Entry sheet for drilling

Patent metadata

Field	Value
Publication number	US-10159153-B2
Application number	US-201314389170-A
Country	US
Kind code	B2
Filing date	Mar 22, 2013
Priority date	Mar 27, 2012
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

The present invention provides an entry sheet for drilling excellent in hole position accuracy compared with the conventional entry sheet for drilling. Such an entry sheet for drilling is an entry sheet for drilling comprising metallic support foil and a layer comprising a resin composition formed on at least one surface of the metallic support foil, in which the resin composition contains a resin and 70 parts by mass to 130 parts by mass of molybdenum disulfide based on 100 parts by mass of the resin, and the layer comprising the resin composition has a thickness in a range from 0.02 to 0.3 mm.

First claim

The invention claimed is:

1. An entry sheet for drilling comprising:
a first side and a second side opposite of the first side wherein,
a metallic support foil as an outermost layer on the first side of the entry sheet; and
a layer comprising a resin composition as an outermost layer on the second side of the entry sheet,
wherein the resin composition comprises a water-soluble resin and 70 parts by mass to 130 parts by mass of molybdenum disulfide as a solid lubricant based on 100 parts by mass of the resin, the water-soluble resin selected from the group consisting of polyethylene oxide, polypropylene oxide, polyalkylene glycol, polyethylene glycol, polypropylene glycol, and combinations thereof, the molybdenum disulfide in the form of solid particles dispersed in the resin composition, and
the layer comprising the resin composition has a thickness in a range from 0.02 to 0.3 mm.

2. The entry sheet for drilling according to claim 1 , wherein the molybdenum disulfide has an average particle diameter of 1 to 20 μm.

3. The entry sheet for drilling according to claim 1 , wherein the molybdenum disulfide has a purity of 85 mass % or more.

4. The entry sheet for drilling according to claim 1 , wherein the resin composition comprises a water-insoluble lubricant that is not a solid lubricant.

5. The entry sheet for drilling according to claim 4 , wherein the water-insoluble lubricant that is not a solid lubricant comprises one or two or more compounds selected from the group consisting of amide compounds, aliphatic acid compounds, aliphatic acid ester compounds, aliphatic hydrocarbon compounds, and higher aliphatic alcohols.

6. The entry sheet for drilling according to claim 1 , wherein the metallic support foil has a thickness in a range from 0.05 to 0.5 mm.

7. The entry sheet for drilling according to claim 1 , further comprising a primer layer being a resin film between the metallic support foil and the layer comprising the resin composition, wherein the primer layer has a thickness in a range from 0.002 to 0.02 mm.

8. The entry sheet for drilling according to claim 7 , wherein the primer layer comprises a solid lubricant comprising molybdenum disulfide.

9. The entry sheet for drilling according to claim 8 , wherein the primer layer comprises 1 part by mass to 50 parts by mass of the molybdenum disulfide based on 100 parts by mass of a composition constituting the primer layer.

10. The entry sheet for drilling according to claim 7 , wherein the resin contained in the primer layer contains one or two or more thermosetting resins selected from the group consisting of epoxy resins and cyanate resins.

11. The entry sheet for drilling according to claim 7 , wherein the resin contained in the primer layer contains one or two or more thermoplastic resins selected from the group consisting of urethane polymers, vinyl acetate polymers, vinyl chloride polymers, polyester polymers, and acrylic polymers, and copolymers of these polymers.

12. The entry sheet for drilling according to claim 7 , wherein the resin contained in the primer layer contains one or two or more adhesive resins selected from the group consisting of melamine resins, urea resins, phenol resins, chloroprene rubber, nitrile rubber, styrene butadiene rubber, and silicone rubber.

13. The entry sheet for drilling according to claim 1 , wherein the layer comprising the resin composition is formed on at least one surface of the metallic support foil by a coating method, the layer comprising the resin composition is obtained by conducting coating on the at least one surface of the metallic support foil with a solution in which the resin composition is dissolved or dispersed in a mixed solvent of water and a solvent having a boiling point lower than the boiling point of water, and the solvent having a boiling point lower than the boiling point of water contains one or two or more solvents selected from the group consisting of alcohols, methyl ethyl ketone, acetone, tetrahydrofuran, and acetonitrile.

14. The entry sheet for drilling according to claim 13 , wherein a blending ratio of the water to the solvent having a boiling point lower than the boiling point of water contained in the mixed solvent is in a range from 90/10 to 50/50 on a mass basis.

15. The entry sheet for drilling according to claim 1 , the entry sheet to be used for hole boring processing with a drill bit having a diameter of 0.2 mm or less.

16. The entry sheet for drilling according to claim 1 , the entry sheet to be used for drilling processing of a laminated board or a multi-layer board.

17. The entry sheet for drilling according to claim 1 , the resin composition comprising 80 parts by mass to 130 parts by mass of molybdenum disulfide based on 100 parts by mass of the resin.

18. A method for drilling a printed wiring board material, comprising the steps of:
arranging the entry sheet of claim 1 on at least a surface of the printed wiring board material,
the entry sheet being arranged so that the metallic support foil side makes contact with the printed wiring board material; and
conducting a drilling process starting from a surface of the layer comprising the resin composition through the entry sheet.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Kamei Takayuki
• Matsuyama Yousuke
• Hasaki Takuya

Classifications

• B26F1/16 Primary

  Perforating by tool or tools of the drill type · CPC title

• B23B2224/16

  Molybdenum disulphide · CPC title

• H05K3/0047 Primary

  Drilling of holes · CPC title

• H05K2203/0214

  Back-up or entry material, e.g. for mechanical drilling · CPC title

• Y10T428/256

  Heavy metal or aluminum or compound thereof · CPC title