TW201941846A - Entry sheet for boring drill hole, and method of boring drill hole using same - Google Patents

Abstract

An entry sheet for boring a drill hole, comprising a metal foil and a resin composition layer formed on at least one surface of the metal foil, wherein the shear storage modulus of the resin composition layer satisfies the relationships represented by formulas (i) and (ii) shown below. -3.0 ≤ [Delta]G' ≤ -1.0...(i) 4.5*10<SP>5<SP> ≤ G' (56) ≤ 100*10<SP>5<SP>...(ii) (In the formulas, [Delta]G'= log10(G'(62))-log10(G'56)), and G'(56) and G'(62) represent the shear storage modulus (units: Pa) of the resin composition at temperatures of 56 DEG C and 62 DEG C respectively.

Description

Auxiliary plate for drilling and drilling processing method using the auxiliary plate

The present invention relates to an auxiliary plate for drilling and a drilling processing method using the auxiliary plate.

As a drilling method for laminated boards and multilayer boards used as printed circuit board materials, generally, one or more laminated boards or multilayer boards are used, and an aluminum foil alone or an aluminum foil as an abutment plate is arranged on the uppermost part. A method of performing a hole-cutting process on a sheet on which a layer of a resin composition is formed on the surface (hereinafter referred to as “sheet” in the present specification as an “assisting plate for drilling”).

In recent years, along with the requirements for improving the reliability of printed circuit boards and the progress of high density, the drilling of laminated or multilayer boards requires the reduction of inner wall roughness during hole drilling and the improvement of hole position accuracy. And other high-quality drilling.

In order to respond to the above-mentioned requirements such as reduction of inner wall roughness and improvement of hole position accuracy during the drilling process, for example, Patent Document 1 discloses an auxiliary plate for drilling, which is water-soluble on aluminum foil on which a thermosetting resin film has been formed. Resin layer. In addition, Patent Document 2 discloses a lubricant sheet for openings, which is obtained by blending a non-halogen coloring agent with a resin composition.

Moreover, an auxiliary plate for drilling using a solid lubricant has also been disclosed. For example, Patent Document 3 discloses an auxiliary plate for openings, which is composed of a lubricating layer, a composite material containing a nanostructured powder such as tungsten disulfide, and a solid wear-resistant lubricating layer of a highly thermally conductive compound, and a support. Further, Patent Document 4 discloses an auxiliary plate for drilling including a layer of a resin composition in which a water-soluble resin, a water-soluble lubricant, and carbon powder are mixed. Furthermore, Patent Document 5 discloses a heat-dissipating and lubricating aluminum cover for perforation, which contains graphite as an inorganic filler in a composite material.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-136485
[Patent Document 2] Japanese Patent Laid-Open No. 2004-230470
[Patent Document 3] Japanese Patent Laid-Open No. 2007-281404
[Patent Document 4] Japanese Patent Laid-Open No. 2008-222762
[Patent Document 5] Japanese Patent Laid-Open No. 2006-346912

[Questions to be Solved by the Invention]

However, with the advancement of semiconductor technology, the requirements for higher density and improved reliability of printed circuit boards have been increasing. In mass production, there are many applications of drill diameters ranging from 0.5mm to 0.105mm. Specifically, there are 0.5mm, 0.45mm, 0.4mm, 0.35mm, 0.3mm, 0.25mm, 0.2mm, 0.15mm, 0.105mm, and the like. In addition, the minimum drill diameter is gradually shifted from 0.105mm to 0.075mm. Against laser drilling technology, very few are trying to drill 0.05mm. In addition, even if the printed circuit board is processed with drill diameters of 0.2 mm and 0.15 mm, there is a strong demand for improvement in hole position accuracy. In addition, due to international competition and the needs of emerging countries, there is a constant demand for better productivity and cost reduction.

In the processing using the conventional auxiliary board for drilling, frictional heat between the drill and the laminated board or the multilayer board may melt the resin composition containing a water-soluble resin and the like around the drill, thereby exhibiting lubricity. However, in the conventional auxiliary plate for drilling, the effect of the lubricity of the resin composition layer is not necessarily satisfactory, and it cannot sufficiently meet the requirements for improving the accuracy of the hole position. That is, it is desired to develop an auxiliary plate for drilling which can respond to a demand for higher hole position accuracy.

On the other hand, from the viewpoint of improving productivity and reducing costs, as described above, it is required to have excellent drill break resistance even when using a drill with a small drill diameter, and it is also required that chips from the auxiliary plate for drilling are not easily attached. In the drill.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an auxiliary plate for drilling, which has excellent drill breakage resistance and accuracy of hole position even when a drill having a small drill diameter is used, and has less coils from the auxiliary plate for drilling, and uses the same. The auxiliary plate drilling method.
[Solution to the problem]

The inventors of the present invention have made intensive studies in order to solve the above problems, and as a result, they have found that the above problems can be solved by adjusting the shear storage elastic modulus of the resin composition layer, and the present invention has been completed.

That is, the present invention is as follows.
[1] an auxiliary plate for drilling, comprising a metal foil and a resin composition layer formed on at least one side of the metal foil,
The shear storage elastic modulus of the resin composition layer conforms to the relationship represented by the following formulae (i) and (ii);
-3.0 ≦ △ G '≦ -1.0… (i)
4.5 × 10 ⁵ ≦ G '(56) ≦ 100 × 10 ⁵ … (ii)
In the above formula, △ G '= log ₁₀ (G' (62))-log ₁₀ (G '(56)), and G' (56) and G '(62) each represent the resin composition at 56 ° C, 62 Shear storage elastic modulus at ℃, the unit is Pa.
[2] The auxiliary plate for drilling according to [1], wherein the resin composition layer is more in accordance with the relationship represented by the following formula (iii);
0.005 × 10 ⁵ ≦ G '(70) ≦ 80 × 10 ⁵ … (iii)
In the above formula, G '(70) represents the shear storage elastic modulus of the resin composition at 70 ° C, and the unit is Pa.
[3] The auxiliary plate for drilling according to [1] or [2], wherein the resin composition contains a water-soluble resin (A).
[4] The auxiliary plate for drilling according to any one of [1] to [3], wherein the resin composition contains a filler (B).
[5] The auxiliary plate for drilling according to [4], wherein the filler (B) is talc and / or molybdenum disulfide.
[6] The auxiliary plate for drilling according to any one of [3] to [5], wherein the water-soluble resin (A) is selected from the group consisting of polyethylene oxide, polypropylene oxide, and polytetramethylene. Monoether compounds of methyl glycol, polyethylene glycol, polypropylene glycol, polyoxyethylene, polyoxyethylene monostearate, polyoxyethylene sorbitan monostearate, polyglycerol monostearate And one or more of the group consisting of a polyoxyethylene propylene copolymer.
[7] The auxiliary plate for drilling according to any one of [1] to [6], wherein the resin composition layer has a thickness in a range of 0.02 to 0.3 mm.
[8] The auxiliary plate for drilling according to any one of [1] to [7], wherein the metal foil has a thickness in a range of 0.05 to 0.5 mm.
[9] A method for drilling, comprising a hole forming step of forming holes in a laminated board or a multilayer board using the auxiliary board for drilling according to any one of [1] to [8].
[Effect of the invention]

According to the present invention, it is possible to provide an auxiliary plate for drilling, which is excellent in resistance to drill breakage and hole position accuracy when using a drill with a small drill diameter, and has less entrapment of chips from the auxiliary plate for drilling, and a drill using the auxiliary plate Hole processing method.

Hereinafter, this embodiment (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various modifications can be made without departing from the gist thereof.

(Auxiliary plate for drilling)
The auxiliary plate for drilling according to this embodiment (hereinafter also simply referred to as an "auxiliary plate") has a metal foil and a resin composition layer formed on at least one side of the metal foil, and the resin composition layer is sheared and stored. The elastic modulus conforms to the relationship represented by the following formulas (i) and (ii).
-3.0 ≦ △ G '≦ -1.0… (i)
4.5 × 10 ⁵ ≦ G '(56) ≦ 100 × 10 ⁵ … (ii)
In the above formula, △ G '= log ₁₀ (G' (62))-log ₁₀ (G '(56)), and G' (56) and G '(62) each represent the resin composition at 56 ° C, 62 Shear storage elastic modulus at ℃, the unit is Pa.

The resin composition layer may be in the form of being formed on one side of a metal foil or in the form of being formed on both sides. When the resin composition layer is formed on both sides, the composition of the resin composition of the layer may be the same or different.

(Resin composition layer)
The resin composition layer in this embodiment is a layer whose shear storage elastic modulus conforms to the relationship represented by the above formulae (i) and (ii). The auxiliary plate of this embodiment can be expected to exert lubricity on the part where the cutting part of the workpiece contacts the cutting tool during cutting, reduce excessive burden on the cutting tool, and improve drill breakage resistance and cutting performance. The hole position accuracy improves such a function, and the chip of the resin composition layer should not be coiled around the cutting tool. The cutting process of the auxiliary plate action is a dynamic process, and the state of the resin composition layer in contact with the cutting edge of the drilling machine during high-speed rotation is used during use. In consideration of the point that the structure designated in such a state exerts each function, in this embodiment, the shear storage elastic modulus among the storage elastic moduli is specified. In particular, it is thought that when the storage elastic modulus rapidly decreases when the temperature is increased, the resin composition layer will change from a solid state to a gel state, and the gel state resin composition layer contributes to the functions of the auxiliary board. If the temperature in the gel state is too high at this time, it is considered that a load is applied to the cutting tool before the lubricity of the auxiliary plate is exerted, and the hole position accuracy and drill breakage are affected during continuous processing. In addition, it is considered that even if it is in a gel state, if the storage elastic modulus in the gel state is high, the lubricity is lacking. If the storage elastic modulus in the gel state is too low, it is difficult to form a lubricating film. The viewpoints of the burden of cutting tools such as drill breakage and the accuracy of hole positions are not ideal. In addition, it is thought that the lower the storage elastic modulus in the solid state, the easier it is for the chips of the resin composition layer to coil around the cutting tool. However, for the mechanism of action, it is not limited to the above viewpoint.

In formula (i), △ G 'represents the common logarithm (log ₁₀ (G' (62))) of the shear storage elastic modulus (G '(62)) at 62 ° C and the shear storage elasticity at 56 ° C The difference between the common logarithm (log ₁₀ (G '(56))) of the modulus (G' (56)). Equation (i) defines the range of ΔG '. Generally speaking, the shear storage elastic modulus tends to decrease with increasing temperature. Equation (i) uses the gap between log ₁₀ (G '(62)) and (log ₁₀ (G' (56)) to specify the shear rate. The storage elastic modulus shows a predetermined tendency.

△ G 'is -3.0 to -1.0, preferably -2.8 to -1.0, more preferably -2.6 to -1.0, still more preferably -2.4 to -1.0, and even more preferably -2.2 to -1.0. When ΔG 'is -3.0 or more, it is possible to further suppress the coiling of the resin composition layer to the cutting tool. In addition, when ΔG 'is equal to or lower than -1.0, the drill breakage resistance and the accuracy of the hole position will be better.

Formula (ii) shows the range of G '(56). G '(56) is 4.5 × 10 ⁵ to 100 × 10 ⁵ , preferably 20 × 10 ⁵ to 100 × 10 ⁵ , more preferably 30 × 10 ⁵ to 100 × 10 ⁵ , and still more preferably 35 × 10 ⁵ ~ 100 × 10 ⁵ , particularly preferably 40 × 10 ⁵ to 100 × 10 ⁵ . When G ′ (56) is 4.5 × 10 ⁵ or more, it is possible to further suppress the swarf of the resin composition layer from being wound on the cutting tool. In addition, when G '(56) is 100 × 10 ⁵ or less, drill breakage resistance and hole position accuracy are better.

G '(62) is preferably 0.010 × 10 ⁵ to 4.4 × 10 ⁵ , more preferably 0.10 × 10 ⁵ to 4.4 × 10 ⁵ , and still more preferably 0.20 × 10 ⁵ to 4.4 × 10 ⁵ , and particularly preferably 0.40 × 10 ⁵ ~ 4.4 × 10 ⁵ . When G '(62) is 0.010 × 10 ⁵ or more, there is a tendency that the chipping of the resin composition layer to the coil of the cutting tool is more suppressed. In addition, when G '(62) is 4.4 × 10 ⁵ or less, drill breakage resistance and hole position accuracy tend to be better.

The resin composition layer is more preferably in accordance with the relationship represented by the following formula (iii).
0.005 × 10 ⁵ ≦ G '(70) ≦ 80 × 10 ⁵ … (iii)
In the above formula, G '(70) represents the shear storage elastic modulus of the resin composition at 70 ° C, and the unit is Pa.

Formula (iii) represents the range of G '(70). G '(70) is preferably 0.005 × 10 ⁵ to 80 × 10 ⁵ , more preferably 0.020 × 10 ⁵ to 40 × 10 ⁵ , and still more preferably 0.150 × 10 ⁵ to 10 × 10 ⁵ . When G '(70) is 0.005 × 10 ⁵ or more, the chipping of the resin composition layer tends to further suppress the coiling of the cutting tool. In addition, when G '(70) is 80 × 10 ⁵ or less, drill breakage resistance and hole position accuracy tend to be better.

The value of △ G 'can be adjusted by controlling the values of G' (56) and G '(62). G '(56), G' (62), and G '(70) can be adjusted by the type and content of the resin used and the type and content of the filler. For example, when comparing a case with a filler and a case without a filler, the inclusion of the filler improves the shear storage elastic modulus as a whole. In addition, as the content of the filler increases, the shear storage elastic modulus generally increases, and particularly, the rate of increase in the shear storage elastic modulus at a high temperature side tends to increase. Moreover, if the particle diameter is reduced without changing the content of the filler, the shear storage elastic modulus will decrease as a whole compared to the case where the particle diameter is large, but the decrease rate tends to be large on the high temperature side.

In this embodiment, the measurement of the shear storage elastic modulus can be performed in accordance with the method described in the examples.

(Composition of resin composition layer)
The component constituting the resin composition layer is preferably a water-soluble resin (A), and may optionally contain a filler (B). Each component is explained in detail below.

<Water-soluble resin (A)>
The water-soluble resin (A) can be further classified into a high-molecular-weight water-soluble resin having a weight-average molecular weight of 1.0 × 10 ⁵ to 2.0 × 10 ⁶ and a weight-average molecular weight of 3.0 × 10 ³ to 7.0 depending on the difference in molecular weight. × 10 ⁴ medium-molecular water-soluble resin and low-molecular-weight water-soluble resin having a weight average molecular weight of 1.0 × 10 ² to 2.5 × 10 ³ . The high-molecular water-soluble resin contributes to the overall improvement of the moldability of the resin composition layer and the shear storage elastic modulus, and also contributes to the improvement of the adhesion with the workpiece, and thereby improves the accuracy of the hole position. In addition, medium-molecular water-soluble resins and low-molecular water-soluble resins contribute to the improvement of lubricity, chip discharge, and hole position accuracy. In the present embodiment, "water-soluble" refers to a property of dissolving 1 g or more in 100 g of water at 25 ° C and 1 atmosphere.

The water-soluble resin (A) is not particularly limited. For example, it is selected from the group consisting of polyethylene oxide, polypropylene oxide, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, monoether compounds of polyoxyethylene, and polyoxyethylene. One or more of oxyethylene monostearate, polyoxyethylene sorbitan monostearate, polyglycerol monostearate compound, and polyoxyethylene propylene copolymer. By using such a water-soluble resin (A), drill breakage resistance and hole position accuracy are better, and coiling tends to be suppressed.

＜ Polymer water-soluble resin (a-1) ＞
The polymer water-soluble resin (a-1) is not particularly limited, such as polyethylene oxide and polypropylene oxide. The polymer water-soluble resin (a-1) may be used singly or in combination of two or more kinds.

The weight average molecular weight of the polymer water-soluble resin (a-1) is 1.0 × 10 ⁵ to 2.0 × 10 ⁶ , preferably 1.0 × 10 ⁵ to 1.0 × 10 ⁶ , and more preferably 1.0 × 10 ⁵ to 6.0 × 10 ⁵ . When the weight-average molecular weight of the polymer water-soluble resin (a-1) is within the above range, the drill breakage resistance and hole position accuracy are better, and coiling tends to be suppressed.

The content of the polymer water-soluble resin (a-1) is preferably 3 to 15 parts by mass, more preferably 5 to 12 parts by mass, and even more preferably 100 parts by mass of the total resin components in the resin composition. 7 to 10 parts by mass. When the content of the polymer water-soluble resin (a-1) is within the above-mentioned range, the film-forming property of the resin composition layer and the pore position accuracy tend to be better.

＜ Molecular-weight water-soluble resin (a-2) ＞
The medium-molecular water-soluble resin (a-2) is not particularly limited, for example, glycol compounds such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol; polyoxyethylene oleyl ether, polyoxyethylene whale Monoether compounds of polyoxyethylene such as wax ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether; polyoxyethylene monostearate, Polyoxyethylene sorbitan monostearate, polyglycerol monostearate compound, polyoxyethylene propylene copolymer, and the like. Among them, polytetramethylene glycol, polyethylene glycol, and polypropylene glycol are more preferred. The medium molecular water-soluble resin (a-2) may be used alone or in combination of two or more.

The weight average molecular weight of the medium molecular water-soluble resin (a-2) is 3.0 × 10 ³ to 7.0 × 10 ⁴ , preferably 3.0 × 10 ³ to 3.0 × 10 ⁴ , and more preferably 3.0 × 10 ³ to 1.0 × 10 ⁴ . When the weight average molecular weight of the medium-molecular water-soluble resin (a-2) is within the above range, drill breakage resistance and hole position accuracy are better, and coiling tends to be suppressed.

The content of the medium-molecular-weight water-soluble resin (a-2) is preferably 40 to 85 parts by mass, more preferably 55 to 85 parts by mass, and more preferably 65 parts by mass with respect to 100 parts by mass of the total resin components in the resin composition. ~ 80 parts by mass. When the content of the medium-molecular water-soluble resin (a-2) is within the above range, the accuracy of the pore position tends to be better.

＜ Low-molecular-weight water-soluble resin (a-3) ＞
The low-molecular-weight water-soluble resin (a-3) is not particularly limited, for example, glycol compounds such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; polyoxyethylene oleyl ether, polyoxyethylene whale Monoether compounds of polyoxyethylene such as wax ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether; polyoxyethylene monostearate, Polyoxyethylene sorbitan monostearate, polyglycerol monostearate compound, polyoxyethylene propylene copolymer, and the like. Among these, polyoxyethylene monoether compounds, polyoxyethylene monostearate, polyoxyethylene sorbitan monostearate, polyglycerol monostearate compounds, and polyoxyethylene propylene copolymers are preferred. . The low-molecular-weight water-soluble resin (a-3) may be used alone or in combination of two or more.

The content of the low-molecular-weight water-soluble resin (a-3) is preferably 3 to 25 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 10 to 100 parts by mass of the total resin components in the resin composition. ~ 20 parts by mass. When the content of the low-molecular-weight water-soluble resin (a-3) is within the above range, the lubricity of the resin composition layer and the accuracy of the pore position tend to be better.

＜ Filling material (B) ＞
There are no special restrictions on the filler (B), for example: silicon dioxide, talc, kaolin, mica, boehmite, molybdenum compounds (molybdenum disulfide, molybdenum oxide, zinc molybdate). Among them, talc and / or molybdenum disulfide are preferred. By using such a filler, drill bit breakage resistance and hole position accuracy are better, and coiling tends to be suppressed.

The median diameter (average particle diameter) of the filler (B) is preferably 0.3 μm to 10 μm, more preferably 0.3 μm to 8 μm, and still more preferably 0.5 μm to 6 μm. When the median diameter of the filler (B) is within the above-mentioned range, drill bit breakage resistance and hole position accuracy are better, and coiling tends to be suppressed. Here, the median diameter refers to a particle diameter (D50) having a height of 50% in a cumulative distribution curve (number basis) of a particle diameter measured by a particle diameter measurement method such as a laser diffraction method.

The content of the filler (B) is preferably 10 to 150 parts by mass, more preferably 30 to 125 parts by mass, and still more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the total resin components in the resin composition. When the content of the filler (B) is within the above-mentioned range, the drill breakage resistance and hole position accuracy are better, and the coiling tends to be suppressed.

The shape of the filler (B) is not particularly limited, for example, a plate shape is preferred. Compared with a roughly spherical shape such as a silicone resin powder, the plate-shaped filler (B) has a large resistance when shearing. Therefore, by setting the content of the filler (B) to the above range, ΔG 'and the like can be adjusted to the range of this embodiment. On the other hand, the closer the shape of the filler (B) to the spherical shape, the smaller the resistance during shearing, and the more difficult it is to adjust ΔG 'or the like.

In consideration of such a viewpoint, it is preferable that the filler (B) be plate-like talc and / or molybdenum disulfide. When the content is within the above range, the drill breakage resistance tends to be better.

＜ Other ingredients ＞
The resin composition layer may contain an additive as needed. The types of additives are not particularly limited, such as: surface modifiers, levelling agents, antistatic agents, emulsifiers, defoamers, wax additives, coupling agents, rheology control agents, preservatives, antifungal agents, antioxidants, Light stabilizers, nucleating agents such as sodium formate, heat stabilizers, and coloring agents.

The thickness of the resin composition layer can be appropriately selected according to the diameter of the drill used in the drilling process, and the structure of the object to be processed (for example, a printed circuit board material such as a laminated board or a multilayer board). Among them, the thickness of the resin composition layer is preferably 0.02 to 0.3 mm, more preferably 0.02 to 0.2 mm, and even more preferably 0.02 to 0.1 mm. When the thickness of the resin composition layer is 0.02 mm or more, a more sufficient lubricating effect can be obtained, and the load on the drill bit can be reduced, so there is a tendency that the drill bit breakage can be more suppressed. In addition, when the thickness of the resin composition layer is 0.3 mm or less, there is a tendency that the resin composition can be prevented from being coiled by the drill.

(Metal foil)
The metal foil used for the auxiliary plate for drilling in this embodiment is not particularly limited, and is preferably a metal material having high adhesion to the resin composition layer and capable of withstanding the impact caused by the drill. The metal type of the metal foil is considered from the viewpoints of availability, cost, and processability, such as aluminum. The material of aluminum foil is preferably aluminum with a purity of 95% or more. Such aluminum foils are, for example, 5052, 3004, 3003, 1N30, 1N99, 1050, 1070, 1085, 8021 according to JIS-H4160. The use of aluminum foil with a purity of 95% or more for metal foils can reduce the impact caused by the drill bit and the biteability of the drill's front end, and complement the lubricating effect of the drill bit obtained by the resin composition, which can further improve the processing Hole position accuracy.

The thickness of the metal foil is preferably 0.05 to 0.5 mm, more preferably 0.05 to 0.3 mm, and still more preferably 0.05 to 0.2 mm. When the thickness of the metal foil is 0.05 mm or more, there is a tendency that the occurrence of burrs of an object to be punched (for example, a laminated board) during drilling is more likely to be suppressed. In addition, when the thickness of the metal foil is 0.5 mm or less, there is a tendency that it is easier to eliminate cutting powder generated during drilling.

The thickness of each layer constituting the auxiliary plate for drilling according to this embodiment is measured as follows. First use a cross-cut polishing machine (made by Japan Electronic Data Corporation, trade name "CROSS-SECTIONPOLISHERSM-09010"), or an ultra microtome (made by Leica, model "EMUC7"), and stack the auxiliary board along each layer. Layer direction cut. After that, using a SEM (Scanning Electron Microscope, Keyence Corporation model "VE-7800"), the section that appears after cutting is cut out, and the section is viewed from the vertical direction, and the constituent layers such as metal foil and metal foil are measured. The thickness of the resin composition layer. The thickness of 5 places was measured for one visual field, and the average value was determined as the thickness of each layer.

(Manufacturing method of auxiliary plate for drilling)
The manufacturing method of the auxiliary board for drilling according to this embodiment is not particularly limited, and for example, it is manufactured by forming a resin composition layer on at least one side of a metal foil. The method for forming the resin composition layer on the metal foil is not particularly limited, and a known method can be adopted. Such a method is, for example, a method in which a solution of a resin composition obtained by dissolving or dispersing a resin or the like in a solvent is applied to a metal foil by a coating method or the like, and then dried and / or cooled and solidified.

When a resin composition solution is coated on a metal foil by a coating method or the like and dried to form a resin composition layer, the solvent used for the resin composition solution is preferably water and a solvent having a lower boiling point than water. The composition of the mixed solution is preferred. Use of a mixed solution composed of water and a solvent having a lower boiling point than water can help reduce residual air bubbles in the resin composition layer. The type of the solvent having a lower boiling point than water is not particularly limited, and examples thereof include alcohol compounds such as ethanol, methanol, and isopropanol. Low-boiling solvents such as methyl ethyl ketone and acetone may also be used. As for other solvents, it is possible to use a solvent in which water and an alcohol compound are mixed with a part of tetrahydrofuran and acetonitrile having high compatibility with the resin composition.

(Drilling method)
The drilling method of this embodiment includes a hole forming step of forming a hole in a laminated board or a multilayer board using the auxiliary board for drilling. The diameter (drill diameter) of the drill used in this drilling process is preferably 0.10 mmφ or less, and more preferably 0.080 mmφ or less. Such a drill is thin, is particularly easy to break, and also requires hole position accuracy. On the other hand, by using the auxiliary plate of this embodiment, particularly in terms of resistance to drill breakage and accuracy of hole position, and the effect of the chipping of the resin composition layer on the suppression of the coiling of the cutting tool, it is more effective. In addition, the auxiliary plate for drilling according to the present embodiment is also applicable to drilling processing using a drill having a diameter exceeding 0.30 mmφ.

The auxiliary board for drilling according to the present embodiment is suitable for use when, for example, a printed circuit board material, and more specifically, when drilling a laminated board or a multilayer board. Specifically, an auxiliary board for drilling may be disposed on at least the topmost surface of the (printed circuit board material) on which one or more laminated boards or multilayer boards are stacked so that the metal foil side contacts the printed circuit board material, and Drilling is performed from the top surface (resin composition layer side) of this auxiliary plate.
[Example]

The effects of the examples of the present invention are compared with comparative examples that fall within the scope of the present invention below.

[Shear storage elastic modulus]
The shear storage elastic modulus of the resin composition layer in Examples and Comparative Examples was measured using a dynamic viscoelasticity measuring device "DISCOVER HR-2" manufactured by TA Instruments. The preparation method of the measurement sample is described below. The auxiliary plate for drilling obtained by the method described in Example 1 was heated at 170 ° C. to soften the resin composition layer. After removing only the resin composition layer, it was cooled and solidified to be a measurement sample. In addition, in terms of the preparation method before the measurement of the dynamic viscoelasticity measuring device, a measurement sample is set on the measurement table of the dynamic viscoelasticity measuring device, and the measurement table is heated to 170 ° C, and then the dynamic viscoelasticity measuring device is attached The resin composition layer was sandwiched between the parallel plate having a diameter of 20 mm and the measurement table until the gap between the parallel plate and the measurement table became 0.2 mm. The measurement table was cooled to 30 ° C. and the temperature was measured. The measurement conditions were measured under the following measurement conditions.

＜ Measurement conditions ＞
Mode: Shear mode Heating rate: 10 ° C / min Temperature range: 30 ~ 150 ° C
Frequency: 1.0Hz
Strain: 0.01%

<Processing Conditions for Evaluation of Hole Position Accuracy and Average Number of Broken Holes (Drill Resistance)
On the top surface of 6 copper-clad laminates (trade name: HL832NS-L, copper foil thickness 5 μm, two panels, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 6 copper-clad laminates are stacked on top of each other and arranged. The auxiliary plate for drilling manufactured in the examples and comparative examples has the resin composition layer side as the top surface, and an abutment plate having a thickness of 1.5 mm is arranged on the back surface (bottom surface) of the lowermost plate of the stacked copper-clad laminate. (Paper phenol laminated board PS1160-G, manufactured by Lichang Co., Ltd.). Then, five 0.060 mmφ drills (manufactured by Uniontool Co., Ltd.) were used, and the following processing conditions were used to set 10,000 holes per drill and the following conditions were used to drill holes until each drill was broken.
Speed: 330,000rpm
Feed speed: 2.94m / min
Number of openings per drill: 10,000 holes set

＜ Evaluation method of hole position accuracy ＞
A hole analyzer (model: HA-1AM, Hitachi Viamechanics (KK) Co., Ltd.) was used to measure the hole position and designation of the back side (bottom side) of the lowermost plate of the stacked copper-clad laminate with respect to the machined holes measured by one drill Coordinate deviation. For each drill bit, the average and standard deviation (σ) are calculated for the deviation, and "average + 3σ" is calculated. In terms of the accuracy of the hole position of the entire drilling process, the average value of each of the five drill bits with respect to the value of "average value + 3σ" was calculated, and the hole position accuracy was evaluated according to the following evaluation criteria. The calculation formula used for hole position accuracy calculation is as follows.

[Number 1]
Here, n represents the number of drill bits used.
[Evaluation criteria]
5: Hole position accuracy is less than 15 μm
4: Hole position accuracy is 15 μm or more and less than 17 μm
3: Hole position accuracy is 17 μm or more and less than 25 μm
2: Hole position accuracy is 25 μm or more and less than 35 μm
1: Hole position accuracy is 35 μm or more

＜ Evaluation method of average number of broken holes (bit breakage resistance) ＞
Calculate the number of openings until the drills are broken under the aforementioned processing conditions, calculate the average value of five, and evaluate the drill break resistance based on the obtained average value (average number of broken holes) according to the following criteria.
[Evaluation criteria]
5: The average number of broken holes is 8000 or more
4: The average number of broken holes is more than 7000 but less than 8000
3: The average number of broken holes is more than 6000 and less than 7000
2: The average number of broken holes is more than 5000 but less than 6000
1: The average number of broken holes is less than 5000

<Coiled>
8 copper-clad laminates (trade name: HL832NS-L, copper foil thickness of 3 μm, two panels, manufactured by Mitsubishi Gas Chemical Co., Ltd.) are stacked on the top surface of the copper-clad laminates with a thickness of 0.06 mm. The auxiliary plate for drilling manufactured in the examples and comparative examples has the resin composition layer side as the top surface, and an abutment plate having a thickness of 1.5 mm is arranged on the back surface (bottom surface) of the lowermost plate of the stacked copper-clad laminate. (Paper-phenol laminated board SPB-W, manufactured by Japan Decoluxe Co., Ltd.). Then, three 0.080 mmφ drill bits (trade name: KMWM476EWU, manufactured by Uniontool Co., Ltd.) were used, and a total of 30,000 holes were drilled for a total of 30,000 holes in accordance with the following conditions.
Speed: 280,000rpm
Feed speed: 1.4m / min
Opening times of 1 drill: 10,000 holes

The recovered drill was observed under a microscope with a magnification of 100 times. For the part where the chip has a resin composition layer coiled state, the maximum diameter in the drill diameter direction (hereinafter referred to as the "maximum diameter of the processing chip coil") was obtained, and the coiling was evaluated according to the following criteria.
[Evaluation criteria]
3: The maximum coiled diameter of the resin composition layer is less than 1.2 times the drill diameter
2: The maximum coiled diameter of the resin composition layer is 1.2 times or more and 2.0 times or less of the drill diameter.
1: The maximum winding diameter of the resin composition layer is more than 2.0 times the drill diameter

＜ Raw materials ＞
Table 1 shows the raw materials used in the manufacture of the auxiliary plate for drilling in the examples and comparative examples.

【Table 1】

<Example 1>
8 parts by mass of polyethylene oxide (AlkoxE-45, manufactured by Meisei Chemical Industry Co., Ltd.) having a weight average molecular weight of 560,000 as a polymer water-soluble resin (a-1), and as a medium-molecular water-soluble resin (a- 2) 77 parts by mass of polyethylene glycol (Sanyo Chemical Industry Co., Ltd., PEG4000S) with a weight average molecular weight of 3,300, and polyethylene glycol with a weight average molecular weight of 1,540 as a low molecular weight water-soluble resin (a-3)- 15 parts by mass of monostearate (Nippon Oil Co., Ltd., Nonion S15.4) was dissolved in a water / methanol mixed solvent so that the solid content concentration of the resin composition solution was 30%. The mixing ratio of the water / methanol mixed solvent was set to 50/50. This resin composition solution was applied on one side of an aluminum foil (using aluminum foil: JIS-A1100H, thickness 0.07 mm, manufactured by Mitsubishi Aluminum Corporation) using a coating bar, so that the thickness of the layer of the resin composition after drying became 50 μm, dried in a dryer at 90 ° C. for 5 minutes, and cooled to normal temperature to obtain an auxiliary plate for drilling.

<Examples 2 to 6, Comparative Examples 1 to 4>
The raw materials used were changed as shown in Table 2, and the same procedure as in Example 1 was performed except that an auxiliary plate for drilling was produced.

Table 2 shows each evaluation result, and FIG. 1 shows the measurement results of the shear storage elastic modulus of Examples 2, 3, and 5, and Comparative Examples 1, 2, and 3.

【Table 2】

This application is based on a Japanese patent application filed with the Japan Patent Office on March 30, 2018 (Japanese Patent Application No. 2018-69169), the contents of which are incorporated herein by reference.
[Industrial availability]

The present invention has industrial applicability as an auxiliary plate for drilling used in drilling and processing of laminated boards and multilayer boards. In particular, according to the present invention, an auxiliary plate for drilling can be provided. Compared with the conventional auxiliary plate for drilling, the hole position accuracy is better, and the drill rig is less damaged due to the peeling of the metal foil and the resin composition layer. In the past, it was a necessary adhesive layer, so it was economical.

[Figure 1] Measurement results of the shear storage elastic modulus of Examples 2, 3, and 5, and Comparative Examples 1, 2, and 3 are shown.

Claims (9)

An auxiliary plate for drilling has a metal foil and a resin composition layer formed on at least one side of the metal foil. The shear storage elastic modulus of the resin composition layer conforms to the following formulae (i) and (ii). Relationship; -3.0 ≦ △ G '≦ -1.0… (i) 4.5 × 10 ⁵ ≦ G' (56) ≦ 100 × 10 ⁵ … (ii) In the above formula, △ G '= log ₁₀ (G' (62 ))-log ₁₀ (G '(56)), G' (56), G '(62) each represents the shear storage elastic modulus of the resin composition at 56 ° C and 62 ° C, and the unit is Pa. For example, the auxiliary plate for drilling of item 1 of the patent application scope, wherein the resin composition layer is more in accordance with the relationship represented by the following formula (iii); 0.005 × 10 ⁵ ≦ G ′ (70) ≦ 80 × 10 ⁵ … (iii ), In the above formula, G '(70) represents the shear storage elastic modulus of the resin composition at 70 ° C, and the unit is Pa. For example, the auxiliary plate for drilling according to the scope of patent application No. 1 wherein the resin composition contains a water-soluble resin (A). For example, the auxiliary plate for drilling according to the first patent application range, wherein the resin composition contains a filler (B). For example, the auxiliary plate for drilling according to item 4 of the patent application scope, wherein the filler (B) is talc and / or molybdenum disulfide. For example, the auxiliary plate for drilling according to item 3 of the patent application scope, wherein the water-soluble resin (A) is selected from the group consisting of polyethylene oxide, polypropylene oxide, polytetramethylene glycol, and polyethylene glycol. Alcohols, polypropylene glycols, monoether compounds of polyoxyethylene, polyoxyethylene monostearate, polyoxyethylene sorbitan monostearate, polyglycerol monostearate compounds, and polyoxyethylene propylene copolymers One or more of the groups. For example, the auxiliary plate for drilling according to the scope of patent application No. 1, wherein the resin composition layer has a thickness in a range of 0.02 to 0.3 mm. For example, the auxiliary plate for drilling according to item 1 of the patent application range, wherein the metal foil has a thickness in the range of 0.05 to 0.5 mm. A drilling processing method includes a hole forming step of forming a hole in a laminated board or a multilayer board using an auxiliary board for drilling as described in item 1 of the patent application scope.