JPH07114221B2 - TAB tape - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has attracted attention in the process of assembling semiconductor devices, such as TAB (TapeAut), which is attracting attention when devices are made to have a large number of pins, a small size, and high density mounting.
The present invention relates to a tape (hereinafter, referred to as a TAB tape) having a three-layer structure of a protective layer, an adhesive layer, and an organic insulating film, which is used for an omni-bonded system.

[0002]

2. Description of the Related Art Conventionally, a TAB tape is processed as follows to form a film carrier tape. 1) Drill sprocket device holes by stamping. 2) After the copper foil is thermocompression bonded to the punched tape, the adhesive is cured by heating. 3) Apply a photoresist, irradiate with ultraviolet rays through a mask, and then develop. 4) Line the device hole, etch copper, remove the resist, remove the line, make a circuit, and apply solder resist. 5) Copper and gold are plated. After the chip is inner-bonded to the tape manufactured through the above steps, the lead is cut, outer-lead bonded to a printed circuit board or the like, and sealed with resin. Alternatively, inner lead bonding is performed, followed by sealing with a resin, cutting including peripheral circuits, and outer lead bonding.

The adhesive layer and the organic insulating film of the TAB tape are often left in the peripheral circuit and the sealing resin. In such a case, as the density becomes higher and higher, the ionic impurities that affect the insulation reliability between the patterns of the copper foil and the corrosion of the Al wiring of the chip become a problem. Corrosion reliability and ionic impurities largely depend on the characteristics of the adhesive. That is, the ionic impurities are exposed to the alkali (for example, chlorine ions and sulfate ions are contained during silver plating) and the etching solution (containing chlorine ions) during the steps 3) to 5). It may occur or be contained in the adhesive itself. Also, the insulation reliability is governed by the moist heat resistance of the adhesive, the electrical resistance, the ionic impurities, and the like.

[0004]

[Problems to be Solved by the Invention]
The adhesive for the AB tape is an epoxy adhesive,
It has the following properties: a) ionic impurities (especially Cl ions) are likely to be contained during processing, b)
Due to properties such as being easily hydrolyzed by wet heat and c) having low electric resistance, insulation deterioration including metal migration between patterns and the like has become a problem. Further, since the adhesive used for the TAB tape constitutes the interlayer between the copper foil which is a metal and the organic insulating film, it is required that both the metal and the organic insulating film have high adhesive strength. . The adhesive layers of the TAB tapes that have been conventionally used are all composed only of a resin. These are: a) In the above process, the adhesive layer has an alkali (for example, during gold plating, When the resist is peeled off), acid (for example, tin plating), the adhesive strength to the copper foil is reduced by being exposed to an etching solution, etc. b) Insulation reliability due to the alkali and acid being occluded in the adhesive layer Decrease, c) Decrease in adhesion to organic insulating film at high temperature during inner lead and under-lead bonding, d)
After the bonding, there are drawbacks such as unevenness of the thickness of the tape body caused by the copper foil pattern digging into the adhesive layer. Or reed deformation,
Peeling off is a problem.

An object of the present invention is to solve the above problems in the conventional TAB tape. That is, an object of the present invention is to provide a TAB tape having excellent chemical resistance and heat resistance and high adhesive strength.

[0006]

A tape for TAB of the present invention comprises a thermosetting adhesive layer containing a polyamide resin as a main component and a protective layer on an organic insulating film.
The adhesive layer contains at least one kind of powdery inorganic filler.

FIG. 1 is a schematic cross-sectional view of a TAB tape of the present invention, in which a semi-cured adhesive layer 2 containing a powdery inorganic filler 4 and a protective layer are provided on one side of an organic insulating film 1. The protective film 3 which becomes a layer is laminated | stacked one by one. In the figure, the adhesive layer 2 has a single layer structure, but the adhesive layer may have a layer structure of two or more layers.

The organic insulating film has a thickness of 25 to 1
88 μm, preferably 50-125 μm polyimide,
Heat-resistant films such as polyetherimide, polyphenylene sulfide, and polyether ether ketone, epoxy resin-glass cloth, epoxy resin-polyimide-
An organic insulating film made of a composite heat resistant film such as glass cloth can be used.

The adhesive layer is a thermosetting type, needs to be semi-cured, and is composed of at least one layer. The thickness of the adhesive layer is in the range of 10 to 50 μm, preferably 15 to 30 μm. Since the adhesive layer is in direct contact with the organic insulating film, it exhibits high tackiness even at high temperatures, exhibits high adhesiveness with the organic insulating film, and also has high adhesiveness with the copper foil and during processing into a film carrier. It is required to have excellent chemical resistance to the exposed chemical liquid. In order to meet such requirements, in the present invention, a polyamide resin as a main component and at least one kind of powdery inorganic filler is used, but as the thermosetting component, chemical resistance is used. It is preferable to contain a phenol resin or an epoxy resin in order to impart When using an epoxy resin, it is preferable to use a curing accelerator such as an imidazole compound in combination. Furthermore, a thermoplastic resin such as polyester resin, NBR or SBR may be used together.

The powdered inorganic filler has a function of suppressing thermal expansion and contraction of the adhesive layer, and is made of powdered silica, alumina, diatomaceous earth, titanium oxide, zinc oxide, magnesium oxide or the like. Stable metal oxides and other inorganic pigments can be used. As the powdery inorganic filler, those having an average particle diameter in the range of 0.1 to 30 μm can be preferably used. The content of the powdery inorganic filler in the adhesive layer is in the range of 1 to 90% by weight, particularly 3
The range of ˜50% by weight is preferred. When the content of the powdered inorganic filler is higher than 90% by weight, when the copper foil is thermocompression-bonded to the perforated tape when the TAB tape is processed, sufficient adhesive strength cannot be obtained, Since the agent itself becomes opaque, during bonding and alignment,
Visibility may be impaired when the tape is used. On the other hand, if it is less than 1% by weight, the effect of adding the powdery inorganic filler will not be obtained. In the present invention, when the adhesive layer is composed of two or more layers, the powdery inorganic filler needs to be contained in the layer that comes into contact with the protective film.

Various well-known polyamide resins can be used as the main component of the adhesive layer. The molecular weight of the polyamide resin used is flexible,
It is related to the melting characteristics when the tape and copper foil are thermocompression-bonded or when the adhesive is cured (adhesion of the adhesive from the device hole). If the molecular weight is too low, the melting temperature will decrease and The problem arises. Further, if the molecular weight is too high, the problem that the thermocompression bonding temperature with the copper foil becomes too high occurs. Therefore, in the present invention, a molecular weight of 30,
Softening temperature of 100 to 1 in the range of 000 to 150,000
A polyamide resin at 80 ° C. is preferably used.

Furthermore, there is a molecular weight distribution as a factor affecting the melting characteristics related to the protrusion of the adhesive from the device hole, and when the molecular weight distribution is narrow,
This is not preferable because the thermocompression bonding condition is narrowed so that the viscosity is rapidly reduced by heat and the tape and the copper foil do not protrude from the device hole during thermocompression bonding. Therefore, the polyamide resin used in the present invention preferably has a wide molecular weight distribution. If, for example, a polyamide resin having an amide group equivalent (molecular weight / one amide group) of 200 to 400 is used as the polyamide resin, the hygroscopicity of the adhesive layer is lowered, and the electric resistance is reduced by the moisture absorption.
It is particularly preferable because it can be suppressed to the order of magnitude, the moisture resistance to hydrolysis and the like is improved, and as a result, insulation deterioration can be prevented.

The polyamide resin has a wide range of hydrocarbon molecular weights between amide groups of 100 to 800 in one molecular chain, and irregular hydrocarbon molecules between amide groups having different molecular weights. You may use the ones lined up in. These polyamide resins can be preferably used because they have adhesiveness and flexibility even though the amide group equivalent is large.

In the present invention, the phenol resin which can be used in combination with the above polyamide resin includes a bisphenol A type whose alkyl group is selected from bisphenol A and an alkylphenol, an alkylphenol type, or a cocondensation type resole type phenol thereof. Resins and novolac type phenolic resins are listed as 1
One kind or two or more kinds can be used in combination. Examples of the alkylphenol type resol type phenol resin include those having a methyl group, an ethyl group, a propyl group, a t-butyl group, a nonyl group or the like at the o- or p-position of the phenolic hydroxyl group. These resol-type phenolic resins are preferable because they react by heating to become an insoluble and infusible solid having an adhesive force, and have an effect of improving the adhesive force, insulation reliability, chemical resistance, and heat resistance of the adhesive. . The phenol resin is added in an amount of 5 to 60 parts by weight based on 100 parts by weight of the polyamide resin.

The epoxy resin reacts at the molecular chain end of the polyamide resin and easily reacts by the action of the imidazole compound to coexist, thereby improving heat resistance and chemical resistance. Examples of the epoxy resin that can be used include bisphenol A diglycidyl ether, epoxidized phenol novolac, and epoxidized cresol novolac. Examples of the imidazole compound coexisting with the epoxy resin include 2-methylimidazole, 2-ethyl-4-methylimidazole, and other methylethylketones, which are soluble in general-purpose solvents, and 2-phenyl-4-benzyl-5.
-Hydroxylmethylimidazole and the like, which are hardly soluble in general-purpose solvents, can be mentioned. The epoxy resin is used in an amount of 9 to 88 parts by weight based on 100 parts by weight of the polyamide resin, and the imidazole compound is the polyamide resin 10
It is used in an amount of 0.03 to 10 parts by weight relative to 0 parts by weight.

A polyester film such as polyethylene, polypropylene or polyethylene terephthalate can be used as the protective film for the protective layer of the adhesive layer. Next, a method for manufacturing the TAB tape of the present invention will be described. FIG. 2 shows a manufacturing process. An adhesive containing a powdery inorganic filler 4 having a predetermined composition is applied onto the protective film 3 so that the film thickness after drying falls within the above range. . At this time, in order to obtain a semi-cured state, it is necessary that the heating condition is drying at 150 to 180 ° C. for 2 minutes.

Next, the organic insulating film 1 is superposed on the surface of the formed adhesive layer 2, and the organic insulating film 1 is placed at 100 to 130 ° C. for 1 hour.
Thermocompression bonding is performed under the condition of kg / cm ² or more. TAB obtained
The tape for use is wound and has a width of 30 to 200 mm, for example.
With a length of 30 to 300 m is obtained.

[0018]

EXAMPLES The present invention will be described below with reference to examples. All "parts" mean "parts by weight". Example 1 A coating film for forming an adhesive having the following composition was applied to a protective film made of a polyethylene terephthalate film having a thickness of 38 μm and dried at 160 ° C. for 2 minutes to form an adhesive layer having a thickness of 20 μm. Polyamide resin (Tomide TXC-232-B, manufactured by Fuji Kasei Kogyo Co., Ltd.) 25% isopropyl alcohol / water mixed solution 70 parts Epoxy resin (Epicoat 828, manufactured by Yuka Shell Co., Ltd.) 6 parts Novolac phenolic resin (Tamanor 752, Arakawa) Chemical Co., Ltd.) 50% methyl ethyl ketone solution 6 parts Resol type phenolic resin (CKM-1282, Showa Polymer Co., Ltd.) 50% methyl ethyl ketone solution 4 parts Silica (HDK H-2000, Wacker Co.) 12 parts Next, thickness An organic insulating film made of a polyimide film having a thickness of 50 μm is overlaid, and the temperature is 130 ° C. and 1 kg / cm ²
Then, the TAB tape was produced by thermocompression bonding.

Next, the protective film of the TAB tape was peeled off, and 1 ounce electrolytic copper foil (thickness: 35 to 40 μm)
Were pasted together and subjected to heat and pressure treatment under the conditions of 130 ° C. and 1 kg / cm ² . Then, at 60 ℃ for 6 hours, 8
6 hours at 0 ° C, 3 hours at 120 ° C, and 5 hours at 150 ° C
The adhesive layer was cured by sequentially heating for an hour. Further, a photoresist film was formed on the copper foil by a conventional method and treated, and the copper foil was etched to form a comb-shaped circuit to produce a film carrier tape.

Example 2 A TAB tape and a film carrier tape were produced in the same manner as in Example 1 except that the following composition was used as the adhesive layer forming coating material. Polyamide resin (Tomide TXC-232-B, manufactured by Fuji Kasei Kogyo Co., Ltd.) 25% isopropyl alcohol / water mixed solution 70 parts Epoxy resin (Epicoat 828, manufactured by Yuka Shell Co., Ltd.) 6 parts Novolac phenolic resin (Tamanor 752, Arakawa) Chemical Co., Ltd.) 50% methyl ethyl ketone solution 6 parts Resol-type phenol resin (CKM-1282, Showa Polymer Co., Ltd.) 50% methyl ethyl ketone solution 4 parts 2-ethyl imidazole 1% methyl ethyl ketone solution 7 parts Titanium oxide (R-550 , Ishihara Sangyo Co., Ltd.) 12 parts

Comparative Example 1 A TAB tape and a film carrier tape for comparison were prepared in the same manner as in Example 1 except that the coating composition for forming the adhesive layer had the following composition. Polyamide resin (Tomide TXC-232-B, manufactured by Fuji Kasei Kogyo Co., Ltd.) 25% isopropyl alcohol / water mixed solution 100 parts Epoxy resin (Epicoat 828, manufactured by Yuka Shell Co., Ltd.) 8 parts Novolac phenolic resin (Tamanor 752, Arakawa) Chemical Co., Ltd.) 50% methyl ethyl ketone solution 8 parts Resol-type phenol resin (CKM-1282, Showa Polymer Co., Ltd.) 50% methyl ethyl ketone solution 6 parts 2-Ethylimidazole 1% methyl ethyl ketone solution 10 parts

(Characteristic Evaluation Test) The film carrier tapes of Examples 1 and 2 and Comparative Example 1 were subjected to the following characteristic tests. The results are shown in Table 1. 1) Time between short circuits under the condition of 121 ° C., 2 atm, and 100 V using a 100 μm pattern between lines. 2) Chemical resistance (dissolved amount by immersion in acetone and methanol): The weight reduction rate after the adhesive layer composition is heat-cured and then immersed in acetone or methanol at 30 ° C. for 1 hour (under ultrasonic waves). (%). 3) Adhesion with copper foil at room temperature (100 μm width, 9
0 ° peeling). 4) Adhesion with copper foil at high temperature (250 ° C, 100
μm width, 90 ° peeling).

[0023]

[Table 1]

As is apparent from Table 1, it was confirmed that the TAB tape of the present invention has high insulation reliability and chemical resistance, and has strong adhesiveness even at normal temperature and high temperature. .

[0025]

EFFECTS OF THE INVENTION Since the TAB tape of the present invention contains the powdery inorganic filler in the adhesive layer, thermal expansion and contraction of the adhesive layer are suppressed, and chemical resistance and heat resistance are improved. . As a result, during the process of assembling the semiconductor device, it is hard to be attacked by the etching solution or the plating solution, so that the adhesive strength to the copper foil can be prevented from being lowered. In addition, since the TAB tape of the present invention has high insulation reliability and high adhesive strength, it is possible to reliably adhere the pattern having a narrow line width due to the increase in the number of pins and the organic insulating film, and to lead. There is no problem with the insulation between them. Therefore, when the chip is used for connecting to an external circuit, the tape can be left on the lead portion even if the number of lead pins increases. Therefore, when a multi-pin chip is mounted, a bonding mistake is unlikely to occur, lead deformation is small in the carrying process, the bonding process, etc., and the yield is greatly improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a TAB tape of the present invention.

FIG. 2 is a manufacturing process diagram of the TAB tape of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Organic insulating film 2 ... Adhesive layer 3 ... Protective film 4 ... Powder inorganic filler

Claims (2)

[Claims] 1. A thermosetting adhesive layer containing a polyamide resin as a main component and a protective layer are provided on an organic insulating film, and the adhesive layer contains at least one kind of powdery inorganic filler. A tape for TAB characterized by containing. 2. The tape for TAB according to claim 1, wherein the content of the powdery inorganic filler is 1 to 90% by weight.