JPH0680700B2 - Method for manufacturing semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device by carrying and arranging a large number of conductors connected to semiconductor elements such as ICs and LSIs on a film.

[0002]

2. Description of the Related Art Conventionally, when assembling a semiconductor device in which a semiconductor element is integrally molded by resin molding and a large number of pins are projected,
A metal lead frame is used. The conventional lead frame is formed by punching a thin metal plate with a press or etching.

By the way, conductors such as extremely thin tab leads, fingers and bumps at the tips thereof are formed on the lead frame. Recently, the width of tab leads and fingers has been increased due to the demand for a semiconductor device having a large number of pins. It is becoming thinner and smaller, and the bumps must be small. Therefore, there is a limit to the simple punching press work of a thin plate, and it is difficult to obtain a highly accurate lead frame.

Therefore, a lead frame having fine fingers and the like is manufactured by etching, but this method has a drawback that the manufacturing process is complicated and the cost is high.

As a method of eliminating these drawbacks, facilitating manufacture, and forming a fine portion, a lead frame using an electroforming technique has recently been developed. In order to improve productivity, various methods for supporting and arranging a large number of leads on a base material have been studied.

FIG. 12 is a sectional view for explaining a conventional manufacturing process of a lead carrier film as a conductor carrying base material, and FIG. 7 is a side view of a wound body of the lead carrier film. The conventional lead carrier film is first shown in FIG.
A metal plate such as an aluminum plate or a stainless plate as shown in 2 (a), or a synthetic resin film such as a polyester film or a pyrimido film, which is provided with conductivity by metal deposition or electroless plating. An electrically insulating resist layer 52 made of synthetic resin is formed in a desired pattern on the base material 51 by printing. In this case, the non-resist portion 53 in which the resist layer 52 is not formed has the same pattern as the conductor shape such as the lead, finger, or bump to be manufactured.

Next, the base material 51 is stripped with selenious acid or the like, and then a metal such as copper, nickel, gold or tin is attached by electroforming to form a conductor 54 made of a conductive metal layer into a predetermined shape. Make (see (b) of the same figure). Subsequent base material 5
1 is removed (see FIG. 2C), and a carrier film 55 having an adhesive applied on one side is formed on the conductor 54.
The conductor 54 by pressing it up and then peeling it off.
Is separated from the base material 51, and as shown in FIG.
Carried on top.

The substrate 55 carrying and arranging a large number of conductors 54 in this manner is wound up as shown in FIG.
It is transported and supplied to the semiconductor device manufacturing line.

[0009]

By the way, in a conventional base material such as a lead carrier film, a growth protrusion 54b of a conductor 54 is adhered onto the base material 55 as shown in FIG. The arrangement is such that 54a faces outward. The growth protrusion 54b is formed during electroforming of the conductor 54, and has fine irregularities on its surface.
Moreover, as shown in the figure, the circumference is rounded and the adhesiveness to the base material 55 is not good.

Therefore, the base material 55 carrying the conductor 54
When the conductor is wound up or the base material wound body is sequentially fed out and supplied to the semiconductor device manufacturing line, the conductor 54 is easily dropped from the base material 55, the yield is poor, and the productivity is lowered. Has the drawback of.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a conductor-carrying base material in which a conductor is surely carried and which is easy to handle. In order to achieve the above-mentioned object, the present invention forms a conductor 6a connected to a semiconductor element on a first substrate 1 and transfers the conductor 6a to a second substrate 9 having an adhesive 8 attached thereto. , An adhesive 11 having a higher adhesive strength than the pressure-sensitive adhesive 8 is applied on the third base material 4, and the second base material 9 and the conductor 6a are applied on the third base material 4. Pressure is applied by stacking in the direction facing the 11 side,
After that, the second base material 9 is peeled off to form the conductor 6a into a third layer.
Is transferred to the base material 4 and the conductor 6a is connected to the semiconductor element.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.
1 to 7 are cross-sectional views for explaining a manufacturing process of a conductor carrying base material according to an embodiment of the present invention. As shown in FIG. 1, a resist layer 2 having a desired pattern is formed on the surface of a first base material 1. As the first substrate 1, a metal plate such as an aluminum plate, a stainless plate or a copper plate, or a synthetic resin film such as a polyester film or a polyimide film is vapor-deposited or electroless-plated with a metal such as copper to have conductivity. The provided one is used. The resist layer 2 is made of synthetic resin or the like and has an electrical insulation property, and is formed by, for example, screen printing or ordinary exposure curing.

The first base material 1 is, for example, a tape-like material that is exhausted in the vertical direction toward the plane of the drawing, and the central non-resist portion 3a where the resist layer 2 is not formed should be manufactured. It has the same pattern as the shape of a conductor such as a lead, finger, or bump, and this central non-resist portion 3a
Non-resist portions 3b for forming the positioning protrusions are formed on both sides of. The non-resist portions 3b are formed at equal pitches along the longitudinal direction of the first base material 1, and are sprocket holes provided at both ends of the third base material 4 such as a carrier film shown in FIG. It is the same as the pitch of 5.

Next, the first base material 1 is stripped with selenous acid or the like, and the non-resist portion 3a of the first base material 1,
After activating the surface corresponding to 3b, electroforming is performed to form the electroformed metal layer 6 on the non-resist portions 3a and 3b to have a slightly thicker thickness than the resist layer 2. FIG. 8 is a view showing an example of the electroformed metal layer 6, in which a coating 6-2 made of an alloy of tin and cobalt is formed on a metal layer main body 6-1 made of an alloy of nickel and cobalt. As another example, the gold or silver coating 6-2 can be formed on the metal layer body 6-1 made of copper. Since this electroformed metal layer 6 is formed to have a slightly thicker thickness than the resist layer 2, a growth protrusion 7 which is slightly overlapped with the upper edge of the resist layer 2 is formed (see FIG. 2).

FIG. 9 is a partial perspective view showing an electroformed state. The electroformed metal layer 6a formed on the central non-resist portion 3a.
Has the shape of a conductor. In addition, the non-resist portion 3b on both sides
The electroformed metal layer 6b formed above has a small frame shape as shown in the figure, and serves as a positioning protrusion described later.

Next, as shown in FIG. 3, a second base material 9 such as a transfer tape having an adhesive 8 formed on the lower surface and having a width substantially the same as that of the first base material 1 is formed on the electroformed metal layer 6. Crimp on,
The second base material 9 is attached to each electroformed metal layer 6. Then, as shown in FIG. 4, when the second base material 9 is peeled off from the first base material 1, the resist layer 2 remains on the first base material 1 and the electroformed metal layers 6a and 6b are adhesive. It is separated from the first substrate 1 while being attached to the substrate 8. This is the non-resist portion 3 as previously described.
This is because the surface of a and 3b has been subjected to a peeling treatment with selenious acid or the like.

By this transfer process, each electroformed metal layer 6a,
6b is transferred to the second base material 9 while maintaining the mutual positional relationship when formed by electroforming. As shown in FIGS. 4 and 5, the electroformed metal layer 6 had its growth protrusion 7 adhered to the adhesive 8 of the second base material 9 and was in contact with the first base material 1. The electroformed base portion 10 of the electroformed metal layer 6 is the second base material 9
Facing out. In this case, since the pressure-sensitive adhesive 8 is soft, it is easy to adhere even if the upper portion of the conductor has roundness.

Next, the second base material 9 is supplied above the third base material 4 such as a carrier film with the electroformed metal layer 6 facing down as shown in FIG. When a carrier film is used as the third base material 4, a tape-shaped material having substantially the same width as that of the second base material 9 is used as shown in FIG. Sprocket holes 5 are arranged in rows at the end portions at equal pitches. Further, an adhesive 11 having a higher adhesive strength than the adhesive 8 such as a thermocompression-bonding type is preliminarily applied and formed on the central portion of the third base material 4.

As shown in FIG. 6, the second base material 9 is superposed on the third base material 4 in the direction in which the conductors of the second base material 9 face each other, and both side ends thereof are lightly pressed by pressing members 12. When pushed down,
The second substrate 9 is slightly deformed downward due to its flexibility,
The electroformed base portions 10 of the electroformed metal layers 6b on both sides are inserted into the sprocket holes 5 of the third base material 4. Since the frame-shaped electroformed metal layer 6b is designed to have substantially the same size as the sprocket hole 5, by inserting the electroformed metal layer 6b into the sprocket hole 5, electroforming on the third base material 4 is performed. The metal layer 6a is positioned, the electroformed metal layer 6a is positioned, and the electroformed metal layer 6b functions as a positioning protrusion. In particular, since the electroformed base layer 10 side of the electroformed metal layer 6b is regulated and formed on the side surface of the resist layer 2, it has high dimensional accuracy. Therefore, the positioning accuracy is good. Since the thermocompression-bonding adhesive 11 is not heated at the time of this positioning, the adhesiveness is not yet high, and therefore the positioning of the electroformed metal layer 6a is not hindered.

After the second base material 9 is positioned on the third base material 4 in this manner, the central upper portion of the second base material 9 is thermocompression bonded toward the third base material 4 side. It As a result, the adhesive 11 is softened and melted, and then cooled, so that the electroformed metal layer 6a serving as a conductor is bonded to the adhesive 11. Next, as shown in FIG. 7, the second base material 9 is peeled off from the third base material 4. At this time, the thermocompression-bonding adhesive 11
Is stronger in adhesive strength than the pressure-sensitive adhesive 8, and the electroformed base portion 10 side of the electroformed metal layer 6 corresponding to the conductor is flatter than the growth protrusion portion 7 side. The layer 6a is adhered and supported on the third base material 4, and only the electroformed metal layer 6b that functions as a positioning protrusion remains on the second base material 9.

The conductor-carrying substrate thus obtained is
As shown in FIG. 11, it is wound up, conveyed and supplied to the semiconductor device manufacturing line, and the sprocket hole 5 of the third base material 4 in turn transfers the electroformed metal layer 6a corresponding to the conductor onto the semiconductor element. It serves as a positioning hole when connecting.

In the above embodiment, the electroformed metal layer 6a which becomes a conductor
And an electroformed metal layer 6b functioning as a positioning projection are electroformed on the first substrate 1 having a predetermined positional relationship, and the electroformed metal layer 6a and the electroformed metal layer 6b are once formed as they are. Two
Of the electroformed metal layer 6b having high surface accuracy and the sprocket hole 5 of the third base material 4 are used to transfer only the electroformed metal layer 6a to the third base material 9. Base material 4
The method of transferring to the top was adopted. According to this method, the first
Electroformed metal layer 6a and electroformed metal layer 6 formed on the substrate 1 of
b with respect to the positional relationship with the sprocket hole 5 on the third substrate 4.
Can be reproduced as a positional relationship between the electroformed metal layer 6b and the electroformed metal layer 6b, and the electroformed metal layer 6a serving as a conductor can be accurately and productively supported at a predetermined position on the third base material 4.

In the above-mentioned embodiment, the thermocompression-bonding type adhesive layer 11 is used for bonding the third base material 4 and the electroformed metal layer 6a.
Other adhesives or pressure-sensitive adhesives can be used as long as they have higher adhesive strength than the pressure-sensitive adhesive 8 of the substrate 1. In the present invention, these are collectively referred to as an adhesive.

[0024]

As described above, according to the present invention, the conductor 6a connected to the semiconductor element is formed on the first base material 1, and the conductor 6a is formed.
a is transferred to the second base material 9 to which the pressure sensitive adhesive 8 is attached, and the adhesive 11 having a higher adhesive strength than the pressure sensitive adhesive 8 is applied onto the third base material 4 and the second base material 9 is also applied. Are overlapped and pressed in a direction in which the conductor 6a faces the adhesive 11 side on the third base material 4, and then the second base material 9 is peeled off to separate the conductor 6a.
a is transferred to the third base material 4, and the conductor 6a and a semiconductor element are connected to each other.

Therefore, according to the present invention, the second substrate 9
Since the so-called intermediate transfer member consisting of 3 is used, the third base material 4 does not come into direct contact with the first base material 1 in which dirt or the like is present in the electroforming process, and the third base material 4 is It is not necessary to invert downward so as to face the base material 1 of
Transfer work can be done reasonably.

Moreover, the transfer can be surely performed due to the difference in the adhesive force between the pressure sensitive adhesive 8 and the adhesive 11, so that when the third substrate 4 is handled, especially when the third substrate 4 is in the form of a film. In this case, the conductor 6a does not drop off from the third base material 4 during winding or unwinding, and productivity and yield can be improved.

[Brief description of drawings]

FIG. 1 is a view for explaining a conductor-carrying substrate according to an embodiment of the present invention, showing a resist layer forming step in a sectional view of a manufacturing step.

FIG. 2 is a view for explaining a conductor-carrying substrate according to an example of the present invention, showing an electroforming step in a sectional view of a manufacturing step.

FIG. 3 is a view for explaining a conductor-carrying substrate according to an example of the present invention, showing a transfer step in a sectional view of a manufacturing step.

FIG. 4 is a view for explaining a conductor-carrying substrate according to an example of the present invention, showing a peeling step in a cross-sectional view of a manufacturing step.

FIG. 5 is a view for explaining a conductor-carrying substrate according to an example of the present invention, and shows a retransfer step in a cross-sectional view of a manufacturing step.

FIG. 6 is a view for explaining a conductor-carrying substrate according to an example of the present invention, showing a pressure bonding step in a cross-sectional view of the manufacturing process.

FIG. 7 is a view for explaining a conductor-carrying substrate according to an example of the present invention, showing a peeling step in a cross-sectional view of a manufacturing step.

FIG. 8 is an enlarged sectional view of an electroformed metal layer.

FIG. 9 is a partial perspective view showing a state of electroforming.

FIG. 10 is a plan view of a third base material.

FIG. 11 is a side view of a wound body of the conductor-carrying substrate, for explaining the conductor-carrying substrate according to the embodiment of the invention.

FIG. 12 is a cross-sectional view showing a manufacturing process of a conventional conductor carrying base material.

FIG. 13 is a side view of a wound body of this conductor carrying base material.

[Explanation of symbols]

 1 1st base material 4 3rd base material 6a Conductor (electroformed metal layer) 6b Electroformed metal layer 8 Adhesive 9 Second base material 11 Adhesive

Claims (1)

[Claims] 1. A first conductor 6a connected to a semiconductor element is provided.
Is formed on the base material 1, and the conductor 6a is transferred to the second base material 9 to which the adhesive 8 is attached, and the adhesive 11 having higher adhesive strength than the adhesive 8 is applied on the third base material 4. The second base material 9 is overlapped and pressed in the direction in which the conductor 6a faces the adhesive 11 side on the third base material 4, and then the second base material 9 is peeled off. The conductor 6a to the third
A method of manufacturing a semiconductor device, which comprises transferring the conductor 6a to a semiconductor element and transferring the conductor 6a to the substrate 4.