JPH11330310A - Laser boring copper-plated laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a laser boring copper-plated laminate where a hole of small diameter can be bored at a high speed with a carbon dioxide laser of high power, and the inner wall of the hole is high in reliability, by a method wherein a glass cloth base is impregnated with thermosetting resin composition where a specific amount of inorganic, filler is uniformly dispersed and dried out into a prepreg, and a double-sided copper plated laminate is formed of the prepregs. SOLUTION: A double-sided copper plated laminate is formed of glass cloth as a base material, the glass cloth is impregnated with thermosetting resin composition, it is preferable that the thermosetting resin composition is compounded with 0.1 to 10 wt.% dye or pigment to turn black, and 10 to 60 wt.% inorganic insulating filler is mixed into the resin composition and uniformly kneaded. In this case, it is preferable that thermosetting resin whose glass transition temperature is 150 deg.C or above is used from the viewpoint of the shape of a through-hole bored by irradiation with a carbon dioxide gas laser beam of high power, and multi-functional cyanic acid ester resin is preferably used from a viewpoint of resistance to moisture and migration and electrical properties after it absorbs moisture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass cloth-based copper-clad laminate for forming through-holes and via-holes by irradiating a laser energy such as a high-output carbon dioxide gas laser instead of a mechanical drill. The present invention relates to a copper-clad laminate of a glass cloth base material which is directly drilled with a carbon dioxide laser at a high output without etching away a surface copper foil in advance. A printed wiring board using the copper-clad laminate obtained by drilling is mainly used for small semiconductor plastic packages.

[0002]

2. Description of the Related Art Hitherto, in high-density printed wiring boards used for semiconductor plastic packages and the like, through holes for through holes have been drilled. In recent years, the diameter of drills has become smaller and smaller, and the hole diameter has been reduced to 0.15 mmφ or less.When drilling such small holes, the drill diameter is small, so the drill bends, breaks, and the processing speed when drilling. It has disadvantages such as slowness, and has problems in productivity, reliability, and the like. Furthermore, if holes of the same size are made in advance by using a negative film on the upper and lower copper foils by a predetermined method, and a through hole that passes through the upper and lower sides with a carbon dioxide laser is to be formed, Causes a gap,
There were drawbacks such as difficulty in forming lands. Thermosetting resin copper-clad laminate of glass cloth base material, when the output is small, it is difficult to process the glass, there are problems such as fluff left on the hole wall, on the other hand, when the output is large, The unevenness became large, which was a problem.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and provides a high-output carbon dioxide laser capable of forming small-diameter holes at a high speed and with a reliable hole wall. With the goal.

[0004]

The energy sufficient to remove the copper foil with a carbon dioxide laser is 20 to 60 mJ / pulse. Using the energy selected from the above energy band, using a supplemental material on the copper-clad laminate by pulse oscillation of a carbon dioxide gas laser, directly irradiating high-output carbon dioxide laser energy, Or, in the configuration of a copper-clad laminate for drilling via holes, 10-60% by weight
An inorganic filler, and further, if necessary, 0.1 to 10% by weight of a black dye or pigment, a thermosetting resin composition uniformly dispersed therein, a glass cloth substrate, glass content is generally 30 ~ 85
By using a prepreg prepared by impregnating and drying to give a weight%, a double-sided copper-clad laminate is used. An auxiliary material for drilling is arranged on the copper-clad laminate. It has become possible to form a through hole for a through hole or a via hole by directly irradiating energy. Thereafter, both surfaces of the metal foil are etched in a plane, and a part of the thickness of the original metal foil is removed by etching. By forming the through-hole plating holes in which the copper foil remains, the copper foil positions of the holes above and below the through-hole do not shift, lands can be formed, and the through-hole can be formed without bending up and down, and Since the copper foil becomes thinner, there is no occurrence of defects such as short-circuits and pattern breaks in the formation of fine wire circuits of the front and back copper foil obtained by plating up with subsequent metal plating, and high-density printed wiring boards can be used. Could be created. In addition, a processing speed was remarkably higher than that of the case of drilling, and a product having good productivity and excellent economic efficiency was obtained. After drilling the through-holes, the surface can be polished by polishing in addition to the method of etching with a chemical, but it is preferable to perform etching with a chemical from the viewpoint of removing burrs and forming a fine pattern. Drilling can be performed not only on a double-sided copper-clad laminate, but also on a multilayer board obtained using the same resin composition. This copper-clad laminate can be suitably used even when directly drilling with a YAG (UV) laser.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a high-output carbon dioxide laser energy to directly irradiate a laser,
The present invention relates to a double-sided copper-clad laminate for forming a through hole for a through hole, a via hole, and particularly a small diameter hole. The perforated printed wiring board is used for mounting a semiconductor chip. When drilling a copper-clad laminate with a carbon dioxide laser, the surface to be irradiated with the laser is subjected to a metal oxide treatment in advance as an auxiliary material to form a film, or has a melting point of 900 ° C or more and a binding energy of 300 kJ / mol or more metal compound powder,
A coating film or sheet containing an organic material containing one or more of carbon powder or metal powder, and other known auxiliary materials are disposed, and high-output carbon dioxide gas laser energy is directly applied to the surface of the copper foil to pass through. This is a double-sided copper-clad laminate for forming through holes for holes or via holes.

[0006] The double-sided copper-clad laminate obtained by the present invention is made of a glass cloth as a base material, and a thermosetting resin composition is preferably blended with 0.1 to 10% by weight of a dye or pigment to make it black, and ,
It is a double-sided copper-clad laminate or multilayer board having a homogeneous composition by mixing 10 to 60% by weight of an inorganic insulating filler. As a substrate,
Generally known glass woven fabric and nonwoven fabric can be used. Specifically, examples of glass fibers include E, S, D, and N glass. The glass content is generally between 30 and 85% by weight.

[0007] As the resin of the thermosetting resin composition used in the present invention, generally known thermosetting resins are used. Specifically, an epoxy resin, a polyfunctional cyanate ester resin, a polyfunctional maleimide-cyanate ester resin, a polyfunctional maleimide resin, an unsaturated group-containing polyphenylene ether resin, and the like, and one or more kinds Are used in combination. From the viewpoint of through-hole shape in processing by high-output carbon dioxide laser irradiation, a thermosetting resin having a glass transition temperature of 150 ° C or higher is preferable, and moisture resistance, migration resistance, electrical characteristics after moisture absorption, etc. Thus, a polyfunctional cyanate resin is preferred.

The polyfunctional cyanate compound which is the thermosetting resin component of the present invention is a compound having two or more cyanato groups in the molecule. Specifically, 1,3-
Or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanato Naphthalene, 1,3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis
(3,5-dibromo-4-cyanatophenyl) propane, bis (4
-Cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite, tris
(4-cyanatophenyl) phosphate, and cyanates obtained by reacting novolak with cyanogen halide.

In addition to these, Japanese Patent Publication Nos. 41-1928 and 43-1846
8, polyfunctional cyanate compounds described in JP-A-44-4791, JP-A-45-11712, JP-A-46-41112, JP-A-47-26853 and JP-A-51-63149 can also be used. Further, a prepolymer having a molecular weight of 400 to 6,000 and having a triazine ring formed by trimerization of a cyanato group of these polyfunctional cyanate compounds is used. This prepolymer is obtained by polymerizing the above-mentioned polyfunctional cyanate ester monomer with a catalyst such as an acid such as a mineral acid or a Lewis acid; a base such as a tertiary amine such as sodium alcoholate; or a salt such as sodium carbonate. It can be obtained by: The prepolymer also contains some unreacted monomers and is in the form of a mixture of the monomer and the prepolymer, and such a raw material is suitably used for the purpose of the present invention. Generally, it is used after being dissolved in a soluble organic solvent.

As the epoxy resin, generally known epoxy resins can be used. Specifically, liquid or solid bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy resin; butadiene, pentadiene, vinylcyclohexene, dicyclopentyl ether, etc. And polyglycidyl compounds obtained by reacting a polyol, a hydroxyl-containing silicone resin with an epohalohydrin, and the like. These may be used alone or in combination of two or more.

As the polyimide resin, generally known ones can be used. Specific examples include a reaction product of a polyfunctional maleimide and a polyamine, and a polyimide having a terminal triple bond described in JP-B-57-005406.

These thermosetting resins may be used alone, but it is preferable to use them in an appropriate combination in consideration of the balance of properties.

Various additives can be added to the thermosetting resin composition of the present invention, if desired, as long as the inherent properties of the composition are not impaired. These additives include polymerizable double bond-containing monomers such as unsaturated polyesters and prepolymers thereof; polybutadiene, epoxidized butadiene, maleated butadiene, butadiene-
Low molecular weight liquid to high molecular weight elastic rubbers such as acrylonitrile copolymer, polychloroprene, butadiene-styrene copolymer, polyisoprene, butyl rubber, fluororubber, natural rubber; polyethylene, polypropylene, polybutene, poly-4-methyl Penten, polystyrene, AS
Resin, ABS resin, MBS resin, styrene-isoprene rubber,
Polyethylene-propylene copolymer, 4-fluoroethylene-
6-fluorinated ethylene copolymers; high molecular weight prepolymers or oligomers such as polycarbonate, polyphenylene ether, polysulfone, polyester, and polyphenylene sulfide; and polyurethane are exemplified and used as appropriate. In addition, other known organic fillers, thickeners, lubricants, defoamers, dispersants, leveling agents, photosensitizers,
Various additives such as a flame retardant, a brightener, a polymerization inhibitor, and a thixotropy-imparting agent are used in an appropriate combination as required.
If necessary, the compound having a reactive group is appropriately blended with a curing agent and a catalyst.

The thermosetting resin composition of the present invention can be cured by heating itself, but has a low curing rate and is inferior in workability and economic efficiency. Therefore, a known thermosetting catalyst is used for the thermosetting resin used. Can be used. The amount used is 0.005 to 10 parts by weight, preferably 0.01 to 5 parts by weight, per 100 parts by weight of the thermosetting resin.

As the inorganic insulating filler, generally known ones can be used. Specifically, silicas such as natural silica, calcined silica, and amorphous silica; white carbon, titanium white, aerosil, clay, talc,
Examples include wollastonite, natural mica, synthetic mica, kaolin, magnesia, alumina, and pearlite. The amount added is 10 to 60% by weight of the total composition, preferably 15%.
~ 50% by weight.

Preferably, a black dye or pigment is added to the resin so that the light is not dispersed by the irradiation of the carbon dioxide laser. The particle diameter is preferably 1 μm or less for uniform dispersion. As the types of the dye and the pigment, generally known insulating ones can be used. The addition amount is preferably 0.1 to 10% by weight. Further, glass fibers or the like in which the surface of the fibers is dyed black may be used. As the outermost copper foil, generally known ones can be used. Preferably, an electrolytic copper foil having a thickness of 3 to 18 μm or the like is used.

The glass cloth substrate-reinforced copper-clad laminate is prepared by first impregnating the above-mentioned glass cloth substrate with a thermosetting resin composition and drying to form a B-stage, and prepreg so that the glass content is 30 to 85% by weight. Create Next, a predetermined number of the prepregs are used, copper foils are arranged on the upper and lower sides, and laminated under heat and pressure to form a double-sided copper-clad laminate. In the cross section of the copper clad laminate, the resin and inorganic filler other than glass are uniformly dispersed, and the holes are uniformly formed when laser drilling is performed. By adding an inorganic insulating filler, and by the glass transition temperature of the thermosetting resin composition is 150 ℃ or more,
Further, by adding a black dye or pigment, the dispersion of the laser beam is suppressed, and the unevenness of the hole wall due to the heat generated by the irradiation of the carbon dioxide gas laser is almost eliminated.

The auxiliary material used in the present invention has a melting point of 90.
As the metal compound having a binding energy of 300 kJ / mol or higher at 0 ° C. or higher, generally known metal compounds can be used. Specifically, as an oxide. Titania such as titanium oxide; magnesia for magnesium oxide window; iron oxide such as iron oxide; nickel oxide such as nickel oxide; manganese oxide such as manganese dioxide; zinc oxide such as zinc oxide. Cobalt oxides such as silicon dioxide, aluminum oxide and cobalt oxide; tin oxides such as tin oxide; and tungsten oxides such as tungsten oxide. Various glass powders such as E, A, C, L, D, S, M, and N glasses are mixtures of the above oxides, and these can also be suitably used.

Examples of the non-oxide include generally known ones such as silicon carbide, tungsten carbide, boron nitride, silicon nitride, titanium nitride, aluminum nitride, barium sulfate, calcium carbonate, and rare earth oxysulfide. In addition, carbons can also be used. These are used alone or in combination of two or more.

As these auxiliary materials, molecules are dissociated into atoms or small molecules by irradiation of a carbon dioxide gas laser or a UV laser, or are scattered by heat, which has a bad influence on a semiconductor chip, adhesion to a hole wall or the like. None are used. N
Since a, K, Cl ions and the like particularly adversely affect the semiconductor, those containing these components are not suitable. The compounding amount is from 3 to 97% by volume, preferably from 5 to 95% by volume, and is usually a powder of 5 μm or less, preferably 1 μm or less. Used dispersed.

Further, as an auxiliary material, metal powder can be used. This is likewise in organic matter
Used in an amount of 3 to 97 vol%. As the metal powder, generally known ones can be used. Specifically, simple substances such as silver, aluminum, bismuth, cobalt, copper, iron, manganese, molybdenum, nickel, vanadium, antimony, silicon, tin, vanadium, and zinc, and alloys thereof are exemplified. These are used alone or in combination of two or more. The average particle size is preferably 1 μm or less. Among them, metal powder that generates heat and ignites when dissolved in water, an organic solvent or the like is not used.

Although there is no particular limitation on the organic material of the auxiliary material, a material which does not peel off or drop off when kneaded and applied to the surface of a copper foil or a film and dried is selected. Generally,
A resin is used, and a water-soluble resin, for example, a generally known resin such as polyvinyl alcohol, polyester, and starch is used from the viewpoint of washing or removing the surface of the copper foil after processing. Further, if necessary, the above-mentioned various resins, additives and the like can be appropriately selected and used.

The method of preparing a composition comprising one or more of metal compound powder, carbon powder, and metal powder and an organic substance is not particularly limited. Using a resin that dissolves in a solvent or water, adding the above powder to the mixture, applying a uniform mixture to the surface of the copper foil as a paint, and drying to form a paint film. A method of directly spraying and drying a foil surface to form a coating film, a method of applying and drying a film to form a sheet with a resin composition, a method of impregnating and drying an organic or inorganic base material and drying to obtain a base-containing sheet, and the like. A generally known method can be used.

Further, as an auxiliary treatment layer, the surface of the copper foil can be perforated by performing a metal oxide treatment. As the metal oxide treatment, a generally known method can be used. Specific examples include black copper oxide treatment and brown copper oxide treatment. In addition, known auxiliary materials can be used.

As the glass-clad laminate of the present invention, a copper-clad laminate obtained by etching a surface of a copper foil with a diameter to be drilled in advance can be used. A carbon dioxide laser is applied to the etched copper-clad laminate. Irradiation forms through holes and via holes.

Using an energy selected from the output of a carbon dioxide gas laser of 20 to 60 mJ / pulse, directly irradiate a through hole,
When a via hole is formed, burrs are generated around the hole. Therefore, after carbon dioxide laser irradiation, both surfaces of the copper foil were etched two-dimensionally, and part of the thickness of the original metal foil was removed by etching, so that burrs were simultaneously removed by etching and obtained. The copper foil is suitable for forming a fine pattern, and a through hole for through-hole plating or a via hole in which copper foil on both sides around a hole suitable for a high-density printed wiring board is formed. Deburring and surface polishing of copper foil are possible if mechanical polishing is performed several times after drilling, but it is preferable to dissolve and remove with chemicals in terms of dimensional stability, thinning of surface copper foil, etc. It is.

The method of etching and removing copper burrs generated in the holes according to the present invention is not particularly limited. For example, Japanese Patent Application Laid-Open Nos. 02-22887, 02-22896, 02-25089 and 02-2.
5090, 02-59337, 02-60189, 02-166789, 03-25
995, 03-60183, 03-94491, 04-199592, 04-263
No. 488 discloses a method of dissolving and removing a metal surface with a chemical (referred to as a SUEP method). The etching rate is generally 0.02 to 1.0 μm / sec.

The carbon dioxide laser is in the infrared wavelength range.
Wavelengths of 9.3 to 10.6 μm are commonly used. Output is 20 ~ 6
The glass-clad base copper-clad laminate is processed at 0 mJ / pulse, preferably 22 to 55 mJ / pulse. The copper-clad laminate of the present invention
It can also be used for processing with a V laser. UV lasers
Generally, a wavelength of 200 to 400 nm is preferably used.

[0029]

The present invention will be specifically described below with reference to examples and comparative examples. Unless otherwise specified, “parts” indicates parts by weight.

Example 1 900 parts of 2,2-bis (4-cyanatophenyl) propane,
100 parts of (maleimidophenyl) methane are melted at 150 ° C,
The mixture was reacted for 4 hours while stirring to obtain a prepolymer. This was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide. Add bisphenol A type epoxy resin (trade name: Epicoat 1001, Yuka Shell Epoxy Co., Ltd.)
) And 600 parts of a cresol novolac type epoxy resin (trade name: ESCN-220F, manufactured by Sumitomo Chemical Co., Ltd.) were uniformly mixed and dissolved. Further, as a catalyst, zinc octylate 0.4
Part, add and dissolve and mix, and add inorganic insulating filler (trade name: BST200, average particle diameter 0.4 μm, manufactured by Nippon Talc Co., Ltd.) 500
Parts, and 2 parts of black pigment, and uniformly stirred and mixed.
I got This varnish is impregnated into a 100 μm thick glass woven fabric.
The prepreg was dried at 150 ° C. to prepare a prepreg (prepreg B) having a gel time (at 170 ° C.) of 120 seconds and a glass cloth content of 57% by weight. Electrodeposited copper foil with a thickness of 12 μm is placed above and below the four prepregs B, and laminated and molded at 200 ° C., 20 kgf / cm2, and a vacuum of 30 mmHg or less for 2 hours. I got On the other hand, black copper oxide powder 8 having an average particle size of 0.86 μm 8
00 parts was added to a varnish prepared by dissolving a polyvinyl alcohol powder in water, and uniformly stirred and mixed (varnish C). This was coated on the double-sided copper-clad laminate at a thickness of 60 μm,
After drying for 0 minutes, a film having a metal oxide content of 80% by weight was formed. From above, a hole with a hole diameter of 100 μm at an interval of 300 μm
With 900 direct carbon dioxide lasers, 7 pulses (short) with an output of 40 mJ / pulse were applied, and 70 blocks of through-holes were drilled. After the coating film on the surface was washed away with hot water at 60 ° C., the copper foil burr around the hole was dissolved and removed by the SUEP method, and the copper foil on the surface was also dissolved to 7 μm. This plate was plated with copper by 15 μm (total thickness: 22 μm) by an ordinary method. All of the land copper foil around this hole remained. On the front and back, circuit (line / space = 50 / 50μm by 200
), Solder ball lands, etc. were formed, covered with a plating resist except for at least the semiconductor chip, bonding pads, and solder ball pads, and were plated with nickel and gold to produce a printed wiring board. Table 1 shows the evaluation results of the printed wiring board.

Example 2 A printed circuit board was prepared in the same manner as in Example 1 except that a black pigment was not used. Table 1 shows the evaluation results.

Example 3 1400 parts of epoxy resin (trade name: Epicoat 5045), 600 parts of epoxy resin (trade name: ESCN220F), dicyandiamide 70
And 2 parts of 2-ethyl-4-methylimidazole were dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide, and 500 parts of talc of Example 1 and 3 parts of black pigment were added. I got This is thickness 100
μm glass woven fabric impregnated, dried, gel time 150 seconds,
A prepreg having a glass cloth content of 55% by weight (prepreg E) was prepared. Use two prepregs E, 18μm on both sides
Was placed and laminated under a vacuum of 190 ° C., 20 kgf / cm 2, and 30 mmHg or less for 2 hours to prepare a double-sided copper-clad laminate.
The thickness of the insulating layer was 200 μm. Circuits are formed on both sides of the double-sided copper-clad laminate, the copper foil surface is subjected to a black copper oxide treatment, and the prepreg E is arranged above and below, and 12 μm
Was placed and similarly laminated and formed into a four-layer plate. On the other hand, an aqueous polyvinyl alcohol solution has an average particle diameter of 0.9.
After mixing and uniformly dispersing the copper powder of μm, a 50 μm thick polyethylene terephthalate was applied so as to have a thickness of 25 μm, dried and water was removed to obtain a sheet with the resin composition having a blending amount of 20 vol%. After that, place the sheet on the above 4-layer plate, and output 3 pulses at 40 mJ / pulse of carbon dioxide laser output
(Shot), one pulse was irradiated at 30 mJ / pulse, and a via hole was made. A part of the bottom copper foil surface of the via hole was processed and removed, and thereafter processed in the same manner to produce a printed wiring board. Table 1 shows the evaluation results.

Comparative Example 1 A double-sided copper-clad laminate was prepared in the same manner as in Example 1 except that no inorganic insulating filler was used, and a carbon dioxide laser was irradiated similarly to form a through hole for a through hole. The mechanical polishing was performed once without performing the processing, and a printed wiring board was prepared. Table 1 shows the evaluation results.

Comparative Example 2 Using the double-sided copper-clad laminate of Example 1, the surface was similarly drilled with a carbon dioxide gas laser without using an auxiliary material, but no holes were formed.

Comparative Example 3 In Example 2, epicoat 50 was used as an epoxy resin.
Using 2,000 parts of 45 alone, and using a double-sided copper-clad laminate prepared in the same way, apply varnish C to the copper foil surface in the same manner.
After drying to form a film having a thickness of 60 μm, the film was similarly irradiated with a carbon dioxide laser at an output of 17 mJ / pulse for 19 shots, and a through hole for a through hole was formed. In this hole wall, glass fiber was found in the hole, and the hole shape was not a perfect circle but an elliptical shape. Mechanical polishing was performed three times without performing the SUEP treatment, and thereafter a printed wiring board was prepared in the same manner. Table 1 shows the evaluation results.

Comparative Example 4 Using the double-sided copper-clad laminate of Example 1, holes were drilled at a pitch of 300 μm with a mechanical drill having a diameter of 100 μm at a rotation speed of 100,000 rpm and a feed speed of 1 m / min. Mechanical polishing once, SU
Similarly, a copper plating was applied at 15 μm without performing the EP treatment, circuits were formed on the front and back surfaces, and processed in the same manner to prepare a printed wiring board. Two drill breaks occurred on the way. Table 1 shows the evaluation results
Shown in

COMPARATIVE EXAMPLE 5 900 holes having a diameter of 100 μm were formed at intervals of 300 μm on the copper foil surface of the double-sided copper-clad laminate of Example 1 by etching the copper foil. Similarly, a hole with a hole diameter of 100 μm
Opening, 900 blocks in one pattern, 70 blocks, total 63,000
7 holes (shots) were applied to the hole from the surface with a carbon dioxide gas laser at an output of 40 mJ / pulse, and a through hole for a through hole was formed. After that, mechanical polishing 1 was performed in the same manner as in Comparative Example 4.
Apply copper plating 15μm only at the time, form a circuit on the front and back,
Similarly, a printed wiring board was prepared. Table 1 shows the evaluation results.

Table 1 Item Practical example Comparative example 1 2 3 1 3 4 5 Position shift of front and back holes 0 0 0 0 0 0 2 5 (μm) Hole shape Round Round Round Round Elliptical Round Top Round Lower Elliptical Shape Inner wall shape Straight Slightly concave Nearly uneven Unevenness Straight line Near straight line Convexed straight line Large Slightly large Pattern cut and 0/200 0/200 0/200 55/200 0/100 57/200 57/200 Short (piece) Glass transition temperature 235 234 160 235 139 235 235 (℃) Through hole / via hole 2.5 2.7 2.7 3.8 25.0 2.6 5.0 Heat cycle test (%)

[0039] Table 2 Item implementation example comparisons Example 1 2 3 1 3 4 5 Pressure cooker -. Insulation resistance value after processing (Omega) normal state 6x10 ¹³ over over over 6x10 ¹³ over over 200hrs 4x10 ¹² 1x10 ⁹ 500hrs ^{. 7x10 11 <10 8 700hrs.} 3x10 11 over 1000hrs. 9x10 ¹⁰ over migration resistance (Omega) normal state 5x10 ¹³ over over over 6x10 ¹³ over over ^{200hrs. 5x10 12 2x10 10 500hrs.} 5x10 11 3x10 9 700hrs. 4x10 11 < 10 ⁸ 1000hrs. 1x10 ^11- Drilling time 21 14 21--630-(min)

<Measurement method> 1) Misalignment of the front and back holes and drilling time Holes with a hole diameter of 100 μm were cut into 900 holes / 250 mm square in the work size.
70 blocks (63,000 holes total) were prepared. Drilling was performed using a carbon dioxide laser and a mechanical drill. The required time and the maximum value of the deviation between the front and back hole positions are shown. 2) Cut and short circuit pattern In the examples and comparative examples, a board without holes was created in the same way, and a comb pattern of line / space = 50 / 50μm was created, and then 200 patterns were etched with a magnifying glass. Was visually observed, and the total of the broken pattern and the short-circuited pattern was shown in the molecule. 3) Glass transition temperature Measured by the DMA method. 4) Through-hole heat cycle test A land diameter of 200 μm is created for each through-hole, and 900 holes are connected alternately on the front and back.
200 cycles were performed from 30 seconds to room temperature for 5 minutes, and the maximum value of the rate of change in resistance was shown. 5) Insulation resistance value after pressure cooker treatment In Examples and Comparative Examples, line / space = 50 / 50μm
Select a pattern with no pattern breaks and shorts, apply blackening to it, place one identical prepreg on it, place a 12 μm electrolytic copper foil on it, and It was laminated and formed into a multilayer board. After forming a circuit on this, put it in 121 ° C and 2 atm for a predetermined time, take it out, leave it at 25 ° C and 60% RH for 2 hours,
For 2 seconds, the insulation resistance between the terminals was measured. 6) Migration resistance One through hole of 300 μm between holes and 100 μm in diameter is connected independently, and 100 sets of these are made.
50 VDC was applied in an atmosphere of% RH, and the insulation resistance between the through holes after the treatment for a predetermined time was measured. 7) Hole shape The shape of the cross section was observed from above.

[0041]

The copper foil of the double-sided copper-clad laminate is produced by pulse oscillation of the carbon dioxide laser using energy selected from a high output of 20 to 60 mJ / pulse sufficient to remove the copper foil with the carbon dioxide laser. A glass-clad laminate used for forming through-holes and via holes in a thermosetting resin laminate of a glass cloth base material, and a glass cloth as a base material, preferably mixed with an insulating dye or pigment. Glass transition temperature 150 ℃
A glass in which an insulating inorganic filler is mixed with the above thermosetting resin in an amount of 10 to 60% by weight, and a ratio of the inorganic filler and the resin in the thermosetting resin composition is uniform in the cross section of the laminate. By using a cloth-base copper-clad laminate, an auxiliary material for laser drilling is placed on the surface of the copper foil to be irradiated with the carbon dioxide laser, and the energy of the carbon dioxide laser selected from 20 to 60 mJ / pulse is directly applied. By irradiating to form a through hole and a via hole, the hole wall was formed well, and there was no deviation in the position of the front and back holes in the through hole, and a through hole having excellent connection reliability could be obtained. Further, the processing speed is much faster than drilling, and the productivity can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a process diagram of a through hole for a through hole [(1), (2)], a burr removal [3], and a copper plating [(4)] using a carbon dioxide gas laser according to a first embodiment. .

FIG. 2 is a similar process drawing using a carbon dioxide gas laser of Comparative Example 5. However, SUEP is not used.

[Explanation of symbols]

a Metal oxide powder-containing resin layer b Copper foil c Glass cloth base thermosetting resin layer d Through-hole through-hole drilling by carbon dioxide laser e Burr generated f Through-hole through-hole with front and back copper foil misalignment Part g Copper plated gap through hole

Claims (2)

[Claims] Claims: 1. An energy selected from 20 to 60 mJ / pulse sufficient to remove a copper foil with a carbon dioxide gas laser, and by pulse oscillation of a carbon dioxide gas laser, the copper foil surface of a double-sided copper-clad laminate is A copper-clad laminate used to form through holes and via holes in a copper foil and glass cloth base thermosetting resin laminate by directly irradiating an auxiliary material and directly irradiating a carbon dioxide gas laser, Using a substrate, glass transition temperature 15
Insulating inorganic filler in thermosetting resin of 0 ° C or more, 10 ~ 6
A copper-clad laminate for laser drilling, wherein the proportion of the inorganic filler and the resin in the thermosetting resin composition is uniform in the cross section of the laminate obtained by mixing 0% by weight. 2. The copper-clad laminate for laser drilling according to claim 1, wherein the thermosetting resin composition contains 0.1 to 10% by weight of a black or brown dye or pigment.