JPH0558570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a lead carrier film in which a large number of leads for connection to semiconductor chips such as ICs and LSIs are supported and arranged on the film.

[Conventional technology]

2. Description of the Related Art Conventionally, metal lead frames have been used to assemble semiconductor devices in which semiconductor chips are integrated with a resin mold and have a large number of protruding pins.
This lead frame is required to have high precision as recent semiconductor devices require a large number of pins.

In order to meet this requirement, lead frames with fine fingers, etc. are manufactured using etching processing, but this method has the drawback that the manufacturing process is complicated and costs are high. .

Recently, lead frames using electroforming technology have been developed as a method that eliminates these drawbacks, is easy to manufacture, and allows molding of minute parts. In order to improve productivity, various lead carrier films in which a large number of leads are supported and arranged on the film have been studied.

FIGS. 4a to 4g are cross-sectional views for explaining the manufacturing process of a lead carrier film that has been proposed as a method that prevents leads from falling off the carrier film and improves yield and productivity.

As shown in FIG. 1A, a resist layer 2 having a desired pattern is formed on the surface of a substrate 1. As shown in FIG.
The substrate 1 is a metal plate such as an aluminum plate, a stainless steel plate, or a copper plate, or a synthetic resin film such as a polyester film or a polyimide film, on which conductivity is imparted by vapor deposition or electroless plating of a metal such as copper. used. The resist layer 2 is an electrically insulating material made of synthetic resin or the like, and is formed by, for example, screen printing or ordinary exposure curing.

The substrate 1 is in the form of a tape that is elongated in the vertical direction toward the plane of the drawing, and the non-resist portion 3a in the center where the resist layer 2 is not formed has the same pattern as the shape of the lead to be manufactured. Non-resist portions 3b for forming positioning protrusions are formed on both sides of this central non-resist portion 3a. The non-resist portions 3b are formed at equal pitches along the longitudinal direction of the substrate 1, and are formed on a carrier film 4 shown in FIG.
This is the same pitch as the sprocket holes 5 provided on both sides of the sprocket.

Next, the surface of this substrate 1 is subjected to a peeling treatment using selenite or the like to activate the surface corresponding to the non-resist portions 3a, 3b of the substrate 1, and then electroforming is applied to the non-resist portions 3a, 3b. The cast metal layer 6 is formed to be slightly thicker than the resist layer 2.

Next, as shown in FIG. 4c, a transfer tape 9 having approximately the same width as the substrate 1 with an adhesive layer 8 formed on the lower surface is pressed onto the electroformed metal layer 6, and the transfer tape 9 is attached to each electroformed metal layer. Paste on layer 6. Then, when the transfer tape 9 is peeled off from the substrate 1 as shown in FIG. Leave. This is because, as described above, the surfaces of the non-resist portions 3a and 3b have been previously subjected to a peeling treatment using selenite or the like.

Through this transfer process, each electroformed metal layer 6a, 6b
are transferred to the transfer tape 9 while maintaining the mutual positional relationship when formed by electroforming. In addition, as shown in FIG. 4d and e, the electroformed metal layer 6 is
The growth protrusion 7 is the adhesive layer 8 of the transfer tape 9.
The electroformed base 10 of the electroformed metal layer 6 which was attached to the substrate 1 and was in contact with the substrate 1 faces outward from the transfer tape 9.

Next, the transfer tape 9 is placed on the carrier film 4 with the electroformed metal layer 6 facing down as shown in FIG. 4e.
is supplied above. The carrier film 4 is a tape-shaped material having approximately the same width as the transfer tape 9, and is made of polyimide film or polyester film, and sprocket holes 5 are arranged at equal pitches at both ends thereof. Further, a thermocompression type adhesive layer 11 is previously applied and formed on the center portion of the carrier film 4.

As shown in FIG. 4f, when the transfer tape 9 is placed on the carrier film 4 and its both ends are lightly pressed down with the pressing members 12, the transfer tape 9 deforms slightly 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 carrier film 4. Since the frame-shaped electroformed metal layer 6b is designed to have approximately the same size as the sprocket hole 5, by inserting the electroformed metal layer 6b into the sprocket hole 5, the carrier film 4
The electroformed metal layer 6a is positioned above, and the electroformed metal layer 6b functions as a positioning protrusion. In particular, the electroformed metal layer 6b on the electroformed base 10 side is formed to be regulated by the side surface of the resist layer 2, so it has high dimensional accuracy and therefore good positioning accuracy. Note that during this positioning, since no heat is applied to the thermocompression adhesive layer 11, it is not sticky, and therefore does not interfere with the positioning of the electroformed metal layer 6a.

After the transfer tape 9 is positioned on the carrier film 4 in this way, the transfer tape 9 is
The center upper part of is heated and pressed toward the carrier film 4 side. This softens the adhesive layer 11,
By melting and then cooling, the electroformed metal layer 6a serving as a lead is bonded to the adhesive layer 11. Next, as shown in FIG. 4g, the transfer tape 9 is separated from the carrier film 4. At this time, the thermocompression type adhesive layer 11 has a stronger adhesive force than the adhesive layer 8, and the electroformed metal layer 6a corresponding to the lead is closer to the electroformed base 10 than the growth protrusion 7 side. Since the electroformed metal layer 6a is also flat, the electroformed metal layer 6a is adhered and supported on the carrier film 4, and only the electroformed metal layer 6b, which functions as a positioning protrusion, remains on the transfer tape 9.

The lead carrier film thus obtained is wound into a roll and transported and supplied to a semiconductor device manufacturing line. carrier film 4
The sprocket holes 5 serve as positioning holes when the electroformed metal layer 6a corresponding to the lead is transferred onto the semiconductor chip, so that no positional shift occurs.

According to the configuration shown in FIG. 4, the electroformed base side of the lead has a flat surface with no minute irregularities or roundness compared to the growth protrusion side, so it can be supported on the carrier film reliably. It is. Therefore, when handling the lead carrier film, especially when winding or unwinding the lead carrier film, the lead does not fall off from the carrier film.
Productivity and yield can be improved.

[Problem that the invention seeks to solve]

However, the conventional manufacturing method for lead carrier film requires a step of transferring onto a transfer tape, which complicates the process and makes it uneconomical because the transfer tape, which is a flexible intermediate medium, is disposable. , there is a tendency for variations in the dimensions between the lead pieces to occur due to the two-time transfer process. Further, if the substrate on the base material side is a rigid body such as a metal plate, it cannot be transferred in a curled state, which imposes restrictions on the manufacturing process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a lead carrier film that eliminates the drawbacks of the prior art described above, simplifies the manufacturing process, and eliminates the need for a tape dedicated to transfer.

[Means for solving problems]

In order to solve the above problems, the present invention forms a resist layer with a predetermined pattern on a substrate whose surface is conductive, forms a first electroformed metal layer on the non-resist part, and After a second electroformed metal layer serving as a lead piece is formed on the metal layer, the second electroformed metal layer is supported on a film carrier tape.

[Effect]

According to the above means, 2
The surface layer of the electroformed metal layer formed on the layer is directly transferred to the film carrier tape, and the film carrier tape is used as both the transfer tape and the film carrier tape. Therefore, it is possible to establish a method for manufacturing a lead carrier film that eliminates the need for a transfer-specific tape.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIGS. 1a to 1e are a perspective view and a sectional view illustrating the manufacturing process of a lead carrier film in the present invention. As shown in FIG. 1a, a resist material 21 made of a photosensitive material is applied to the surface of the base tape 20 whose surface is made conductive.
This base tape 20 has the same shape as the carrier film which is the final manufactured product, has a width of 35 mm, and has sprocket holes 22 provided at regular intervals along both sides.

As a means for imparting conductivity to the base tape 20, the means shown in FIG. 4 can be used, but the difference is that the base tape 20 is thin enough to be bent and wound, and flexible. A pattern film 23 on which a predetermined pattern is printed is placed in close contact with the resist material 21 of the base tape 20 (this is done by aligning the sprocket holes 22 and 24).

Next, the pattern film 23 is irradiated with light to expose the resist material 21 to a pattern. By developing and baking this,
As shown in FIG. 1b, a resist layer 25 having non-resist portions 26 is formed on the base tape 20. As shown in FIG.

Next, as shown in FIG.
Then, electroforming is performed using materials such as copper and nickel,
An electroformed metal layer 27 is formed in the non-resist portion 26 to be slightly thicker than the resist layer 25 .

Further, on the surface of the electroformed metal layer 27, selenite
After peeling using potassium dichromate or the like, secondary electroforming is performed on the surface of the electroformed metal layer 27 using copper, nickel, etc. to form the electroformed metal layer 28 as shown in FIG. 1d. do. As the above peeling treatment, the electroformed metal layer 2
By electroforming a thin layer of chromium on the seven surfaces, the chemical treatment described above is not required, and once the chromium electroforming treatment is performed, the base tape 20 can be repeatedly used as a permanent matrix.

Next, as shown in FIG. 1e, the electroformed metal layer 28 is bonded to a film carrier tape 30 made of polyimide or the like having approximately the same width as the base tape 20, which has a thermosetting adhesive layer 29 applied to one side. let This adhesion is performed while applying heat and pressure from the outside.

Specifically, as shown in FIG. 2, the pressure roller 31a is heated by a heater (not shown).
and 31b, the film carrier tape 30 and the base tape 20 in the process shown in FIG.
They are aligned by the sprocket holes and fed in an overlapping state. Both are conveyed at a constant speed and are pressed together by rollers 31a and 31b, so that only the electroformed metal layer 28 formed on the peeled surface adheres to the film carrier tape 30, and the electroformed metal layer 27 is bonded to the film carrier tape 30. torn off. At the same time, the adhesive layer 29 applied to the film carrier tape 30 is cured by the heat applied by the rollers 31a and 31b.

The electroformed metal layer 28 is peeled off, and the resist layer 25,
The base material 33, which now consists of only the electroformed metal layer 27 and the base tape 20, can be reused by forming the electroformed metal layer 28 again on the electroformed metal layer 27. The lead carrier film 32 can be manufactured many times by eliminating the steps up to c. The base material 33 is wound onto a roll 34,
The lead carrier film 32 formed by adhering the electroformed metal layer 28 as a lead piece to the lead carrier film 32 is wound up onto a roll 35 . In order to prevent the lead carrier film 32 wound on the roll 35 from adhering to each other,
A separator 36 is inserted between the films.

By making the base tape 20 flexible, it can be curled and deformed, and the peeling process after heat and pressure bonding can be facilitated.

FIG. 3 shows an example of the lead carrier film 32 manufactured through the above process, in which the sprocket holes 37 provided at both ends of the lead carrier film 30 are aligned with the sprocket holes 22 of the base tape 20. Since the lead pieces are conveyed and bonded in a state in which they are aligned with each other, the lead pieces can be accurately transferred onto the tape.

〔Effect of the invention〕

As is clear from the above, according to the present invention, it is possible to use both a transfer tape and a film carrier tape, eliminating the need for a dedicated transfer tape and reusing the base material that has been subjected to resist treatment, which simplifies the process and reduces manufacturing costs. It is possible to reduce the Furthermore, since positioning can be performed using sprockets, misalignment of the lead pieces can be eliminated.

[Brief explanation of the drawing]

Figures 1 a, b, c, d, and e are perspective views and sectional views showing the manufacturing process of the lead carrier film according to the present invention, Figure 2 is an explanatory view showing the adhesion (transfer) process, and Figure 3 is the invention. FIG. 4 is a perspective view showing a completed state of a lead carrier film according to the present invention, and FIGS. 20...Base tape, 25...Resist layer,
27... Electroformed metal layer, 28... Electroformed metal layer (lead piece), 30... Film carrier tape.

Claims (1)

[Claims] 1 A resist layer with a predetermined pattern is formed on a substrate whose surface is made conductive, and a first resist layer is formed on the non-resist part.
After forming an electroformed metal layer, and forming a second electroformed metal layer to serve as a lead piece on the electroformed metal layer, the second electroformed metal layer was supported on a film carrier tape. A method for producing a lead carrier film characterized by: