JP2001085474A - Film carrier tape for electronic component mounting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize fine pitch by mechanically polishing a mat surface once and forming a wiring pattern by using a finished electrolytic copper foil which is obtained by chemically polishing the mechanically polished mat surface. SOLUTION: A mat surface of a rolled electrolytic copper foil with projection part 112 is subjected to buff polishing in the arrow direction, the projection part 112 is deformed along the rotation direction of a buff, and a deformation part 111 such as burr is formed in the projection part 112 at a buff polishing on the downstream side. In the projection part 112 which comes into contact with a buff first, a boundary part 120 is formed between a polished part and an unpolished part. After the deformation part 111 and the boundary part 120 are polished by a first buff, a wiring pattern is formed by using a finished electrolytic copper foil which is obtained by chemically polishing the polished mat surface. As a result, fine pitch can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier tape (e.g.,
TAB (Tape Automated Bonding) tape, T-BGA (Tape B
all Grid Array) tape, ASIC (Application Specific I)
ntegrated Circuit) tape). More specifically, the present invention relates to a film carrier tape for mounting electronic components, which can form a lead pattern having a narrow pitch.

[0002]

BACKGROUND OF THE INVENTION In recent years, electronic devices such as notebook personal computers have become smaller and lighter. Semiconductor I
The wiring of C is further miniaturized. In particular, there is a strong demand for fine pitch wiring patterns such as TAB tape in order to mount ICs or LSIs of high density on printed wiring boards.

Conventionally, in the above-described device, a device hole larger than a device to be mounted is formed in an insulating film as a substrate, and a large number of inner leads are formed from the edge of the device hole toward the inside of the device hole. After the inner leads are plated with tin, the bump electrodes formed on the device are attached to the inner leads from the side of the insulating film where the wiring pattern is not formed (back side). In other words, the device is inserted from the back side of the insulating film, and the bump electrode formed on the device and the inner lead are hot-bonded, so that the gold forming the bump electrode and the tin from the tin plating layer on the inner lead surface coexist. The inner lead and the bump electrode are bonded by forming a crystal alloy.

[0004] Conventionally, film carrier te for mounting electronic parts.
Inner lead pitch (P ₀) Is about 100 μm
Degree, but recently this lead pitch (P₀) From 60 to
A thickness of 80 μm has been proposed (for example,
5-160208) and more recently,
Consider making this lead pitch narrower than 60 μm
Is being done.

On the other hand, as the lead pitch width becomes narrower as described above, the copper foil forming the inner lead is becoming thinner, and a copper foil having a thickness of about 15 to 35 μm is used. Copper foil used in film carrier tapes for mounting electronic components includes rolled copper foil and electrolytic copper foil.To form film carrier tapes for mounting electronic components with fine pitch, use thinner copper foil. It is preferable to use a possible electrolytic copper foil.

[0006] Such an electrolytic copper foil has a surface (shine surface) peeled off from the drum and a surface (mat surface) where copper deposition is completed in the manufacturing process, and is usually made of an insulating film. In consideration of the adhesiveness to the substrate, the mat is arranged and bonded so that the mat surface faces the surface of the insulating film. The surface roughness of the matte surface is usually 2.5 to 1
It is about 0 μm, and the surface is rougher than the shine surface, and the rough surface exerts an anchor effect on the adhesive, so that it can be firmly bonded to the insulating film.

However, when a film carrier tape having a fine lead pitch and a fine pitch for mounting electronic components is arranged and bonded so that the bump electrodes are bonded to the mat surface, the film carrier tape is formed for bonding the bump electrodes. It has been found that the gold-tin eutectic alloy is excessively supplied and leaks laterally from the lead to cause a short circuit between the adjacent lead.

Recently, such TAB tapes are used in large quantities for driving liquid crystal elements. In such a TAB tape for liquid crystal, output-side outer leads to be joined to a liquid crystal element are formed on an insulating film. Since the output-side outer leads are formed by etching a copper foil laminated on an insulating film, etching is more difficult than the inner leads having no insulating film on the back surface. In particular, when a conventional copper foil is used, the cross section (longitudinal section) of the output-side outer lead is often trapezoidal, and the wiring pattern formed by etching with the conventional copper foil has low linearity. There is a problem that a short circuit is easily formed between adjacent leads on the insulating film.

Japanese Patent Application Laid-Open No. 5-160208 discloses a carrier tape in which a lead pattern is formed by using an electrolytic copper foil whose entire surface is matted and obtained by electrolytic deposition. In this publication, the pitch is 6
It discloses that when forming a lead pattern of 0 to 80 μm, the surface of the matte surface is chemically copper-plated to 1 to 2 μm to use an electrolytic copper foil. The copper foil thickness after the surface conditioning treatment is 18 to 30 μm. It is disclosed that a carrier tape having a required lead strength and high reliability is provided by using a copper foil whose entire surface of the mat surface is chemically surface-treated in this manner.

[0010] However, according to the mat surface treatment as described above, the inner lead strength is reduced until the thickness of the electrolytic copper foil is approximately 35 μm (1 ounce) or 18 μm (オ ン ounce). The inner leads can be formed without lowering, but when a thinner electrolytic copper foil is used, sufficient strength is not guaranteed by such chemical surface treatment (chemical polishing). In addition, it is difficult to control the chemical polishing reaction so that the matte surface is uniformly processed by such a chemical surface treatment, and if the chemical polishing reaction does not proceed uniformly, the strength of the inner lead is partially reduced. There is.

Japanese Unexamined Patent Publication (Kokai) No. 3-296238 discloses a TAB tape using a non-roughened copper foil as a copper foil, and the surface roughness of the non-roughened copper foil is 0.1%.
It is described that it is in the range of 01 to 1 μm. However, the non-roughened copper foil having an average surface roughness in the range of 0.01 to 1 μm disclosed in this publication is a rolled copper foil, and such a non-roughened rolled copper foil has a low surface roughness. Since the roughness is too low, sufficient peel strength (adhesive strength) cannot be secured. For this reason, with the preheating of the copper foil or the enlargement of the roller, it is necessary to form a thin cuprous oxide film on the surface of the rolled copper foil, and there is a problem that the preparation process becomes complicated. In addition, when such a rolled copper foil is used, the pitch width is 30 to 60 μm.
It is extremely difficult to form a very fine pitch TAB tape such as m.

Japanese Patent Application Laid-Open No. 9-195096 discloses that the surface roughness of the roughened surface of the electrolytic copper foil before the bumping treatment is 1.
5 μm or less, the invention of an electrolytic copper foil for a printed wiring board, characterized in that the surface roughness after the bumping treatment on the rough surface is 1.5 to 2.0 μm, Such an electrolytic copper foil, the rough surface side of the electrolytic copper foil is polished with a buff and the surface roughness before the bumping treatment is set to 1.5 μm or less,
The roughened surface is roughened to a surface roughness of 1.5 to 2 μm.
It is described that it can be produced by the method described below.

However, when the copper foil is buffed at a stretch as described in this publication, stripe-shaped polishing marks may be formed on the buffed surface. The polishing marks are scratches caused by polishing deeper than a predetermined polishing amount. When using a thick electrolytic copper foil as in the past, some polishing marks did not matter, but since such polishing marks are excessively polished with copper, when using thin copper foil In this case, the strength of such a polished mark portion is significantly reduced, and the possibility of disconnection in this portion in a wiring pattern or the like is increased, which is likely to cause defective products.
Further, when performing such buff polishing, a deformation stress is applied to the projections on the surface of the copper foil along the rotation direction of the buff, and the projections on the surface of the copper foil are easily deformed along the rotation direction of the buff. It is difficult to uniformly bump the buff-polished copper foil having the deformed convex portions. Then, the unevenness of the bumping process causes a problem that the adhesion to the insulating film, the uniformity of etching, the reliability of bonding, and the like are reduced. In particular, such a problem is likely to occur when a thin electrolytic copper foil is mechanically polished.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a film carrier tape for mounting electronic components such as a TAB tape, a T-BGA tape, an ASIC tape, etc., which can be formed into a fine pitch. More specifically, the present invention provides
It is an object of the present invention to provide a film carrier tape for mounting electronic components such as a TAB tape, a T-BGA tape, and an ASIC tape, which has high uniformity of the leads and can maintain conductivity even when the pitch width of the leads is made fine. And

Further, the present invention provides a TAB tape, a T-BGA tape, and a tape, which are not likely to cause a short circuit when a device is bonded, despite having a fine pitch as described above.
An object is to provide a film carrier tape for mounting electronic components such as an ASIC tape. Still another object of the present invention is to provide a film carrier tape for mounting electronic components, in particular, a TAB tape for liquid crystal, in which insulation failure does not easily occur in a narrow pitch lead portion such as an output outer lead portion formed on an insulating film. And

[0016]

SUMMARY OF THE INVENTION A film carrier tape for mounting electronic components according to the present invention is a film carrier tape for mounting electronic components in which a copper foil is laminated on an insulating film and the copper foil is etched to form a desired wiring pattern. The above-mentioned wiring pattern is characterized in that the matte surface is mechanically polished at least once, and thereafter the mechanically polished matte surface is chemically polished, and is formed using a flattened electrolytic copper foil.

In particular, in the film carrier tape for mounting electronic parts of the present invention, the wiring pattern has an average surface roughness of 2.
The electrolytic copper foil having a matte surface in the range of 5 to 10 μm is mechanically polished at least once so that the average surface roughness of the matte surface is 1.5 to 3.0 μm, Mat surface with an average surface roughness of 0.8 to 2.5 μm
It is preferable to use a flattened electrolytic copper foil obtained by selective chemical polishing so that

Further, as the electrolytic copper foil for forming the film carrier tape for mounting electronic parts of the present invention, it is preferable to use a roughened surface-treated electrolytic copper foil obtained by roughening the above-mentioned surface-modified electrolytic copper foil. Furthermore, in the present invention, the roughened surface-treated electrolytic copper foil is obtained by forming the surface-regulated electrolytic copper foil by mechanically polishing the raw electrolytic copper foil at least twice, reversing the polishing direction, and further chemically polishing. It is preferable that the surface-formed electrolytic copper foil is formed by performing a roughening treatment.

In the film carrier tape for mounting electronic parts such as TAB tape, T-BGA tape and ASIC tape of the present invention, the matte surface of the electrolytic copper foil is mechanically polished at least once and then chemically polished. A wiring pattern is formed using the surface-adjusted electrolytic copper foil. By gradually polishing the matte surface of the electrolytic copper foil by mechanical polishing and chemical polishing in this manner, the amount of polishing at one time can be reduced, and for example, polishing marks due to mechanical polishing are hardly formed. Further, by performing chemical polishing after mechanical polishing, it is possible to correct physical deformation, intrinsic stress, and the like of the mat surface, which may be caused by mechanical polishing, by chemical polishing. Therefore, the electronic component mounting film carrier tape formed using the above-mentioned surface-formed electrolytic copper foil,
The matte surface of the flattened electrolytic copper foil is very homogeneous and has high adhesion to the insulating film. Moreover, the surface-adjusted electrolytic copper foil has very good etching characteristics, the formed wiring pattern has a high linearity, and the vertical cross-section is such that the side wall of the etched electrolytic copper foil is substantially perpendicular to the insulating film. And the shape of the vertical cross section of the wiring pattern becomes substantially rectangular, and surplus copper hardly remains on the surface of the insulating film due to etching. Therefore, it is possible to form a wiring pattern with a very narrow pitch on the film carrier tape for mounting electronic components of the present invention by using such a surface-adjusted electrolytic copper foil, and thus, the wiring thus formed can be formed. Insulation failure and the like hardly occur in the pattern, especially in the lead portion. In addition, since the wiring pattern thus formed has a very uniform surface of the lead for bonding the device, the amount of plating metal of the plating layer formed on the surface of the lead is uniform. When bonding to the leads, the eutectic of the gold and the plating metal is not excessively supplied, and even during such bonding, there is little possibility that a short circuit or the like occurs between adjacent leads.

Further, since the surface-deposited electrolytic copper foil used in the present invention is chemically polished after being mechanically polished, it can be mechanically polished under very mild conditions during mechanical polishing. Polishing marks are hardly generated, and even if polishing marks are generated, such polishing marks are corrected by chemical polishing, so that the formed wiring pattern has almost no defects, and the mechanical strength of the lead caused by the copper foil used is low. Deterioration hardly occurs.

[0021]

Next, the film carrier tape for mounting electronic parts according to the present invention will be specifically described with reference to the drawings. In the drawings shown below, common members are assigned common numbers. FIG. 1A is a plan view schematically showing an example of an electronic component mounting film carrier tape of the present invention on which a device is mounted, and FIG.
FIG. 1 is an enlarged view showing an inner lead portion, and FIG.
(C) is an XX cross-sectional view in FIG. 1 (A).

As shown in FIG. 1, a film carrier tape 1 for mounting electronic parts according to the present invention comprises an insulating film 10,
It consists of the insulating film 10 and a wiring pattern 14 formed by using the laminated surface-formed electrolytic copper foil. The wiring pattern 14 is formed on the bump electrode 2 provided on the device 23.
An inner lead 15 is a connecting portion (bonding portion) to the outer lead 5, and an outer lead 16 extends outward from the inner lead 15 and is connected to an external electronic member.

The insulating film 10 constituting the electronic component mounting film carrier tape 1 of the present invention is made of a flexible resin film. The insulating film 10 has a chemical resistance that is not affected by such a chemical because it comes into contact with an etching solution such as an acid during etching, and a heat resistance that does not deteriorate even by heating during bonding. Examples of the resin forming such a flexible resin film include polyester, polyamide, and polyimide. Particularly, in the present invention, it is preferable to use a film made of polyimide.

Examples of the polyimide film constituting the insulating film 10 include a wholly aromatic polyimide synthesized from pyromellitic dianhydride and an aromatic diamine, and a polyimide film synthesized from biphenyltetracarboxylic dianhydride and an aromatic diamine. Wholly aromatic polyimide having a biphenyl skeleton. Particularly, in the present invention, a wholly aromatic polyimide having a biphenyl skeleton (eg, trade name: Upilex, manufactured by Ube Industries, Ltd.) is preferably used. The thickness of the insulating film 10 is usually 25 to 125.
μm, preferably in the range of 50 to 75 μm.

The insulating film 10 is formed with a device hole 20, a sprocket hole 21, a cutting hole for an outer lead (not shown), and the like by punching. The wiring pattern 14 is formed by laminating a surface-adjusted electrolytic copper foil on the insulating film 10 in which the predetermined holes are formed as described above, etching the photoresist, and then etching.

The lamination of the flattened electrolytic copper foil and the insulating film is as follows.
It can be carried out without using an adhesive, or both can be laminated via an adhesive layer. When an adhesive is used for this lamination, for example, an insulating adhesive is applied to an insulating film to form an adhesive layer 12.
And the surface to be bonded (usually a mat surface) of the flattened electrolytic copper foil is placed and bonded. Next, a wiring pattern is formed by etching the thus-stacked electrolytic copper foil.

When an adhesive is used when laminating the surface-adjusted electrolytic copper foil and the insulating film, the adhesive used must have properties such as heat resistance, chemical resistance, adhesive strength, and flexibility. become. Examples of the adhesive having such characteristics include an epoxy-based adhesive and a phenol-based adhesive. Such an adhesive may be modified with a urethane resin, a melamine resin, a polyvinyl acetal resin, or the like, or the epoxy resin itself may be modified with a rubber. Such an adhesive is heat-curable. The thickness of such an adhesive layer is usually in the range of 3.7 to 23 μm, preferably 10 to 21 μm. The adhesive layer 12 made of such an adhesive may be provided on the surface of the insulating film 10 by coating, or may be provided by coating on the surface of the flattened electrolytic copper foil.

A photoresist is applied to the surface of the flattened electrolytic copper foil laminated on the insulating film 10 as described above, a wiring pattern is baked, and then developed to remove the excess photoresist, and then etched. By doing so, the wiring pattern 14 is formed. In the film carrier tape 1 for mounting electronic components of the present invention, the copper foil on which the wiring pattern is formed as described above is an electrolytic copper foil whose surface has been adjusted by a predetermined method.

The flattened electrolytic copper foil used in the present invention is obtained by mechanically polishing the matte surface of an electrolytic copper foil having a shiny surface and a matte surface at least once, and then chemically polishing the mechanically polished matte surface. It is a surface-adjusted electrolytic copper foil obtained by: The average thickness of the flattened electrolytic copper foil is usually 5 to 35 μm.
m, preferably in the range of 9-35 μm,
Also, the average surface roughness of the matte surface of this surface-deposited electrolytic copper foil is
It is in the range of 0.8 to 2.5 μm, preferably in the range of 1.0 to 1.8 μm.

The flattened electrolytic copper foil used in the production of the TAB tape of the present invention was prepared by mechanically polishing the matte surface of the raw electrolytic copper foil at least once and then chemically polishing the mechanically polished surface. Things. Hereinafter, a production example of this surface-deposited electrolytic copper foil will be described. Electrolytic copper foil which is mechanically polished here (electrolytic copper foil raw material)
The average thickness before mechanical polishing is usually in the range of 5 to 35 μm, preferably in the range of 9 to 35 μm, and the average surface roughness (Rz) of the matte surface is usually 2.5 μm. -10
μm, preferably about 3 to 8 μm, and even an electrolytic copper foil having a small surface roughness has an average surface roughness (R
z) is 3 to 7 μm. Examples of the electrolytic copper foil having such an average surface roughness include a VLP foil (average surface roughness:
HTE foil (average surface roughness: 4-7 μm)
Can be mentioned.

FIG. 2 shows a typical surface of a matte surface of an electrolytic copper foil (18 μm thick electrolytic copper foil) having an average thickness (T ₀ ) of 18 μm and an average surface roughness (Rz ₀ ) of 3.6 μm. FIG. 3 is a cross-sectional view showing the state. FIG. 3 is a cross-sectional view of an electrolytic copper foil whose average surface roughness (Rz ₁ ) has been adjusted to 2.0 μm through a mechanical polishing step. FIG. 3 is a cross-sectional view of a flattened electrolytic copper foil whose average surface roughness (Rz ₂ ) has been flattened to 1.5 μm. FIG. 11 is an electron micrograph showing the state of the mat surface before polishing of the 18 μm-thick electrolytic copper foil.

In FIGS. 2 to 4, the M surface is the matte surface of the electrolytic copper foil, and the S surface is the shiny surface. As shown in FIG. 2, the average surface roughness of the matte surface is generally represented by a ten-point average roughness (Rz) of the matte surface, and the ten-point average roughness (Rz) is a concave portion formed on the matte surface. 5 points from the bottom to the highest top of the convex portion, and 5 points from the minimum, a total of 10 points are selected and the average value is obtained. The irregularities formed on the mat surface are shown in FIGS.
The distance (C ₀ ) from the deepest bottom of the concave portion to the highest peak of the convex portion is not uniform as shown in FIG. 5, and the distance (C ₀ ) is 5 μm even in the electrolytic copper foil having the average surface roughness (Rz ₀ ) of 3.6 μm.
m.

The matte surface of the raw electrolytic copper foil is first mechanically polished to grind the tops of the protruding portions of the matte surface as shown in FIG. Such mechanical polishing, the average surface roughness of the matte side of the electrodeposited copper foil (Rz ₁₎ is usually 1.5-3.0, preferably comprised within the range of 1.8～2.5Myuemu. This mechanical polishing can be performed using, for example, a rotating buff.

That is, while passing the raw material of electrolytic copper foil, which is the object to be polished, through the guide roll, a rotating buff is pressed against the mat surface side to polish. In this buffing, usually 10
Mechanical polishing is performed while rotating the buff in a single direction at a rotation speed of 0 to 1500 rpm, preferably 1000 to 1300 rpm. If the rotation speed of the buff is less than 100 rpm, it is difficult to uniformly polish the mat surface, which is the surface to be polished.
If it exceeds 0 rpm, the rotation of the buff becomes unstable and the electrolytic copper foil may be broken.

The pressure of the buff against the electrolytic copper foil as the object to be polished in the buff polishing can be appropriately adjusted so that the electrolytic copper foil is not broken and the mat surface is not excessively polished by the buff polishing. Although it is possible, in a normal case, this pressing is converted into a buff motor current value, and is usually 10.1 to
30A (the current value of the buff motor at the time of no load is about 10A, and therefore, the substantial pressing of the buff (current conversion substantial pressing) is usually 0.1 b when converted to the buff motor current value.
２０20 A), preferably with a substantial current conversion pressure of 13
~ 18A. If this current conversion substantial pressing is less than 0.1 A, it may not be possible to polish the electrolytic copper foil effectively or the time required for polishing may be significantly long,
On the other hand, if it exceeds 20A, breakage of the electrolytic copper foil frequently occurs.

When the electrolytic copper foil is mechanically polished by the rotating buff as described above, the moving speed of the electrolytic copper foil to be polished, ie, the line speed of the electrolytic copper foil, is usually 3 to 15 m / m.
Set within the range of minutes. This line speed may affect the uniformity of mechanical polishing, and if the line speed deviates from this range, the uniformity of mechanical polishing tends to be impaired.

In the above-described mechanical polishing, for example, when a buff is used, there is no particular limitation on the type of abrasive used.
A rotary buff of about 0 to 3000 can be used. The above mechanical polishing may be performed once,
It is preferable to perform it twice or more. That is, mechanical polishing
For example, since the mat surface is polished by bringing the rotating buff into contact with the matte surface of the electrolytic copper foil, the relative mechanical polishing directionality occurs due to the rotating direction of the rotating buff and the moving direction of the electrolytic copper foil, In one mechanical polishing, deformation of the convex portion along the polishing direction (buff rotation direction) may occur. For example, when the matte surface of the raw electro-deposited copper foil having the convex portions 112 as shown in FIG. 5A is buffed in the direction of the arrow, as shown in FIG. 112 may be deformed, and the convex portion 112 on the downstream side of the buffing may form a deformed portion 111 like a burr. In addition, a boundary portion 120 is formed between the polished portion and the unpolished portion of the convex portion 112 that first contacts the buff. The directionality of the mechanical polishing formed on such a mat surface is determined by polishing the first buff, and then bringing the second buff rotating opposite to the first buff into contact with the mat surface and polishing. Can be corrected to some extent. Also,
By dividing the mechanical polishing step into a plurality of steps as described above, the polishing amount per polishing can be set to be small.
Further, since the pressing of each rotating buff can be set low, the electrolytic copper foil to be polished is not easily broken, and the directionality of polishing in each mechanical polishing step is hardly generated.

When the mechanical polishing steps are dispersed as described above, it is preferable to set the conditions in each mechanical polishing step to be milder than those described above. Further, when a rotating buff is used, it is preferable that the first buff and the second buff have opposite rotation directions, and the third buff,
When a large number of rotating buffs are used, such as the fourth buff, it is preferable to reverse the rotating direction of the next rotating buff with respect to the rotating direction of the previous rotating buff. Further, it is preferable that the roughness of the rotating buff is equal to that of the preceding rotating buff or the roughness of the rotating buff after the former is smaller than the roughness of the preceding buff.

Further, by polishing the matte surface of the electrolytic copper foil by using a plurality of rotating buffs as described above, it is difficult to form a streak-like polishing mark. This polishing mark is a mark in which the copper foil is excessively ground, and by polishing so that such a polishing mark is not formed, the mechanical strength of the wiring pattern formed using the surface-adjusted electrolytic copper foil is reduced. It is possible to prevent the occurrence of poor conduction and the like.

By performing the mechanical polishing as described above, the relatively high tops of the protrusions on the mat surface are selectively polished. For example, C ₀ = 5 μm shown in FIG. 2 becomes as shown in FIG. Then, it is polished to C ₁ = 2.5 to 3.2 μm.
That is, in the mechanical polishing, with respect to C ₀ before facing integer, C ₁
Decreases by 17-36%. When the degree of the mechanical polishing performed in this manner is represented by an average surface roughness, the average surface roughness by the mechanical polishing is in the range of 1.5 to 3.0 μm, preferably 1.8 to 2.5 μm. become. For example, in the electrolytic copper foil shown in FIG. 2, the average surface roughness (Rz ₀ ) is 3.
The average surface roughness (Rz ₁ ) was 2.0 μm as shown in FIG. 3 by mechanical polishing.
The average surface roughness (Rz) is reduced by 17-47%.

In the present invention, it is preferable that the mechanical polishing of the mat surface is performed a plurality of times as described above. When the mechanical polishing is performed a plurality of times as described above, the total amount of mechanical polishing is as described above. To FIG. 12 is an electron micrograph showing the mat surface of the 18 μm thick electrolytic copper foil having the mat surface shown in FIG. 11 when the mat surface is polished once, and FIG. 13 shows the first buff. It is an electron micrograph showing the mat surface after performing the 2nd buff polishing using the 2nd rotation buff which differs from the 1st rotation direction after polishing.

After the matte surface of the electrolytic copper foil is mechanically polished at least once as described above, the mechanically polished matte surface is chemically polished. As a chemical polishing liquid for the mechanically polished mat surface, a nitric acid-sulfuric acid-hydrochloric acid-based polishing liquid (a rinsing liquid), a polishing liquid obtained by further adding chromic acid to this rinsing liquid, a nitric acid-based polishing liquid, a phosphoric acid-based polishing liquid, Chromic acid-based polishing liquid, sulfuric acid-based polishing liquid, hydrogen peroxide-based polishing liquid, sulfuric acid / hydrogen peroxide-based polishing liquid, copper chloride-based polishing liquid, iron chloride-based polishing liquid, ammonium persulfate-based polishing liquid, ammonia-alkali-based polishing liquid A polishing liquid or the like can be used.

Examples of the polishing liquid that can be used here are shown below. Each component of the polishing liquid shown below is a central component ratio in the polishing liquid. (1) Nitric acid 200 parts by volume Sulfuric acid 400 parts by volume Hydrochloric acid 2 parts by volume Water 300 parts by volume. (2) 320 parts by volume of nitric acid 640 parts by volume of sulfuric acid 10 parts by volume of hydrochloric acid 640 parts by volume of water. (3) Nitric acid 20 to 80 parts by volume Sulfuric acid 20 to 80 parts by volume Hydrochloric acid 0.1 to 10 parts by volume Chromic acid 5 to 200 parts by volume Water Appropriate amount. (4) phosphoric acid 30-80 parts by volume nitric acid 5-20 parts by volume glacial acetic acid 10-50 parts by volume water (5) Phosphoric acid 500 parts by volume Nitric acid 200 parts by volume Glacial acetic acid 50 parts by volume Hydrochloric acid 5 parts by volume Water 300 parts by volume. (6) 40 parts by volume of phosphoric acid 15 parts by volume of nitric acid 1.5 parts by volume of hydrochloric acid 48 parts by volume 90 parts by weight of ammonium nitrate (7) Phosphoric acid 45 to 60 parts by volume Nitric acid 8 to 15 parts by volume Sulfuric acid 15 to 25 parts by volume Water 10 to 20 parts by volume (8) Chromic acid 450 parts by weight Sulfuric acid 125 parts by volume Hydrochloric acid 5 parts by volume Glacial acetic acid 75 parts by volume Water 200 parts by volume. (9) Sodium dichromate 70 to 120 parts by weight Sulfuric acid 100 to 200 parts by weight Benzotriazole 2 to 40 parts by weight Add water to make up to 1000 parts by volume. (10) Hydrogen peroxide 100 mol / l Sulfuric acid 2 mol / l Saturated alcohol A small amount. (11) Hydrogen peroxide 100 mol / l Hydrofluoric acid 2 mol / l saturated alcohol A small amount. (12) Hydrogen peroxide 100 mol / l Nitric acid 2 mol / l Saturated alcohol A small amount. (13) Nitric acid 40 parts by volume Cuprous chloride 3 parts by weight Glacial acetic acid 60 parts by volume Potassium dichromate 5 parts by weight Water Appropriate amount. (14) (NH ₄ ) ₃ S ₂ O ₂ etc. 8.2 to 9.5N Cu as NH ₃ 150 to 180 g / liter Pure balance.

The following polishing liquids can be mentioned as commercially available polishing liquids. (15) (Polishing solution manufactured by MEC) Pure water 60.7 (W / W%) Sulfuric acid (62.5%) 22.2 (W / W%) Hydrogen peroxide (35%) 16.1 (W / W%) ) Mech Power Etching HE-700 1 (W / W%). (16) (Meltex polishing solution) Meripoliche CU-67 100 g / liter Meripoliche CU-78B 50 ml / liter sulfuric acid (98%) 75 ml / liter pure water Remainder. (17) (Shipley polishing solution) ChemPolish 151L-2 stock solution.

The above-mentioned chemical polishing liquid is used to polish and remove a predetermined amount of copper from the matte surface by appropriately setting the contact conditions with the matte surface of the electrolytic copper foil, for example, the contact temperature and stirring conditions. Can be. For example, the surface of the mat surface can be brought into a desired polishing state by bringing the chemical polishing solution (the rinse solution) shown in the above (1) into contact with the mat surface that has been mechanically polished at room temperature for 10 to 30 seconds. By bringing the matte surface polished by the chemical polishing liquid shown in the above (3) and the mechanically polished mat surface into contact at 50 to 80 ° C. for 2 to 6 minutes, the mat surface can be brought into a desired polishing state.
In the case of polishing solutions containing nitric acid-sulfuric acid-hydrochloric acid, such as Kirin's solution, the reaction is violent, and a certain amount of chemical polishing should be performed by immersion at a temperature near room temperature for a relatively short time. Can be. On the other hand, in order to use a phosphoric acid-based liquid, the polishing liquid is heated (or heated) and the mat surface and the polishing liquid which have been mechanically polished at a temperature equal to or higher than room temperature for a relatively long time, for example, 1 to several minutes. And need to contact.

By contacting the mechanically polished mat surface with the chemical polishing liquid as described above, the mechanically polished mat surface can be substantially uniformly polished as shown in FIG. 4, for example. . And, for example, FIG.
The deformed portion 111 such as a burr generated by mechanical polishing as shown in FIG. 3B is almost completely removed because the contact area with the chemical polishing liquid increases. Also, the boundary portion by mechanical polishing as shown by reference numeral 120 in FIG.
As shown in (C), the surface is polished by contact with a chemical polishing liquid to form a curved surface 121. Furthermore, since such chemical polishing liquid uniformly contacts the entire mat surface, the chemical polishing liquid also penetrates into a portion where the rotating buff did not come into contact during mechanical polishing, and the entire mechanically polished mat surface was chemically polished. Chemical polishing is performed according to the contact area with the liquid.

Therefore, the surface polished by the chemical polishing has a continuous smooth curve as a whole as shown in FIG. 4. For example, after the chemical polishing step, the entire mat surface can be uniformly roughened. it can. In this chemical polishing step, the chemical polishing liquid is selectively brought into contact with the mechanically polished mat surface, and chemical polishing of the shiny surface is not planned. Before contacting with a polishing liquid, masking is performed with an acid-resistant resin or the like to protect the shiny surface from being chemically polished.
However, when it is necessary to chemically polish the shiny surface, the matte surface and the shiny surface can be simultaneously chemically polished without masking.

By performing the chemical polishing as described above, the entire mat surface is polished, for example, C ₁ shown in FIG.
= 3.2 μm is polished down to C ₂ = 2.6 μm as shown in FIG. That is, the chemical polishing, with respect to C ₀ before (FIG. 2) facing integer, C ₂ shown in FIG. 4, 60-80
% Decrease. Therefore, in the previous step of mechanical polishing, C ₁ is reduced by about 30 to 40% with respect to C ₀ ,
In the chemical polishing is a process subsequent to mechanical polishing, C ₂ is reduced by about 40-50% relative to C _1. When the degree of the chemical polishing performed in this way is represented by the surface roughness changed by the chemical polishing, the average surface roughness is 0.8 to 2.5 μm, preferably 1.0 to 1.8 μm. For example, in the electrolytic copper foil shown in FIG. 2, the average surface roughness (Rz ₀ ) is 3.6 μm, and the average surface roughness (Rz ₁ ) is 2.0 μm as shown in FIG. And the average surface roughness (Rz) was reduced by 47% by mechanical polishing.
Average surface roughness (Rz ₂₎ As shown in the results in 1.5 [mu] m, the chemical polishing, the average surface roughness with respect to an average surface roughness of the matte surface obtained by mechanical polishing (Rz ₁₎ (Rz ₂ )
Decreases by about 60%.

Moreover, by performing chemical polishing after mechanical polishing as described above, sharp portions such as burrs generated by mechanical polishing are selectively chemically polished, so that the entire mat surface has a gentle curved surface. It becomes a continuous state, and it becomes possible to perform a roughening process uniformly at the time of a roughening process usually performed later. In FIG. 14, two 18 μm thick electrolytic copper foils were
An electron micrograph of the mat surface chemically polished as described above after step buff polishing is shown. By performing the chemical polishing in this manner, the thickness (gauge thickness) of the flattened electrolytic copper foil usually falls within a range of 4 to 34 μm.

The average thickness (gauge thickness) of the 18 μm-thick electro-deposited copper foil which has been subjected to chemical polishing and then surface-polishing after the matte surface is mechanically polished is equal to the average thickness of the electro-deposited copper foil before mechanical polishing.
If it is 00%, 90-97% of this average thickness,
It is preferably 94 to 96%, and from this value, the matte surface of the electrolytic copper foil becomes a continuation of a gentle curved surface, and in consideration of the average surface roughness of the matte surface before polishing, the thickness of the entire electrolytic copper foil becomes It can be seen that there is no significant change in That is, most of the protruding projections of the mat surface are ground by the mechanical polishing and the chemical polishing in the present invention, and the mechanical polishing marks generated by the mechanical polishing such as sharp grinding marks that are often seen on the mechanically polished surface are chemically polished. It disappears by polishing. Therefore, according to this method, a very thin electrolytic copper foil (for example, average thickness;
Even when 8 μm) is used, even if the matte surface is mechanically polished and then chemically polished, the polishing does not cause a significant decrease in the strength of the electrolytic copper foil.

After the matte surface of the electrolytic copper foil is mechanically polished and then chemically polished as described above, the matte surface is preferably roughened as shown in FIG. . The roughening process is a process of attaching fine copper particles to the matted surface that has been adjusted as described above. This is a process for forming copper fine particles.

In this roughening treatment, the mechanically polished surface of the copper foil has an average surface roughness of 1.5 to 4.0 μm to maintain the etching property while improving the adhesion between the insulating substrate and the copper foil.
m, preferably within a range of 3.5 μm, particularly preferably within a range of 1.5 to 2.5 μm. And after mechanical polishing, by polishing the mat surface through the process of chemical polishing,
The matte surface can be polished uniformly, and uniformly fine copper particles are electrodeposited on such uniform polished surface at high density.

This roughening process is performed by a series of plating processes of burn plating, bead plating, and whisker plating. This series of plating processes is performed, for example, under the following plating conditions. (1) Burn plating After mechanical polishing, an insoluble electrode is placed opposite to the mat side of the surface-adjusted electrolytic copper foil that has been surface-polished by chemical polishing and plated under the following conditions.

Copper concentration: 3 to 30 g / liter Sulfuric acid concentration: 50 to 500 g / liter Liquid temperature: 20 to 30 ° C. Current density: 20 to 40 A / dm ² hours: 5 to 15 seconds According to these plating conditions, particles called burnt plating A copper electrodeposit layer is formed on the matted matte surface of the electrolytic copper foil.

(2) Cover plating Next, the surface subjected to burn plating as described above is further subjected to cover plating under the following conditions. Copper concentration: 40 to 80 g / liter Sulfuric acid concentration: 50 to 150 g / liter Liquid temperature: 45 to 55 ° C. Current density: 20 to 40 A / dm ² hours: 5 to 15 seconds According to these plating conditions, a copper thin film called “kabuse plating” can be formed. The particulate copper electrodeposit layer is coated.

(3) Beard plating Further, the surface subjected to the fog plating treatment in this manner is subjected to a beard plating under the following conditions. Copper concentration: 5 to 30 g / liter Sulfuric acid concentration: 30 to 60 g / liter Liquid temperature: 20 to 30 ° C. Current density: 10 to 40 A / dm ² hours: 5 to 15 seconds Under these plating conditions, mustard copper called mustard plating is obtained. Deposits are formed on the copper coating formed by the blanket plating.

FIG. 15 shows an electron micrograph of the matte surface of the 18 μm-thick electrolytic copper foil roughened as described above. The above description shows an example of the roughening process,
Further, the roughening process (roughing) can be performed according to other conventionally used roughening process conditions. After the roughening treatment, the matted mat surface is preferably subjected to rust prevention treatment. This rust-preventive treatment causes a base metal to be more electrochemically deposited than copper such as zinc and chromium on the roughened surface. Specifically, a thin plating layer of a metal having a rust-proof effect on such copper is formed.

For example, the rust-preventive treatment using zinc and / or chromate is performed by mechanical polishing as described above, and then chemically polishing to roughen the surface of the electrolytic copper foil, and then roughen the electrolytic copper foil. This is performed by a series of steps of dipping a copper foil in a galvanized layer and further performing a chromate treatment. An example of the zinc treatment conditions employed here is shown. Zinc treatment is
For example, using an electrolytic solution having a zinc concentration of 5 g / liter, a sulfuric acid concentration of 50 g / liter, and a liquid temperature of 25 ° C., a current density of 5 A
An electric current is passed for 8 seconds at / dm ² to galvanize the roughened mat surface.

After the formation of the galvanized layer, the surface of the galvanized layer is subjected to a chromate treatment. This chromate treatment is carried out, for example, by adding 2 g / liter of chromic anhydride, pH
The current is applied at a current density of 1 A / dm ² for 5 seconds using an electrolytic solution having a value of 4. Further, it is preferable to form a silane coupling agent layer by applying a silane compound such as γ-glycidoxypropyltrimethoxysilane as a silane coupling agent to the surface subjected to the chromate treatment.

For example, using the 18 μm thick electrolytic copper foil described above, mechanical polishing, chemical polishing, roughening treatment,
By performing the rust prevention treatment and the chromate treatment, the average thickness (gauge thickness) of the electrolytic copper foil is usually 16 to 20 μm.
m, preferably 17 to 19 μm. That is, after the roughening treatment, the rust-preventive treatment and the chromate treatment of the surface-regulated electrolytic copper foil (preferably the roughened surface-regulated electrolytic copper foil) are usually 5
-35 μm, preferably 12-25 μm, and assuming that the average thickness of the electrolytic copper foil before surface preparation is 100%,
The average thickness of the flattened electrolytic copper foil (preferably roughened flattened copper foil) prepared as described above is usually 90 to 97.
%, Preferably in the range of 94 to 96%, and no significant copper polishing loss occurs. Furthermore, the average surface roughness (R) of the matte surface of the 18 μm-thick roughened surface-regulated electrolytic copper foil obtained as described above (the surface-regulated electrolytic copper foil roughened after polishing) was obtained.
z) is usually 1.0 to 3.0 μm, preferably 2.0 to 3.0 μm.
２．５2.5 μm, for example, when laminated on an insulating film with or without an adhesive layer, has a very uniform and high peel strength.

Further, by performing the chemical polishing after the mechanical polishing in this manner, the convex portions of the mat surface are selectively polished, and the entire mat surface becomes a state in which a gentle curved surface is continuous. The polished surface can be subjected to a very uniform roughening treatment (coping). In the method of the present invention, the matte surface of the electrolytic copper foil is selectively mechanically polished and then chemically polished. In this chemical polishing, the shiny surface (the average surface roughness is usually 1.2 ~ 2.5μ
m) is usually masked, and its surface roughness does not fluctuate before and after the surface smoothing treatment.

The surface-formed electrolytic copper foil manufactured as described above, preferably a roughened surface-formed electrolytic copper foil, and an insulating film are laminated, a photoresist layer is formed and masked, and excess copper is removed. The desired wiring pattern is formed on the insulating film by elution with an etchant, and the T
AB tape (Film carrier tape for mounting electronic components)
Can be formed. In addition, when laminating an insulating film and a flattened electrolytic copper foil, preferably a roughening-treated flattened electrolytic copper foil, it is possible to remove the silane coupling agent layer, the rust-preventive layer, etc. from the flattened copper foil before use. it can.

As shown in FIG. 8, the pitch of the inner leads 15 formed on the film carrier tape 1 for mounting electronic components using the above-mentioned surface-formed electrolytic copper foil, preferably a roughened surface-formed electrolytic copper foil, is used. The width (P ₀ ) is usually 30 to 60 μm
And preferably within a range of 35 to 55 μm, which is smaller than the pitch width of the inner leads formed on the conventional film carrier tape for mounting electronic components. The width (W ₀ ) of the inner lead 15 formed at such a pitch width is usually 10 to 50 μm, preferably 15 to 50 μm.
And the gap width (S ₀ ) between the adjacent inner leads 15 is usually 10 to 50 μm.
Preferably it is in the range of 15 to 45 μm.

Various plating layers can be formed on the surface of the inner lead 15. Examples of such a plating layer include a tin plating layer, a gold plating layer, a nickel base gold plating layer, and a solder plating layer. 8 and 9 show an example in which the plating layer is a tin plating layer. When a tin plating layer is formed on the surface of the inner lead, a gold-tin eutectic is formed by tin supplied from the tin plating layer and gold supplied from the bump of the device, and the gold-tin eutectic is formed. Depending on the object, the device is mounted on the lead. Then, the lead formed as described above is plated with an appropriate amount of tin as shown in FIG. 8 (c), and a bump electrode is arranged and press-bonded with heat to form an appropriate amount of gold on the bonding portion. -The tin eutectic is supplied, and the lead and the bump electrode are satisfactorily joined, and no short circuit occurs between the adjacent leads.

The tin plating layer 21 is preferably formed by an electroless plating method. The thickness of the tin plating layer 31 thus formed is usually 0.001 to 1 μm,
Preferably it is in the range of 0.005 to 0.7 μm. When tin is plated in this manner, a part of the copper on the surface of the inner lead 15 is replaced with tin to form a tin plating layer. Further, a tin plating layer is formed once as described above, and a heat treatment is performed to prevent the generation of whiskers. Then, a very thin tin plating layer is formed by flash plating, so that the purity of the surface of the inner lead 15 is improved. High tin plating layer 31 can be formed. Whisker hardly grows on the tin plating layer formed by such a flash plating method without heat treatment. The thickness of the tin plating layer formed by the flash plating method is usually 0.01 to 1 μm, preferably 0.05 to 0.1 μm.
The total thickness of the tin plating layer 31 thus formed is usually in the range of 0.2 to 2 μm, preferably in the range of 0.1 to 1 μm.

The tin plating layer 31 formed as described above is uniformly formed almost following the surface shape of the matte surface of the roughened surface-treated electrolytic copper foil which has been mechanically polished. The tin plating is usually applied to the exposed leads after the solder resist (not shown) is exposed and hardened after exposing the leads. However, the tin plating is applied to the entire wiring pattern formed before the solder resist is applied. It is also possible to form a thin tin-plated layer, then apply and cure a solder resist, and re-tin-plate the exposed leads.

Since the surface of the surface-adjusted electrolytic copper foil forming the inner lead 15, preferably the surface of the roughened surface-adjusted electrolytic copper foil is very uniform, the surface of the inner lead 15 to which the bump electrode is bonded is uniform. Because a tin plating layer is formed,
As shown in FIGS. 8B and 8C, when the bump electrode is bonded, the gold-tin eutectic 33 necessary and sufficient to bond the entire bottom surface of the bump electrode to the inner lead 15 is formed. You.

On the other hand, FIGS. 9A, 9B, and 9 C
As shown in FIG. 5, when the copper foil 15 whose mat surface is not uniformly arranged is used, the tin plating layer 31 is formed on the mat surface of the inner lead 15 in the same manner as described above.
Tin plating layer 3 in concave and convex portions on the surface of inner lead 15
1 tends to be thicker. When the bump electrode 25 is bonded to the tin plating layer 31 lacking uniformity in this manner, the gold-tin eutectic alloy 33 is excessively supplied, and FIG.
As shown in (C), the gold-tin eutectic alloy 33 may protrude from the bonding position of the bump electrode 25 formed on the device 23. In a TAB tape having a small pitch width, the excessively supplied gold-tin eutectic alloy may flow out in the lateral direction, and a short circuit 35 may occur between the TAB tape and the bonding portion of the adjacent inner lead 15.

In the film carrier tape for mounting electronic parts of the present invention, since the matte surface is mechanically polished at least once and then chemically polished, the matte surface has excellent adhesion to the insulating film. In addition, a film carrier tape for mounting electronic components having excellent characteristics such as uniform and high lead strength, short-circuiting during bonding, and high bonding reliability can be obtained.

The film carrier tape for mounting electronic components of the present invention is suitable as a TAB tape for a liquid crystal element having output-side outer leads. FIG. 10 shows a film carrier tape for mounting electronic components (for example, T
FIG. 3 is a plan view showing an example of an AB tape.

In FIG. 10, reference numeral 10 denotes an insulating film, and a sprinket hole is formed on both side edges thereof. A device (not shown) is provided on the insulating film 10.
Is formed in the device hole 20 for mounting the device. An inner lead 15 extends from the wiring pattern 14 in the device hole 20. An input outer lead 18 is formed at the other end of the wiring pattern 14 having one end as an inner lead. An input outer lead for cutting the input outer lead 18 is formed below the input outer lead. A cutting hole 17 is formed, and the input-side outer lead 18 is formed so as to straddle the cutting hole 17.

On the other hand, another inner lead 15 extending to the device hole 20 is connected to the output outer lead 19 via the wiring pattern 14. The surface of the wiring pattern 14 excluding these lead portions is protected by a solder resist 36 or the like. The output side outer lead 19 can be joined to an electrode of a liquid crystal element, and the pitch width of the output side outer lead 19 is usually in the range of 30 to 75 μm, preferably 40 to 70 μm. The lead width of the side outer lead 19 is usually in the range of 15 to 45 μm, preferably 20 to 40 μm.

As described above, the output side outer lead 19 is
Very narrow pitch width and narrow lead width. Moreover, the insulating film 10 is provided below the output side outer lead 19, and the output side outer lead 19 is joined to the insulating film 10 at the lower end. Using conventional electrolytic copper foil,
As shown in FIG. 10A, the output side outer lead 19
Is likely to be trapezoidal in vertical section. That is, the upper width La and the lower width Lb of the output-side outer lead 19 in FIG.
In such a case, the output side outer leads 19 adjacent to the output film near the surface of the insulating film 10 may be trapezoidal.
May form a short circuit between them. Further, even when the output-side outer leads 19 do not have linearity, that is, when etching cannot be performed linearly, a short circuit may occur near the surface of the insulating film.

In the film carrier tape for mounting electronic parts of the present invention, the above-mentioned surface-formed electrolytic copper foil, preferably a roughened surface-formed electrolytic copper foil, has very good etching properties, and the wiring pattern formed by etching is excellent. The upper width La and the lower width Lb of the vertical section are substantially the same. That is, the side wall surface of the formed wiring pattern is substantially perpendicular to the insulating film, and the vertical cross section of the formed wiring pattern is substantially rectangular or square. In particular, as shown in FIG. 10B, in the output-side outer lead 19 having a small pitch width, the upper width La and the lower width Lb are substantially the same, so that the adjacent wiring pattern is formed on the surface of the insulating film substrate. There is no excessive proximity, and short-circuiting or poor insulation due to such proximity of the leads is unlikely to occur. Further, even when the wiring pattern 14 formed by etching has a high linearity and therefore a wiring pattern having a very narrow pitch width such as the output-side outer leads 19 is formed,
Short circuits are not easily formed between adjacent wiring patterns. Furthermore, the flattened electrolytic copper foil (preferably a roughened flattened electrolytic copper foil) forming the film carrier tape for mounting electronic components of the present invention has very good etching characteristics, and copper on the surface of the insulating film 10 or the like. Residuals (residues of unetched copper) hardly occur.

Therefore, the film carrier tape for mounting electronic parts of the present invention is very suitable for a thin wire portion requiring very high etching accuracy, such as the output outer leads 19, such as a TAB tape for liquid crystal. Etching is excellent, and short-circuiting or poor insulation is unlikely to occur in such fine wire portions. The characteristics of the copper foil at the time of such etching are not only TAB tape but also TAB tape.
T-BGA tapes, which are becoming thinner like tapes,
This is a very useful property even in an ASIC tape or the like.

[0076]

The wiring pattern constituting the film carrier tape for mounting electronic parts according to the present invention is a uniform electrolytic copper foil obtained by first mechanically polishing and then chemically polishing the matte surface of the raw electrolytic copper foil. It is formed using. The matte surface is mechanically polished in this manner, and the chemically polished surface-deposited electrolytic copper foil is a uniform matte surface in which mechanical polishing traces such as the directionality of mechanical polishing and distortion have disappeared by chemical polishing. By subjecting the matted surface thus roughened to a roughening treatment, fine copper particles can be formed uniformly. Since the film carrier tape for mounting electronic components of the present invention has a wiring pattern formed by laminating a flattened electrolytic copper foil having a uniform matte surface with an insulating film, the wiring pattern for the insulating film is formed. Has a high peel strength and the strength is stable throughout. Further, the wiring pattern formed by using the flattened electrolytic copper foil that has been flattened as described above, polishing unevenness or polishing marks caused by mechanical polishing, distortion and the like have been corrected by chemical polishing, and formed. There is no polishing mark and uneven strength in the wiring pattern, and the incidence of defective products is significantly reduced. Further, the surface-adjusted copper foil has good etching properties, can form a wiring pattern having a rectangular cross section, and has good linearity of the formed wiring pattern.

That is, in the film carrier tape for mounting electronic components of the present invention, the difference between the width of the upper end portion and the width of the lower end portion of the formed wiring pattern (particularly, the lead portion) is small, and Is etched substantially perpendicularly to the insulating film, so that a very fine pitch film carrier tape for mounting electronic components can be formed. Also, the lower end of the wiring pattern is linearly etched. Further, almost no copper residue on the insulating substrate surface is observed. These characteristics are important for the inner leads, for example, but are extremely important for the output outer leads that are electrically connected to the liquid crystal element, for example. That is, the output-side outer leads electrically connected to the liquid crystal element are connected to the pixels of the liquid crystal, and the output-side outer leads are formed to have a very narrow lead width and a narrow pitch width. Therefore, the adjacent output-side outer leads are likely to cause insulation failure between the adjacent leads. For example, even if the linearity of the output-side outer leads is slightly impaired, insulation failure may occur. If the lower end of the output-side outer leads is slightly wider than the upper end, insulation failure may occur on the surface of the insulating substrate. In addition, even if a small amount of copper remains on the insulating substrate, there is a possibility that insulation failure may occur. The output-side outer lead portion connected to such a liquid crystal element needs to be etched with a copper foil with a precision equal to or higher than that of the inner lead on which the electronic component is mounted. In particular, it is necessary to form leads on the insulating substrate by etching the electrolytic copper foil laminated on the insulating substrate, for example, as in a TAB tape for a liquid crystal element, and extend into the device hole and extend to the lower end surface. The cross-sectional shape of the lead is more likely to be trapezoidal than the inner lead without the insulating substrate, and copper residue is more likely to occur due to the presence of the insulating substrate. I have.

However, since the film carrier tape for mounting electronic parts of the present invention uses the above-mentioned surface-formed electrolytic copper foil, it is formed on the side wall of the wiring pattern formed by etching, for example, on the TAB tape for liquid crystal. The cross-sectional shape of the output side outer lead to be formed becomes rectangular or square (the width of the upper end face and the width of the lower end face are almost the same),
Moreover, the formed leads have high linearity. Also, no copper remains on the surface of the insulating substrate.

Further, the film carrier tape for mounting electronic parts of the present invention, by forming a wiring pattern using the surface-formed electrolytic copper foil whose surface has been flattened as described above, allows the insulating film as a substrate and the wiring pattern to be formed. And the mounting yield when mounting devices on the film carrier tape for mounting electronic components is extremely high.

Further, a wiring pattern is formed by using a surface-adjusted electrolytic copper foil having a mat surface which has been surface-adjusted by mechanical polishing and chemical polishing as described above, and is formed on a lead portion of the wiring pattern thus formed. The plated layer has a very high uniformity.Therefore, when welding the bump to the narrow pitch lead, the eutectic of the plated layer forming metal and the bump forming metal is not excessively supplied, and the In such a case, a short circuit due to excess eutectic does not occur between adjacent leads, so that the mounting yield of the device is very high.

[0081]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples of the present invention, but the present invention is not limited thereto.

[0082]

Embodiment 1 The average surface roughness of the shiny surface is 1.2 μm
And the average surface roughness (Rz ₁ ) of the matte surface is 3.6 μm.
m, an electrolytic copper foil having an average thickness of 18 μm was prepared. An electron micrograph of the matte surface of the electrolytic copper foil is shown in FIG.
While the electrolytic copper foil passes through the guide roll, a 1000-number buff (a product of Kakuda Brush Co., Ltd.) whose abrasive grains are aluminum oxide is applied to the mat surface, and the rotating direction of the buff is opposite to the traveling direction of the electrolytic copper foil. The first stage buff rotation speed 1200 rpm, buff motor current value conversion press 19A,
The matte surface of the above-mentioned electrolytic copper foil was buff-polished at a line speed of 8 m / min (first mechanical polishing).

FIG. 12 shows an electron micrograph of the mat surface after the first mechanical polishing is completed. This first
A mat polished by the first mechanical polishing while rotating the 1000th buff on the electrolytic copper foil that has been mechanically polished so that the rotation direction of the buff is the same as the traveling direction of the electrolytic copper foil. The surface was buffed. At this time, the rotation speed of the second stage buff is 1200 rpm, the buff motor current value conversion pressure is 1.6 A, and the line speed is 8 m / min (second mechanical polishing).

FIG. 13 shows an electron micrograph of the matte surface of the electrolytic copper foil after mechanical polishing twice as described above.
The average surface roughness of the matte surface thus mechanically polished is 2.0 μm, and 18% of the average surface roughness of the matte surface of the electrolytic copper foil before mechanical polishing is polished by this mechanical polishing. Was. As is clear from FIG. 12, mechanical polishing marks remain on the mat surface despite mechanical polishing twice.

After buffing twice in reverse rotation in this manner, the electrolytic copper foil coated with an acid-resistant resin on the shiny surface and masked was brought into contact with a chemical polishing solution having the following composition at 30 ° C. for 5 seconds, and the chemical polishing solution was removed. Chemical polishing under circulation. Basic composition of chemical polishing liquid In addition, the fluctuation range of the composition of the chemical polishing liquid was adjusted within a range of 5 to 15% with respect to the above basic composition.

After the matte surface is chemically polished as described above, the flattened electrolytic copper foil is sufficiently washed with water.
FIG. 14 shows an electron micrograph of the matted surface after the chemical polishing. In this manner, the chemical polishing substantially completely removes the mechanical polishing marks and the directionality of the polishing seen on the mechanically polished mat surface, and the sharp portions such as burrs generated by the mechanical polishing. Such a matte surface was obtained.

The matte surface thus chemically polished has an average surface roughness of 1.5 μm, and 25% of the average surface roughness of the matte surface of the electrolytic copper foil after mechanical polishing is 25%. Polished by polishing. The average thickness of the flattened electrolytic copper foil obtained by chemical polishing after mechanical polishing was about 16.8 μm in gauge thickness, and the average thickness of the electrolytic copper foil before mechanical polishing used in this example was used. The thickness was 17.1 μm in gauge thickness, and no extreme copper loss due to copper eluted from the electrolytic copper foil was observed.

Next, the matte surface of the electrodeposited copper foil whose matte surface was adjusted was roughened under the following conditions. (1) Burn plating Plating was performed under the following conditions by disposing an insoluble electrode on the matte side of the electrolytic copper foil surface-regulated by mechanical polishing and chemical polishing.

Copper concentration: 3 to 30 g / liter Sulfuric acid concentration: 50 to 500 g / liter Liquid temperature: 20 to 30 ° C. Current density: 20 to 40 A / dm ² hours: 5 to 15 seconds By burn plating under the above conditions, A particulate copper electrodeposit layer was deposited on the surface of the flattened electrolytic copper foil.

(2) Cover plating After burn plating as described above, cover plating was performed under the following conditions. Copper concentration: 40 to 80 g / liter Sulfuric acid concentration: 50 to 150 g / liter Liquid temperature: 45 to 50 ° C. Current density: 20 to 40 A / dm ² hours: 5 to 15 seconds A copper thin film called "Kabse plating" was formed so as to cover.

(3) Beard plating Further, a beard plating was performed on the surface subjected to the fog plating treatment under the following conditions. Copper concentration: 5 to 30 g / liter Sulfuric acid concentration: 30 to 60 g / liter Liquid temperature: 20 to 30 ° C. Current density: 10 to 40 A / dm ² hours: 5 to 15 seconds Under these plating conditions, mustard copper called mustard plating is obtained. Deposits formed on the copper coating formed by the turn plating.

The matte surface of the polished and roughened electrolytic copper foil was observed with an electron microscope. An optical micrograph of this matte surface is shown in FIG. The average surface roughness of the matte surface thus roughened is 2.5 μm. Furthermore, the average thickness (gauge thickness) of the roughened surface-treated electrolytic copper foil thus roughened was 17.5 μm. Accordingly, the roughening treatment restored the thickness to approximately 98% of the average thickness of the electrolytic copper foil.

A rust-preventing layer was formed on the roughened surface of the roughened surface-treated electrolytic copper foil thus roughened. This rust prevention layer was formed using zinc. The rust-preventive treatment with zinc is performed at a current density of 5 A / d using an electrolytic solution having a zinc concentration of 5 g / l, a sulfuric acid concentration of 50 g / l, and a liquid temperature of 25 ° C.
The test was performed for 8 seconds at m ² . The thickness of the formed zinc layer is very thin, usually less than 100 °. Further, after the zinc layer was formed in this way, a current density of 1 A / dm ² was obtained using an electrolytic solution having a chromic anhydride content of 2 g / liter and a pH value of 4.
The electrolytic chromate treatment was performed for seconds. The surface of the chromate layer thus subjected to the chromate treatment was coated with γ-glycidoxypropyltrimethoxysilane.

The roughened surface-treated electrolytic copper foil thus obtained was surface-regulated on one surface of a 125 μm-thick polyimide film (with a thermosetting adhesive) in which sprocket holes and device holes were formed. The matted surface was placed so as to face the polyimide film, and was heated and pressed. Further, a photoresist is applied to the surface of the roughened copper foil, and a pattern as shown in FIG. 10 is exposed to remove excess photoresist, and the photoresist is exposed by contacting with an etching solution. The copper foil was removed to form a wiring pattern.

After removing the photoresist, a solder resist was applied on the wiring pattern except for the tips of the leads to be bonded. Furthermore, a tin plating layer was formed on the surfaces of the inner leads, the input side and the output side outer leads, thereby producing the TAB tape of the present invention. The TAB tape thus obtained had a remarkably low defect rate due to disconnection of the wiring pattern, and the wiring pattern and the polyimide film were stably and very stably bonded. Further, the tensile strength of the lead was also high. Also, when the formed output-side outer leads were observed, the cross-section of the output-side outer leads was rectangular, and the output-side outer leads were formed linearly, and further formed on a polyimide film that was an insulating film. No copper residue was found.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an example of an electronic component mounting film carrier tape of the present invention on which a device is mounted, and an enlarged view and a cross-sectional view of an inner lead portion.

FIG. 2 is a cross-sectional view showing an example of a cross-sectional view of a mat surface of a normal electrolytic copper foil.

FIG. 3 is a cross-sectional view showing a state of a mat surface after buffing.

FIG. 4 is a cross-sectional view showing a state of a mat surface after buffing and chemical polishing.

FIG. 5 is an explanatory diagram schematically showing a change in a convex portion of a mat surface when polished.

FIG. 6 is a view schematically showing a state in which the surface of the surface-regulated electrolytic copper foil has been subjected to a roughening treatment.

FIG. 6 is a diagram schematically showing a state in which a surface-adjusted electrolytic copper foil is adhered to a polyimide film.

FIG. 8 is a view showing a state in which devices are bonded to a film carrier tape for mounting electronic components of the present invention.

FIG. 9 is a view showing a state where a device is bonded to a conventional film carrier tape for mounting electronic components using a copper foil that has not been flattened.

FIG. 10 is a diagram illustrating an example of a film carrier tape for mounting electronic components having output-side outer leads.

FIG. 11 is an electron micrograph showing an example of a matte surface of an electrolytic copper foil before mechanical polishing.

FIG. 12 is an electron micrograph showing an example of a mat surface after the first mechanical polishing.

FIG. 13 is an electron micrograph showing an example of a mat surface after the second mechanical polishing.

FIG. 14 is an electron micrograph showing an example of a mat surface after chemical polishing.

FIG. 15 is an electron micrograph showing an example of a mat surface of a roughened electrolytic copper foil subjected to a roughening treatment.

[Explanation of symbols]

 111 ... deformed part (burr) 112 ... convex part of mat surface 120 ... boundary part 121 ... curved surface 10 ... substrate 12 ... adhesive 14 ... surface-regulated electrolytic copper foil ( 15 ... Inner lead 16 ... Outer lead 17 ... Input side outer lead cutting hole 18 ... Input side outer lead 19 ... Output side outer lead 20 ... Device hole 21 ...・ Sprocket hole 23 ・ ・ ・ Device 25 ・ ・ ・ Bump electrode 30 ・ ・ ・ Matte surface 31 ・ ・ ・ Tin plating layer 33 ・ ・ ・ Gold-tin eutectic alloy 35 ・ ・ ・ Short circuit 36 ・ ・ ・ Solder resist

Claims (10)

[Claims] 1. A film carrier tape for mounting electronic components, wherein a copper foil is laminated on an insulating film, and the copper foil is etched to form a desired wiring pattern, wherein the wiring pattern has a mat surface at least once. A film carrier tape for mounting electronic components, which is formed using a surface-regulated electrolytic copper foil obtained by mechanically polishing and then chemically polishing the matte surface which has been mechanically polished. 2. The flattened electrolytic copper foil has a matte surface having an average surface roughness in the range of 2.5 to 10 μm, and the matte surface has an average surface roughness of 1.5 to 3.0μ
m, and then mechanically polished at least once to obtain a mat surface having an average surface roughness of 0.8 to 2.5.
2. A surface-plated electrolytic copper foil obtained by selective chemical polishing to a thickness of .mu.m.
The film carrier tape for mounting electronic components according to the above item. 3. The flattened electrolytic copper foil is prepared by mechanically polishing the matte surface of the electrolytic copper foil at least once and then chemically polishing the matte surface. 2. The film carrier tape for mounting electronic components according to claim 1, wherein the matted surface is a roughened surface-regulated electrolytic copper foil having a roughened surface. 4. The roughened surface-regulated electrolytic copper foil, after mechanically polishing the matte surface of the electrolytic copper foil at least twice by reversing the polishing direction, chemically polishing the mechanically polished matte surface,
4. The film carrier tape for electronic component mounting according to claim 3, wherein the mat surface is formed by roughening the mat surface which has been adjusted by the chemical polishing. 5. The wiring pattern according to claim 1, wherein a side wall surface in a longitudinal section of the wiring pattern formed on the surface of the insulating film is etched substantially at right angles to the surface of the insulating film. Item 10. The film carrier tape for mounting electronic components according to any one of the above items. 6. The flattened electrolytic copper foil has a thickness of 5 to 35 μm.
The film carrier tape for mounting electronic components according to any one of claims 1 to 3, wherein the thickness is within a range of m. 7. A lead portion is formed on the film carrier tape for mounting electronic components, and the lead has a thickness of 0.1 mm.
4. A plating layer selected from the group consisting of a tin plating layer, a gold plating layer, a nickel base plating-gold plating layer and a solder plating layer having a thickness of 01 to 1 [mu] m. The film carrier tape for mounting electronic components according to the item. 8. A tin plating layer is formed on the lead, and the tin plating layer is formed by tin plating to a thickness of 0.001 to 1 μm and then flash tin plating to a thickness of 0.01 to 1 μm. 7. The film carrier tape for mounting electronic parts according to claim 6, wherein: 9. The electronic component mounting film carrier tape according to claim 1, wherein the insulating film surface has a lead portion on which a plurality of narrow pitch leads are formed. The film carrier tape for mounting electronic components according to the item. 10. The electronic component mounting film carrier tape according to claim 9, wherein the electronic component mounting film carrier tape is a liquid crystal TAB tape.