JPH06220410A - Adhesive tape for lead frame - Google Patents

Abstract

PURPOSE:To obtain the subject tape excellent in adhesive power, heat resistance, reliability in respect of insulation, etc., by forming an adhesive layer containing a phenol resin and an insulating inorganic filler on an organic insulating film. CONSTITUTION:An adhesive layer containing a phenol resin and an insulating inorganic filler (e.g. silica or alumina) as the essential constituents is formed at least on one side of an organic insulating film (e.g. polyimide film) to produce the objective tape. As the phenol resin, a thermosetting one which contains structural units of the formula (wherein R is H or 1-12C hydrocarbon) and is solid at ordinary temperature is preferably used. It is desirable that the electrical conductivity of water extract of the inorganic filler is at most 50muS/cm and that the adhesive layer also contains an acrylonitrile-butadiene copolymer and/or a polyamide resin as the essential constituent. The obtained adhesive tape is useful for application to a resin-sealed semiconductor.

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,
DIP (Dual In Line Package), QFP (Quad Flat)
Package), PLCC (Plastic Leaded Chip Carrier)
) And the like, as shown in FIGS. 3 and 4, a lead frame 5 such as 42 alloy or copper alloy.
Is fixed between the pins with an adhesive tape 4 for a lead frame, and a semiconductor chip 7 is die-attached onto the lead frame 5 using an epoxy-based or imide-based silver paste or solder paste, and a gold wire wire bonding method or This is performed by electrically connecting the semiconductor chip 7 and the lead frame 5 with a wire 6 by a copper wire wire bonding method and sealing the same with a molding material such as resin. Further, in recent years, as electronic devices have become smaller and have higher performance, small, thin, lightweight, and
Since a high-performance package is required, as shown in FIG. 5, the lead frame 5 and the semiconductor chip 7 are fixed to each other with the adhesive tape 4 for the double-sided lead frame.
On Chip) has been developed and is already in mass production. These adhesives are required to have various properties such as adhesiveness, insulation and heat resistance.

[0003]

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. 510710), and examples using nylon / inorganic or organic fillers (Japanese Patent Laid-Open No. 3-41743) are known, but the adhesive-attached tape using these conventional adhesives has its original purpose. Can no longer be achieved. 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 extent and there was resistance, becomes remarkable phenomenon that current flows conductive adhesive tape section with the passage time of the test, decrease gradually resistor, after lapse of 100 hours, a short circuit occurs between the lead frame, 10 ³
The following resistance will result. 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 it takes a long time to short-circuit 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.

[0005]

The object of the present invention is as follows.
An adhesive tape for lead frame, comprising an organic insulating film and an adhesive layer formed on at least one surface of the organic insulating film, wherein the adhesive layer comprises (a) a phenol resin and (b) an insulating inorganic filler. This is achieved by a tape with an adhesive for a lead frame, which is characterized by containing as an essential component.

The organic insulating film used in the adhesive tape for lead frame of the present invention includes polyimide, polyetherimide, polyphenylene sulfide, polyetheretherketone, so-called heat resistant film such as aromatic polyamide, polyethylene terephthalate, or the like. 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) a phenol resin and (b) an insulating inorganic filler as essential components.

As the phenolic resin as the component (a), known phenolic resins such as novolac phenolic resins such as alkylphenolic resins and paraphenylphenolic resins, and thermosetting phenolic resins can be used, but they have high insulation properties. Therefore, it is preferable to include a thermosetting phenolic resin that is solid at room temperature. As for the mixing ratio,
It is preferably 30% by weight or more, more preferably 50% by weight or more, based on the total phenolic resin. The thermosetting type that is liquid at room temperature or the thermosetting type alone has low heat resistance. When sealing with a molding agent such as resin, the adhesive melts due to pressure and temperature, and the adhesive strength, insulation, etc. The characteristics deteriorate. The thermosetting phenolic resin which is solid at room temperature can be easily obtained as a commercially available product. Specifically, Gunei Chemical Co., Ltd. PS2780, Showa High Polymer Co., Ltd. CKM
1282, TD-2625 manufactured by Dainippon Ink and others, and the like.

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 insulating inorganic filler of the component (b), known inorganic oxide, hydroxide and carbonate particles having an insulating property can be appropriately used, and silica, alumina, zirconia, titania are usable. It is preferable to appropriately select and use an oxide having an extracted water conductivity of 50 μS / cm or less from oxides such as the above, or complex oxides such as aluminum silicate and calcium silicate. Where "extracted water conductivity"
Is a pre-cooker (121 ° C., 2 atm, 24 atm
The electrical conductivity of the extracted water after being subjected to hrs).
More preferably, the conductivity of the extracted water is 20 μS / cm or less. If the insulating property of the inorganic filler is low, it becomes difficult to obtain high insulating reliability.

The shape of the particles of the insulating inorganic filler may be any of powder, flake, fiber, balloon, etc., but powder is preferable from the viewpoint of dispersibility in resin. Also, as the particle size,
Those having an average particle size of 0.01 to 10 μm, and preferably 0.1 to 5 μm, in terms of apparent size by an electron microscope, a centrifugal sedimentation method, a specific gravity balance method and the like. If the average particle size is smaller than 0.01 μm, it is difficult to uniformly disperse the resin in the resin, and if it exceeds 10 μm, the adhesive force tends to be lowered.

The adhesive layer can also achieve the object of the present invention by using a phenol resin / insulating inorganic filler system, but the overall performance as an adhesive tape for lead frames such as adhesiveness, chemical resistance and heat resistance. In order to satisfy the above condition, it is preferable to use it by mixing with other resin. As the miscible resin, acrylonitrile acrylic acid ester copolymer, acrylic acid ester-based resin, acrylonitrile butadiene copolymer, soluble polyamide resin, epoxy resin, butyral resin, soluble polyester resin, polyimide resin and the like can be used. 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, acrylamide,
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 a resin which 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 by weight, the insulating inorganic filler is preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight. When another resin is mixed, the acrylonitrile butadiene copolymer, the polyamide resin or the mixture of the acrylonitrile butadiene copolymer and the polyamide resin is 60
To 200 parts by weight, more preferably 80 to 15 parts by weight
0 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 compounding ratio of acrylonitrile butadiene copolymer: polyamide resin or polyamide resin: acrylonitrile butadiene copolymer is 1:99 to 10:90.
The range of (weight ratio) is preferable, and more preferably 1: 9.
9-5: 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. 1 and 2. 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.

[0022]

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

<Insulation measurement 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 at 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” 100V manufactured by DuPont Toray Co., Ltd.) 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.

<Adhesive composition> 100 parts by weight of acrylonitrile butadiene resin (PNR-1HA manufactured by Japan Synthetic Rubber Co., Ltd.) 80 parts by weight of thermosetting alkylphenol resin (CKM1282 manufactured by Showa Polymer Co., Ltd., solid at room temperature, R = t-butyl group) 20 parts by weight of silica (FB-5S (X) manufactured by Denki Kagaku KK, particle size of 4 μm by centrifugal sedimentation method, conductivity of 4.8 μS / cm) A piece of 2 mm in width and 10 mm in length is made from this tape to fix the lead frame. And 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.

<Adhesive Composition> 100 parts by weight of polyamide resin (Nylon 6.36 “PRIADIT” 2053 manufactured by Unichema, dimer acid and hexamethylenediamine as main components, weight average molecular weight of 100,000, MI value at 175 ° C. of 10 gr / Min) Thermosetting alkylphenol resin 100 parts by weight (Gunei Chemical Co., Ltd. PS2780, normal temperature solid, R = t-butyl group) Silica 20 parts by weight (Electrochemical Co., Ltd. FB-5S (X)) Example 3 Adhesive component An adhesive tape for performance study was prepared in the same manner as in Example 1, except that

<Adhesive Composition> Polyamide resin 100 parts by weight (Unichema nylon 6.36 “PRIADIT” 2053) Thermoplastic alkylphenol resin 40 parts by weight (PSM4326 manufactured by Gunei Chemical Co., Ltd.) Silica 40 parts by weight (Electrochemical Company) FB-5S (X) manufactured by Comparative Example 1 An adhesive tape for performance study was prepared in the same manner as in Example 1 except that the adhesive components were as follows.

<Adhesive composition> 100 parts by weight of acrylonitrile butadiene resin (PNR-1HA manufactured by Japan Synthetic Rubber Co., Ltd.) 80 parts by weight of thermoplastic phenol resin (PSM4326 manufactured by Gunei Chemical Co., solid at room temperature) 20 parts by weight of aluminum hydroxide ( Showa Denko H-34, particle size 3.5 μm by specific gravity balance method, conductivity 150 μS / cm) Comparative Example 2 Adhesion for performance study by the same method as in Example 1 except that the adhesive components are as follows. I made a tape.

<Adhesive composition> 100 parts by weight of acrylonitrile butadiene resin (PNR-1HA manufactured by Japan Synthetic Rubber Co., Ltd.) 80 parts by weight of thermoplastic phenolic resin (PSM4326 manufactured by Gunei Chemical Co., Ltd., solid at room temperature) Comparative Example 3 An adhesive tape for performance study was prepared in the same manner as in Example 1 except as described below.

<Adhesive Composition> 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) Obtained in Examples and Comparative Examples. The insulating property and the adhesive strength of the adhesive tape for performance examination were measured. The test results are shown in Table 1.

[0033]

[Table 1]

[0034]

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 an 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 (7)

[Claims] 1. A tape with an adhesive for a lead frame, which comprises an organic insulating film and an adhesive layer formed on at least one surface of the organic insulating film, wherein the adhesive layer comprises (a) a phenol resin and (b). A tape with an adhesive for a lead frame, which contains an insulating inorganic filler as an essential component. 2. The phenol resin includes a thermosetting phenol resin that is solid at room temperature as the phenol resin.
Adhesive tape for lead frame as described above. 3. A thermosetting phenolic resin which is solid at room temperature is represented by the general formula (1): The tape with an adhesive for lead frames according to claim 2, comprising a structural unit represented by the formula (wherein R represents hydrogen or a hydrocarbon group having 1 to 12 carbon atoms). 4. The conductivity of the extracted water of the insulating inorganic filler is 5
It is 0 micro S / cm or less, The Claims 1-3 characterized by the above-mentioned.
Tape with an adhesive for lead frames according to any of the above. 5. The tape with an adhesive for a lead frame according to claim 1, wherein the adhesive layer further contains an acrylonitrile butadiene polymer and / or a polyamide resin as an essential component. 6. The adhesive tape for lead frames according to claim 1, further comprising a protective film on the adhesive layer. 7. The adhesive tape for lead frames according to claim 6, wherein the protective film is polyethylene terephthalate, polypropylene, polyethylene or polyphenylene sulfide.