JP2855821B2 - Drilling method for printed wiring boards - Google Patents

Description

The present invention relates to a method for drilling through holes in a double-sided or multilayer printed wiring board, and by disposing a water-soluble lubricant to reduce heat generation of a drill bit during drilling. It suppresses and produces high quality and high efficiency drilling.

[Conventional technology and its problems]

US Pat. No. 4,781,495 and US Pat. No. 4,929,3, US Pat.
70, these methods use a sheet of paper or the like impregnated with a mixture of glycols such as diethylene glycol and dipropylene glycol, which are solid water-soluble lubricants, rigid waxes such as fatty acids, and a nonionic surfactant. It is disclosed.

However, these methods have the drawbacks that the effect of preventing heat generation from the drill is insufficient, the impregnating ability of the porous sheet with these mixtures is poor, and that there is stickiness.

[Means for solving the problem]

As a result of intensive studies to solve the above-mentioned problems, the present invention has found a method of using a monoester of polyoxyethylene sorbitan as a water-soluble lubricant, and has completed the present invention.

That is, the present invention relates to a method in which a water-soluble lubricant is disposed on one or both sides of the laminate by performing drilling for front and back conduction in a laminate in which a metal foil is adhered to an insulator. A method for boring a printed wiring board, characterized in that the monoester of polyoxyethylene sorbitan is a monoester of polyoxyethylene sorbitan, wherein the water-soluble lubricant is a water-soluble lubricant sheet in which the monoester of polyoxyethylene sorbitan is disposed on a porous sheet. As a water-soluble lubricant sheet in which the polyoxyethylene sorbitan monoester is applied to a plastic sheet or metal foil, or as a plastic sheet or metal foil. It is to be arranged as a water-soluble lubricant sheet sandwiching sorbitan monoester, Water-soluble lubricant is a drilling method of the printed wiring board, characterized in that it is intended to place by applying a mono-ester of polyoxyethylene sorbitan the laminate.

 Hereinafter, the configuration of the present invention will be described.

The laminate in which the metal foil is bonded to the insulator of the present invention is a material used for various printed wiring boards in which the metal foil and the electrical insulator are integrated, and includes a metal foil-clad laminate, an inner layer And a multilayer metal foil-clad laminate having a printed wiring network in the inner layer, a metal foil-clad plastic film, and the like.

The monoester of polyoxyethylene sorbitan, which is a water-soluble lubricant of the present invention, is generally obtained by addition polymerization of sorbitol with ethylene oxide and then esterification with a fatty acid, and specifically, polyoxyethylene sorbitan monostearate. Rate, and the like.

As a method of disposing the water-soluble lubricant of the present invention in the laminate of the present invention, a method of simply forming a coating layer having a thickness of 0.01 to 3 mm as a water-soluble lubricant as appropriate by heating, heating or aqueous solution;
A method in which a sheet of 0.01 to 3 mm in thickness is formed by appropriately heating, heating or impregnating a water-soluble lubricant as an aqueous solution on paper, plastic nonwoven fabric, porous metal sheet, or the like;
A method in which at least one surface of plastics or metal foil is appropriately heated, heated or coated with an aqueous solution lubricant layer having a thickness of 0.01 to 3 mm as an aqueous solution, and the coated surface side is stacked; Alternatively, a method of forming an aqueous lubricant layer having a thickness of 0.01 to 3 mm as a heating or aqueous solution and laminating a sandwich sheet sandwiched between the layers may be employed. In the case of a single-sided arrangement on the laminate, the water-soluble lubricant of the present invention is preferably arranged on the drill bit side, and more preferably on both sides.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples and the like.

Example 1 Polyoxyethylene sorbitan monostearate (Nonion S-221: manufactured by NOF CORPORATION) was added to 10 pieces of paper having a thickness of 0.15 mm.
The composition was melted at 0 ° C., applied using a roll so that the applied amount was 60% by weight, and then cooled to room temperature to obtain a water-soluble lubricant sheet (hereinafter referred to as “the present sheet 1”).

Using a 1.6 mm-thick glass epoxy 6-layer plate (4 inner layers, inner copper foil thickness of 70 μm, outer layer thickness of 18 μm copper foil), drilling was performed under the following conditions.

[Drilling conditions]

・ Drill bit 0.35mmφ.・ Rotational speed 80,000rpm ・ Feed speed 1.6mm / min. ・ Number of stacked sheets 2 sheets. [Arrangement] (From the drill bit side) ・ 100μm aluminum foil / book sheet 1/6 layer board / book sheet
1 / 6-layer board / paper-phenol laminate board The results of tests for the presence or absence of stickiness and the occurrence of smear on this sheet are shown in Table 1.

After drilling, the 6-layer plate was immersed in 4N HCl at 25 ° C. for 5 minutes, and the occurrence of halos was evaluated. The results are shown in Table 2.

Comparative Example 1 100 μm aluminum foil / 6-layer plate / 6 without using this sheet
Example 1 except that the arrangement of the laminated board / paper phenol laminate was adopted.
Tables 1 and 2 show the results obtained in the same manner as described above.

Comparative Example 2 670 ml of PEG200 trihydroxystearin was heated to 54 ° C.
250 ml of dipropylene glycol was added thereto and mixed.
80 ml (Cen) was added and mixed.

60% by weight of the mixture obtained above at 60 ° C in 0.15 mm thick paper
And then cooled to room temperature to obtain a water-soluble lubricant sheet (hereinafter referred to as "sheet 2").

Tables 1 and 2 show the results obtained in the same manner as in Example 1 except that the sheet 2 was used instead of the sheet 1.

Example 2 Polyoxyethylene sorbitan monostearate was added to 10
After melting at 0 ° C and applying it to one side of a 100 μm thick aluminum foil to a thickness of 0.3 mm, a thickness of 1
A 00 μm aluminum foil was placed and cooled to room temperature to obtain a water-soluble lubricant sheet (hereinafter referred to as “the present sheet 2”).

The results are shown in Tables 1 and 2 in the same manner as in Example 1 except that the arrangement was changed from the drill bit side to the present sheet 2 / 6-layer board / 6-layer board / paper phenol laminate.

[Operation and Effect of the Invention] As described above, as is clear from the detailed description of the invention and the examples and comparative examples, the method using the water-soluble lubricant of the present invention is easy to handle because there is no stickiness, and also has a drill hole. The properties are improved, and the industrial practicality is extremely high.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H05K 3/00, 3/46 B23B 41/00 B23Q 11/10 B01F 17/00-17/56

Claims (5)

(57) [Claims] 1. A method in which a water-soluble lubricant is placed on one or both surfaces of a laminate in which a metal foil is adhered to an insulator, and drilling for front and back conduction is performed on one or both sides of the laminate. A method for boring a printed wiring board, characterized by being a monoester of oxyethylene sorbitan. 2. The method according to claim 1, wherein the water-soluble lubricant is arranged as a water-soluble lubricant sheet in which the polyoxyethylene sorbitan monoester is arranged on a porous sheet. 3. A perforated printed wiring board according to claim 1, wherein said water-soluble lubricant is arranged as a water-soluble lubricant sheet obtained by applying said polyoxyethylene sorbitan monoester to a plastic sheet or metal foil. Processing method. 4. The hole in a printed wiring board according to claim 1, wherein said water-soluble lubricant is arranged as a water-soluble lubricant sheet comprising said polyoxyethylene sorbitan monoester sandwiched between plastic sheets or metal foil. Dawn processing method. 5. The method according to claim 1, wherein the water-soluble lubricant is disposed by applying the polyoxyethylene sorbitan monoester to the laminate.