JPH06212129A - Adhesive-coated tape for lead frame - Google Patents

Abstract

PURPOSE:To provide an adhesive-coated tape having adhesive force, heat resistance, etc., necessary as an adhesive-coated tape for lead frames, taking a long time for short circuiting when subjected to the unsaturation pressure cooker bias test, having high reliability of insulation and therefore being useful for a resin-sealed semiconductor. CONSTITUTION:The tape is composed of an organic insulation film and an adhesive layer formed on at least either surfaces of the film. The adhesive layer contains a phenolic resin as the essential component, and the phenolic resin contains a normally solid thermosetting phenolic resin as the essential component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed semiconductor, when fixing the pins of a lead frame, or when adhering the pins of the lead frame to a semiconductor chip mounting substrate or the semiconductor chip itself. The present invention relates to an adhesive tape for a lead frame used.

[0002]

2. Description of the Related Art As shown in FIGS. 1 and 2, the basic structure of an adhesive tape for a lead frame is usually a poly-metal coated on one side or both sides of a heat-resistant organic insulating film 1 such as polyimide. The adhesive layer 2 is made of an acrylic ester resin, an epoxy resin, a synthetic rubber resin such as an acrylonitrile butadiene copolymer, and the protective film 3 is provided on the adhesive layer 2 if necessary.

When manufacturing resin-sealed semiconductors, DI
P (Dual In Line Package), QFP (Quad Flat Pack)
age), PLCC (Plastic Leaded Chip Carrier), etc., as shown in FIG. 3 and FIG.
A lead frame 5 made of 2 alloy or copper alloy is fixed between the pins with an adhesive tape 4 for the lead frame, and the semiconductor chip 7 is mounted on the lead frame 5 by using an epoxy-based or imide-based silver paste or solder paste. It is carried out by die-attaching, electrically connecting the semiconductor chip 7 and the lead frame 5 with the wire 6 by the gold wire wire bonding method or the copper wire wire bonding method, and sealing this with a molding material such as resin. There is. Further, in recent years, as electronic devices have been made smaller and have higher performance, smaller, thinner, lighter, and higher performance packages are required in the semiconductor field as well, so as shown in FIG. 5, the lead frame 5 and the semiconductor chip 7 are provided. LOC (Lead On Chi
p) was developed and is already in mass production. These adhesives are required to have various properties such as adhesiveness, insulation and heat resistance.

[0004]

In recent years, due to the demand for smaller, thinner, lighter, and higher-performance packages in electronic equipment, higher insulation reliability has been required. As a conventional adhesive tape for lead frames, a mixed system of polyacrylonitrile, butyl polyacrylate and resol type phenol resin (abbreviated as "polyacrylonitrile / butyl polyacrylate / resole type phenol resin system") is used. / △△△ system "is □□
It represents a mixed system of □ and △△△. ) (JP-A-61)
No. 510706), and an example using a nylon / inorganic or organic filler system (Japanese Patent Laid-Open No. 3-41743) is known, but an adhesive tape using these conventional adhesives is originally used. It is not possible to achieve the purpose. That is, when the electrical characteristics are evaluated by an unsaturated pressure cooker bias test (temperature 130 ° C., humidity 85%, applied voltage 100 V) as so-called insulation evaluation, the unsaturated pressure cooker bias test starts at 10 ⁸ to 10 ⁹ ohms. The resistance, which was about the same level, becomes more and more conspicuous in that the current flows through the adhesive tape portion as the test elapses, and the resistance gradually decreases.
After a lapse of time, a short circuit occurs between the lead frames and 10
The resistance is less than ³ . The time until short circuit by unsaturated pressure cooker bias test needs to be 100 hours or more to obtain high insulation reliability. If the reliability is insufficient, small, thin, lightweight and high density packages can be used. In the required semiconductor mounting, the performance as an adhesive tape for lead frames cannot be exhibited.

Therefore, an object of the present invention is to have adhesiveness, heat resistance, etc. which have been conventionally required as an adhesive for lead frames, and a long time is required until a short circuit occurs between lead frames in an unsaturated pressure cooker bias test. An object of the present invention is to provide a lead frame adhesive tape having high insulation reliability.

[0006]

The object of the present invention is as follows.
In a tape with an adhesive for a lead frame having an organic insulating film and an adhesive layer formed on at least one surface of the organic insulating film, the adhesive layer contains a phenol resin as an essential component, and the phenol This is achieved by a tape with an adhesive for a lead frame, which comprises a thermosetting phenolic resin which is solid at room temperature as a resin.

Examples of the organic insulating film used in the adhesive tape for lead frames of the present invention include so-called heat resistant films such as polyimide, polyetherimide, polyphenylene sulfide, polyether ether ketone, and aromatic polyamide, polyethylene terephthalate, or Examples include flexible epoxy / glass cloth and other composite materials.

An adhesive layer is formed on at least one surface of the organic insulating film. The adhesive layer contains a phenol resin as an essential component, and also contains, as the phenol resin, a thermosetting type solid at room temperature.
Thermosetting type or thermoplastic type that is liquid at room temperature has low heat resistance, and when sealing with a molding material such as resin, the adhesive begins to melt due to pressure and temperature, and the characteristics such as adhesive strength and insulation are Will fall. The thermosetting phenolic resin which is solid at room temperature can be easily obtained as a commercially available product. Specific examples include PS2780 manufactured by Gunei Chemical Co., CKM1282 manufactured by Showa High Polymer Co., Ltd. and TD-2625 manufactured by Dainippon Ink and Chemicals.

Further, a thermosetting phenolic resin which is solid at room temperature is represented by the general formula (1)

[Chemical 2] (In the formula, R represents hydrogen or a hydrocarbon group having 1 to 12 carbon atoms.) It is preferable to include a structural unit.
As the carbon number of R increases, the adhesive strength increases,
Further, it is preferable because it has high compatibility when mixed with other resins, but if it is too much, heat resistance is lowered, so a butyl group having 4 carbon atoms is preferable, and a t-butyl group is preferable because it is easily available. Is more preferable. Further, the higher the content of the structural unit represented by the general formula (1) is, the longer the time until a short circuit in the unsaturated pressure cooker bias test is, so the content is preferably 35% by weight or more,
It is more preferably 50% by weight or more. Specific examples include PS2780 manufactured by Gunei Chemical Co., Ltd., CKM1282 manufactured by Showa High Polymer Co., Ltd., and the like.

As the phenol resin, all known phenol resins other than thermosetting resins which are solid at room temperature can be used in combination. Specifically, phenol resin (novolak type, resol type), alkylphenol resin (novolak type,
Resol type), polyparaphenylphenol resin, polyparavinylphenol resin and the like. As the mixing ratio, at least 20 is a thermosetting type solid at room temperature.
The content is preferably at least 40% by weight, more preferably at least 40% by weight.

The phenol resin may be used alone,
In order to satisfy the overall performance of the adhesive tape for lead frames, such as adhesiveness, chemical resistance, and heat resistance, it is preferable to use it by mixing with other resins. Examples of the miscible resin include acrylonitrile acrylic acid ester copolymer, acrylic acid ester-based resin, acrylonitrile butadiene copolymer, soluble polyamide resin, epoxy resin, butyral resin, soluble polyester resin, and polyimide resin. Acrylonitrile butadiene copolymer and / or polyamide resin are particularly preferable for exhibiting specific performance.

The acrylonitrile-butadiene copolymer, that is, the acrylonitrile-butadiene copolymer, preferably has an acrylonitrile content of 10 to 45% by weight, more preferably 25 to 35% by weight. Further, as the third component other than acrylonitrile and butadiene, the components having a reactive functional group are 1 to 1
You may contain in the range of 0 weight%. As the component having a reactive functional group, specifically, acrylic acid, hydroxymethyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate, acrylic acid,
Examples include dimethylaminomethacrylate. Since acrylonitrile butadiene copolymer is usually synthesized by emulsion polymerization, sodium, as a surfactant residue,
It contains impurity ions such as potassium, calcium and chlorine. In the present invention, the polymerization method is not particularly limited, but it is preferably one synthesized by a nonionic surfactant and having a total impurity ion of 50 ppm or less. More preferably, the total impurity ions are 30p
It is preferably pm or less.

The polyamide resin is obtained by thermally polymerizing a mixture of an acid and a diamine, and one that can be dissolved in a mixed solvent containing alcohols such as methanol as a main component is used. Above all, a so-called dimer acid-based polyamide having a dicarboxylic acid having 36 carbon atoms (so-called dimer acid) as a main component as a raw material of the polyamide resin is preferable.

The dimer acid type polyamide is obtained by thermally polymerizing an equimolar mixture of dimer acid and a diamine component such as hexamethylenediamine or ethylenediamine, and not only dimer acid but also azelaic acid and sebacine as dicarboxylic acid components. It may contain other dicarboxylic acid such as acid. Further, as the diamine component, not only the above-mentioned ones are used alone, but also a mixture of other diamines can be used. Other diamine components that can be mixed include piperazine, bis (4-aminocyclohexyl) methane, and bis (4-amino, 1,2-
Methylcyclohexyl) methane and the like. When these dimer acid-based polyamides are made to have a high degree of polymerization, they have an advantage that the water absorption becomes relatively low and the electric insulation becomes high even in a high humidity atmosphere. Among the dimer acid-based polyamides, those containing hexamethylenediamine as a main component as a diamine component are particularly preferable because they exhibit excellent properties in overall performance.

The ratio of each component is 100 for phenol resin.
When the amount is 60 parts by weight, the acrylonitrile butadiene copolymer, the polyamide resin or the mixture of the acrylonitrile butadiene copolymer and the polyamide resin is 60 parts by weight to 2 parts by weight.
The amount is preferably 00 parts by weight, more preferably 80 parts by weight to 150 parts by weight. When the amount of phenolic resin is low, the insulating property tends to deteriorate. Further, if the amount of the phenol resin is too much, the adhesive force tends to decrease. When a mixture of an acrylonitrile butadiene copolymer and a polyamide resin is used, the mixing ratio of the acrylonitrile butadiene copolymer: polyamide resin or the polyamide resin: acrylonitrile butadiene copolymer is 1:99 to 10:90 (weight ratio). ) Is preferable, and more preferably 1:99 to.
It is 5:95.

An adhesive resin mixture solution is obtained by dissolving the above components in a solvent. As a solvent for dissolving each component of the adhesive, a mixed solvent of an aromatic solvent such as toluene, xylene, chlorobenzene, and benzyl alcohol and an alcohol solvent such as methanol, ethanol, isopropyl alcohol, and butyl alcohol is suitable.

Further, in the present invention, a protective film is formed on the adhesive layer, if necessary. The protective film is used for the purpose of preventing dust or handling, and polyethylene terephthalate, polypropylene, polyethylene, polyphenylene sulfide, polyethylene naphthalate, etc. are preferably used. Among them, polyethylene terephthalate, polypropylene, polyethylene and polyphenylene sulfide are preferable.

The adhesive tape for lead frame is usually produced by the following method.

That is, the adhesive resin mixture solution is applied onto the organic insulating film and dried. At this time, it is preferable to apply so that the film thickness after drying is about 5 to 50 μm. The drying condition is usually 100 to 20.
The range is 0 ° C. and 1 to 5 minutes. Furthermore, in the case of having an adhesive layer on both sides of the organic insulating film, in the same manner as above,
An adhesive layer is also formed on the other surface. If necessary, a protective film having releasability is attached and slit to a desired width and size.

A schematic cross-sectional view of the adhesive tape for lead frames according to the present invention is shown in FIGS. Figure 1
Is composed of an organic insulating film 1 and a protective film 3 adhered to one surface of the organic insulating film 1 via an adhesive layer 2. Figure 2
Is composed of an organic insulating film 1 and a protective film 3 adhered to both surfaces thereof via an adhesive layer 2.

[0021]

EXAMPLES The present invention will be described below with reference to examples. Each test in this example was performed as follows.

<Insulation Measuring Method> Adhesive tape for performance study Width 2 mm, length 10 mm Lead frame 42 alloy, pitch 300
The resistance value between the lead frames of the μm adhesive tape is continuously measured under the conditions of 130 ° C., 85% and 100V. The time to short circuit is required to be 150 hours or longer, and particularly preferably 200 hours or longer.

<Adhesive force measurement method> Adhesive tape for performance examination Width 2 mm, length 10 mm Lead frame 42 alloy measuring machine Orientec tensile tester Adhesive tape polyimide film speed 90 ° direction 5
Peel off at 0 mm / min and measure the stress at that time. Generally, 0.5 kg / cm or more is required.

Example 1 A polyimide film having a thickness of 50 μm (“Kapton” 200 V manufactured by DuPont Toray) was dissolved in a mixed solution of methanol / monochlorobenzene so that the weight of the solid content was 20%. The obtained adhesive solution was applied so that the dry film thickness was 20 μm, and dried using an air oven at 100 ° C. for 1 minute and 150 ° C. for 2 minutes.

Acrylonitrile butadiene resin 100 parts by weight (Japan Synthetic Rubber Co., Ltd. PNR-1HA) Thermosetting alkylphenol resin 80 parts by weight (Showa Polymer Co., Ltd. CKM1282, solid at room temperature, R = t-butyl group) 2 mm width from this tape , 10 mm long pieces were made and used as a lead frame fixing tape. The semiconductor is mounted on the lead frame whose pins are fixed by this film piece,
After fixing the semiconductor to the frame, the pins of the frame and the semiconductor terminals were joined and sealed with an epoxy resin to obtain an adhesive tape for examining the performance of the sample.

Example 2 An adhesive tape for performance study was prepared in the same manner as in Example 1 except that the adhesive components were as follows.

Polyamide resin 100 parts by weight (Unichema nylon 6.36 “PRIADIT” 2053, dimer acid and hexamethylenediamine as main components, weight average molecular weight 100,000, MI value at 175 ° C. 10 gr / min) Thermosetting type Alkylphenol resin 100 parts by weight (Kunei Chemical Co., Ltd. PS2780, normal temperature solid, R = t-butyl group) Comparative Example 1 Adhesive tape for performance study by the same method as in Example 1 except that the adhesive components are as follows. Was produced.

Acrylonitrile butadiene resin 100 parts by weight (Japan Synthetic Rubber Co., Ltd. PNR-1HA) Thermoplastic phenol resin 80 parts by weight (Gunei Chemical Co., Ltd. PSM4326, normal temperature solid) Comparative Example 2 The adhesive components are as follows. An adhesive tape for performance study was produced in the same manner as in Example 1 except for the above.

100 parts by weight of acrylonitrile butadiene resin (PNR-1HA manufactured by Japan Synthetic Rubber Co., Ltd.) 100 parts by weight of thermosetting phenolic resin (PR50087 manufactured by Sumitomo Chemical Co., Ltd., liquid at room temperature) Adhesion for performance study obtained in Examples and Comparative Examples The tape was measured for insulation and adhesion. The test results are shown in Table 1.

[0030]

[Table 1]

[0031]

The tape with an adhesive for lead frames according to the present invention has the adhesive strength, heat resistance and the like conventionally required as a tape with an adhesive for lead frames, and has a short circuit due to an unsaturated pressure cooker bias test. Since it takes a long time to have high insulation reliability,
It is highly practical as an adhesive tape for resin-sealed semiconductors.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a tape with an adhesive for lead frames of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the adhesive tape for lead frames of the present invention.

FIG. 3 is a schematic view showing an example in which the pins of the lead frame are fixed by a tape with an adhesive for the lead frame.

FIG. 4 is a schematic view showing another example in which the pins of the lead frame are fixed by the tape with the adhesive for the lead frame.

FIG. 5 is a schematic view showing an example of a case where a lead frame and a semiconductor chip are bonded together with an adhesive tape for a lead frame.

[Explanation of symbols]

 1: Organic insulating film 2: Adhesive layer 3: Protective film 4: Adhesive tape for lead frame 5: Lead frame 6: Wire 7: Semiconductor chip

Claims (5)

[Claims] 1. An adhesive tape for lead frame, comprising an organic insulating film and an adhesive layer formed on at least one side of the organic insulating film, wherein the adhesive layer contains a phenol resin as an essential component. A tape with an adhesive for lead frames, characterized in that a thermosetting phenolic resin which is solid at room temperature is contained as the phenolic resin. 2. A thermosetting phenolic resin which is solid at room temperature is represented by the general formula (1): The tape with an adhesive for a lead frame according to claim 1, comprising a structural unit represented by the formula (wherein R represents hydrogen or a hydrocarbon group having 1 to 12 carbon atoms). 3. The adhesive tape for lead frames according to claim 1, wherein the adhesive layer further contains an acrylonitrile butadiene copolymer and / or a polyamide resin as an essential component. 4. The adhesive tape for lead frames according to claim 1, further comprising a protective film on the adhesive layer. 5. The adhesive tape for lead frames according to claim 4, wherein the protective film is polyethylene terephthalate, polypropylene, polyethylene or polyphenylene sulfide.