JPH01136345A - Manufacture of tape carrier with bump - Google Patents

Abstract

PURPOSE:To prevent damage during manufacture and during bonding of a lead of a finger and the like by coating with an insulating resin and fixing a finger corresponding section having a bump and a conductor circuit pattern. CONSTITUTION:A conductor layer 2 is laminated onto one surface of a metallic carrier 1, and a conductor circuit pattern 4 is formed through photoetching. An insulating resin pattern 5 is shaped onto the pattern 4, and an opening section 6 is formed to a lead pattern (a conductor circuit pattern) to which a bump must be shaped. The bump 7 is grown from the exposed section 6 through plating, and the metallic carrier 1 is peeled and removed. The conductor circuit pattern is formed through plating or the application of conductive paste. The metallic carrier is gotten rid of partially, and a tape carrier can be reinforced mechanically by the remainder. An electrode section for a chip 8 can be brought into contact directly and joined to the bump 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to the manufacture of flexible circuit boards, and more particularly to a method of manufacturing bumped tape carriers.

[Conventional technology]

Flexible circuit boards are made by expressing the electrical wiring that connects circuit components in a wiring diagram based on a circuit design, and then using techniques such as photo-etching to create a wiring diagram in a conductive layer on a flexible insulating substrate. This board has both wiring and component mounting functions.

As a method for mounting chip components such as IC chips on a flexible circuit board that has a predetermined conductive pattern expressed in a wiring diagram based on this circuit design, the IC chip is housed in a package and soldered onto the board. The flat package method for mounting and the direct integration of paired chips such as bare IC chips into flexible wiring boards (
There is a chip-on-board method (Chipon Board), etc.

The former flat package method has the disadvantage that there is a limit to the miniaturization of the lead frame, and due to its thickness and weight, it cannot sufficiently respond to higher density, lighter weight, and thinner wiring boards. .

On the other hand, in the chip-on-board method, the IC chip is directly mounted on the lead pattern of the flexible wiring board.
Due to its structure, it is suitable for high integration and lower manufacturing costs. In addition to the wire bonding method, which has traditionally been the main method, the pair chip mounting method in this chip-on-board method includes the TA method, which mounts the chips on a flexible table.
B method (Tape Automated Bondln
g). This technology can be used to check characteristics before integration, can be applied to ICs with smaller packages or short pad pitches, and can be used in calculators, watches, IC cards, memory cards, etc. because it allows for thin mounting and continuous integration. Applications are rapidly expanding.

Conventionally, the production of tape carriers without bumps involves preparing a laminate made of polyimide film and copper foil, applying photosensitive resin to both sides of the copper foil and polyimide film, and photo-etching to coat the sides of the polyimide. An opening for arranging a semiconductor element is formed, and a conductive circuit pattern of a lead including fingers for connecting the semiconductor element is formed on the side surface of the copper foil. As shown in FIG.
The semiconductor element (chip) 8 can be mounted by bonding gold bumps 9 to the electrode portion thereof.

On the other hand, in the conventional production of tape carriers with bumps, for example, a photosensitive resin is applied to both sides of a laminate of a polyimide film with excellent heat resistance and copper foil, and openings for forming bumps are formed in the polyimide film by photo-etching. forming a section;
Bumps are formed by plating on the copper foil surface exposed at the opening, and a conductor circuit pattern of the lead including fingers for connecting semiconductor elements is formed by photo-etching the copper foil surface (Japanese Patent Laid-Open No. 55-48954). Public bulletin). The electrode portion of the semiconductor element can be directly connected to the bumps of this tape carrier for mounting.

[Problem that the invention seeks to solve]

However, in the above method for manufacturing a tape carrier without bumps, the resulting tape carrier has fingers protruding into openings (device holes) for arranging semiconductor elements, so during manufacturing and bonding. Deformation such as bending is likely to occur.

This invention was made based on the above-mentioned background, and its purpose is to enable the characteristics to be checked before installation, and to reduce the size of the package or shorten the pad pitch of the IC.
The tape for TAB can be applied to C chips and improves shape stability by preventing deformation of the fingers that connect with chips such as ICs without impairing the functions of the TAB method, which allows thin mounting and continuous integration. It is an object of the present invention to provide a method for manufacturing a tape carrier with bumps, which can increase the yield of the carrier and prevent defective bonding with chips.

[Means for solving problems]

The above problems are solved by the method of manufacturing a bumped tape carrier of the present invention.

That is, the method for producing a bumped tape carrier of the present invention involves forming a conductive circuit pattern including a lead pattern on a tape-shaped metal carrier, forming a patterned layer of insulating resin thereon, and forming bumps on the surface of the lead pattern. forming a bump on the surface of the lead pattern exposed through the exposure hole, and then removing at least an area of the metal carrier corresponding to the lead pattern of the metal carrier. .

In preferred embodiments of the invention, the formation of the conductor circuit pattern on the tape-like metal carrier can be accomplished by photoetching, conductive paste application, or plating.

In a preferred embodiment of the invention, the insulating resin pattern layer can be formed by applying the insulating resin by photoetching or screen printing.

In the food of this invention, for example, polyimide resin,
When forming a pattern layer of an insulating resin selected from polyamide resin, polyimide amide resin, polyetherimide resin, polysulfone resin, polyallylsulfone resin, polyester resin, and epoxy resin, the thickness of the insulating resin can be partially reduced. This partial thinning allows easy positioning of the front and back sides of the tape carrier.

In a preferred embodiment of the invention, the removal of the metal carrier selected from, for example, copper foil, aluminum foil, nickel foil, stainless steel foil, and etchable composites comprises:
This can be done by chemical etching or mechanical peeling.

This invention will be explained in more detail below.

Conductor circuit pattern formation The method for manufacturing the bumped tape carrier of the present invention first includes:
A conductor circuit pattern including a lead pattern is formed on the tape-shaped metal carrier.

The tape-shaped metal carrier that can be used in the present invention is one that can provide mechanical support for the tape carrier during the manufacturing process of the present invention and can be easily removed from the formed circuit pattern. Such examples include copper foil, aluminum foil, nickel foil, stainless steel foil, and etchable composite materials.

A conductive circuit pattern can be formed on a tape-shaped metal carrier by photo-etching a laminate of a conductor layer and a metal carrier to form a conductor layer into a conductor pattern, or by screen printing a conductive circuit pattern onto a tape-shaped metal carrier. This can be carried out by applying a conductive paste in a pattern, or by forming a conductive pattern on a tape-shaped metal carrier by partial plating.

The material of the conductor circuit pattern to be formed is, for example, metals and alloys such as copper, nickel, aluminum, gold, and silver;
Examples include oxide conductors such as ITO.

Formation of Insulating Resin Pattern In the method for manufacturing a bumped tape carrier of the present invention, a patterned layer of insulating resin is then formed, and the lead pattern surface is exposed at the bump-forming exposure opening.

The insulating resin that can be used in this invention is a resin that has heat resistance and electrical insulation properties, such as polyimide resin, polyamide resin, polyimide amide resin, polyetherimide resin, polysulfone resin, polyallylsulfone. At least one resin selected from resin, polyester resin, and epoxy resin.

The insulating resin pattern layer can be formed by various methods, such as a photo-etching method in which a photoresist is coated, exposed and developed, or a method in which an insulating resin is applied in a pattern by screen printing.

The insulating resin pattern layer is formed in such a way that the lead pattern surface on which bumps are to be formed is exposed at the bump forming exposure opening. It is desirable that the patterned insulating resin layer covers at least the area where the soldered flap 4 is formed so as to fix a fragile lead frame such as a finger.

In a preferred embodiment of the present invention, when forming the patterned layer of insulating resin, it is desirable to partially reduce the thickness of the insulating resin in order to facilitate positioning of the front and back sides of the tape carrier.

Formation of Bumps In the method for manufacturing a tape carrier with bumps according to the present invention, after forming an insulating resin pattern, bumps are grown from the lead pattern surface exposed at the exposed opening, particularly from the finger surface.

This bump formation can be performed by, for example, electrolytic or electroless partial plating (pattern plating), dipping, solder preforming, or the like. In pattern plating, insulating resin, resist, etc. can be used as a mask material.

The material of the bump that can be used in the present invention is a metal or alloy such as gold, silver, copper, lead, or solder, or may be a composite material.

Metal Carrier Removal In the method for manufacturing a bumped tape carrier of the present invention, after the bumps are formed, at least the area of the metal carrier corresponding to the lead pattern of the hooker is removed.

In the present invention, any means can be used to remove the metal carrier as long as it does not substantially damage the conductor circuit pattern, insulating resin pattern, and bumps. For example, there is an etching gas using an etching liquid. At this time, the etching solution varies depending on the type of metal carrier; if the metal carrier is aluminum or zinc, sodium hydroxide,
An alkaline solution such as potassium hydroxide, and in the case of iron or nickel, an acidic solution such as hydrochloric acid or dilute sulfuric acid can be used. In addition, it can be removed by etching using etching gas or mechanical peeling.

Next, the process of manufacturing the bumped tape carrier of the present invention will be explained with reference to the accompanying drawings.

First, a material is prepared in which a conductor layer 2 is laminated on one side of a metal carrier 1 (FIG. 1A). This laminate may be a metal carrier laminated with a metal foil, or a metal carrier plated with a metal.

Next, apply resist 3 to the 2nd surface of the conductor layer (Figure 1B).
, this resist 3 is exposed and developed (FIG. 1C). The exposed conductor layer is etched (FIG. 1D) and unnecessary resist is removed to form a conductor circuit pattern 4 (FIG. 1E).
).

An insulating resin pattern 5 is formed on the formed conductor circuit pattern 4 (FIG. 1F), and an opening (exposed opening) 6 is provided in the lead pattern (conductor circuit pattern) in which bumps are to be formed.

Bumps 7 are grown from this exposure hole 6 by plating (
Figure 1G). Finally, the metal carrier 1 is peeled off and removed (FIG. 1H).

This invention is not limited to the above embodiments, and various modifications are possible as described above. For example, the conductor circuit pattern can be formed by applying a resist directly to a metal carrier, exposing and developing the resist, and plating the exposed metal carrier surface.

Also, as shown in FIG. 2, the metal carrier can be partially removed and the remaining metal carrier portions mechanically reinforce the tape carrier of the present invention.

In the tape carrier of the present invention, for example, as shown in FIG. 2, the electrode portions of the chips 8 can be bonded to the bumps 7 by directly contacting them.

[Action and effect of the invention]

By the method of manufacturing a bumped tape carrier of this invention,
The following actions and effects can be obtained.

(a) Since the conductor circuit pattern is covered and fixed with insulating resin, it is possible to prevent the fingers and other leads, which have traditionally been easily bent, from being damaged during manufacturing and bonding. It increases the yield of tape carriers and enables good bonding with chips.

(b) Similarly, since the portion corresponding to the finger with the bump is covered with insulating resin and fixed, there is no misalignment with the IC chip, and continuous and good bonding can be performed.

(C) Since the bumps are provided on the tape carrier side, problems such as increased cost and damage to the chip that would otherwise occur when bumps are provided on the chip side can be avoided.

〔Example〕

This invention will be specifically explained by examples.

Example A copper foil with a thickness of 50 μm was prepared, and after cleaning and etching, a photosensitive resist was applied to the surface with a thickness of 5 μm.
A resist pattern was formed by overlapping pattern masks and exposing and developing them. Next, a Ni layer was grown to a thickness of 3 μm on the exposed copper foil surface in a sulfamine-based Ni plating solution, and the resist was peeled off to form a Ni circuit pattern.

Apply 20 μm of photosensitive polyimide on the Ni circuit pattern side.
An insulating resin pattern was formed by applying a thick layer, exposing it to light, and developing it. Add 25 μm of gold bumps to this using a cyan gold plating bath.
It was grown to about m thickness.

Finally, the tape carrier was produced by selectively etching the copper foil with an aqueous solution of ammonium persulfate and ammonium chloride.

Using the tape carrier thus obtained, a bonding test with an IC chip was conducted. As a result, the bonding condition was good.

Further, the tape carrier and the IC chip could be easily positioned by using the thin layered portion of the insulating resin.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing each step of the method for producing a tape carrier with bumps according to the present invention, and FIG. 2 shows an example of a tape carrier with bumps obtained by the method according to the present invention. FIG. 3 is a cross-sectional view showing an example of a conventional tape carrier. DESCRIPTION OF SYMBOLS 1... Metal carrier, 2... Conductor layer, 3... Resist, 4... Conductor circuit pattern, 5... Insulating resin pattern, 6... Opening, 7... Bump, 8 ...Chip, 9...Finger, 10...Polyimide film. Applicant's agent Mr. Sato

Claims (1)

[Claims] 1. A conductor circuit pattern including a lead pattern is formed on a tape-shaped metal carrier, a pattern layer of insulating resin is formed on the conductor circuit pattern, and the lead pattern surface is exposed through an exposure hole for forming bumps. . A method for manufacturing a bumped tape carrier, comprising forming a bump on the lead pattern surface exposed at the exposed opening, and then removing at least a portion of the metal carrier corresponding to the lead pattern of the fingers. 2. The method for producing a bumped tape carrier according to claim 1, wherein the conductor circuit pattern is formed on the tape-shaped metal carrier by plating. 3. The method for manufacturing a bumped tape carrier according to claim 1, wherein the conductor circuit pattern is formed on the tape-shaped metal carrier by photo-etching. 4. A method for manufacturing a bumped tape carrier according to claim 1, wherein the conductive circuit pattern is formed on the tape-shaped metal carrier by applying a conductive paste. 5. The method for manufacturing a tape carrier with bumps according to any one of claims 1 to 4, wherein the insulating resin pattern layer is formed by photo-etching. 6. The method for manufacturing a tape carrier with bumps according to any one of claims 1 to 4, wherein the insulating resin pattern layer is formed by applying an insulating resin by screen printing. 7. Claims 1 to 6, in which the thickness of the insulating resin is partially reduced when forming the insulating resin pattern layer.
A method for producing a bumped tape carrier according to any one of paragraphs. 8. The method for manufacturing a bumped tape carrier according to any one of claims 1 to 7, wherein the metal carrier is removed by chemical etching. 9. The method for producing a bumped tape carrier according to any one of claims 1 to 7, wherein the metal carrier is removed by mechanical peeling. 10. The bumped tape according to any one of claims 1 to 9, wherein the metal carrier is selected from copper foil, aluminum foil, nickel foil, stainless steel foil, and etchable composite materials. Method of manufacturing carrier. 11. Insulating resin is polyimide resin, polyamide resin,
The bumped tape carrier according to any one of claims 1 to 10, which is selected from polyimide amide resin, polyetherimide resin, polysulfone resin, polyallylsulfone resin, polyester resin, and epoxy resin. manufacturing method.