JP2003127013A - Drilling method - Google Patents

Abstract

(57) [Summary] (Corrected) [Problem] An entry sheet for drilling with excellent hole shape and excellent hole positioning accuracy even in drilling using a drill bit of 0.3 mmφ or less, and the drill sheet. Provide high quality drilling method using drilling entry sheet. SOLUTION: An entry sheet for drilling holes for a printed wiring board material, which is formed by forming a thermosetting resin coating film having an average thickness of 1 to 10 μm on one side of an aluminum foil having a thickness of 20 to 200 μm; A method for forming a hole in a printed wiring board material, wherein an aluminum foil side of an entry sheet for drilling is placed in contact with a printed wiring board material, and drilling is performed from a resin side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling operation in the field of printed wiring board materials, and relates to a drilling method which is excellent in productivity and hole quality.

[0002]

2. Description of the Related Art When a printed wiring board material is subjected to drilling for conduction between the front and back, an aluminum foil has been generally used as an entry sheet.
In recent years, for the purpose of improving the hole wall condition and the hole position accuracy of the obtained holes, a method of making holes using a sheet made of polyethylene glycol or polyether ester and a water-soluble lubricant is disclosed in JP-A-4-92494 and JP-A-4-92494. -344297, it has been put to practical use as a drilling punching process for various printed wiring board materials, as an aluminum foil composite sheet for punching, in which the organic material layer is formed on one surface of the aluminum foil.

On the other hand, with respect to the drill bit, it is indispensable to reduce the bit diameter as the density of the printed wiring board material increases, but at the same time, the number of printed wiring board materials to be drilled is overlapped. Is increased,
Applying the aluminum foil composite sheet for punching,
As the bit diameter used became smaller, the drill bit was more likely to break, and further improvement was necessary to improve productivity in extremely small diameter drill applications.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to a drill hole which suppresses breakage of a drill bit when punching a plurality of printed wiring board materials with a very small diameter drill and is excellent in hole quality. It provides the dawn processing method.

[0005]

Means for Solving the Problems The inventors of the present invention, when stacking a plurality of printed wiring board materials and performing drilling at the same time, attach a sheet containing a water-soluble polymer to the printed wiring board material in advance. After sticking, by drilling the drill bit, the effect of reducing shock and heat due to friction of the drill bit is produced, and as a result, the drill bit is less likely to break and at the same time the drilled printed wiring board material The inventors have found that the hole quality is improved and have completed the present invention.

That is, according to the present invention, a plurality of printed wiring board materials are superposed, and an aluminum foil composite sheet (A) for punching, in which an organic layer containing a water-soluble compound is formed on one surface of an aluminum foil on the upper surface thereof. , And at the same time performing drilling processing, a sheet (C) containing a water-soluble polymer (B) in advance in one or more printed wiring board materials which does not exceed half of the entire printed wiring board material. Is adhered, and then drilling is performed from the aluminum foil composite sheet (A) surface side for punching, which is a method for punching a printed wiring board material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum foil composite sheet (A) for punching used in the present invention is a composite sheet in which an organic material layer containing a water-soluble compound is formed on one surface of an aluminum foil, It is not particularly limited. Examples of the water-soluble compound used for the punching aluminum foil composite sheet (A) include polyethylene glycol, polyvinyl alcohol, polyamide, polyvinylpyrrolidone, etc., and one kind or two or more kinds are appropriately used in combination. It is also possible. The thickness of the organic material layer containing the water-soluble compound is preferably 20 to 500 μm.

Aluminum foil composite sheet for punching (A)
Examples of the material of the aluminum foil used in the above include pure aluminum-based, alloy aluminum-based, hard, semi-hard, and soft aluminum, and it is also possible to use one kind or a combination of two or more kinds as appropriate. The thickness of the aluminum foil is preferably 20 to 500 μm.

The water-soluble polymer (B) used in the present invention refers to 100 g of water at room temperature and atmospheric pressure.
There is no particular limitation as long as it is a polymeric substance capable of dissolving 1 g or more. Although these are well known, more preferable examples include polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, polyvinyl alcohol, sodium polyacrylate, polyacrylamide, polyvinylpyrrolidone, carboxymethylcellulose, polytetramethylene glycol, poly An ether ester (D) is mentioned, and it is also possible to use 1 type (s) or 2 or more types, mixing them suitably. The melting point or softening point of the water-soluble polymer (B) is 20
Those having a temperature of 0 ° C or lower are selected, and those having a temperature of 150 ° C or lower are preferably used.

The polyether ester (D) which is a preferred embodiment of the present invention is not particularly limited as long as it is an esterified product of polyalkylene oxide. As typical examples, polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, glycols exemplified by polytetramethylene glycol and copolymers thereof, or a polymer of ethylene oxide, phthalic acid, and isophthalic acid. , Terephthalic acid, sebacic acid, etc., and their dimethyl esters, diethyl esters, etc., polyvalent carboxylic acids exemplified by pyromellitic acid anhydride, etc., resins obtained by reacting them with anhydrides, or their esters, etc. Named 1
It is also possible to use one kind or a mixture of two or more kinds as appropriate.

The water-soluble polymer (B) used in the present invention can be mixed with the water-soluble polymer (B) to the extent that it can be formed into a sheet, and other polymer substances, organic substances,
It is also possible to mix an inorganic filler. These are well known and are not particularly limited as long as they are commonly used. Specifically, as the polymer substance, a thermoplastic resin such as polyvinyl acetate or polyamide,
Thermosetting resins such as polyurethane, cellulose and the like, organic substances such as polyoxyethylene ether, polyoxyethylene ester, esters of glycerin and sorbit, and inorganic fillers such as calcium carbonate, talc, mica, and hydroxide. Examples include aluminum, copper oxide, glass fine powder, and the like, and it is also possible to use one kind or two or more kinds as appropriate as a mixture.

The proportion of the water-soluble polymer (B) in the sheet (C) containing the water-soluble polymer (B) is 20 wt.
% Or more is preferable, and 40 wt% or more is more preferable. The sheet (C) containing the water-soluble polymer (B) used in the present invention is a film for reinforcing or protecting the sheet (C) containing the water-soluble polymer (B), if necessary. It is also possible to use, etc., and specific examples of the film include polyester and polyethylene terephthalate.

The method for producing the sheet (C) containing the water-soluble polymer (B) is not particularly limited as long as it is a known method used industrially. Specifically, a water-soluble polymer and, if necessary, other substances are used in a stirrer, a kneader, or other mixing means, and appropriately heated or heated to form a homogeneous mixture, and the roll method or the curtain coating method is used. And the like, a method of forming a coating layer on a film or the like; a method of forming the mixture into a sheet having a desired thickness in advance using a press, a roll, a T-die extruder, or the like. The thickness of the sheet (C) containing the water-soluble polymer (B) used in the present invention is 1
It is in the range of 0 to 200 μm, preferably 20 to 100
It is in the range of μm.

If the thickness of the sheet (C) containing the water-soluble polymer (B) is less than 10 μm, the effect of suppressing breakage of the drill bit is small, and if it is 200 μm or more, the resin is wrapped around the drill bit, which is not preferable. .

In the present invention, the sheet (C) containing the water-soluble polymer (B) used must be adhered to the printed wiring board material. The method of sticking is not particularly limited as long as the sheet (C) containing the water-soluble polymer (B) can be stuck to the printed wiring board material. Examples of a more suitable method for adhesion include heating, pressurization, and an adhesive, and it is also possible to use one type or two or more types in combination.

Specific examples of the pressure-sensitive adhesive include polyvinyl alcohol-based, polyurethane-based, polyolefin-based, carboxycellulose-based and polyglycol-based pressure-sensitive adhesives. When the sheet (C) containing the water-soluble polymer (B) used in the present invention is not adhered to the printed wiring board material and is simply sandwiched between the printed wiring board materials and drilled, water solubility is obtained. The cutting powder accumulates between the sheet (C) containing the polymer (B) and the printed wiring board material, resulting in generation of burrs and deterioration of the obtained pore quality, which does not meet the object of the present invention.

The drilling method of the present invention uses one or more printed wiring boards that do not exceed half of all printed wiring board materials (eg, copper clad laminates and multilayer boards) that are simultaneously drilled. A sheet (C) containing a water-soluble polymer (B) in advance is adhered to the material by heating, pressurizing, or an adhesive agent, and a sheet adhesive printed wiring board material is combined with an ordinary printed wiring board material. Further, the aluminum foil composite sheet (A) for punching is arranged on the upper surface, and the drilling process is performed from the surface side of the aluminum foil composite sheet (A) for punching.

The sheet (C) containing the water-soluble polymer (B) is preferably adhered to one surface of the printed wiring board material and arranged so that the sheet surface is the upper surface. The sheet adhesive printed wiring board material is preferably arranged at a position not in contact with the aluminum foil composite sheet (A) for punching, and further arranged at a position not contacting the sheet adhesive printed wiring board material, It is more suitable.

The number of the printed wiring board materials to be arranged on the front and back surfaces of the sheet adhesive printed wiring board material is not particularly limited if they are the same or different on the front and back sides, and the number is the thickness of the printed wiring board material to be used. Although it depends on the material, the drilling conditions, etc., usually about 1 to 3 sheets is preferably used.

The present invention will be described in detail below by showing Examples and Comparative Examples.

Example 1 Polyethylene glycol having a number average molecular weight of 1000 4
After dissolving and mixing 0 part by weight and 60 parts by weight of a water-soluble polyether resin (trade name: Melpol F-220, manufactured by Sanyo Kasei Co., Ltd.) in water / methanol, it was coated on a PET film and heated at 130 ° C. And dried to prepare two sheets of a water-soluble polymer-containing sheet having a thickness of 30 μm. Separately, five double-sided copper-clad (copper foil thickness: 18 μm) glass epoxy laminates (a) having a thickness of 0.1 mm were prepared, and two of them were separately prepared to contain the water-soluble polymer. The water-soluble polymer side of the sheet was placed on one side of the laminate (a) so as to face each other, and both were adhered by a heating roll to prepare two sheet adhesive laminates (b).

The remaining three ordinary laminated plates (a) and the two obtained sheet adhesive laminated plates (b) are alternately arranged so that the sheet surface of the sheet adhesive laminated plates (b) faces upward. Then, a polyethylene glycol-based aluminum foil composite sheet for punching (product name: LE700, manufactured by Mitsubishi Gas Chemical) is placed on the upper surface, and a backing plate (paper phenol laminated plate) is placed on the lower surface, and a drill bit: 0 .1 mmφ, rotation speed: 150,000 rpm, feed rate: 1.1 m / min. Table 1 shows the results of the hole evaluation performed by drilling under the conditions of.

Example 2 Polyethylene glycol having a number average molecular weight of 8000 5
0 parts by weight and 50 parts by weight of polyethylene glycol / dimethyl terephthalate polycondensate (trade name: Paogen PP-15, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were kneaded and mixed at a temperature of 140 ° C., and then formed into a sheet by an extruder, A water-soluble polymer-containing sheet having a thickness of 80 μm was prepared. A polyvinyl alcohol-based pressure-sensitive adhesive was applied to one surface of the obtained water-soluble polymer-containing sheet, and the pressure-sensitive adhesive surface side was a 0.1 mm thick double-sided copper-clad (copper foil thickness: 12 μm) glass substrate screw. The maleimide-triazine-based laminate (c) was placed on one side of the laminate so as to face each other, and both were adhered by a heating roll to prepare a sheet adhesive laminate (d).

The sheet adhesive laminate (d) thus obtained was superposed on one ordinary laminate (c) with the sheet surface facing upward, and then the ordinary laminate ( c) 2
A stack of sheets, a polyethylene glycol-based aluminum foil composite sheet for perforation (LE700) is placed on the upper surface, and a backing plate (paper phenol laminated sheet) is placed on the lower surface. Drilling is performed under the same conditions as in Example 1. Table 1 shows the results of processing and hole evaluation.

Example 3 Polyethylene glycol having a number average molecular weight of 1000 3
5 parts by weight, water-soluble polyether resin (Melpol F
-220) 45 parts by weight and 20 parts by weight of talc (trade name: Microace P-3, manufactured by Nippon Talc) are mixed in water / methanol, and then coated on a PET film.
It was dried at 0 ° C. to obtain a water-soluble polymer-containing sheet having a thickness of 20 μm. The water-soluble polymer surface of the obtained water-soluble polymer-containing sheet was made to face one surface of a 0.15 mm-thick double-sided copper clad (copper foil thickness: 12 μm) glass-based bismaleimide-triazine-based laminate (e). And the both were adhered by a heating roll to prepare a sheet adhesive laminate (f). With the sheet surface of the obtained sheet adhesive laminate (f) facing upward, one ordinary laminate (e) was placed on each of the front and back surfaces, and a polyethylene glycol-based aluminum for punching was placed on this upper surface. Foil composite sheet (LE700)
Is placed, a backing plate (paper phenol laminated plate) is placed on the lower surface, and drilling is performed under the same conditions as in Example 1,
The results of the pore evaluation are shown in Table 1.

Comparative Example 1 A double-sided copper-clad (copper foil thickness: 12 μm) glass-based bismaleimide-triazine-based laminate (c) having a thickness of 0.1 mm was used as 3
Laminate the sheets and place a polyethylene glycol-based aluminum foil composite sheet (LE700) for punching on the upper surface,
A backing plate (paper phenol laminated plate) was placed on the lower surface, drilling was performed under the same conditions as in Example 1, and the results of hole evaluation are shown in Table 1.

Comparative Example 2 Comparative Example 1 was repeated except that four 0.1 mm thick double-sided copper clad (copper foil thickness: 12 μm) glass-based bismaleimide-triazine-based laminates (c) were stacked. Drill drilling was performed in the same manner as above, but the drill bit broke in the middle, and the process was retried, but it was the same.

Comparative Example 3 Three sheet adhesive laminates (b) obtained in Example 1 were laminated, one ordinary laminate (a) was laminated on the upper surface thereof, and polyethylene glycol-based perforations were further formed on the upper surface thereof. Aluminum foil composite sheet (LE700) for use was placed, a backing plate (paper phenol laminated plate) was placed on the lower surface, and drilling was performed under the same conditions as in Example 1, but the drill bit broke in the middle. Occurred and tried again, but it was the same.

[0028]

(Test Method) Pore Wall Roughness: Each laminated plate after 2000 hits was plated with 20 holes, and then a cross-section was observed with a microscope to measure the roughness of the hole wall and the average value and the maximum value. value

[0030]

According to the drilling method of the present invention,
When drilling multiple printed wiring board materials, it suppresses bit breakage due to impact of the drill bit, and at the same time improves the quality of the drilled holes. Since the number of stacked plate materials can be increased and the productivity can be significantly improved, the industrial practicality is extremely high.

[Brief description of drawings]

FIG. 1 is a material configuration diagram in Examples and Comparative Examples.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Nagai             6-1, 1-1 Shinjuku, Katsushika-ku, Tokyo Mitsubishi tile             The chemical company Tokyo factory F-term (reference) 3C036 AA01                 3C060 AA11 BA05 BH01

Claims (7)

[Claims] 1. An aluminum foil composite sheet (A) for perforation, wherein a plurality of printed wiring board materials are stacked, and an aluminum foil composite sheet (A) for perforation, in which an organic material layer containing a water-soluble compound is formed on one surface of an aluminum foil, is arranged. When performing drilling at the same time, after adhering the sheet (C) containing the water-soluble polymer (B) in advance to one or more printed wiring board materials that do not exceed half of the entire printed wiring board material, A method for drilling a hole in a printed wiring board material, which comprises performing a drilling process from the surface side of the aluminum foil composite sheet (A) for drilling. 2. As a method for adhering the sheet (C) containing the water-soluble polymer (B) to a printed wiring board material, one or two selected from the group consisting of heating, pressurizing and adhesives. The drilling method according to claim 1, wherein one or more kinds are used. 3. A sheet (C) containing the water-soluble polymer (B) is adhered to one surface of a printed wiring board material, and is arranged so that the sheet surface is the upper surface.
The method of drilling a hole according to claim 2. 4. A printed wiring board material to which the sheet (C) containing the water-soluble polymer (B) is adhered is arranged at a position where it does not come into contact with the aluminum foil composite sheet (A) for punching. The drill drilling method according to claim 1, wherein 5. A print in which a sheet (C) containing the water-soluble polymer (B) is adhered to a printed wiring board material to which a sheet (C) containing the water-soluble polymer (B) is adhered. The drilling method according to claim 4, wherein the method is arranged at a position where it does not contact the wiring board material. 6. The water-soluble polymer (B) is polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, polyvinyl alcohol, sodium polyacrylate, polyacrylamide, polyvinylpyrrolidone, carboxymethylcellulose, polytetramethylene glycol, poly. The drill drilling method according to any one of claims 1 to 5, wherein the method is one or more selected from the group consisting of ether ester (D). 7. The method according to claim 6, wherein the sheet (C) containing the water-soluble polymer (B) has a thickness of 10 to 200 μm.