches the film. A punching / pressing mechanism 4 for pressing the removed insulating film (hereinafter referred to as “film”) onto the lead frame 3, a positioning mechanism (not shown) for setting the lead frame 3 at a predetermined position, and heating for heating the lead frame 3. And mechanism 5.

Although not shown, the adhesive-attached film feeding mechanism is composed of a reel, a film feed roller, a stepping motor, and the like, and the die 6 constituting the punching / pressing mechanism 4 is formed from the adhesive-attached film wound on the reel.
It is designed to be fed into the upper surface of each by a predetermined length.

The punching and pressing mechanism 4 holds a die 6 which is a punching die, a punching punch (hereinafter referred to as a "punch") 7 which is fitted into the die 6 and punches the film 2 with an adhesive, and the punch 7. The punch plate 8 is composed of an upper die 10 that holds the punch plate 8 and is movable up and down along an upper die guide 9, and a punching air cylinder 11 that drives the upper die 10 up and down.

The heater block 12 and the heater 13 constitute a heating mechanism 5.

14 is a heat insulating material, 15 is a heater base, 16
Is a slider. Reference numeral 17 denotes a constant pressure sticking air cylinder that moves the heating mechanism 5, the heat insulating material 14, and the heater base 15 up and down along the slider 16.

When such a film sticking apparatus 1 operates, first, the strip-shaped lead frame 3 in which the lead frames 3a shown in FIG. 4 are connected in N pieces (for example, 5 pieces) is connected to the die 6 and the heater block 12. It is supplied horizontally (perpendicular to the paper surface) and the lead frame 3 is set at a predetermined position by the positioning mechanism. Along with this, the adhesive-attached film feeding mechanism supplies the adhesive-attached film 2 having a predetermined length into the groove formed in the die 6. 3b is a sprocket hole for positioning the lead frame 3,
3c is an internal lead.

When the upper die 10 is lowered by the punching air cylinder 11, the punched film 7 punches the adhesive-attached film 2. The punched film 2a is attached to the tip of the inner lead 3c of the lead frame 3. That is, the punch 7 has a punching function for the adhesive-attached film 2,
It also has a function of attaching the punched film 2a to the lead frame 3.

Here, the lead frame 3 is preliminarily provided with the heater 1.
It is heated by 3 and the pressure at the time of sticking the film 2a is kept constant by the constant pressure sticking air cylinder 17 arranged below the heater base 15.

Below, the film 2 with the adhesive is sent.
The film 2a is attached to the lead frame 3 while punching each piece into a predetermined shape by the punching and pressing mechanism 4. This attaching step is repeated N times for the number of pieces. N
By repeating the process, the film 2a is attached to all the pieces of the lead frame 3 as shown in FIG.

Therefore, the film sticking apparatus 1 can significantly improve the sticking speed of the sticking of the insulating film to the lead frame by the high temperature softening type adhesive while obtaining a high sticking position accuracy.

[0016]

By the way, the above-mentioned FIG.
In the film sticking apparatus 1 shown in FIG. 3, the lead frame 3 is heated by the heater 13 in advance, and the pressure at the time of sticking is kept constant by the constant pressure sticking air cylinder 17 arranged below the heater base 15. There is.

FIG. 6 shows the heater block 12 immediately after the start of operation.
It is a figure which shows the temperature change of. In the figure, the horizontal axis is the time axis and the vertical axis is the temperature axis.

From the figure, it can be seen that the temperature drops after the film sticking operation starts, and it takes some time for the temperature to return. If the temperature at the time of sticking the film does not reach the required temperature, the film 2a may be unbonded or peeled off, and the product manufactured during this period becomes defective.

The cause of this temperature decrease is heat conduction to the punch 7. During continuous operation, heat is transferred from the heater block 12 to the punch 7 via the lead frame 3, and the temperature is higher than room temperature (constant).

However, during standby, since there is no heat conduction from the heater block 12 to the punch 7, the punch 7 is naturally cooled and its temperature drops. After that, when the operation is started, the temperature of the heater block 12 temporarily drops because the punch 7 takes heat from the heater block 12,
It may cause the film sticking failure.

Therefore, an object of the present invention is to solve the above problems and to provide a film sticking device for a lead frame which can prevent a sticking defect of an insulating film on the lead frame immediately after the start of operation.

[0022]

In order to achieve the above object, the present invention punches a film with an adhesive with a punch and a die in order to stick an insulating film to a large number of internal leads of a lead frame. In the film sticking device for a lead frame, which is for sticking the insulating film punched out in step 1 to the lead frame, the punch is provided with a heater.

In addition to the above structure, in the present invention, a heater may be provided on the surface of the punch.

In addition to the above structure, in the present invention, a heater may be provided inside the punch.

With the above construction, since the heater is provided in the punch for both punching and pasting the film with adhesive,
By energizing the heater during standby, the temperature of the punch does not decrease, the temperature decrease at the start of operation is prevented, and defective attachment of the insulating film to the lead frame is prevented.

[0026]

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

FIG. 1 is a partial sectional view of an embodiment of a film sticking apparatus for a lead frame according to the present invention.
FIG. 2 is a partially enlarged view of the punch section shown in FIG. 1. FIG.
Since the structure is almost the same as that of the film sticking device shown in FIG.

The film sticking device 2 shown in FIGS. 1 and 2.
In No. 0, a sheet-shaped heater 21 is bonded to the surface of the punch 7. The position of the heater 21 is closer to the tip of the punch 7 (lower end in the figure), but the residual heat efficiency is better,
There is a risk that it will be caught on the inner wall of the die 6 when it penetrates vertically in order to prevent this, and the tip of the punch 7 is bonded so as to be above the upper surface of the die 6 when it is located at the bottom dead center. . A heater power source and a switch (not shown) are connected to the heater 21 so that the heater 21 is turned on when the film sticking apparatus 20 is on standby and is turned off when the film sticking apparatus 20 is in operation.

When the film sticking device 20 is in the standby state, the heater 21 is energized so that the temperature of the punch 7 does not decrease.

With this configuration, the temperature of the punch 7 is almost constant in both the operating state and the standby state without lowering, so that defective film sticking immediately after the start of operation can be reduced.

As described above, in this embodiment, since the heater is provided in the punch, it is possible to realize a film sticking apparatus for a lead frame which can reduce sticking defects immediately after the start of operation.

In the present embodiment, the sheet-shaped heater is adhered to the surface of the punch, but the present invention is not limited to this, and the heater may be provided inside the punch. In addition, since heat is conducted to the punch via the lead frame during continuous operation after the film is attached to the lead frame, the heater can be firmly adhered in a short time even if the heater is de-energized. A temperature sensor may be provided in the block, and a controller may be provided that automatically controls the heater to turn on when the temperature falls below a certain value and to turn off the heater when the temperature rises above a certain temperature. .

[0033]

In summary, according to the present invention, the following excellent effects are exhibited.

Since the heater is provided in the punch for both punching and pasting the film with the adhesive, the temperature of the punch does not drop even in the standby state by energizing the heater, and there is no temperature drop immediately after the start of operation, and the lead frame is It is possible to prevent defective attachment of the insulating film.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an embodiment of a film sticking device for a lead frame of the present invention.

FIG. 2 is a partially enlarged view of a punch unit shown in FIG.

FIG. 3 is a partial cross-sectional view of a conventional film sticking device for a lead frame.

FIG. 4 is a partial plan view of the lead frame before the film is attached.

FIG. 5 is a partial plan view of the lead frame after the film is attached.

FIG. 6 is a diagram showing a temperature change of a heater block immediately after the start of operation.

[Explanation of symbols]

 2 Film with adhesive 2a Insulating film (film) 3 Lead frame 6 Die 7 Punch (punching punch) 21 Heater

Claims (3)

[Claims] 1. An insulating film with an adhesive is punched by a punch and a die to attach an insulating film to a large number of internal leads of a lead frame, and the insulating film punched by the punch is used as a lead frame. A film sticking device for a lead frame to be stuck, wherein the punch is provided with a heater. 2. An apparatus for attaching a film to a lead frame according to claim 1, wherein the heater is provided on the surface of the punch. 3. The film sticking device for a lead frame according to claim 1, wherein the heater is provided inside the punch.