JP4657138B2 - Conductive material for packaging electronic parts and packaging container for electronic parts - Google Patents

Description

  The present invention is used to assist mounting processes such as carrier tapes and trays for storing and transporting electronic components such as LSIs and capacitors, TAB (Tape Automated Bonding), BGA (Ball Grid Array), CSP (Chip Scale Package), etc. In particular, the present invention relates to a conductive material for packaging electronic parts used in the manufacture of spacers and the like.

  In recent years, surface mounting of electronic components has greatly advanced, and along with this, surface mounting technology has also advanced greatly. In addition, higher-performance and smaller chip-type electronic components have been developed. Embossed carrier tape is known as one of the packaging forms for storing, transporting, storing, and using the chip-type electronic components for surface mounting. Yes.

  The embossed carrier tape stores chip-type electronic components in recessed pockets formed at predetermined intervals, and seals the recessed portions with a cover tape to wrap the chip-type electronic components and store them in a state of being wound on a reel. It is to be transported. Then, the transported embossed carrier tape is mounted on the cassette feeder of the surface mounter, the cover tape is peeled off while feeding the embossed carrier tape in order, and the chip-type electronic components are automatically picked up to the predetermined part of the circuit board. Thus, the chip-type electronic component is assembled to the circuit board.

  By the way, during the storage, transport, and surface mounting processes using embossed carrier tape, the embossed carrier tape is charged by static electricity caused by friction between the pocket inner surface of the embossed carrier tape and chip-type electronic components, or static electricity generated during the process of peeling the cover tape. For this reason, there is a problem that electrostatic breakdown occurs in the chip-type electronic component. Therefore, in order to prevent electrostatic breakdown, the embossed carrier tape is made conductive to prevent the accumulation of static electricity. A sheet in which a conductive filler such as carbon black is kneaded into the resin is used. A conductive coat layer is applied to the surface of the sheet (see Patent Documents 1, 2, 3, and 4).

  Moreover, as shown in FIG. 1, the spacer used for TAB, BGA, CSP, etc. uses the electroconductive tape 10 which gave the electroconductive coating layer containing carbon black on both surfaces of the sheet | seat formed in tape shape, The Embossing is carried out by alternately repeating convex portions (concave portions when viewed from the back surface) 11 and concave portions (convex portions when viewed from the back surface) 12 at both ends. Then, this spacer is cleaned with ultrapure water or alcohol such as methanol or ethanol to remove the adhering foreign matter, and then overlapped with a tape 20 such as TAB to form a reel as shown in FIG. It is wound, stored, transported and used for surface mounting. At this time, the lead and the semiconductor chip are repeatedly formed at a predetermined interval on the tape such as TAB, but the convex portion 11 and the concave portion 12 formed on both surfaces of the spacer form a gap between the TAB tape. Therefore, the lead and the semiconductor chip are prevented from contacting the spacer.

  Further, in the above-described embossed carrier tape, spacer, and the like, a top coat layer is provided on the surface of the conductive coat layer in order to protect the conductive coat layer.

  By the way, the embossed carrier tape is used to clean the conductive sheet by vacuum forming, vacuum-pressure forming, or press forming, and then washing with ultrapure water or alcohol such as methanol or ethanol to remove adhering foreign matter. It is manufactured by removing. In addition, as described above, alcohol cleaning such as methanol or ethanol is performed on spacers used for TAB or the like. Therefore, conventionally, the top coat layer coated on the surface of the conductive coat layer has been made of a chlorinated rubber-based resin that is resistant to alcohol cleaning.

JP-A-7-132963 Japanese Patent Laid-Open No. 8-323932 Japanese Patent Laid-Open No. 2000-15564 JP 2000-21247 A

  However, the chlorinated rubber-based resin used for the top coat layer has a risk of causing metal corrosion on electronic parts due to chlorine, and also has a problem of generating dioxins and the like when burned. If the topcoat layer is formed of a resin component that does not contain chlorine, the problem of chlorine can be solved, but the resistance to alcohol washing is poor, and the topcoat layer does not contain chlorine and has good alcohol resistance. However, an effective top coat layer has not been proposed.

  An object of the present invention is to solve the above problems and to provide a conductive material for packaging electronic parts that is resistant to alcohol washing and has no harmful effects due to chlorine.

  In order to achieve the above-mentioned object, the present inventors diligently studied a resin suitable for a top coat layer that does not contain chlorine and is resistant to alcohol washing, and contains MMA (methyl methacrylate) monomer at 75% by weight or more. It has been found that the use of an acrylic resin copolymerized with the resin has high resistance to alcohol washing, and the present invention has been completed.

The conductive material for packaging electronic parts according to claim 1 comprises a conductive composition containing a base sheet or base film and carbon black provided on one or both sides of the base sheet or base film. A conductive coat layer and a top coat layer provided on the conductive coat layer, the top coat layer comprising an acrylic resin copolymerized using MMA (methyl methacrylate) monomer at 75% by weight or more. Thus, the top coat layer is formed by applying a coating solution shown below .
Coating liquid:
Acrylic resin 8-22% by weight
Nitrified cotton resin 1-3% by weight
Toluene 40-50% by weight
Methyl ethyl ketone 10-20% by weight
Acetic acid propyl ester 10-20% by weight
Isopropyl alcohol 5-10% by weight

  In the conductive material for packaging electronic parts according to claim 2, the acrylic resin is composed of MMA monomer, n-butyl methacrylate, 2-ethylhexyl methacrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate. The copolymer is characterized by being a copolymer with one or more selected monomers.

The conductive material for packaging electronic parts according to claim 3 has a surface resistance value of 1 × 10 ⁸ Ω or less.

  In the conductive material for packaging electronic parts according to claim 4, the base sheet or base film is made of PET (polyethylene terephthalate), PC (polycarbonate), PP (polypropylene), PI (polyimide), PS (polystyrene) or It is characterized by being a sheet or film of HIPS (high impact polystyrene).

  According to a fifth aspect of the present invention, there is provided an electronic component packaging container characterized by being formed of the conductive material for electronic component packaging.

  In the conductive material for packaging electronic parts according to claim 1, since the top coat layer is made of an acrylic resin copolymerized using MMA (methyl methacrylate) monomer by 75% by weight or more, resistance to alcohol washing is large, In addition, since it does not contain chlorine, there is no metal corrosion of electronic parts due to chlorine, and there is no generation of dioxins or the like.

  In the conductive material for packaging electronic parts according to claim 2, the acrylic resin comprises MMA monomer, n-butyl methacrylate, 2-ethylhexyl methacrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate. Since it is a copolymer with one or more monomers selected from the above, it is soluble in the solvent for coating the topcoat layer, and the coated topcoat layer is insoluble in alcohol and has alcohol washing resistance.

In the conductive material for packaging electronic parts according to claim 3, since the surface resistance is 1 × 10 ⁸ Ω or less, charging can be prevented as much as possible, and foreign matter such as dust is not adsorbed. . Therefore, it is possible to prevent dust from adhering to the electronic component.

  In the conductive material for packaging electronic parts according to claim 4, the base sheet or base film is made of PET (polyethylene terephthalate), PC (polycarbonate), PP (polypropylene), PI (polyimide), PS (polystyrene) or HIPS. By forming with (high impact polystyrene), the optimum one can be selected from the viewpoint of function, application, cost and the like.

  Since the electronic component packaging container according to claim 5 is formed of the conductive material for electronic component packaging according to any one of claims 1 to 3, the electronic component has high resistance to alcohol washing and is not harmful by chlorine. A packaging container for parts can be obtained.

  The conductive material for packaging electronic parts of the present invention is provided with a base sheet or base film. Examples of the base sheet or base film include PET, PC, PP, PI, PS, and HIPS. Sheets or films are preferred.

  The thickness of the base sheet and the base film varies depending on the rigidity and use of each sheet and film and the method of use, but is preferably 100 to 300 μm. In the case of a TAB spacer, 125 μm of a PET film is suitable, and in the case of an embossed carrier tape used for a chip-type electronic component, 250 to 300 μm is suitable.

  A conductive coat layer made of a conductive composition is provided on one side or both sides of the base sheet or base film. For example, when used for an embossed carrier tape, a chip-type electronic component is housed in a pocket and sealed with a cover tape. Therefore, a conductive coating layer may be provided only on one side, and when used for a TAB spacer. Since the TAB tape and the spacer are overlapped and wound in a reel shape, both surfaces of the spacer face the TAB tape. Therefore, it is necessary to provide a conductive coat layer on both surfaces of the base sheet.

  The conductive composition is composed of carbon black and a fixing resin for fixing the carbon black to the base sheet or base film, and is composed of 15 to 30% by weight of carbon black and 70 to 85% by weight of the fixing resin. Is preferred. The fixing resin is selected from resins that firmly adhere to the base sheet or base film. For example, when the base sheet and film are PET, PP, PC, PI, urethane resin 30 to 40% by weight, polyester Resin consisting of 60 to 70% by weight of resin is used. In the case of PS, 65 to 75% by weight of acrylic resin, 20 to 30% by weight of fiber-based resin and 3 to 5% by weight of wax are used. In the case of HIPS, a constituent resin comprising 35 to 45% by weight of a vinyl chloride / vinyl acetate copolymer, 35 to 45% by weight of an acrylic resin, 15 to 25% by weight of a fiber-based resin, and 2 to 3% by weight of a wax. Used.

Carbon black is blended in an amount of 15 to 30% by weight. If the blending amount of carbon black is less than 15% by weight, the conductivity becomes poor and the surface resistance value becomes higher than 1 × 10 ⁸ Ω. . Moreover, when a compounding quantity exceeds 30 weight%, it will become impossible to fix to a base material sheet or a base film with fixing resin, and also cost will become high.

  The average particle diameter of the carbon black is preferably less than 1.0 μm. By using the carbon black having such an average particle diameter, the carbon black of the conductive coating layer is uniformly dispersed in the solvent in which the fixing resin is dissolved. Coated.

  To coat the conductive coating layer on the base sheet or base film, the conductive composition as described above is dissolved in a mixed solvent such as toluene, ethyl acetate, methyl ethyl ketone, isopropyl alcohol, and the base sheet or base film is dissolved. After applying to the material film, it is dried.

Examples of the coating liquid for the conductive coating layer coated on a PET, PP, PC, PI base sheet or film include those described below.
Carbon black 3-5% by weight
4-6% by weight urethane resin
7-10% by weight polyester resin
Toluene 20-30% by weight
Methyl ethyl ketone 40-50% by weight
Isopropyl alcohol 1-5% by weight

Examples of the coating solution for the conductive coating layer coated on the PS base material sheet or film include those described below.
Carbon black 1-3% by weight
Acrylic resin 7-10% by weight
2-5% by weight of fiber base resin
Acetic acid ethyl ester 15-25% by weight
Acetic acid propyl ester 15-25% by weight
Isopropyl alcohol 40-50% by weight
Wax 0.3-0.6% by weight

The application method is not particularly limited, but application by a gravure roll is the most common and can be applied effectively. The coating amount is 0.5 to 5.0 g / m ² after drying, preferably 1.0 to 4.0 g / m ² . When the coating amount is less than 0.5 g / m ² , when molding such as embossing, the conductivity of the portion stretched by the molding becomes inferior, and the coating amount is 5.0 g / m ² . If exceeded, the effect remains the same and the cost is high.

  A top coat layer is applied to the surface of the conductive coat layer in order to protect the conductive coat layer. The top coat layer is formed of an acrylic resin copolymerized using 75% by weight or more of MMA monomer, that is, formed of a copolymer of MMA monomer and other acrylic acid or methacrylic acid ester monomers. ing. Examples of these monomers include monomers such as n-butyl methacrylate, 2-ethylhexyl methacrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate.

  If the MMA monomer is less than 75% by weight, sufficient resistance to alcohol washing cannot be obtained. However, if the MMA monomer is 75% by weight or more, it is difficult to use it in the solvent of the coating solution and it is difficult to use it.

Examples of the coating solution for the top coat layer include those described below.
Acrylic resin * 8-22% by weight
Nitrified cotton resin 1-3% by weight
Toluene 40-50% by weight
Methyl ethyl ketone 10-20% by weight
Acetic acid propyl ester 10-20% by weight
Isopropyl alcohol 5-10% by weight
* Acrylic resin; copolymer consisting of 80% by weight of MMA monomer and 20% by weight of n-butyl methacrylate monomer

  The resin component of the top coat layer is a resin component of a conductive coat layer coated on a PET, PP, PC, PI base sheet or film, and a resin conductively coated on a PS base sheet or film. Since it adheres to both of the components and solidifies, it can be coated with the same topcoat layer coating component regardless of the material of the base sheet or film.

  The application method is not particularly limited, but application by a gravure roll is the most common and can be applied effectively.

The coating amount of the coating solution, after drying, 0.5 to 5.0 g / m ^2, preferably a 1.0~4.0g / m ^2. When the coating amount is less than 0.5 g / m ² , when molding such as embossing, there is a risk that the top coat layer is lost in the portion stretched by molding and the lower conductive coating layer is exposed. Yes, and if it exceeds 5.0 g / m ² , the conductivity becomes inferior.

The surface resistance value of the electronic component packaging for the conductive material of the present invention is preferably at most 1 × 10 ⁸ Ω, and more preferably ^{1 × 10 4 Ω~1 × 10 8} Ω. If 1 × 10 ⁸ Ω or more can not be foreign matter adhesion prevention is expected, such as dust and dirt, but only increases the cost in the 1 × 10 ⁴ Ω or less.

  Applications of the conductive material for packaging electronic parts of the present invention include carrier tapes and trays used for storing electronic parts, spacers used for mounting processes such as TAB, BGA, and CSP.

[Example 1]
Set a PET film “Lumirror S10” (thickness 125 μm × width 1020 mm × length 1200 m) manufactured by Toray Industries, Inc. as a base film in the feeding section of the GX-II-1500 manufactured by Nakajima Seiki Co., Ltd. A coating liquid having the following composition is coated by a gravure plate cylinder having 60 screen lines by Helio engraving of the first color printing unit, and then dried under conditions of a hot air temperature of 70 ° C. and a speed of 60 m / min. Formed.

Coating solution: “PET-PL EC Black” manufactured by Osaka Ink Manufacturing Co., Ltd.
4% carbon black
Urethane resin 5% by weight
10% by weight polyester resin
Toluene 28 wt%
Methyl ethyl ketone 49% by weight
Isopropyl alcohol 4% by weight

Next, a coating liquid having the following composition was coated by a gravure plate cylinder having 60 screen lines by ohio engraving of the second color printing unit, and then dried under conditions of a hot air temperature of 70 ° C. and a speed of 60 m / min to form a top coat layer. Formed.
Coating solution;
“PET-AC Overcoat Medium No. 6” manufactured by Osaka Ink Manufacturing Co., Ltd.
Acrylic resin * 20% by weight
Nitrified cotton resin 2% by weight
Toluene 43 wt%
14% by weight methyl ethyl ketone
Acetic acid propyl ester 14% by weight
Isopropyl alcohol 7% by weight
* Acrylic resin; copolymer consisting of 80% by weight of MMA monomer and 20% by weight of n-butyl methacrylate monomer

  After winding up the film having the conductive coat layer and the top coat layer formed on one side of the film, the film is once again set on the feeding portion of the GX-II-1500, 4-color printing machine manufactured by Nakajima Seiki Co., Ltd. A conductive coat layer and a top coat layer are formed on the opposite surface of the surface on which the layer and the top coat layer are formed under the same conditions with the same coating liquid as above, and the top coat layer / conductive coat layer / PET A conductive tape composed of five layers of film / conductive coat layer / topcoat layer was produced. The surface resistance value and alcohol resistance of this conductive tape were evaluated.

[Surface resistance value]
According to the method of JIS K 6911, the measurement was performed in an atmosphere having a temperature of 20 ° C. and a humidity of 65% RH.
As a result of the measurement, the surface resistance value was 1 × 10 ⁷ Ω. Therefore, it was confirmed that it can prevent that a foreign material adheres.

[Alcohol resistance]
Methanol was included in a cotton swab, and the surface of the conductive tape was rubbed 10 times with force, and the surface was observed for gloss and erosion.
As a result of observation, there was no gloss and no appearance of being attacked by alcohol. Therefore, it was confirmed that it can withstand alcohol washing.

  Next, the conductive tape was slit to a width of 35 mm, and the wound roll was continuously fed out and sandwiched between metal rolls formed with embossing while being heated. At both ends, a diameter of 4.0 mm and a depth of 1 A hemispherical convex part and a concave part of 0.0 mm were continuously formed so as to be alternately arranged one by one.

  The conductive tape on which the convex portions and the concave portions were formed was subjected to ultrasonic cleaning while passing through the methanol liquid while being continuously drawn out, and then dried to produce a spacer tape such as TAB. The surface resistance value and alcohol resistance of this spacer tape were evaluated by the methods described above.

[Surface resistance value]
The surface resistance value was 1 × 10 ⁷ Ω. Therefore, it was confirmed that it can prevent that a foreign material adheres.

[Alcohol resistance]
There was no glossy appearance of being attacked by alcohol. Therefore, it was confirmed that it can withstand alcohol washing.

[Example 2]
As a base sheet, A-PET (Toyobo Co., Ltd. PETMAXW565SEOR) thickness 200 μm × width 640 mm × length 1000 m is set in the feeding section of GX-II-1500, 4-color printing machine manufactured by Nakajima Seiki Co., Ltd. The conductive coating layer was coated by drying under the same conditions as in Example 1 with the same coating solution as in Example 1 using a gravure plate cylinder having 60 screen lines by Helio engraving of a color printing unit.

  Next, the top coat layer was dried with a top coat coating solution exactly the same as in Example 1 and coated with a top coat layer by a gravure cylinder having 60 screen lines by ohio engraving of the second color printing unit.

  After winding up the conductive coated and top coated sheet on one side, set it once again on the feeding section of GX-II-1500, 4-color printing machine manufactured by Nakajima Seiki Co., Ltd. A conductive coat layer and a top coat layer are coated on the opposite side of the coated surface with the same coating solution as described above under the same conditions, and the top coat layer / conductive coat layer / A-PET / conductive coat layer is coated. / A conductive sheet having a conductive coat on both sides of the PET sheet of the top coat layer was prepared.

  The surface resistance value and alcohol resistance of this conductive sheet were evaluated in the same manner as in Example 1.

[Surface resistance value]
The surface resistance value was 1 × 10 ⁷ Ω. Therefore, it was confirmed that it can prevent that a foreign material adheres.

[Alcohol resistance]
There was no glossy appearance of being attacked by alcohol. Therefore, it was confirmed that it can withstand alcohol washing.

  Next, this conductive sheet was heated while feeding a roll that was slit and wound up to a width of 40 mm, and vacuum forming was performed to form a concave pocket portion of 30 mm × 30 mm × depth 3.0 mm. Next, after conducting the ultrasonic cleaning while passing through the methanol liquid while continuously feeding out the conductive sheet in which this pocket is formed, it is dried to produce a conductive embossed carrier tape for storing, transporting and mounting electronic components etc. did.

  The surface resistance value and alcohol resistance of this conductive embossed carrier tape were evaluated in the same manner as in Example 1.

[Surface resistance value]
The surface resistance value at the lower corner of the pocket portion was 1 × 10 ⁷ Ω. Therefore, it was confirmed that even at the lower corners of the pocket portion extended by molding, it is possible to prevent the foreign matter from adhering without decreasing the surface resistance.

[Alcohol resistance]
There was no glossy appearance of being attacked by alcohol. Therefore, it was confirmed that it can withstand alcohol washing.

Top view of spacer used for TAB tape Partial side view of TAB tape and spacer wound in a reel

Explanation of symbols

10 conductive tape 11 convex portion 12 concave portion 20 TAB tape

Claims (5)

A conductive coating layer made of a conductive composition containing a base sheet or a base film, carbon black provided on one or both sides of the base sheet or base film, and the conductive coating layer. and a topcoat layer, said topcoat layer, Ri Do from using MMA (methyl methacrylate) monomer 75 wt% or more copolymerized acrylic resin, the topcoat layer, the coating solution shown below A conductive material for packaging electronic parts, characterized by being formed by coating .
Coating liquid:
Acrylic resin 8-22% by weight
Nitrified cotton resin 1-3% by weight
Toluene 40-50% by weight
Methyl ethyl ketone 10-20% by weight
Acetic acid propyl ester 10-20% by weight
Isopropyl alcohol 5-10% by weight The acrylic resin is a copolymer of MMA monomer and one or more monomers selected from n-butyl methacrylate, 2-ethylhexyl methacrylate, ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate. The conductive material for packaging electronic parts according to claim 1, wherein 3. The conductive material for packaging electronic parts according to claim 1, wherein the surface resistance value is 1 × 10 ⁸ Ω or less. The substrate sheet or substrate film is a sheet or film of PET (polyethylene terephthalate), PC (polycarbonate), PP (polypropylene), PI (polyimide), PS (polystyrene) or HIPS (high impact polystyrene). The conductive material for packaging electronic parts according to claim 1, 2 or 3. A packaging container for electronic parts, characterized in that it is formed of the conductive material for packaging electronic parts according to claim 1, 2, 3 or 4.

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