JP2000218599A - Resin sheet for boring work and boring method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of heat caused by frictional heat of drill gear at the time of boring work and peeling or damage of copper foil of copper applied lamination board by using a resinous sheet made from a polyester resin composition composed of a mixture of a specified quantity of granule inorganic compound and a specified quantity of lubricant. SOLUTION: A resin sheet for boring work is composed of a polyester resin composition is prepared by mixing 3-50 pts.wt. of granular inorganic compound and 1-10 pts.wt. of soluble lubricant with 1O0 pts.wt. of thermoplastic polyester resin. By the use of the resin sheet a copper applied lamination board is bored. Accordingly, the purpose is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the drilling of copper-clad laminates and plastic plates for drilling holes in copper-clad laminates for double-sided or multi-layer printed circuit boards and plastic plates for precision equipment. A resin sheet that is placed on the insertion surface side of the hole to prevent heat generation due to the frictional heat of the drill teeth during drilling and to prevent the copper foil of the copper-clad laminate from being turned upside down, providing high-quality, high-efficiency drilling And a punching method using the sheet.

[0002]

2. Description of the Related Art In recent years, various electronic devices and the like have become lighter, thinner and shorter, and the density of printed wiring boards mounted thereon has been increasing. The diameter of the through hole for conduction formed in the hole has been steadily miniaturized, and has shifted from 0.4 mmφ to 0.15 mmφ. Also, in various applications of precision instruments, products with minute holes are increasing, and requirements for hole diameter accuracy and the like are increasing more and more.

Conventionally, when drilling holes in a product such as a multilayer printed circuit wiring board or precision equipment by using drilling, it is necessary to prevent the generation of smear, burr, halo, etc. due to the heat generated by the drill teeth, and to prevent the copper foil from being turned up. In order to prevent this, an aluminum plate was placed as a plate on the side of the insertion surface of the drill teeth of the circuit wiring board or the like for processing. However, although this method is effective for preventing burrs and smears, the aluminum plate itself tends to be broken and handling is extremely difficult. Furthermore, it was difficult to drill holes.

As a method for solving this problem, US Pat.
No. 1,495 and US Pat. No. 4,929,370 disclose a method of drilling by disposing a water-soluble lubricant on one or both sides of a copper-clad laminate as a backing plate. This is a method using a sheet in which a mixture of glycols such as diethylene glycol and dipropylene glycol, rigid waxes such as fatty acids, and anionic surfactants is impregnated into paper or the like, but the above sheet has a sticky feeling and is handled. Was difficult. Further, there is also a problem that the impregnating property of the solvent has many irregularities and the performance is varied.

In addition to the above method, the polymer layer is formed by using a water-soluble polymer such as polyethylene glycol or polypropylene glycol alone or a mixture of these water-soluble polymers, and further using a fatty acid ester thereof. A method has been proposed in which a sheet is placed on a copper-clad laminate and drilled by drilling (JP-A-4-92488, JP-A-4-92489, JP-A-4-92490, 4-924
Nos. 91, 4-92492, 4-92493, 4
-92494). Furthermore, a water-soluble lubricant sheet in which a polyetherester and a water-soluble lubricant are blended in a specific ratio,
A drilling method used for drilling a copper-clad laminate has been proposed (Japanese Patent Laid-Open No. 6-344297).

However, in any of the above methods, the effect of preventing the drill bit from generating heat during drilling is insufficient, stickiness occurs, or the water-soluble polymer is hardened and melted during drilling. However, there is a problem that the lubricant effect cannot be obtained and that the film has poor thermoplasticity and is inferior in film formability and is difficult to form into a sheet.

[0007]

DISCLOSURE OF THE INVENTION The present invention is intended to prevent the heat generated by the frictional heat of drill teeth during drilling and to prevent the copper foil of a copper-clad laminate from being turned and damaged, and to provide high quality and high efficiency drilling. And a perforation method using the sheet.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the present invention has been made of a polyester resin composition containing a specific amount of a specific particulate inorganic compound and a water-soluble lubricant. The present inventors have found that this object can be achieved by using a resin sheet, and have reached the present invention.

That is, the gist of the present invention is as follows. (1) A perforating resin sheet comprising a polyester resin composition in which 3 to 50 parts by weight of a granular inorganic compound and 1 to 10 parts by weight of a water-soluble lubricant are mixed with respect to 100 parts by weight of a thermoplastic polyester resin. (2) The resin sheet for drilling according to the above (1), wherein the water-soluble lubricant is an anionic surfactant or a polyether surfactant. (3) The resin sheet for drilling according to (1), which is formed by extrusion using a T die. (4) A method for perforating a copper-clad laminate or a plastic plate using the resin sheet for perforation according to the above (1) to (3).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The thermoplastic polyester resin in the present invention contains a dicarboxylic acid component and a diol component as main components, and has a Tm (melting point) of 200 ° C. or more in consideration of reduction of smear due to heat generation during drilling. T
Those having a g (glass transition temperature) of 60 ° C. or higher are preferred.

The dicarboxylic acid component includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylsulfonedicarboxylic acid, p- (2-hydroxyethoxy) benzoic acid, 5-sodium sulfoisophthalic acid, Adipic acid, azelaic acid, sebacic acid, dodecane-1,12-dicarboxylic acid, tetradecane-1,14-dicarboxylic acid, octadecane-1,18-dicarboxylic acid, 6-ethyl-hexadecane-1,16-dicarboxylic acid, etc. Among them, terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid are preferable, and terephthalic acid is particularly preferable. In addition, one or more of these dicarboxylic acid components can be used.

The diol component includes ethylene glycol, propylene glycol, butylene glycol, 1,4-
Cyclohexylene dimethanol, diethylene glycol, 1,6-hexanediol, neopentyl glycol and the like, among which ethylene glycol,
Butylene glycol and 1,4-cyclohexylene dimethanol are preferred, and ethylene glycol is particularly preferred. In addition, one or more of these diol components can be used.

Preferred examples of the combination of the dicarboxylic acid component and the diol component include terephthalic acid and ethylene glycol, terephthalic acid and butylene glycol, terephthalic acid and / or isophthalic acid and 1,4-cyclohexylene dimethanol, Examples include 2,6-naphthalenedicarboxylic acid and ethylene glycol. Preferable specific examples of the thermoplastic polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, and polyethylene naphthalate, and PET is particularly preferable.

The effect of the granular inorganic compound of the present invention varies depending on the particle size, shape, chemical composition, etc., but it is a material for improving the penetration of drill teeth, a surface smoothness improving material, a reinforcing material, and an anisotropic material for mechanical properties. , And exhibit functions such as a crystal nucleating agent. If the average particle size exceeds 100 μm, the penetration of the drill teeth and the surface smoothness deteriorate, so that the average particle size is usually 1 to 60.
Those in the μm range are useful.

Specific examples of the particulate inorganic compound include mica, glass flake, talc, wollastonite, silica, calcium carbonate, synthetic silicic acid, natural silicate, zinc white, halocytoclay, kaolin, basic magnesium carbonate , Quartz powder, titanium oxide, barium sulfate, calcium sulfate, alumina and the like. Among these, mica, talc are considered in consideration of the insertability of drill teeth, sheet surface smoothness, sheet elasticity, sheet bending resistance and the like. Is preferred, and mica is particularly preferred.

The mixing ratio of the particulate inorganic compound must be 3 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin in consideration of the balance between mechanical properties and surface smoothness. Preferably it is 45 parts by weight.
If the compounding ratio is less than 3 parts by weight, the effect of improving the drill workability is small, and if it exceeds 50 parts by weight, the mechanical properties decrease and the insertability of the drill teeth deteriorates.

The water-soluble lubricant in the present invention has an effect of reducing the frictional resistance between the resin sheet and the drill teeth, and includes an anionic surfactant and a polyether-based surfactant. Examples of the anionic surfactant include an aliphatic amine salt, a phosphoric acid ester of a higher alcohol, an alkyl sulfate, an alkyl aryl sulfate, and sodium alkane sulfonate. As the polyether-based surfactant, for example, polyethylene glycol, polypropylene glycol,
Examples include polytetramethylene glycol, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene dodecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, and the like.

The mixing ratio of the water-soluble lubricant must be 1 to 10 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin in consideration of mechanical properties and lubricant effect.
Preferably, the amount is up to 8 parts by weight. If the compounding ratio is less than 1 part by weight, the effect of suppressing the heat generation of the drill teeth is small. Conversely, if it exceeds 10 parts by weight, a decrease in the viscosity at the time of melting becomes large and a good resin sheet cannot be obtained. The water-soluble lubricant breathes out from the water, making handling difficult.

The method of blending the water-soluble lubricant is not particularly limited. However, in consideration of the dispersibility of the lubricant and sheet productivity, the water-soluble lubricant is previously contained in a thermoplastic polyester resin such as PET. The method used as a master pellet is preferable.

In the present invention, in addition to the above-mentioned compounds, if necessary, heat stabilizers, antioxidants, light stabilizers, pigments, plasticizers, crosslinkers, impact modifiers, flame retardants, flame retardant auxiliaries, etc. Various plastic additives can also be used in combination.

Particularly for applications requiring heat resistance, crosslinking can be carried out at the time of sheet extrusion molding, or at the time of hot rolling or after hot rolling, by high-temperature heat treatment, high-energy treatment such as ultraviolet irradiation or electron beam irradiation. It is extremely effective to incorporate a post-crosslinking type crosslinking agent. Examples of such a crosslinking agent include triaryl isocyanurate, triaryl cyanurate and the like.

The method for producing the resin sheet of the present invention is not particularly limited, and conventionally known methods such as an extrusion molding method using a T die, a calendar molding method, an injection molding method, and a compression molding method. However, in consideration of production efficiency, uniformity of the obtained resin sheet, surface flatness, and the like, an extrusion molding method using a T die is preferable.

[0024]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the measuring method of the characteristic value in an Example and a comparative example is as follows. (a) Intrinsic viscosity The intrinsic viscosity was measured at a temperature of 20 ° C. using an equal weight mixture of phenol and tetrachloroethane as a solvent. (b) Sheet formability The following three stages were evaluated according to the situation when the sheet was formed. ：: No sheet break occurs at all. Δ: Sheet breakage occurs 1 to 3 times per hour, but sheet molding is possible. X: Sheet breakage occurred at a rate of 4 times or more per hour, and sheet molding was impossible. (c) Sheet tensile strength Measured according to the method described in ASTM 638. (d) Sheet Surface Condition The tackiness of the water-soluble lubricant on the sheet surface was evaluated on the following three levels. ：: There is no stickiness at all. Δ: The sheet is slightly sticky. ×: Stickiness is present on the entire sheet. (e) Drillability Two 1.6mm-thick glass mat laminates with 18μm copper foil on both sides are stacked, and a resin sheet is placed on the insertion side of the drill teeth, and drilling is performed under the following drilling conditions. Carry out processing,
About 50 out of 1000 through-hole holes, the number of smears generated was observed with an optical microscope, and evaluated in the following three stages. (Drilling conditions) ・ Drill bit 0.2mm φ ・ Rotational speed 7000rpm ・ Feed speed 1.6 m / min ○: Smear generation is less than 5 △: Smear generation is 5 or more and less than 15 ×: Smear generation is 15 or more ( f) Straightness of drill teeth Under the same conditions as in (e), drill holes were made, and for 50 out of 1000 through-holes, the positions of the uppermost and lowermost holes were observed with an optical microscope. Was evaluated in the following three stages depending on whether or not was inserted in the direction perpendicular to the sheet surface. ：: The through-hole is at right angles to the sheet surface. Δ: The through-hole hole is slightly off the right angle to the sheet surface. X: The through-hole hole deviated from a right angle to the sheet surface.

Examples 1 to 4 PET (NEH-2050, manufactured by Unitika Ltd.) 100 having an intrinsic viscosity of 0.78
Mica having an average particle size of about 15 μm (M-400, manufactured by Repco) as a granular inorganic compound was prepared in parts by weight as shown in Table 1, and a twin screw extruder (PCM-, manufactured by Ikegai Iron Works, Ltd.) was prepared. 30)
The mixture was melt-kneaded at 280 ° C., extruded into strands, and cut to obtain pellets. This pellet was blended with a master pellet (manufactured by Sumika Color Co., Ltd., EPM-7E747) containing 20% by weight of sodium alkane sulfonate as a water-soluble lubricant so that the ratio of the water-soluble lubricant was as shown in Table 1. After melting and kneading, the mixture was molded by an extrusion molding apparatus using a T die to obtain a resin sheet having a thickness of about 0.3 mm. Next, this resin sheet was arranged on the insertion side of the drill teeth of a 1.6 mm-thick glass mat laminated plate (two laminated) having 18 μm copper foil on both sides, and drilling was performed. However, a favorable drilling process in which generation of smear was small and the drill teeth were perpendicular to the surface of the laminated plate could be performed.

Examples 5 to 6 PET (NEH-2050, manufactured by Unitika Ltd.) 100 having an intrinsic viscosity of 0.78
Mica having an average particle size of about 13 μm (M-400, manufactured by REPCO Corporation) was prepared as a granular inorganic compound in parts by weight as shown in Table 1, and a twin-screw extruder (PCM-, manufactured by Ikeigai Iron Works Co., Ltd.) was prepared. 30)
The mixture was melt-kneaded at 280 ° C., extruded into strands, and cut to obtain pellets. The pellets were mixed with polyethylene glycol (PEG-6000, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) as a water-soluble lubricant so that the ratio of the water-soluble lubricant was as shown in Table 1, and the mixture was melt-kneaded. The resin sheet was molded with an extruder to obtain a resin sheet having a thickness of about 0.3 mm. Next, using this resin sheet, drilling was performed in the same manner as in Examples 1 to 4, and a good hole in which the occurrence of smear was small and the drill teeth were also perpendicular to the surface of the laminated plate. The opening process was completed.

Comparative Examples 1 to 3 Except that the mixing ratio of PET, mica and sodium alkane sulfonate was changed to the amount shown in Table 2, Examples 1 to 3 were used.
A resin sheet was prepared in the same manner as in No. 4, and the drilling workability was evaluated.

Comparative Example 4 A resin sheet was prepared in the same manner as in Examples 5 to 6, except that the mixing ratios of PET, mica and polyethylene glycol were changed to the amounts shown in Table 2, and the drilling workability was evaluated. .

Tables 1 and 2 show the evaluation results of the compounding ratios, resin sheet properties (moldability, tensile strength, surface state), drilling workability and drill straightness in Examples 1 to 6 and Comparative Examples 1 to 4. Shown in

[0030]

[Table 1]

[0031]

[Table 2]

In Examples 1 to 6, resin sheets excellent in moldability, tensile strength and surface condition were obtained. Also, the drilling workability using these resin sheets was good.

On the other hand, the comparative example had the following problems. In Comparative Example 1, since the amount of mica was small, the occurrence of smear during drilling tended to increase. In Comparative Example 2, since the amount of mica was too large, the sheet strength was weak, and cracks occurred during handling. Also, the occurrence of smear tends to increase during drilling, and the straightness of the drill teeth is also poor. In Comparative Examples 3 and 4, since the amount of the water-soluble lubricant was too large, the sheet strength was weak, and cracking was likely to occur during handling. In addition, stickiness was observed in the surface state of the sheet.

[0034]

According to the present invention, when drilling a copper-clad laminate for a double-sided or multilayer printed circuit wiring board or a plastic board for precision equipment, frictional heat of a drill tooth at the time of drilling. This can prevent heat generation and copper foil of the copper-clad laminate from being turned and damaged, and can perform high-quality and high-efficiency drilling.

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Claims (4)

[Claims] 1 to 100 parts by weight of a thermoplastic polyester resin, 3 to 50 parts by weight of a particulate inorganic compound and 1 to 1 part of a water-soluble lubricant.
A resin sheet for drilling comprising a polyester resin composition blended with 10 parts by weight. 2. The perforating resin sheet according to claim 1, wherein the water-soluble lubricant is an anionic surfactant or a polyether-based surfactant. 3. The resin sheet according to claim 1, wherein the resin sheet is formed by extrusion using a T die. 4. A method for perforating a copper-clad laminate or a plastic plate using the resin sheet for perforation according to claim 1.