JP2001244641A - Method for manufacturing printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed wiring board that prevents misalignment between through hole and via hole. SOLUTION: On an interlayer resin insulation layer 40 in a core substrate 30, an opening 42 for via holes is formed by laser. Before and after that, the same laser machining equipment is used for forming a through hole 46, thus preventing the misalignment between the through hole and via hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board in which interlayer resin insulation layers and conductor circuits are alternately laminated on one side of a substrate electrically connected through a through hole, and each conductor layer is connected by a via hole. The present invention relates to a method for manufacturing a printed wiring board.

[0002]

2. Description of the Related Art Conventionally, build-up multilayer printed wiring boards are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 9-130050 and 9-1.
53683, JP-A-9-172261, JP-A-9-172
It is manufactured by a method disclosed in JP-A-246724, JP-A-10-135538 and the like. That is, a through hole is formed in the core substrate with a drill, and a through hole is formed in the core substrate. Thereafter, an interlayer resin insulating layer is laminated on the substrate, and a via hole is formed in the interlayer resin insulating layer by exposure and development processing or laser to form a circuit pattern. By repeating this, a build-up multilayer printed wiring board is obtained. Here, the through-hole and the via-hole are aligned based on the positioning marks formed on the core substrate, and are opened by separate devices.

[0003]

However, since the formation of the through-hole and the formation of the via-hole are performed by different devices and methods, an error occurs in the positioning mark every time the alignment is performed, and the through-hole and the via-hole are formed. Misalignment has occurred between via holes. Further, there is a problem that the positioning mark itself is shifted. This will be described with reference to FIG. As shown in FIG. 11A, a conductor circuit 343 and a positioning mark 345 are provided on a core substrate 330, and an interlayer resin insulating layer 340 is formed on the conductor circuit 343. First, the positioning mark 345 is photographed by the camera 80, the positioning is performed, and a through hole 346 for a through hole is formed by a drill (not shown) (FIG. 11B). Then, after the resin residue remaining in the through hole 346 is removed by desmearing, annealing is performed to remove the interlayer resin insulating layer 34.
Cure 0. At this time, as shown in FIG. 11C, the entire substrate 430 shrinks due to heat shrinkage, and the positioning mark 345 shifts. Then, even if the shifted positioning mark 345 is imaged by the camera 80 and the opening 348 for the via hole is formed by the laser, the through hole 34
6 and the conductor circuit 343 is displaced (FIG. 11C). As a result, there is a problem in that the via hole 360 has a poor connection to the conductor circuit 343 as shown in FIG. 11 (F2) or a poor connection as shown in FIG. 11 (F2). Here, FIG.
1 (F1) is a via hole 3 with respect to the conductor circuit 343.
Reference numeral 60 indicates a state in which the connection is normally established.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to propose a method of manufacturing a printed wiring board in which no positional displacement occurs between a through hole and a via hole. Is to do.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, an interlayer resin insulating layer and a conductor circuit are alternately provided on one surface of a substrate whose front and back are electrically connected through a through hole. And a method of manufacturing a printed wiring board in which conductor layers are connected by via holes, wherein the through holes and the via holes are formed by the same laser processing. That is,
They are formed by the same laser processing device.

According to the first aspect, the through hole and the via hole are formed using the same laser processing apparatus. That is, since the positioning is not separately performed in the through-hole forming step and the via-hole forming step, there is no positional error due to the device and the method in the through-hole forming step and the via-hole forming step. Further, since no heat or stress is applied to the substrate between the through-hole forming step and the via-hole forming step, the positioning mark does not shift due to contraction or warpage of the substrate, and the through-hole and via hole are formed in the substrate. Holes can be formed. Therefore, there is no displacement between the through hole and the via hole, and it is possible to prevent disconnection, poor connection and short circuit of the wiring.

[0007] According to a second aspect of the present invention, there is provided a method of manufacturing a printed wiring board.
Technical features include at least the following steps (a) to (d): (a) a step of forming an interlayer resin insulating layer on one surface of a core substrate on which a conductor circuit is formed; (b) a laser processing apparatus Placing the core substrate on a worktable of (a), and irradiating a laser to the interlayer resin insulating layer to form an opening for forming a via hole; (c) before and after the step (b), A) forming a through hole for a through hole in the substrate while being mounted on a processing table of the laser processing apparatus used in the step of); and (d) forming a conductive film in the through hole and the opening. Step of providing via holes.

According to a second aspect of the present invention, an interlayer resin insulating layer is laminated on one surface of a core substrate made of an insulating resin on which a conductive circuit is formed,
Thereafter, a via hole opening is formed by laser. Further, before and after the via hole opening forming step, through-holes for through holes are formed by the same laser processing apparatus. That is, since alignment is not performed by a separate apparatus and method in the through-hole forming step and the via-hole forming step, the position error due to the apparatus and the construction method is reduced in the through-hole forming step and the via-hole forming step. Does not occur.
Further, since no heat is applied to the substrate between the through-hole forming step and the via-hole forming step, the through-holes and via-holes are formed on the substrate without any displacement of the positioning mark due to contraction or warpage of the substrate. Can be formed. Therefore, there is no displacement between the through hole and the via hole, and it is possible to prevent disconnection or short circuit of the wiring.

The method of manufacturing a printed wiring board according to a third aspect of the present invention is characterized by including at least the following steps (a) to (d): (a) one side of a core substrate on which a conductor circuit is formed; Forming an interlayer resin insulation layer; (b) placing the core substrate on a processing table of a laser processing apparatus, irradiating a laser to the interlayer resin insulation layer, and forming an opening for forming a via hole and forming a through hole. (C) irradiating a laser to the opening for forming the through-hole while being placed on the processing table of the laser processing apparatus used in the step (b), and penetrating the substrate for the through-hole. Forming a hole; (d) forming a conductive film in the through hole and the opening, and forming a through hole and a via hole.

According to a third aspect of the present invention, an interlayer resin insulating layer is laminated on one surface of a core substrate made of an insulating resin on which a conductive circuit is formed,
Then, a via hole opening and a through hole forming opening are formed in the interlayer resin insulating layer by laser. Then, the through-hole forming opening is formed by irradiating a laser to the through-hole forming opening with the same laser processing apparatus.
That is, since alignment is not performed by a separate apparatus and method in the through-hole forming step and the via-hole forming step, the position error due to the apparatus and the construction method is reduced in the through-hole forming step and the via-hole forming step. Does not occur. Further, since no heat is applied to the substrate between the through-hole forming step and the via-hole forming step, the through-holes and via-holes are formed on the substrate without any displacement of the positioning mark due to contraction or warpage of the substrate. Can be formed. Further, since the opening for forming the via hole and the opening for forming the through hole are formed at the same time, when the through hole is formed in the opening for forming the through hole with a laser, the opening for the via hole and the through hole are formed. Misalignment with the through hole can be reduced. Therefore, it is possible to prevent disconnection or short circuit of the wiring.

According to claim 4, the opening diameter of the through hole is set to 8
It is 0 to 250 μm. If it is less than 80 μm, it becomes difficult to form a conductor layer, and if it exceeds 250 μm, it becomes difficult to increase the density, and the superiority of laser processing over drilling is lost. A desirable range is 100 to 200
μm. This range is because the aperture of the laser is stable.

According to claim 5, the opening diameter of the via hole is set to 2
It is 5 to 125 μm. If it is less than 25 μm, it will be difficult to connect to the upper wiring, and if it exceeds 125 μm, it will be difficult to achieve high density. A desirable range is 50-1.
00 μm. This range is because the aperture of the laser is stable.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, the configuration of the printed wiring board according to the first embodiment of the present invention will be described with reference to FIG.

The printed wiring board 10 has a build-up wiring layer 80 formed on the upper surface of the core substrate 30. The build-up wiring layer 80 includes the conductor circuit 58 and the via hole 6.
0 and the conductor circuit 158.
And interlayer resin insulation layer 1 in which via hole 160 is formed
40. A solder resist layer 70 is formed on the upper surface of the interlayer resin insulating layer 140 and the lower surface of the core substrate 30, and a solder bump 76U is formed in the via hole 160 via the opening 71U of the solder resist 70 on the upper surface. Solder bump 76D is formed in via hole 160 via opening 71D of solder resist 70. The solder bumps 76U on the upper surface side of the printed wiring board and the solder bumps 76D on the lower surface are connected via through holes 62 formed in the core substrate 30.

Next, a laser processing apparatus for processing the through hole 62 and the via hole 60 of the printed wiring board will be described with reference to FIG. Laser oscillator 18
The light emitted from 1 enters the galvano head 170 via a transfer mask 182 for sharpening the focus on the substrate. The galvano head 170 includes a galvanometer mirror 174X that scans the laser beam in the X direction and a galvanometer mirror 174Y that scans the laser beam in the Y direction.
4Y is driven by control motors 172X, 172Y. The motors 172X and 172Y adjust the angles of the mirrors 174X and 174Y in accordance with a control command from a control device (not shown), and transmit detection signals from a built-in encoder to the control device. .

The laser light is applied to galvanomirrors 174X, 1
Vias 74 </ b> Y are scanned in the X and Y directions, respectively, pass through the f-lock lens 176, and via holes 44 are formed in the multi-piece core substrate 30 via the mask 44. The multi-cavity substrate 30 has X
It is placed on an XY table 90 that moves in the −Y direction. The laser processing apparatus includes a camera 180,
The positioning is performed by imaging the positioning mark on the substrate 30.

Next, the method of manufacturing a printed wiring board according to the first embodiment of the present invention will be described. B. a resin film for an interlayer resin insulation layer; The resin filler will be described.

A. Preparation of Resin Film for Interlayer Resin Insulation Layer Bisphenol A type epoxy resin (Epoxy equivalent 46
9. Yuka Shell Epoxy Epicoat 1001) 30
Parts by weight, 40 parts by weight of a cresol novolak type epoxy resin (epoxy equivalent: 215, Epicron N-673 manufactured by Dainippon Ink and Chemicals, Inc.) Light KA-705
2) 30 parts by weight were dissolved by heating in 20 parts by weight of ethyl diglycol acetate and 20 parts by weight of solvent naphtha while stirring, and epoxidized polybutadiene rubber (Denalex R-45EPT manufactured by Nagase Kasei Kogyo Co., Ltd.) was added thereto.
15 parts by weight, 1.5 parts by weight of a crushed product of 2-phenyl-4,5-bis (hydroxymethyl) imidazole, 2 parts by weight of finely divided silica, and 0.5 part by weight of a silicon-based antifoaming agent are added to the epoxy resin composition. Is prepared. The resulting epoxy resin composition is applied on a 38 μm-thick PET film using a roll coater so that the thickness after drying becomes 50 μm, and then dried at 80 to 120 ° C. for 10 minutes to form an interlayer resin. A resin film for an insulating layer is produced.

B. Preparation of Resin Filler 100 parts by weight of bisphenol F type epoxy monomer (manufactured by Yuka Shell Co., molecular weight: 310, YL983U), silane coupling agent coated on the surface, average particle diameter is 1.6 μm, maximum particle diameter Is less than 15 μm
iO ₂ spherical particles (CRS 1101- manufactured by Adtech Co., Ltd.)
CE) 170 parts by weight and 1.5 parts by weight of a leveling agent (Perenol S4 manufactured by San Nopco Co.) are placed in a container, and the mixture is stirred and mixed to have a viscosity of 45-4 at 23 ± 1 ° C.
A resin filler of 9 Pa · s is prepared. In addition, as a curing agent, an imidazole curing agent (2E4MZ- manufactured by Shikoku Chemicals Co., Ltd.)
CN) 6.5 parts by weight are used.

Next, a method of manufacturing the printed wiring board described above with reference to FIG. 5 will be described with reference to FIGS.

(1) A starting material is a copper-clad laminate 30A in which a 18 μm copper foil 32 is laminated on both sides of a substrate 30 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 0.8 mm. (Figure 1
(A)). As the core substrate 30, a core material such as glass cloth impregnated with a resin can be used, and BT, FR-4, FR-5, double-sided copper foil plate, RCC
Etc. can be suitably used. Next, by etching this copper-clad laminate 30A in a pattern,
A lower conductor circuit 34 is formed on both surfaces of the substrate 30 (FIG. 1).
(B)).

(2) Substrate 3 on which lower conductor circuit 34 is formed
After washing with water and drying, a roughened surface 34α is formed on the entire surface of the lower conductor circuit 34 with an etching solution containing a cupric complex and organic hydrochloric acid (see FIG. 1C). Instead,
NaOH (10 g / l), NaClO ₂ (40 g /
l), a blackening treatment using an aqueous solution containing Na ₃ PO ₄ (6 g / l) as a blackening bath (oxidizing bath), and NaOH (10 g).
/ L) and a reduction treatment using an aqueous solution containing NaBH ₄ (6 g / l) as a reducing bath can also form a roughened surface.
Furthermore, a roughened surface can also be formed by forming an electroless plating film made of a Cu-Ni-P alloy.

(3) On both surfaces of the substrate 30, a resin film for an interlayer resin insulating layer slightly larger than the substrate 30 prepared in the above A is placed on the substrate 30, and the pressure is 4 kgf / cm ² , the temperature is 80 ° C., and the pressure is crimped. After temporarily compressing and cutting under the condition of a time of 10 seconds, the interlayer resin insulating layer 40 is formed by pasting using a vacuum laminator apparatus by the following method (see FIG. 1D). That is, a resin film for an interlayer resin insulating layer is formed on the substrate 30 with a degree of vacuum of 0.5 Torr,
The final press bonding is performed under the conditions of a pressure of 4 kgf / cm ² , a temperature of 80 ° C., and a pressing time of 60 seconds, and then heat curing at 170 ° C. for 30 minutes. The interlayer resin insulating layer is formed by application or pressure bonding of a film. The film is a thermosetting resin, a thermoplastic resin or a composite thereof, as specific examples, an epoxy resin film, an olefin-based film,
A resin composite film of an epoxy resin-phenoxy resin or the like can be used. Further, resin particles, inorganic particles and the like may be blended in the above-mentioned resin. Alternatively, a portion that is hardly soluble in an acid or an oxidizing agent and a portion that is soluble in an acid or an oxidizing agent may be separately provided (in this case, the hardly soluble portion,
Soluble is the difference in the dissolution rate of the same solution, and relatively slow ones are called poorly soluble, and fast ones are called chemical solubility).
However, since the melting point of the interlayer resin insulating layer is 300 ° C. or less, if a temperature exceeding 350 ° C. is applied, the interlayer resin insulating layer is dissolved and carbonized.

(4) Next, the core substrate 30 is placed on the XY table 90 of the laser processing apparatus described above with reference to FIG.
An image is taken at 0 and positioning is performed. Then, on the basis of the positioning mark, a through-hole (diameter: 1.0 mm) 44 a having a thickness of 1.0 mm is formed on the interlayer resin insulating layer 40 of the core substrate 30.
A 2 mm mask 44 is placed. Thereafter, a beam diameter of 4.0 mm, a single mode, and a pulse width of 8.0 μm are output from a laser oscillator (CO ₂ gas laser having a wavelength of 10.4 μm) 181.
The laser beam is applied to the interlayer resin insulation layer 4 under the condition of one second and one shot.
Then, a via hole opening 42 having a diameter of 80 μm is formed (see FIG. 2A). The opening diameter of the via hole opening 42 is desirably 50 to 100 μm. 50
If it is less than μm, it is difficult to connect to the upper layer wiring,
If the thickness is 0 μm or more, it is difficult to increase the density.

(5) Next, while the core substrate 30 is placed on the XY table 90 of the above-mentioned laser processing apparatus, a through hole (diameter 1.2 mm) 48a is formed with reference to the positioning mark of the core substrate. A 1.2 mm thick mask 48 is placed. Laser oscillator (C of wavelength 10.4μm
A laser beam is applied to the interlayer resin insulation layer 40 from the O ₂ gas laser 181 under the conditions of a beam diameter of 4.0 mm, a single mode, a pulse width of 60.0 μsec, and 12 shots.
A 0 μm through hole 46 for a through hole is formed (FIG. 2).
(B)). In addition, the opening diameter of the through hole 46 for a through hole is desirably 100 to 200 μm. If the thickness is less than 100 μm, it becomes difficult to form a conductor layer, and if it is more than 200 μm, it becomes difficult to increase the density, and the superiority of laser processing over drilling is lost.

In the manufacturing method of the present embodiment, since the alignment is not performed by a separate apparatus and method in the step of forming the through hole 46 for the through hole and the step of forming the opening 42 for the via hole, the through hole 46 for the through hole 46 is not formed. And the via hole opening 42 does not cause a position error. Further, since no heat is applied to the substrate between the step of forming the through hole 46 for the through hole and the step of forming the opening 42 for the via hole, the positioning mark does not shift due to contraction or warpage of the substrate.
A through hole 46 for a through hole and an opening 42 for a via hole can be formed in the substrate. Therefore, there is no displacement between the through hole and the via hole, and it is possible to prevent disconnection, poor connection and short circuit of the wiring.

(6) A masking 53 is attached to the back surface of the substrate 30 in which the opening 42 for the via hole and the through hole 46 for the through hole are formed, and then immersed in a solution containing 60 g / l of permanganic acid at 80 ° C. for 10 minutes. And the interlayer resin insulation layer 4
The surface of the interlayer resin insulating layer 40 including the inner wall of the via hole opening 42 and the through-hole 46 for the through-hole are formed by dissolving and removing the epoxy resin particles present on the surface of No. 0 (see FIG. 2). (See FIG. 2C).

(7) Next, the substrate 30 after the above treatment is immersed in a neutralizing solution (manufactured by Shipley) and then washed with water.
Further, the substrate 30 subjected to a surface roughening treatment (roughening depth: 3 μm)
By applying a palladium catalyst to the surface of the substrate, catalyst nuclei are attached to the surface of the interlayer resin insulating layer 40, the inner wall surface of the via hole opening 42, and the through hole 46.

(8) Next, the substrate 30 is immersed in an electroless copper plating aqueous solution having the following composition to form an electroless copper plating film 50 having a thickness of 0.6 to 3.0 μm over the roughened surface 40α. (See FIG. 2D). [Electroless plating aqueous solution] NiSO ₄ 0.003 mol / l tartaric acid 0.200 mol / l copper sulfate 0.030 mol / l HCHO 0.050 mol / l NaOH 0.100 mol / l α, α'-bipyridyl 40 mg / l Polyethylene glycol (PEG) 0.10 g / l [Electroless plating conditions] 40 minutes at a liquid temperature of 35 ° C

(9) A commercially available photosensitive dry film is affixed to the electroless copper plating film 50, and a mask is placed thereon.
Exposure is performed at 0 mJ / cm ² and development processing is performed using a 0.8% aqueous sodium carbonate solution to provide a plating resist 52 having a thickness of 30 μm (see FIG. 3A).

(10) Then, the substrate 30 is washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions, 2
A 0 μm electrolytic copper plating film 54 is formed. (FIG. 3 (B)
reference). [Electroplating aqueous solution] sulfuric acid 2.24 mol / l copper sulfate 0.26 mol / l additive 19.5 ml / l (manufactured by Atotech Japan, Capparaside HL) [electroplating conditions] current density 1 A / dm ² hours 65 minutes Temperature 22 ± 2 ℃

(11) The plating resist 52 is made of 5% NaO
After removing with H, the electroless plating film 50 under the plating resist 52 is dissolved and removed by etching treatment with a mixed solution of sulfuric acid and hydrogen peroxide, and is composed of the electroless copper plating film 50 and the electrolytic copper plating film 54. A conductor circuit 58 (including the via hole 60) and a through hole 62 having a thickness of 18 μm are formed. Thereafter, the substrate 30 is rinsed with water, acid-degreased, and then soft-etched. Then, an etching solution is sprayed on both surfaces of the substrate 30 to spray the surface of the conductor circuit 58 and the surface of the land 62a of the through hole 62. Thus, a roughened surface 64β is formed on all surfaces of the conductor circuit 58 and the through hole 62 (see FIG. 3C). As an etching solution, an etching solution (Mec etch bond, manufactured by Mec Co.) consisting of 10 parts by weight of imidazole copper (II) complex, 7 parts by weight of glycolic acid, and 5 parts by weight of potassium chloride is used.

(12) After preparing the resin filler described in B above, a layer of the resin filler 66 is formed in the through hole 62 within 24 hours after the preparation by the following method. That is, first, the resin filler 66 is pushed into the through hole 62 using a squeegee, and then dried at 100 ° C. for 20 minutes (see FIG. 3D).

(13) After the steps (3) and (4) are repeated, the steps (6) and (11) are further repeated to form an interlayer resin insulating layer 140 on the substrate.
Then, a conductor circuit 158 (including the via hole 160) is formed, and then the masking 53 is peeled off (see FIG. 4A).

(14) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) so as to have a concentration of 60% by weight, and an epoxy group of 50% was acrylated. Oligomer for imparting properties (molecular weight: 4000) 46.6
7 parts by weight, 80% by weight dissolved in methyl ethyl ketone
Of bisphenol A type epoxy resin (manufactured by Yuka Shell Co., Ltd.
Trade name: Epicoat 1001) 15.0 parts by weight, imidazole hardener (manufactured by Shikoku Chemicals, trade name: 2E4MZ-C)
N) 1.6 parts by weight, a bifunctional acrylic monomer which is a photosensitive monomer (trade name: R604, manufactured by Nippon Kayaku Co., Ltd.) 4.5
Parts by weight, also polyvalent acrylic monomer (manufactured by Kyoei Chemical Co.,
A trade name: 1.5 parts by weight of DPE6A) and 0.71 parts by weight of a dispersion defoaming agent (manufactured by San Nopco, S-65) are placed in a container, stirred and mixed to prepare a mixed composition, and the mixed composition is prepared. Of benzophenone (Kanto Chemical Co., Ltd.) as a photopolymerization initiator and 0.2 part by weight of Michler's ketone (Kanto Chemical Co., Ltd.) as a photosensitizer at 25 ° C. A solder resist composition adjusted to 2.0 Pa · s is obtained. The viscosity was measured with a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.) when the rotor No. was 60 rpm. In the case of 4, 6 rpm, the rotor No. Three
According to

(15) Next, the solder resist composition is applied on both surfaces of the multilayer wiring board in a thickness of 20 μm.
After performing a drying treatment at 70 ° C. for 20 minutes and at 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the solder resist opening is drawn is brought into close contact with the solder resist layer 70 to be 1000 mJ / cm ^2. Exposure with ultraviolet light and development processing with a DMTG solution are performed to form openings 71U and 71D having a diameter of 200 μm. And furthermore, 80
1 hour at 100 ° C, 1 hour at 100 ° C, 1 hour at 120 ° C,
Heat treatment is performed at 50 ° C. for 3 hours to cure the solder resist layer, and a solder resist layer 70 having openings 71U and 71D and a thickness of 20 μm is formed (see FIG. 4B). . As the solder resist composition, a commercially available solder resist composition can be used.

(16) Next, the substrate on which the solder resist layer 70 has been formed is coated with nickel chloride (2.3 × 10 ^-1 mol).
/ L), sodium hypophosphite (2.8 × 10 ^-1 mol)
/ L), sodium citrate (1.6 × 10 ^-1 mol /
2) in the electroless nickel plating solution having pH = 4.5 containing l)
By immersing for 0 minute, a nickel plating layer 72 having a thickness of 5 μm is formed in the openings 71U and 71D. Furthermore, the substrate gold potassium cyanide ^{(7.6 × 10 -3 mol / l} ), ammonium chloride ^{(1.9 × 10 -1 mol / l} ), sodium citrate (1.2 × 10 ^-1 mol / l), immersed in an electroless gold plating solution containing sodium hypophosphite (1.7 × 10 ^-1 mol / l) at 80 ° C. for 7.5 minutes to form a layer having a thickness of A gold plating layer 74 of 0.03 μm is formed (see FIG. 4C).

(17) Thereafter, a tin-lead-containing solder paste is printed on the opening 71U of the solder resist 70 on the surface of the substrate on which the IC chip is mounted, and further on the opening 71D on the other surface. Print a solder paste containing tin-antimony. Thereafter, the solder bumps 76U and 76D are formed by reflow at 200 ° C., and the printed wiring board 10 is completed (see FIG. 5).

(Second Embodiment) The printed wiring board of the second embodiment is almost the same as the first embodiment. However, the second
In the embodiment, when forming the via hole opening 42 in the interlayer resin insulating layer 40, the through hole forming opening 45 is also formed at the same time. By forming an opening 45 for forming a through-hole in the interlayer resin insulating layer 40 in advance, the core substrate 30 is directly irradiated with a laser, and the through-hole 4 for a through-hole is formed.
6 is formed.

A method for manufacturing a printed wiring board according to the second embodiment will be described with reference to FIGS.

(1) A starting material is a copper-clad laminate 30B in which an 18 μm copper foil 32 is laminated on one surface of a substrate 30 made of glass epoxy resin or BT (bismaleimide triazine) resin having a thickness of 0.8 mm. (FIG. 7
(A)). As the core substrate 30, a core material such as a glass cloth impregnated with a resin can be used. Next, the copper-clad laminate 30B is etched in a pattern to form a lower conductive circuit 34 on the upper surface of the substrate 30 (see FIG. 7B).

(2) Substrate 3 on which lower conductor circuit 34 is formed
0 is washed with water, dried, and then subjected to a blackening process and a reducing process to form a roughened surface 34α on the entire surface of the lower conductive circuit 34 (see FIG. 7C).

(3) On the upper surface of the substrate 30, a resin film for an interlayer resin insulating layer similar to that of the first embodiment is placed on the substrate 30 and attached to form an interlayer resin insulating layer 40 (FIG. 7). (D)). (4) The core substrate 30 is placed on the XY table 90 of the laser processing apparatus in the same manner as in the first embodiment, and a positioning mark (not shown) of the core substrate is imaged by the camera 180 and positioned. Then, based on the positioning mark, a through hole (diameter of 1.0 m)
m) Place the 1.2 mm thick mask 44 on which the 44a is formed. Thereafter, a via hole having a diameter of 80 μm was formed in the interlayer resin insulating layer 40 under the conditions of a beam diameter of 4.0 mm, a single mode, a pulse width of 8.0 μsec, and one shot from a laser oscillator (CO ₂ gas laser having a wavelength of 10.4 μm). Openings 42 and through-hole forming openings 45 are formed (see FIG. 8A).

(5) Next, while the core substrate 30 is mounted on the XY table 90 of the above-mentioned laser processing apparatus, the above-mentioned mask 44 is removed, and the laser oscillator (wavelength 10.
4 μm CO ₂ gas laser) 181 to beam diameter 4.0
Under a condition of mm, single mode, pulse width of 60.0 μsec, and 12 shots, a laser beam is applied to the through-hole forming opening 45 of the interlayer resin insulating layer 40 to form a through-hole for through-hole 46 having a diameter of 120 μm ( FIG. 8 (B)).

In the second embodiment, a via hole forming opening 42 and a through hole forming opening 45 are simultaneously formed using a mask 44. Therefore, when the through-hole 46 is formed in the through-hole forming opening 45 by laser thereafter, the positional deviation between the via-hole opening 42 and the through-hole through-hole 45 is made smaller than in the first embodiment. be able to.

(6) The substrate 30 in which the via hole opening 42 and the through hole through hole 46 are formed is immersed in a solution containing permanganic acid to form the interlayer resin insulating layer 40 including the inner wall of the via hole opening 42. A roughened surface 40α is formed on the surface and in the through hole for through hole 46 (see FIG. 8C).

(7) Next, the substrate 30 after the above treatment is immersed in a neutralizing solution (manufactured by Shipley Co., Ltd.) and washed with water.
Further, the substrate 30 subjected to a surface roughening treatment (roughening depth: 3 μm)
By applying a palladium catalyst to the surface of the substrate, catalyst nuclei are attached to the surface of the interlayer resin insulating layer 40, the inner wall surface of the via hole opening 42, and the through hole 46.

(8) Next, the substrate 30 is immersed in an electroless copper plating aqueous solution having the same composition as that of the first embodiment, and a 0.6 to 3.0 μm thick electroless A copper plating film 50 is formed (see FIG. 8D).

(9) A commercially available photosensitive dry film is affixed to the electroless copper plating film 50, and a mask is placed thereon.
Exposure is performed at 0 mJ / cm ² and development processing is performed using a 0.8% aqueous sodium carbonate solution to provide a plating resist 52 having a thickness of 30 μm (see FIG. 9A).

(10) Then, the substrate 30 is washed with water at 50 ° C., degreased, washed with water at 25 ° C., further washed with sulfuric acid, and then subjected to electrolytic copper plating under the same conditions as in the first embodiment. To form an electrolytic copper plating film 54 having a thickness of 20 μm (see FIG. 9B).

(11) The plating resist 52 is made of 5% NaO
After removing with H, the electroless plating film 50 under the plating resist 52 is dissolved and removed by etching treatment with a mixed solution of sulfuric acid and hydrogen peroxide, and is composed of the electroless copper plating film 50 and the electrolytic copper plating film 54. A conductor circuit 58 (including the via hole 60) and a through hole 62 having a thickness of 18 μm are formed. Thereafter, a roughened surface 64β is formed on all surfaces of the conductor circuit 58 and the through hole 62 (see FIG. 9C).

(12) After preparing a resin filler in the same manner as in the first embodiment, the resin filler is filled in the through hole 62 to form a layer of the resin filler 66. (See FIG. 9D). Note that the subsequent manufacturing steps are the same as (13) to (17) of the first embodiment, and thus description thereof will be omitted.

(Third Embodiment) A printed wiring board according to a third embodiment is almost the same as the first embodiment. However, the third
In the embodiment, an olefin resin film is used for the interlayer resin insulating layer 40 instead of the epoxy resin film. In order to use an olefin-based film, in the third embodiment,
The condition of the CO ₂ gas laser at the time of providing the via hole opening is a pulse width of 15.0 μsec and 5 shots.

(Fourth Embodiment) The printed wiring board of the fourth embodiment is almost the same as the second embodiment. However, the fourth
In the embodiment, an olefin resin film is used for the interlayer resin insulating layer instead of the epoxy resin film. In order to use an olefin-based film, in the fourth embodiment, the condition of the CO ₂ gas laser at the time of providing the via hole opening is set to a pulse width of 15.0 μsec and five shots.

(Fifth Embodiment) The printed wiring board of the fifth embodiment is almost the same as the first embodiment. However, the fifth
In the embodiment, an epoxy resin-phenoxy resin composite film is used for the interlayer resin insulating layer instead of the epoxy resin film. In the fifth embodiment, an excimer laser is used as a laser, and 150 shots are irradiated at a frequency of 200 Hz and an energy of 1.0 J to form a via hole having an extremely small diameter of 25 μm.

(Sixth Embodiment) The printed wiring board of the sixth embodiment is almost the same as the second embodiment. However, the sixth
In the embodiment, an epoxy resin-phenoxy resin composite film is used for the interlayer resin insulating layer instead of the epoxy resin film. In the sixth embodiment, an excimer laser is used as a laser, 150 shots are irradiated at a frequency of 200 Hz and an energy of 1.0 J to form a via hole having a very small diameter of 25 μm.

(Seventh Embodiment) FIG. 10 shows a seventh embodiment of the present invention.
FIG. 2 is a cross-sectional view of the printed wiring board according to the embodiment. The printed wiring board of the seventh embodiment is almost the same as the first embodiment. However, in the seventh embodiment, the through holes 62
A lid plating 161 is formed on the top of the
, A via hole 160 is formed immediately above the through hole 62. In the seventh embodiment, as in the first embodiment, the laser processing of the via hole 60 of the interlayer resin insulating layer 40 and the laser processing of the through hole 62 are performed in the same step.

[0058]

According to the present invention, as described above, the through hole and the via hole are formed using the same laser processing apparatus. That is, since positioning is not separately performed in the through hole forming step and the via hole forming step, no positional error occurs between the through hole forming step and the via hole forming step. Further, since no heat is applied to the substrate between the through hole forming step and the via hole forming step, the through holes and via holes are formed in the substrate without the positioning marks being displaced by contraction or warpage of the substrate. Can be formed. Therefore, there is no displacement between the through hole and the via hole, and it is possible to prevent disconnection, poor connection and short circuit of the wiring.
In addition, laser damage and deterioration of the interlayer resin insulating layer can be reduced, and the adhesion of the wiring, which is the upper conductive layer, can be improved.

[Brief description of the drawings]

FIGS. 1A, 1B, 1C, and 1D are manufacturing process diagrams of a printed wiring board according to a first embodiment of the present invention.

FIGS. 2A, 2B, 2C, and 2D are manufacturing process diagrams of the printed wiring board according to the first embodiment of the present invention.

FIGS. 3A, 3B, 3C, and 3D are manufacturing process diagrams of the printed wiring board according to the first embodiment of the present invention.

FIGS. 4A, 4B, and 4C are manufacturing process diagrams of the printed wiring board according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view of the printed wiring board according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of a laser processing apparatus used for through-hole and via-hole processing.

FIGS. 7A, 7B, 7C, and 7D are manufacturing process diagrams of a printed wiring board according to a second embodiment of the present invention.

FIGS. 8A, 8B, 8C, and 8D are manufacturing process diagrams of a printed wiring board according to a second embodiment of the present invention.

FIGS. 9A, 9B, 9C, and 9D are manufacturing process diagrams of the printed wiring board according to the second embodiment of the present invention.

FIG. 10 is a sectional view of a printed wiring board according to a seventh embodiment of the present invention.

11A, 11B, 11C, and 11D are manufacturing process diagrams of a conventional printed wiring board, and FIGS.
(F2) and (F3) are explanatory diagrams of a connection state between a via hole and a conductor circuit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 30 core substrate 34 lower conductive circuit 40 interlayer resin insulating layer 42 opening for via hole 45 opening for forming through hole 46 through hole for through hole 50 electroless plating film 54 electrolytic plating film 58 conductor circuit 60 via hole 62 through hole 66 resin Filler 70 Solder resist layer 71U, 71D Opening 72 Nickel plating layer 74 Gold plating layer 76U, 76D Solder bump 80A, 80B Build-up wiring layer 144 Interlayer resin insulation layer 158 Conductor circuit 160 Via hole

Claims (5)

[Claims] 1. A printed wiring board in which interlayer resin insulating layers and conductive circuits are alternately laminated on one surface of a substrate whose front and back surfaces are electrically connected via through holes, and each conductive layer is connected by a via hole. The method for manufacturing a printed wiring board according to claim 1, wherein the through hole and the via hole are formed by the same laser processing. 2. A method for manufacturing a printed wiring board, comprising at least the following steps (a) to (d): (a) forming an interlayer resin insulating layer on one surface of a core substrate on which a conductor circuit is formed; (B) placing the core substrate on a processing table of a laser processing apparatus, and irradiating a laser to the interlayer resin insulating layer to form an opening for forming a via hole; (c) the step (b). Forming a through hole for a through-hole in a substrate before and after the step (b) while being placed on a processing table of the laser processing apparatus used in the step (b); Forming a conductive film and providing through holes and via holes; 3. A method for manufacturing a printed wiring board, comprising at least the following steps (a) to (d): (a) forming an interlayer resin insulating layer on one surface of a core substrate on which a conductor circuit is formed; (B) placing the core substrate on a processing table of a laser processing apparatus, and irradiating a laser to the interlayer resin insulating layer to provide an opening for forming a via hole and an opening for forming a through hole; (C) a step of irradiating the opening for forming a through hole with a laser while being placed on a processing table of the laser processing apparatus used in the step (b) to form a through hole for a through hole in a substrate; (D) forming a conductive film in the through hole and the opening, and providing a through hole and a via hole; 4. The through hole has an opening diameter of 80 to 2
The method for producing a printed wiring board according to claim 1, wherein the thickness is 50 μm. 5. An opening diameter of said via hole is 25-1.
The method for manufacturing a printed wiring board according to claim 1, wherein the thickness is 25 μm.