KR20140022781A - Drill entry sheet - Google Patents

Abstract

Compared with the conventional drill entry sheet, the present invention provides a drill entry sheet which is excellent in hole positional accuracy and reduces the breakage of the drill bit.
In a drill entry sheet in which a layer made of a resin composition is formed on at least one surface of a metal support foil, a solid lubricant containing at least one of zinc molybdate and molybdenum trioxide is blended into the resin composition, The drill entry sheet characterized by the thickness of 0.02-0.3 mm.

Description

Drill Entry Sheet {DRILL ENTRY SHEET}

This invention relates to the drill entry sheet used at the time of the drill processing of a copper clad laminated board or a multilayer board.

In the drill processing method of the copper clad laminated board or multilayer board used for a printed wiring board material, one or more copper clad laminated boards or a multilayer board are piled up, and a metal foil single body or metal foil, such as aluminum, as a reinforcing board on the top. The method of arrange | positioning the sheet | seat which forms the resin composition layer on the surface (henceforth this sheet in this specification, a "drill entry sheet" normally), and performing drill processing is generally employ | adopted.

In recent years, as a demand for copper clad laminates or multilayer boards, which are printed wiring board materials, there have been advances in high density, productivity improvement, cost reduction, and reliability improvement, and high quality drill processing such as improvement of hole location accuracy has been required. have. In order to respond to these demands, for example, Patent Document 1 proposes a drill processing method using a sheet made of a water-soluble resin such as polyethylene glycol. Moreover, in patent document 2, the drill lubricant sheet which provided the water-soluble resin layer in the metal foil is proposed. And in patent document 3, the drill entry sheet which provided the water-soluble resin layer in the aluminum foil in which the thermosetting resin thin film was formed is proposed. In addition, Patent Literatures 4 to 5 propose auxiliary materials which blend nanoparticles to extend the life of a drill bit.

However, compared with the progress of the semiconductor technology, the progress of the printed wiring board technology is slow, and there exists a deviation from the semiconductor technology. For this reason, the demand for higher density and improved reliability for printed wiring boards is becoming more advanced. For example, the minimum drill bit diameter in mass production is shifting from 0.1 mm mm to 0.105 mm mm through 0.18 mm mm and 0.15 mm mm. In addition, against a laser drilling technique, drilling of 0.08 mm phi, 0.075 mm phi, and 0.05 mm phi has been tried in a very small part. Furthermore, to meet the challenges of globalization and emerging country demand, productivity and cost reduction needs continue to grow. Accordingly, there is a desire for the development of a new drill entry sheet in accordance with this demand.

Japanese Patent Application Laid-Open No. H04-92494 Japanese Patent Application Laid-Open No. H05-169400 Japanese Patent Application Laid-Open No. 2003-136485 Japanese Utility Model Publication 3134128 Japanese Patent Publication No. 2007-281404

SUMMARY OF THE INVENTION An object of the present invention is to provide a drill entry sheet which is superior in hole position accuracy in view of such a phenomenon as compared with a conventional drill entry sheet. Development of such a drill entry sheet is eager to contribute to higher density, higher reliability, improved productivity, and lower cost.

MEANS TO SOLVE THE PROBLEM As a result of performing various examination in order to solve the said subject, as a solid lubricant (B), at least one of zinc molybdate and molybdenum trioxide was mix | blended with the resin composition of a drill entry sheet, and the compounding quantity was optimized. . As a result, it has been found that the drill bit is easy to bite and the hole position accuracy is improved by improving the centripetality of the drill bit. Furthermore, as the solid lubrication action of zinc molybdate and molybdenum trioxide improves the lubricity, and the discharge of cutting chips is smooth, the cutting powder is prevented from falling off and the drill bit is cut into the lumped cutting powder. It has been found that the problem of drill bit breakage due to stepping can be prevented.

The centripetality here means the straightness of a cutting direction at the time of cutting. For example, at the point where the drill bit contacts the resin composition layer of the drill entry sheet, the cutting blade of the tip of the rotating drill bit slides on the surface of the resin composition layer while sliding. Not only does it improve the lubricity, but also the cutting edge of the drill bit tip is easily slipped to the side, which impairs the centripetality and deteriorates the hole positioning accuracy.

This invention is made | formed based on such knowledge, The summary is as follows.

(1) A drill entry sheet in which a layer made of a resin composition is formed on at least one side of a metal support foil, wherein the resin composition contains at least one of zinc molybdate and molybdenum trioxide as a solid lubricant (B), and The thickness of a composition layer is the range of 0.02-0.3 mm, The drill entry sheet | seat characterized by the above-mentioned.

(2) Said resin composition contains water-soluble resin (A), The drill entry sheet as described in said (1) characterized by the above-mentioned.

(3) Said resin composition mix | blends the said solid lubricant (B) with a total of 1 weight part-40 weight part with respect to 100 weight part of the resin powders, The drill entry sheet as described in said (1) characterized by the above-mentioned.

(4) Said zinc molybdate is 1-7 micrometers in average particle diameter, The drill entry sheet as described in said (1) characterized by the above-mentioned.

(5) The said molybdenum trioxide is an average particle diameter of 3-35 micrometers, The drill entry sheet as described in said (1) characterized by the above-mentioned.

(6) The drill entry sheet according to the above (1), which is applied to a drill bit diameter of 0.2 mmφ or less.

(7) The said metal support foil is 0.05-0.5 mm in thickness, The drill entry sheet as described in said (1) characterized by the above-mentioned.

(8) The drill entry sheet as described in said (1) which has a primer layer which is a resin film on the said metal support foil.

(9) The drill entry sheet according to (8), wherein the primer layer contains the solid lubricant (B).

(10) The compound entry amount of the said solid lubricant (B) in a primer layer is 1 weight part-20 weight part with respect to 100 weight part of compositions of a primer, The drill entry sheet as described in said (9) characterized by the above-mentioned.

(11) The drill entry sheet according to the above (1), which is used for processing a copper clad laminate or a multilayer board.

By using the drill entry sheet of the present invention, the cutting of the drill bit at the time of drilling can be reduced by the excellent hole position accuracy at the time of drilling and the excellent lubricity of the resin composition layer. As a result, high-density design becomes possible further, and high quality and the productivity with excellent drill processing is attained. Alternatively, the number of overlapping sheets to be drilled at once can be increased, thereby contributing to productivity and cost reduction.

Fig. 1 is a scanning electron micrograph (× 10000) of zinc molybdate (manufactured by Nippon Inorganic Color & Chemical Co., Ltd., particle size 0.4 µm to 13 µm, average particle diameter 3 µm, layered structure). .
Fig. 2 is a scanning electron micrograph (x10000) of molybdenum trioxide (Nippon Inorganic Color & Chemical Co., Ltd., particle size 0.7 to 55 m, average particle size 16 m, columnar structure).
3 is a comparison diagram of the hole positional accuracy in Examples and Comparative Examples when processed under the drill processing condition 1. FIG.
4 is a comparison diagram of hole positions accuracy in Examples and Comparative Examples when processed under drill processing condition 2. FIG.

The drill entry sheet of this invention is a drill entry sheet which provided the layer (henceforth a "resin composition layer") which consists of a resin composition in at least one surface of metal support foil. The drill entry sheet of this invention is characterized by the resin composition containing a solid lubricant (B).

In the present invention, the solid lubricant (B) is any solid used as a thin film or powder to protect the surface from damage during relative movement and to reduce friction and wear, and has a melting point of 300 ° C. or more. It means that it is thermally stable in air at a temperature of 200 ° C. higher than the use temperature and is not melted but solid.

And as a solid lubricant (B), the compounding quantity of at least 1 of zinc molybdate and molybdenum trioxide is optimized. As a result, the drill bit is easy to bite and the centripetality of the drill bit is improved, so that the accuracy of hole position is improved, and further, the lubricity is improved and the discharge of the cutting powder is smoothed. It contributes to preventing the problem of drill bit breakage as the drill bit hits the agglomerated cutting powder.

Moreover, it is preferable that the resin composition of this invention is a composition containing water-soluble resin (A). Here, the said water-soluble resin (A) means water-soluble lubricant which is not a water-soluble resin and a solid lubricant (B).

Of course, the resin composition may include a known thermoplastic water-insoluble resin, a water-insoluble lubricant other than the solid lubricant (B), and other additives, for example, a nucleating agent, a colorant, a heat stabilizer, and the like.

As a resin part of the said resin composition, a water-insoluble lubricant other than a water-soluble resin (A) and a solid lubricant (B), and thermoplastic water-insoluble resin are mentioned. In addition to the original role, the resin powder of the resin composition also plays a role of a carrier for transporting the solid lubricant (B) to the drill bit and the printed wiring board material.

Although the said solid lubricant (B) is mix | blended so that it may be a total of 1 weight part-40 weight part with respect to 100 weight part of resin powder of a resin composition, it is preferable to mix | blend 1 weight part-30 weight part, and it is 5 weight part-20 weight part It is more preferable to mix | blend by addition, and it is most preferable to mix | blend 10 weight part-20 weight part. When the solid lubricant (B) is less than 1 part by weight, no effect is expressed. If the solid lubricant (B) exceeds 40 parts by weight, there is no economic rationality, and the solid lubricant (B) easily aggregates. As a result, difficulty arises in manufacturing, and as a result, hole positional accuracy may deteriorate.

In the present invention, the solid lubricant (B) is at least one of zinc molybdate (MoO ₄ Zn, melting point 900 ° C.) and molybdenum trioxide (MoO ₃ , melting point 795 ° C.). Although molybdenum trioxide has been known to not exhibit solid lubricity conventionally, it has been found to be useful as a solid lubricant (B) to be blended into a drill entry sheet. The solid lubricant (B) should just contain at least 1 sort (s) among these.

Since the said solid lubricant (B) expresses remarkable effect by a small amount mix | blending, compared with solid lubricants, such as molybdenum disulfide and mica, it is preferable. It is preferable also to express a remarkable effect in a small quantity by the point which expands the choice of resin as a resin composition.

The mechanism of action of the solid lubricant (B) is considered to be approximately as follows. First, by including solids of appropriate hardness in the lubricant layer, the tip of the drill bit touches and rubs on the solid lubricant (B). Therefore, the initial hole position accuracy is good. Second, since the solid lubricant (B) is blended into the lubricant layer, the solid lubricant (B) is attached to the surface or groove of the drill bit and the hole wall of the printed wiring board material. Since the solid lubricant (B) is solid and has a volume and hardness, the solid lubricant (B) is always present between the copper clad laminate or multilayer board and the drill bit to increase lubricity and to suppress drill bit wear. Third, since the solid lubricant B adheres to the grooves of the drill bit, the lubrication property is increased by the solid lubrication action, and the cutting powder is smoothed, so that the cutting powder is prevented from agglomerating.

By the way, the wear of a drill bit can be classified into two types. First, there is initial wear. That is, when the drill bit starts to be used, the portion to be impacted is broken. By the remarkable lubricating effect peculiar to the solid lubricant (B) described above, the initial wear of the drill bit is suppressed as compared with the case where the solid lubricant (B) is not contained. Second, there is normal wear. That is, the drill bit wears together with the accumulated drilling water. However, since there is a lubricating effect peculiar to the solid lubricant (B), the normal wear is also suppressed as compared with the case of not containing the solid lubricant (B). Therefore, the hole positional accuracy deteriorates in proportion to the cumulative number of drillings when it does not contain the solid lubricant (B), but may be gradually suppressed when it contains the solid lubricant (B).

Solid lubricant (B) can also be mix | blended with the resin film (henceforth called a primer layer) provided on metal support foil. Since the primer layer is an interface in contact with the aluminum foil, fine filling of the primer layer contributes to the pore position accuracy. Although the said solid lubricant (B) mix | blends a total of 1 weight part-20 weight part with respect to 100 weight part of compositions of a primer, it is more preferable to mix | blend 5 weight part-10 weight part. When the compounding quantity of a solid lubricant (B) is less than 1 weight part, an effect is not expressed. When the compounding quantity of a solid lubricant (B) exceeds 20 weight part, there is no economic rationality and the adhesiveness of a thin thickness primer layer and metal support foil may be impaired. Resin of the primer layer which mix | blends a solid lubricant (B) can be applied to both a thermosetting resin or a thermoplastic resin. It is more preferable for the pore position accuracy that the resin of the primer layer is a thermosetting resin.

As for the solid lubricant (B), it is more preferable to select the optimum type, particle size, and compounding amount according to the specifications of the copper clad laminate or multilayer board.

As the solid lubricant (B), for example, zinc molybdate exhibits an effect as follows. Zinc molybdate has a layered structure, is in the range of 0.2 µm to 15 µm in particle size, has an average particle diameter of 1 to 7 µm, and is a solid having a volume and appropriate hardness. Preferably it is 2-6 micrometers in average particle diameter. More preferably, it is 3-5 micrometers in average particle diameter. Because of its characteristics, the drill bit is easy to bite in a small diameter drill bit where hole position accuracy is important. In addition, zinc molybdate has a layered structure and is thin so that it is easy to be rolled into the groove at the time of rotation of the drill bit, thus contributing to the discharge of the cutting powder.

The reason for the effect of molybdenum trioxide is as follows. Molybdenum trioxide oxidizes molybdenum disulfide, has a columnar structure, has a particle size of 0.7 µm to 55 µm, an average particle diameter of 3 to 35 µm, and is a solid having a volume and appropriate hardness. Preferably it is 5-20 micrometers in average particle diameter. More preferably, it is an average particle diameter of 10-18 micrometers. Because of its characteristics, the drill bit is easy to bite in a small diameter drill bit where hole position accuracy is important. In addition, since molybdenum trioxide has a smaller average particle diameter than the depth of the groove of the drill bit, the molybdenum trioxide is easily incorporated into the groove during rotation of the drill bit, thus contributing to the discharge of the cutting powder.

For the particle size of the solid lubricant (B), the average particle size value is more important than the maximum particle size value. The reason for this is that the particle diameter of the solid lubricant having a high proportion of the resin composition affects the hole positional accuracy and the lubricity characteristic of the drill entry sheet. Therefore, managing the average particle diameter of the solid lubricant (B) becomes important for improving the performance of the drill entry sheet. Therefore, the ratio of the maximum particle size to the particle size distribution of the solid lubricant (B) is high, and it is not preferable to increase the average particle diameter value largely because it may reduce the originally expected solid lubricity. In the particle size measurement method of the solid lubricant (B), the sample is dispersed in a solution consisting of a 0.2% hexametaphosphate solution and a few drops of 10% triton, and a laser diffraction particle size distribution measuring device (model number: SALD-2100, manufactured by Shimadzu Corporation) Using, the maximum length of each particle | grain of the projected solid lubricant (B) is measured. The particle size distribution curve is then calculated. The range of the curve was made into the particle size of a solid lubricant (B), and the particle size at the time of maximum component amount peak of a curve was made into the average particle diameter.

In particular, when the solid lubricant (B) is zinc molybdate and molybdenum trioxide, it is not completely insoluble in water but is non-swellable. Therefore, like the swellable solid lubricant, it is not necessary to strictly control the degree of moisture, which is industrially advantageous. Here, the definition of non-swelling property is until it mixes enough to mix the aqueous solution which mix | blended 10 weight part of solid lubricants with 90 weight part of water, and after settling for 1 hour, the sedimentation height of a solid lubricant is measured and sedimentation height ratio 90% The above-mentioned dispersion or swelling and sedimentation height ratio of 50% or more and less than 90% are defined as swelling and sedimentation height ratio of less than 50% as non-swelling. In the zinc molybdate of the present application, there is an example in which the height is 66 mm to the liquid level and 21 mm to the upper surface of the settling portion of zinc molybdate, and the sedimentation height ratio is 32% and two layers are clearly separated. Similarly, in the molybdenum trioxide of the present application, the height is 35 mm to the liquid level, 5 mm to the upper surface of the settling portion of molybdenum trioxide, and there is an example where the sedimentation height ratio is 14% and the turbidity is from the upper surface of the settling portion of molybdenum trioxide to the liquid level.

These characteristics have the following advantages when producing a solution of the water-soluble resin (A). It is easy to disperse | distribute uniformly, and it is hard to aggregate. When the molybdenum zinc and molybdenum trioxide remain in the hole after the drilling, it is easy to wash. However, when manufacturing the solution of water-soluble resin (A), since the concentration gradient of solid lubricant (B) is formed, it is necessary to stir.

The hardness of the solid lubricant (B) is not suitable because, for example, an area exceeding Mohs hardness 5 becomes an abrasive. The optimum compounding quantity of a solid lubricant (B) differs in the specification of the printed wiring board to drill. Compared with the printed wiring board material which does not contain an inorganic filler, since the wear of a drill bit is comparatively large in the printed wiring board material which contains an inorganic filler, it may be preferable to mix | blend many solid lubricants (B).

Although the kind of the said water-soluble resin (A) is not specifically limited, As water-soluble resin, polyethylene oxide, a polypropylene oxide, sodium polyacrylate, polyacrylamide, polyvinylpyrrolidone, carboxymethyl cellulose, polytetra It is preferable that it is 1 type (s) or 2 or more types chosen from the group which consists of polyesters of methylene glycol and polyalkylene glycol. Polyester of polyalkylene glycol is a condensate obtained by making polyalkylene glycol and dibasic acid react. Examples of the polyalkylene glycols include glycols exemplified by polyethylene glycol, polypropylene glycol, polytetramethylene glycol and copolymers thereof, and polyhydric acids such as phthalic acid, isophthalic acid, terephthalic acid, sebacic acid and pyromellitic acid as dibasic acids. It is preferable to select from partial esters of carboxylic acids, acid anhydrides and the like. As a water-soluble lubricant which is not a solid lubricant (B), For example, polyethyleneglycol, polypropylene glycol; Polyoxyethylene monoethers such as polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether, Ryu; Polyoxyethylene monostearate, polyoxyethylene sorbitan monostearate; Polyglycerin monostearates exemplified by hexaglycerin monostearate, decahexa glycerin monostearate and the like; Polyoxyethylene propylene copolymer etc. are mentioned, It is preferable to mix | blend 1 type or 2 or more types suitably.

The thermoplastic water-insoluble resin is not particularly limited, and a known substance can be applied. For example, amide elastomer, butadiene elastomer, ester elastomer, olefin elastomer, urethane elastomer, styrene elastomer, polybutene, low density polyethylene, chlorinated polyethylene, metallocene polyolefin resin, ethylene acrylic acid ester, maleic anhydride Copolymer, ethylene glycidyl (meth) acrylate copolymer, ethylene vinyl acetate copolymer resin, modified ethylene vinyl acetate copolymer resin, ethylene (meth) acrylic acid copolymer resin, ionomer resin, ethylene (meth) acrylic acid Ester copolymer resin etc. are illustrated.

The water-insoluble lubricant other than the solid lubricant (B) is not particularly limited, and a known substance can be applied. For example, an amide compound exemplified by ethylenebisstearamide, oleic acid amide, stearic acid amide, methylene bis stearamide, and the like, a fatty acid compound exemplified by lauric acid, stearic acid, palmitic acid, oleic acid, butyl stearate, Fatty acid ester compounds exemplified by butyl oleate, glycol laurate and the like, aliphatic hydrocarbon compounds exemplified by liquid paraffin, polyethylene wax and the like, and higher aliphatic alcohols exemplified by oleyl alcohol and the like.

Although the thickness of the said resin composition layer differs according to the drill bit diameter used at the time of drill processing, the structure of the copper clad laminated board or a multilayer board, etc. which are processed, it is usually in the range of 0.02-0.3 mm, and suitably in the range of 0.02-0.2 mm. It is preferred to be selected. If the thickness of the resin composition layer is less than 0.02 mm, sufficient lubrication effect cannot be obtained, and the load on the drill bit may increase, and there is a fear that breakage of the drill bit occurs. On the other hand, when the thickness of a resin composition layer exceeds 0.3 mm, the winding of the said resin composition with a drill bit may increase.

Moreover, as a method of forming the said resin composition layer, on the said metal support foil, the method of coating and drying a hot melt and a solution of a direct resin composition by a coating method etc., or the sheet of a resin composition is produced previously, The hot-melt method etc. which are bonded with the said metal support foil are illustrated. At this time, since the resin film (primer layer) is previously formed in the metal support foil, since the layer of a metal support foil and a resin composition is integrated together, it is preferable. The details will be described later.

Furthermore, when employ | adopting the method of coating and drying the solution of a resin composition directly on a metal support foil by a coating method etc., it is preferable that the solution used is a solution containing water and a solvent whose boiling point is lower than water. The kind of the solvent having a lower boiling point than water is not particularly limited. Examples thereof include ethanol such as alcohols, methanol and isopropyl alcohol, and low boiling point solvents such as methyl ethyl ketone and acetone can also be used. As another solvent, the solvent etc. which mixed tetrahydrofuran and acetonitrile which are highly compatible with resin composition in water or alcohol can be used. Although the compounding ratio of water and the solvent whose boiling point is lower than water needs to be the range of 90/10-50/50, the range of 80/20-50/50 is preferable, and the range of 70/30-50/50 Is more preferable, and the range of 60 / 40-50 / 50 is still more preferable. When the compounding ratio of the solvent whose boiling point is lower than water is less than 10, the said water-soluble resin (A) may be difficult to produce a dense spherical crystal. When the compounding ratio of the solvent whose boiling point is lower than water exceeds 50, there exists a possibility that it may interfere with industrial stable production.

In addition, when employ | adopting the method of coating and heat-drying the solution of a resin composition directly on a metal support foil by coating method, a hot-melt method, etc., the temperature of the said drill entry sheet is 5-30 from 120 degreeC-160 degreeC It is necessary to do it at room temperature early. High drying temperature beyond 160 degreeC is unpreferable since it may interfere with industrial stable production. Moreover, since cooling temperature lower than normal temperature may cause dew condensation in a post process, it is not preferable.

About the metal support foil used for the drill entry sheet of this invention, if adhesiveness with the said resin composition is high, and it is a metal material which can endure the impact by a drill bit, it will not specifically limit. The thickness of a metal support foil is 0.05-0.5 mm normally, Preferably it is 0.05-0.3 mm. When the thickness of this metal support foil is less than 0.05 mm, burrs of a laminated board are likely to occur at the time of drilling, and when it exceeds 0.5 mm, it is difficult to discharge the cutting powder generated at the time of drilling. As a metal type of metal support foil, aluminum can be used, for example. As the material of the aluminum foil, aluminum having a purity of 95% or more is preferable, and examples thereof include 5052, 3004, 3003, 1N30, 1N99, 1050, 1070, 1085, 8021, and the like, which are specified in JIS-H4160. By using a high-purity aluminum foil for the metal support foil, the impact caused by the drill bit is alleviated, the biting property with the tip of the drill bit is improved, and the lubrication effect of the drill bit with the resin composition is processed. The hole position accuracy of the hole can be improved. Moreover, it is preferable to use the metal support foil in which the resin film (primer layer) of thickness 0.002-0.02mm was previously formed in the surface from the adhesive point with a resin composition. When mix | blending a solid lubricant (B) with the said resin film, the thickness of a resin film is suitably selected according to the particle diameter of a solid lubricant (B). About resin used for this resin film, if adhesiveness with the said resin composition can be improved, it will not specifically limit, Any of a thermoplastic resin and a thermosetting resin can be used. For example, a urethane type polymer, a vinyl acetate type polymer, a vinyl chloride type polymer, a polyester type polymer, an acrylic type polymer, and copolymers thereof are illustrated as a thermoplastic resin. Examples of the thermosetting resin include resins such as an epoxy resin and a cyanate resin.

The drill entry sheet of this invention is used when drilling a printed wiring board material, for example, a copper clad laminated board or a multilayer board. Specifically, a drill entry sheet is disposed on the top of one or more sheets of copper-clad laminates or multilayer boards so that the metal support foil side is in contact with the printed wiring board material, and drill processing is performed from the surface of the resin composition layer. I can do it.

The above has just shown an example of embodiment of this invention, and can be variously changed in the range as described in a claim.

Example

Hereinafter, the effect of the Example of this invention is demonstrated compared with the comparative example which departed from the range of this invention. On the other hand, "polyethylene glycol" may be abbreviated as "PEG" and "polyethylene oxide" as "PEO".

≪ Example 1 >

30 parts by weight of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., ALTOP MG-150) having a weight average molecular weight of 150,000, and 70 parts by weight of polyethylene glycol (manufactured by Sanyo Chemical Industries, Ltd., PEG20000) having a weight average molecular weight of 20,000 The solution was dissolved in water / MeOH (methanol) mixed solution so as to reach 30%. The ratio of water and MeOH at this time was 60/40. Then, 100 parts by weight of zinc molybdate (manufactured by Nippon Inorganic Color & Chemical Co., Ltd., particle size 0.4 µm to 13 µm, average particle diameter 3 µm) was added to the solution of the water-soluble resin composition as a solid lubricant (B). About 5 parts by weight of the mixture, the mixture was sufficiently dispersed. The solution of this water-soluble resin composition is dried on the aluminum foil (used aluminum foil: 1N30, thickness 0.1mm, Mitsubishi Aluminum Co., Ltd.) which formed the epoxy resin film of thickness 0.01mm on one side using the bar coater. After apply | coating so that the water-soluble resin composition layer of thickness might be 0.05 mm, it dried at 120 degreeC and 5 minutes with a drier, and cooled to normal temperature, and produced the drill entry sheet.

<Examples 2-14>

According to Example 1, the water-soluble resin composition shown in Table 1 was prepared, and the drill entry sheet whose thickness of the water-soluble resin composition layer after drying is 0.05 mm was produced.

<Comparative Examples 1-11>

According to Example 1, the water-soluble resin composition shown in Table 1 was prepared, and the drill entry sheet whose thickness of the water-soluble resin composition layer after drying is 0.05 mm was produced.

<Evaluation method>

The following evaluation was performed about each sample of the drill entry sheet produced by the Example and the comparative example.

(1) hole position accuracy

On the copper-clad laminate, the drill entry sheet was placed with the resin composition layer faced up and drilled. 6,000 hits per drill bit were drilled and repeated using four drill bits. For every 1 to 1,500 and 1 to 6,000 hits of holes per drill bit, the hole position on the back of the bottom plate of the stacked copper clad laminate and the misalignment between the specified coordinates and the hole analyzer (Model No .: HA-1AM) , Manufactured by Hitachi Via Mechanics, Ltd.), and the average value and the standard deviation (?) Were calculated to calculate “average value + 3σ”. And the average value of "average value +3 (sigma)" for four drill bits is calculated, and a result is shown in Table 1. FIG.

As a criterion for determining the hole position accuracy, it is determined by the hole position precision of 1 to 1,500 hits where the drill bit wear is not advanced and the hole position precision of 1 to 6,000 hits where the drill bit wear is advanced. When judgment of 1-1,500 and 1-6,000 hits is "○", it is set as "○" by comprehensive evaluation.

(2) Particle size measurement method of solid lubricant (B)

In the particle size measurement method of the solid lubricant (B), the sample is dispersed in a solution consisting of a 0.2% hexametaphosphate solution and a few drops of 10% triton, and a laser diffraction particle size distribution measuring device (model number: SALD-2100, manufactured by Shimadzu Corporation) Using, the maximum length of each particle | grain of the projected solid lubricant (B) is measured. The particle size distribution curve is then calculated. The range of the curve was made into the particle size of a solid lubricant (B), and the particle size at the time of maximum component amount peak of a curve was made into the average particle diameter.

[Table 1]

Composition of Water-Soluble Resin (A):

1) 30 parts by weight of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., ALTOP MG-150, Mw = 150,000), 70 parts by weight of polyethylene glycol (manufactured by Sanyo Chemical Industries, Ltd., PEG20000, Mw = 20,000), total 100 parts by weight part.

2) 20 parts by weight of polyether ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Paogen PP-15, Mw = 100,000), 80 parts by weight of polyethylene glycol (manufactured by Sanyo Chemical Industries, Ltd., PEG4000S, Mw = 4,000) 100 parts by weight in total.

Type of solid lubricant (B):

3) Zinc molybdate (manufactured by Nippon Inorganic Color & Chemical Co., Ltd., particle size 0.4㎛ ~ 13㎛, average particle diameter 3㎛, layered structure)

4) Molybdenum trioxide (manufactured by Nippon Inorganic Color & Chemical Co., Ltd., particle size: 0.7 μm to 55 μm, average particle size: 16 μm, columnar structure)

5) Molybdenum disulfide (made by Daizo Corporation, M-5 Powder, particle size 0.5 ~ 29㎛, average particle diameter 5㎛, layered structure)

6) Swellable Mica (manufactured by Co-op Chemical Co., Ltd., ME-100, particle size 5 ~ 7㎛, layer structure)

7) Non-swellable mica (manufactured by Co-op Chemical Co., Ltd., MK-200, particle size 5 ~ 8㎛, layered structure)

8) Solid lubricant (B) not blended

Compounding amount of solid lubricant (B):

A solid lubricant (B) mix | blends one of 0, 5, 10, 20, 40, 60, 80 weight part with respect to 100 weight part of resin powder of a resin composition.

Drilling condition:

1) Drill bit diameter: 0.2 mmφ (C-CFU020S manufactured by Tunaloy Corporation), rotation speed: 200,000 rpm, feed speed: 20 µm / rev., Ascending speed: 25.4 m / min, and the processing material is an inorganic filler. HL832 0.2 mmt without, Cu12μ, 5-sheet overlap

2) Drill bit diameter: 0.2 mmφ (C-CFU020S manufactured by Tunaloy Corporation), rotation speed: 200,000 rpm, feed speed: 20 µm / rev., Ascending speed: 25.4 m / min, and the processing material is an inorganic filler. HL832HS0.2mmt, Cu12μ, 5-sheet nested

From the results of Table 1, it can be seen that the samples of Examples 1 to 14 are excellent in hole position accuracy in both the stage where the drill bit wear does not progress and the stage where the wear progresses, as compared with the samples of Comparative Examples 1 to 11. That is, the zinc molybdate and molybdenum trioxide of the present invention are remarkably superior in pore position accuracy compared to molybdenum disulfide, swellable mica, and non-swellable mica, which are conventional technologies.

Industrial availability

According to the present invention, it is possible to provide a drill entry sheet which is superior in hole positional accuracy and that the breakage of the drill bit is reduced as compared with the conventional drill entry sheet.

Claims (11)

In the drill entry sheet in which the layer which consists of a resin composition was formed in at least one surface of metal support foil, The said resin composition contains at least one of zinc molybdate and molybdenum trioxide as a solid lubricant (B), The said resin composition layer The thickness of 0.02-0.3 mm of drill entry sheet | seat characterized by the above-mentioned.
The method of claim 1,
The said resin composition contains water-soluble resin (A), The drill entry sheet | seat characterized by the above-mentioned.
The method of claim 1,
The said resin composition mix | blends the said solid lubricant (B) with a total of 1 weight part-40 weight part with respect to 100 weight part of the resin powder, The drill entry sheet characterized by the above-mentioned.
The method of claim 1,
The said zinc molybdate has an average particle diameter of 1-7 micrometers, The drill entry sheet | seat characterized by the above-mentioned.
The method of claim 1,
The molybdenum trioxide is a drill entry sheet, characterized in that the average particle diameter of 3 ~ 35㎛.
The method of claim 1,
A drill entry sheet, which is applied at a drill bit diameter of 0.2 mmφ or less.
The method of claim 1,
The said metal support foil has a thickness of 0.05-0.5 mm, The drill entry sheet | seat characterized by the above-mentioned.
The method of claim 1,
The drill entry sheet which has a primer layer which is a resin film on the said metal support foil.
9. The method of claim 8,
The said primer layer contains the said solid lubricant (B), The drill entry sheet | seat characterized by the above-mentioned.
10. The method of claim 9,
The compounding quantity of the said solid lubricant (B) in a primer layer is 1 weight part-20 weight part with respect to 100 weight part of compositions of a primer, The drill entry sheet characterized by the above-mentioned.
The method of claim 1,
A drill entry sheet used for processing copper clad laminates or multilayer boards.

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