JP2013099848A - Metal foil composite sheet for drilling, and drilling machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal foil composite sheet for drilling, having an excellent hole shape and high hole position precision of a drill bit of 0.3 mmφ or less, and a high-quality drilling method using the metal foil composite sheet for drilling, in the drilling process of a printed wiring material.SOLUTION: In the metal foil composite sheet for drilling for a printed wiring material, with an organic layer formed on one surface of the metal foil, the organic layer is made of water-soluble polymer and has a thickness of 0.02-1.0 mm, and the metal foil is an aluminum foil having aluminum purity of 99.5% or higher.

Description

  The present invention relates to a metal foil composite sheet for punching used in the field of printed wiring materials, and to a punching method that enables high-quality punching.

  When drilling holes for front and back conduction on printed wiring materials, water-soluble lubricants, specifically, glycols such as diethylene glycol and dipropylene glycol, and rigid waxes such as fatty acids, Although a method of arranging a sheet impregnated with paper or the like with a mixture of an ionic surfactant is disclosed (see, for example, Patent Documents 1 and 2), these methods are insufficient in the effect of preventing drill heat generation. Or the impregnation property of the mixture into the porous sheet is poor, and there are further disadvantages such as stickiness.

  As a solution to these problems, JP-A-6-344297 proposes a drilling method using a sheet composed of a polyether ester and a water-soluble lubricant. However, in this processing method, the quality of the drill hole is improved and the stickiness is increased. Although improvement was observed, there was a tendency for hole position accuracy to decrease as the drill bit diameter used decreased, and improvement was required for application to extremely small diameter drill applications.

US Pat. No. 4,781,495 US Pat. No. 4,929,370

  The present invention uses a metal foil composite sheet for drilling that has excellent hole shape and good hole positioning accuracy even in drilling of a drill bit of 0.3 mmφ or less, and the metal foil composite sheet for drilling. Provide high quality drilling method.

  The present inventors have found that by using a metal foil composite sheet for drilling comprising a water-soluble polymer layer and an aluminum foil of a specific aluminum purity, a good hole shape and excellent hole position accuracy can be obtained, The present invention has been completed.

  That is, the present invention is a perforated metal foil composite sheet in which an organic layer is formed on one side of a metal foil, and the organic layer is a layer having a thickness of 0.02 to 1.0 mm made of a water-soluble polymer. The metal foil is an aluminum foil having an aluminum purity of 99.5% or more, and is a metal foil composite sheet for punching for printed wiring materials, and the metal foil surface of the metal foil composite sheet for punching The printed wiring material drilling method is characterized in that the side is arranged in contact with the printed wiring material, and drilling is performed from the sheet surface side.

  The drilling method using the metal foil composite sheet for drilling of the present invention includes the effect of reducing the frictional heat of the drill bit when drilling with the water-soluble polymer, and the impact mitigation and drilling when drilling with the high-purity aluminum foil. By improving the biting property of the bit, high-quality drilling with excellent hole shape and hole position accuracy becomes possible, and industrial practicality is extremely high.

  The water-soluble polymer used in the present invention is not particularly limited as long as it is a polymer compound that dissolves 1 g or more in 100 g of water at room temperature and normal pressure. Representative examples include polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, carboxymethyl cellulose, polytetramethylene glycol, and fatty acid ester. It is also possible to use 1 type or 2 types or more mixed appropriately. The melting point or softening point of the water-soluble polymer is selected in the range of 30 to 200 ° C, preferably in the range of 40 to 150 ° C.

  The polyether ester (A) which is a preferred embodiment of the present invention is not particularly limited as long as it is an esterified product of polyalkylene oxide. Typical examples include polyethylene glycol, polyethylene oxide, polypropylene glycol, polytetramethylene glycol, glycols exemplified by polypropylene oxide and copolymers thereof, or polymers of ethylene oxide, and phthalic acid, isophthalic acid. Terephthalic acid, sebacic acid, and the like, and dimethyl esters, diethyl esters and the like, polymellitic carboxylic acids exemplified by pyromellitic acid anhydride, the anhydrides, or resins obtained by reacting the esters, etc. It is also possible to use one kind or a mixture of two or more kinds as appropriate. Moreover, it is also possible to mix and use the polyether ester (A) with polyethylene oxide having a number average molecular weight of 10,000 or more.

  The blending amount of the polyether ester (A) is in the range of 20 to 90 parts by weight with respect to 100 parts by weight in total of the blending amount of the polyether ester (A) and the water-soluble lubricant (B) described later, and 20 parts by weight. If the ratio is less than 90 parts by weight, the strength of the sheet is insufficient, and if it exceeds 90 parts by weight, the wettability is insufficient, which is not suitable for the purpose of the present invention.

  The water-soluble lubricant (B) which is a preferred embodiment of the present invention specifically includes polyethylene glycol having a number average molecular weight of 1000 to 9000; polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, Polyoxyethylene monoethers exemplified by polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, etc .; polyoxyethylene monostearate, polyoxyethylene sorbitan monostearate; hexaglycerin mono Polyglycerol monostearates exemplified by stearate, decahexaglycerol monostearate and the like; polyoxyethylenepropylene block polymers are included, and one or two It is also possible to use a mixture of seeds or more as appropriate. The blending amount of the water-soluble lubricant (B) is in the range of 10 to 80 parts by weight with respect to the total blending amount of the polyether ester (A) and the water-soluble lubricant (B), and less than 10 parts by weight. If the viscosity becomes too high and exceeds 80 parts by weight, the sheet becomes brittle, which is not preferable.

  The metal foil used in the present invention is not particularly limited as long as the aluminum foil has an aluminum purity of 99.5% or more, but an aluminum foil having a purity of 99.7% or more is more preferable. The use of high-purity aluminum foil improves the impact and bite of the drill bit, and combined with the effect of reducing the heat generated by the frictional heat of the drill bit by the water-soluble polymer, position accuracy when drilling And the hole quality can be greatly improved. Specific examples of the aluminum foil include 1050, 1070, 1085 and the like defined in JIS H-4160, and 1070, 1085 are particularly preferable. The thickness of the aluminum foil is in the range of 50 to 500 μm, and if it is less than 50 μm, burrs of the substrate are likely to be generated, and if it exceeds 500 μm, it is difficult to discharge the generated chips.

  As a manufacturing method of the metal foil composite sheet for punching, if it is a well-known method used industrially, there will be no restriction | limiting in particular. Specifically, the water-soluble polymer is appropriately heated or heated using a roll, kneader, or other kneading means, and is preferably a uniform mixture having a viscosity of about 50,000 to 200,000 centipoise (150 ° C.). And a method of forming a coating layer on the metal foil by a roll method or a curtain coating method; the mixture is formed into a sheet having a desired thickness in advance using a press, a roll, or a T-die extruder. This is exemplified by a method in which this is laminated on an aluminum foil, heated and pressurized with a press or roll, and bonded with an adhesive or the like as necessary.

  The thickness of the metal foil composite sheet for punching is in the range of 0.02 to 1.0 mm. If the thickness is less than 0.02 mm, the quality of the obtained hole is deteriorated. Wrapping occurs, which is not desirable

  In the drilling method of the present invention, the metal foil composite sheet for punching is provided on the uppermost surface of a printed wiring material, for example, a copper-clad laminate, a multilayer board, etc., and the metal foil surface side of the metal foil composite sheet for drilling is It arrange | positions so that a printed wiring material may be touched, and drills a hole from the sheet | seat surface side of this metal foil composite sheet for drilling.

Example 1
Polyethylene glycol / dimethyl terephthalate polycondensate (trade name: Paogen PP-15, manufactured by Daiichi Kogyo Seiyaku) 50 parts by weight, polyoxyethylene monostearate (trade name: Nonion S-40, manufactured by Nippon Oil & Fats) 50 parts by weight After kneading in a nitrogen atmosphere at a temperature of 150 ° C. using a kneader, a water-soluble polymer sheet having a thickness of 0.1 mm was prepared with an extruder. This water-soluble polymer sheet was laminated on one side of a 100 μm-thick aluminum foil (material: 1070, aluminum purity: 99.7%) and adhered using a heating roll to obtain an aluminum foil composite sheet for drilling. . The obtained aluminum foil composite sheet for drilling is placed on the top surface of three glass epoxy plates having a thickness of 0.1 mm, a backing plate (paper phenol laminate) is placed on the bottom surface, and a drill bit: 0.1. 1 mmφ, rotation speed: 150,000 rpm, feed rate: 2.5 μ / rev. Table 1 shows the results of drilling and drilling of 2000 hits under the conditions described above.

Example 2
Polyethylene glycol dimethyl terephthalate polycondensate (trade name: Paogen PP-15) 70 parts by weight, 30 parts by weight of polyethylene glycol having a number average molecular weight of 8000 were used, and water-soluble with a thickness of 0.1 mm in the same manner as in Example 1. A functional polymer sheet was prepared. This water-soluble polymer sheet was placed on one side of a 100 μm thick aluminum foil (material: 1085, aluminum purity: 99.85%) and adhered using a heating roll to obtain an aluminum foil composite sheet for punching. . The obtained aluminum foil composite sheet for punching was subjected to hole evaluation in the same manner as in Example 1, and the results are shown in Table 1.

Example 3
Polyethylene glycol dimethyl terephthalate polycondensate (trade name: Paogen PP-15) 20 parts by weight, polyethylene oxide (trade name: Alcox R-150, manufactured by Meisei Chemical) 10 parts by weight, polyoxyethylene propylene block polymer (trade name) : Pronon 208, manufactured by NOF Corporation) Using 70 parts by weight, an aluminum foil composite sheet for punching was obtained in the same manner as in Example 1. The obtained aluminum foil composite sheet for punching was subjected to hole evaluation in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1
The water-soluble polymer sheet obtained in Example 1 is laminated on one side of a 100 μm thick aluminum foil (material: IN30, aluminum purity: 99.3%), and bonded using a heating roll to form aluminum for punching. A foil composite sheet was obtained. The obtained aluminum foil composite sheet for punching was subjected to hole evaluation in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2
As a result of drilling under the same drilling conditions as in Example 1 except that aluminum foil (material: IN30) having a thickness of 150 μm was used instead of the aluminum foil composite sheet for drilling, The drill bit was broken, and it was tried again.

(Test method)
-Hole wall roughness: An average value and a maximum value (20 holes after 2000 hits) obtained by performing cross-sectional observation with a microscope after the sample was plated, and measuring the roughness of the hole wall.
-Hole position accuracy: For 2000 hits, the average value and the maximum value of values obtained by measuring the amount of deviation between the hole position reference value and the hole position of the lower plate after drilling with a coordinate measuring machine.

Claims (5)

In a metal foil composite sheet for punching in which an organic material layer is formed on one side of a metal foil, the organic material layer is a layer having a thickness of 0.02 to 1.0 mm made of a water-soluble polymer, and the metal foil is made of aluminum. A perforated metal foil composite sheet for printed wiring materials, wherein the aluminum foil has a purity of 99.5% or more. 2. The pore according to claim 1, wherein the water-soluble polymer is a composition comprising 20 to 90 parts by weight of a polyether ester (A) and 10 to 80 parts by weight of a water-soluble lubricant (B) as essential components. Metal foil composite sheet for dawn. 3. The metal foil composite sheet for punching according to claim 2, wherein polyethylene oxide having a number average molecular weight of 10,000 or more is mixed with the polyether ester (A). The water-soluble lubricant (B) is a polyethylene glycol having a number average molecular weight of 1000 to 9000, polyoxyethylene monoether, polyoxyethylene ester, polyoxyethylene sorbitan monostearate, polyglycerin monostearate, polyoxyethylene propylene The perforated metal foil composite sheet according to claim 2, wherein the composite sheet is one or more selected from the group consisting of block polymers. 5. A printed wiring, wherein the metal foil surface side of the punched metal foil composite sheet according to claim 1 is disposed in contact with the printed wiring material and drilled from the sheet surface side. Material drilling method.