JPH02142152A - Manufacture of film carrier - Google Patents

Abstract

PURPOSE:To make the thickness of a back-fixing coating film uniform, to prevent the occurrence of voids and to improve working efficiency to a large extent by spraying back-fixing paint on the rear surface of the copper foil of a device hole on which a semiconductor chip is mounted before etching a film carrier, and smoothing the coated surface by squeezing. CONSTITUTION:A polyimide film 1 is set in a spray device 7. Acrylic paint is supplied from a spray gun 8 by a weight falling method. A spray paint 9 is blown on a rear surface 5 of a device hole. When the spray work is finished, the film 1 is moved in the direction of an arrow A. At this time, the coated surface is in contact with a doctor bar 13 and undergoes squeezing. Thereafter, squeezing is performed with a doctor bar 14, and the perfectly smooth surface is shaped. The film is sent into a drying furnace. A fluororesin is used on the side where the spray device is in contact with the copper foil part of the film. Fluororubber is used for the side where the device is in contact with the film part, including the doctor bars. The other parts are made of metal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to the manufacture of a film carrier used in tape bonding for simultaneously connecting a large number of leads formed on a deep film to electrode portions of semiconductor chips. It is about the method.

[Prior Art] Up until now, semiconductor mounting methods have been based on packaging of semiconductor chips and lead frames (20 μr/1 to 70 μl)! Wire for bonding pure gold, aluminum, copper, etc.
The mainstream was the wire bonding method, which automatically soldered each pin according to the number of pins. However, as semiconductor chips become more highly integrated, the number of lead pins increases as well, leading to ultra-automated and labor-saving bonding technology, and ultra-small and thin bonding technology. Mo1IIL! It is now required by TAB is a mounting method that meets these strict demands for semiconductors.
(tape automated bonding) method is adopted. In the rAB method, copper foil is bonded to a film that will become the V plate, and then a wiring pattern is formed by photo-printing. This is a method of bulk bonding. As a film carrier for this T A B,
For example, as shown in FIG. 4(a), a copper foil 2 (J9 size: 35 μm) is adhered to a polyimide film 1 with a thickness of 75 μm using an adhesive 3, and then a photosensitive resist is applied on the copper foil 2. The film is coated with a coating film 5, and the wiring pattern is exposed and baked using a prescribed negative film, and the resist in the non-exposed areas is dissolved and removed.
As shown in b), the copper in the resist-removed portion is removed during etching to form the pin 4 (wiring pattern), which is often used.

In this way, a large number of culms are required for IIJ construction of the film 17 and 7, but during these steps, #4 of the device hole where resist is applied before the etching process is used.
There is a so-called backing process in which paint is applied to the back side of the foil.

FIGS. 3(a) and 3(b) show a partial cross-sectional view and a partial plan view of the film carrier, in which 1 is a polyimide film, 2 is a copper foil, and 5 is the back surface of a device ball on which a chip is mounted. , 6 drills the subrokets 1-hole.

As mentioned above, in the back coating process, the back surface 5 of the device pole is coated with a paint before etching, and this coating film is called a back coating.

When performing the back-stitching work, either the botting method in which the paint is dropped onto the coating surface or the brush coating method in which the paint is applied with a brush is used.

[Problem to be solved by the invention] As mentioned above, the botting method or the brush coating method is used to back-stack the back side of the device hole, but these methods have their own unique characteristics. On the other hand, there are some problems: Botting is relatively easy to work with, but the efficiency is low.

To improve this, it is possible to arrange a large number of paint dripping ports along the length of the tape gear and drip the paint at -.degree., but considering workability and difficulty in maintenance, the number of paint dripping holes should be limited to about 10. Yes, the processing speed of this IM is 2-3 m7
The efficiency is still poor.

- On the other hand, when applying with a brush, the application speed is approximately 5 m/7 minutes, which is more efficient than botting and manual etching, but the occurrence of uneven coating is unavoidable. As a result, the etched surface becomes uneven.
Particularly in the case of fine patterns, defects are likely to occur.

As described above, a common drawback that requires improvement in both is the occurrence of voids, which remains an important issue.

An object of the present invention is to provide a method for manufacturing a film carrier in which the back coating film is uniform, does not generate voids, and greatly improves work efficiency.

1 Means for Solving the Problem 1 The present invention is a method for manufacturing a film 4=17 rear used in a tape bonding method, in which the inertial surface of a copper foil in a device hole in which a semiconductor chip is attached is sprayed before etching. J3 is characterized by smoothing the painted surface by squeezing after applying the backing paint.
We aim to achieve our goal by ensuring that the first coating film has a uniform thickness and no voids, allowing for efficient work.

[Function] In the method for producing a film carrier of the present invention, when coating the back surface of the device hole copper foil portion of the tape carrier, after back-tacking using a spray, this surface is further flattened with skizinc. Irinote°, bodding method and hi! 1) The coating thickness is uniform and the voids are 51. Able to work with high efficiency without having to live.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing an embodiment of a spray device to which the method of manufacturing a C lum carrier of the present invention is applied.
1 is a spray device, 8 is a spray gun, 9 is a spray paint, 10 is a spray and ski zinc chamber, 11 is a ski zinc chamber, and 12a.

121) indicates one vent of solvent vapor or air filled in the spray device @7, and 13 and 17I indicate doctor bars.

Figure 2 is a cross-sectional view of the device shown in Figure 1, viewed from above.
The polyimide film 1 is the same as the platform shown in FIG. 3(b).

In both figures, polyimide film 11, thickness 125 μm, width 3
5 mm, and a copper foil with a thickness of 35 μm and a width of 25 H is adhered to this using a T-box adhesive. FRI behind device hole
The dimensions of 5 are -. i1 rectangle with 8# sides, and the Nj method of Subu [] Kekerat 6 is -. a square with 2 qm sides.

When operating this spray [1, as shown in both figures, the polyimide film 1 is applied to the spray device 7, and the spray paint 9 is sprayed from the spray gun 8 onto the back surface 5 of the device hole. Gun 8 has a nozzle diameter of 0.2 mrs 1 air usage & tlOI)/min and a charge of 04 d! : M/min, and an acrylic paint was used as the paint, which was supplied by weight drop method.

When the spraying work is finished, the polyimide film 1 moves in the direction of the arrow, but at this time the coated surface is
Dr. Par 14 again after being skijinked in contact with
It is then skizinced and shaped into a completely smooth surface before being sent to the next process, a drying oven.

When the polyimide film 1 is moved, a mono-nitrogen resin is used on the side where the spray device contacts the copper tin part of the film.
Fluororubber was used on the side in contact with the film part, including the doctor pad. Other parts are made of metal.

In this way, the back surface of the device hole was back-stacked at a speed of 10 m/min. As a result, no voids occur and the coating film
9 was found to be uniform.

I also tried etching after finishing the process, and good results were obtained.

The interior of the spray device is constantly ventilated with the air inside the room to prevent air from forming on the surface to be coated. Moreover, when the spraying work is completed, the interior of the room can be cleaned by blowing out the spray gun 8.

Effects of the Invention 1 As described above, according to the present invention, the following effects can be achieved by 1q.
It will be done.

(1) Voids occur in the backing coating I! It is possible to perform stable etching with uniform thickness.

(2) Work efficiency can be significantly improved.

(3) Aim to reduce product costs by improving quality and work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a spray device used for opening the film carrier of the present invention;
2 is a top sectional view of FIG. 1, FIG. 3 is a partial sectional view and a side view of the film carrier, and FIG. 4 is an explanatory diagram of the film carrier. 1: Film carrier, 2: Copper a5. 5: Back side of device hole. 7: Spray equipment, 8 Varnish spray gun, 13.14. : Doctor bar 2nd opening 2: 4F; I't S knee i hasst tf -, -, back side 6t/, + complete (α)

Claims (1)

[Claims] 1. A method for producing a film carrier in which a copper foil for a wiring conductor is adhered to the entire surface of an insulating plastic film serving as a base material of the film carrier, and then the copper foil is etched to form a desired wiring conductor. Production of a film carrier characterized in that, before etching the film carrier, a backing paint is applied by spraying to the back side of the copper foil of the device hole in which the semiconductor chip is mounted, and then the applied surface is smoothed by skizinc. Method.