JP2001015931A - Multilayer printed wiring board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of signal delay and signal error by forming multilayer printed wiring board comprising wiring circuits on the substrate and cyclo-olefin resin insulating layers laminated in order, and connecting these wiring circuits by means of via holes. SOLUTION: A copper stuck laminate is formed with copper foil laminated on both sides of a substrate 1. Then, a via hole 9 is formed in the substrate 1 and lower layer conductive circuits 4 as inner copper pattern are formed on both sides of the substrate 1. Roughening surfaces 4a and 9a are formed all over the lower layer conductive circuits 4 and then resin filler 10 mainly consisting of cycloolefin resin is filled among the lower layer conductive circuits 4 or in the via hole 9. This laminates the cycloolefin resin with vacuum compression bonding to form the interlayer resin insulation layer 2 consisting of cycloolefin resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board having an interlayer resin insulating layer made of a cycloolefin resin having a low dielectric constant and excellent mechanical properties such as rigidity, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A multilayer printed wiring board called a so-called multilayer build-up wiring board is manufactured by a semi-additive method or the like.
m on a resin substrate reinforced with glass cloth, etc.
It is manufactured by alternately laminating a conductor circuit made of copper or the like and an interlayer resin insulating layer. The connection between the conductor circuits via the interlayer resin insulation layer of the multilayer printed wiring board is performed by via holes.

Conventionally, build-up multilayer printed wiring boards have been manufactured by a method disclosed in, for example, Japanese Patent Application Laid-Open No. 9-130050. That is, first, a through-hole is formed in the copper-clad laminate on which the copper foil is stuck, and then a through-hole is formed by performing an electroless copper plating process. Subsequently, the surface of the substrate is etched into a conductor pattern to form a conductor circuit, and a roughened surface is formed on the surface of the conductor circuit by electroless plating, etching, or the like. After forming an interlayer resin insulation layer, an exposure and development process is performed, or a via hole opening is formed by laser processing, and then the interlayer resin insulation layer is formed through UV curing and main curing.

Further, after a roughening treatment is performed on the interlayer resin insulating layer, a thin electroless plating film is formed on the formed roughened surface, a plating resist is formed on the electroless plating film, and then an electrolytic plating film is formed. Thickening is performed by plating, and etching is performed after the plating resist is stripped to form a conductive circuit connected to the lower conductive circuit by a via hole.

After repeating this, a solder resist layer for protecting the conductor circuit is formed as an outermost layer, an opening is formed in the solder resist layer, and the conductor layer in the opening is plated or the like to form a pad. Then, a build-up multilayer printed wiring board is manufactured by forming solder bumps.

However, the multilayer printed wiring board manufactured in this manner has a high dielectric constant of 3.5 or more in the GHz region because a mixture of an epoxy resin, an acrylic resin, and the like is used for the interlayer resin insulating layer. for that reason,
When an LSI chip or the like using a high-frequency signal in the GHz band is mounted, there is a problem that signal delay or signal error is likely to occur due to the high dielectric constant of the interlayer resin insulating layer.

[0007]

In order to solve such a problem, a printed wiring board using a linear polyolefin resin as an interlayer resin insulating layer has been proposed. In this printed wiring board, although the dielectric constant of the interlayer resin insulating layer decreases, the interlayer resin insulating layer itself is too soft, so that the formed conductor circuit easily sinks in the interlayer resin insulating layer, and as a result, There is a problem that a connection problem easily occurs and the reliability of the printed wiring board is low.

When forming an interlayer resin insulation layer using the linear polyolefin resin, the interlayer resin insulation layer is formed by pressing and laminating a resin sheet on a conductor circuit. There was also a problem that handling was difficult because it was too soft.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and has as its object to reduce the dielectric constant and the dielectric loss tangent even when a high-frequency signal in the GHz band is used. Provided is a multilayer printed wiring board having an interlayer resin insulating layer with high reliability in connection between conductor circuits because the delay and signal errors are less likely to occur and excellent in mechanical properties such as rigidity, and a method of manufacturing the same. It is in.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies for realizing the above object, and have found that cycloolefin resins, particularly thermosetting cycloolefin resins, are used for the interlayer resin insulating layer. By the low dielectric constant described above,
With regard to the electrical characteristics such as low dielectric loss tangent and the mechanical characteristics such as rigidity, the present inventors have found that an interlayer resin insulating layer can be formed which sufficiently satisfies the required characteristics, and the present invention which has the following contents as a summary configuration I thought.

That is, the multilayer printed wiring board of the present invention is a multilayer printed wiring board in which a conductive circuit and a resin insulating layer are sequentially formed on a substrate, and these conductive circuits are connected via via holes. The insulating layer is made of a cycloolefin-based resin.

In the multilayer printed wiring board, the cycloolefin resin is preferably a homopolymer or a copolymer of a monomer comprising 2-norbornene, 5-ethylidene-2-norbornene or a derivative thereof. . The dielectric constant of the resin insulating layer at 1 GHz is preferably 3 or less, and the dielectric loss tangent is preferably 0.01 or less. Further, the cycloolefin-based resin,
A thermosetting cycloolefin-based resin is desirable.

Further, according to the method of manufacturing a multilayer printed wiring board of the present invention, a conductive circuit and a resin insulating layer are sequentially formed on a substrate, and these conductive circuits are connected via via holes. The manufacturing method is characterized in that an interlayer resin insulating layer is formed by laminating a film made of a cycloolefin-based resin on a conductor circuit formed on a substrate by vacuum compression bonding.

In the above method for manufacturing a multilayer printed wiring board, an interlayer resin insulating layer is formed from a cycloolefin resin on a conductor circuit formed on a substrate, and then the interlayer resin insulating layer is irradiated with laser light. It is desirable to form an opening for a via hole.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The multilayer printed wiring board of the present invention
In a multilayer printed wiring board in which a conductor circuit and a resin insulation layer are sequentially formed on a substrate and these conductor circuits are connected via via holes, the resin insulation layer is made of a cycloolefin resin. I do.

According to such a multilayer printed wiring board of the present invention, since the interlayer resin insulating layer is made of a cycloolefin resin, the dielectric constant and the dielectric constant are higher than those of the interlayer resin insulating layer made of epoxy resin or the like. The tangent is greatly reduced, and signal errors due to signal propagation delay, signal transmission loss, etc. can be prevented.

Further, since the cycloolefin resin has high mechanical properties, particularly high rigidity, a conductor circuit can be formed on a firm interlayer resin insulating layer, and therefore, the connection reliability between the conductor circuits can be improved. Can be sufficiently secured.

Further, since the cycloolefin-based resin has excellent adhesion to the conductor circuit, the interlayer resin insulation layer can be prevented from peeling off from the conductor circuit, and the interlayer resin insulation layer caused by the peeling can be prevented. Cracks can also be prevented. Further, the cycloolefin-based resin,
Since the water absorption is small, the electrical insulation between the conductor circuits is increased, and the reliability is also improved.

The type of the cycloolefin resin is not particularly limited, but the dielectric constant at 1 GHz is preferably 3.0 or less and the dielectric loss tangent is preferably 0.01 or less. The dielectric constant is more preferably 2.4 to 2.7. By using such a material having a low dielectric constant, it is possible to prevent a signal error due to a delay in signal propagation, a signal transmission loss, and the like.

The above cycloolefin-based resin is
It is preferably a homopolymer or a copolymer of monomers composed of -norbornene, 5-ethylidene-2-norbornene or a derivative thereof. As the above derivatives,
Examples thereof include those in which an amino group for forming a crosslink, a maleic anhydride residue, or a maleic acid-modified one is bonded to the cycloolefin such as 2-norbornene. Examples of monomers for synthesizing the copolymer include ethylene and propylene.

The cycloolefin resin may be a mixture of two or more of the above resins, or may contain a resin other than the cycloolefin resin. When the cycloolefin-based resin is a copolymer, it may be a block copolymer or a random copolymer.

The cycloolefin resin is preferably a thermosetting cycloolefin resin.
This is because by performing the heating to form the crosslinks, the rigidity is further increased and the mechanical properties are improved. The glass transition temperature (Tg) of the cycloolefin resin is 13
Desirably, the temperature is 0 to 200 ° C.

As the cycloolefin-based resin, those already formed as a resin sheet (film) may be used, and a monomer or a low-molecular-weight polymer having a constant molecular weight may be used as a solvent such as xylene or cyclohexane. It may be in the state of an uncured solution dispersed in. In the case of a resin sheet, a so-called RCC (RESIN COATE
D COPER: resin-coated copper foil).

The cycloolefin resin may not contain a filler or the like, or may contain a flame retardant such as aluminum hydroxide, magnesium hydroxide, or a phosphate.

Next, a method of manufacturing a multilayer printed wiring board using such a cycloolefin resin will be described.

(1) First, a wiring board having a lower conductive circuit on the surface of a resin substrate is manufactured. As the resin substrate, a resin substrate having inorganic fibers is desirable, specifically, for example, a glass cloth epoxy substrate, a glass cloth polyimide substrate,
A glass cloth bismaleimide-triazine resin substrate, a glass cloth fluororesin substrate, and the like can be given. Further, a copper-clad laminate in which copper foil is stuck on both surfaces of the resin substrate may be used.

Usually, a through hole is formed in the resin substrate by a drill, and a through hole is formed by applying electroless plating to the wall surface of the through hole and the surface of the copper foil. Copper plating is preferred as the electroless plating. Further, electroplating may be performed for thickening the copper foil. Copper plating is preferred as the electroplating. Thereafter, the inner wall of the through-hole may be subjected to a roughening treatment, the through-hole may be filled with a resin paste or the like, and the conductive layer covering the surface may be formed by electroless plating or electroplating.

Examples of the method of the above-mentioned roughening treatment include blackening (oxidation) -reduction treatment, spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, and treatment with Cu-Ni-P needle-like alloy plating. No. Through the above steps, an etching resist is formed on the solid copper pattern formed on the entire surface of the substrate by using a photolithography technique, and then etching is performed to form a lower conductive circuit. Thereafter, if necessary, by forming a conductor circuit,
A portion which has been etched and becomes a concave portion may be filled with a resin or the like. (2) Next, the formed lower conductor circuit is subjected to a roughening treatment if necessary. As the method of the roughening treatment, the method described above,
That is, a blackening (oxidation) -reduction treatment, a spray treatment with a mixed aqueous solution of an organic acid and a cupric complex, a treatment with Cu-Ni-P needle-like alloy plating, and the like can be given. Also, by immersing the substrate on which the lower conductor circuit is formed in a solution in which the resin component is dissolved, without subjecting the lower conductor circuit to a roughening treatment,
A layer made of a resin may be formed on the surface of the lower conductive circuit, and adhesion to the interlayer resin insulating layer formed thereon may be ensured.

(3) Next, an interlayer resin insulating layer made of the cycloolefin resin is formed on both surfaces of the wiring board having the lower conductive circuit prepared in the above (2). This interlayer resin insulating layer is formed by applying an uncured liquid for forming a cycloolefin-based resin and then curing it by heating or the like, or by laminating a resin sheet under vacuum with heating. For simplicity, a method of laminating a resin sheet is preferable. The heating conditions in this case are preferably 100 to 180 ° C. and 0.5 to 20 minutes.

(4) Next, a laser beam is applied to the interlayer resin insulation layer.
By irradiation, a via hole opening is provided. this
When the laser light used is, for example, carbon dioxide
(CO _Two ) Laser, ultraviolet laser, excimer laser, etc.
Of these, excimer lasers and short
A pulsed carbon dioxide laser is preferred.

The excimer laser can form a large number of via holes at once by using a mask or the like in which a through hole is formed in a portion where the via holes are formed. This is because the carbon dioxide gas laser has a small amount of resin remaining in the opening and little damage to the resin at the periphery of the opening. The through hole of the mask needs to be a perfect circle in order to make the spot shape of the laser beam a perfect circle, and the diameter of the through hole is desirably about 0.1 to 2 mm.

When the opening is formed by a laser beam, particularly when a carbon dioxide gas laser is used, desmearing is preferably performed. The desmear treatment can be performed using an oxidizing agent composed of an aqueous solution such as chromic acid and permanganate. Alternatively, the treatment may be performed using oxygen plasma, a mixed plasma of CF ₄ and oxygen, corona discharge, or the like. The surface can also be modified by irradiating ultraviolet rays using a low-pressure mercury lamp.

(5) The interlayer resin insulating layer may be formed with a metal layer thereon without performing any particular roughening treatment or the like, and may be subjected to plasma treatment or treatment with an acid or the like.
After roughening the surface, a metal layer may be formed. When the plasma treatment is performed, a metal such as Ni, Ti, Pd, etc. having excellent adhesion to the interlayer resin insulation layer is used to secure the adhesion between the conductor circuit formed as the upper layer and the interlayer resin insulation layer. It may be formed as an intermediate layer. The intermediate layer made of the metal is desirably formed by physical vapor deposition (PVD) such as sputtering.
It is desirable to be about 2.0 μm.

(6) After the above steps, a thin film layer made of metal is formed. The material of the thin film layer is preferably copper or a copper-nickel alloy. This thin film layer is formed by physical vapor deposition (PVD).
Method), a chemical vapor deposition method (CVD method), or an electroless plating. As the PVD method, for example, sputtering,
Ion beam sputtering, etc .;
The method is PE-CVD using organic metal as a feed material.
(Plasma Enhanced CVD) method.

The thickness of this thin film is preferably from 0.1 to 5 μm. The thickness is set so that the film can be removed by etching without impairing the function as a conductive layer in electroplating performed later. The step of forming the thin film is not essential and can be omitted.

(7) A plating resist is formed on the electroless plating film formed in (6). This plating resist
After laminating a photosensitive dry film, it is formed by performing exposure and development processing.

(8) Next, electroplating is performed using the thin metal film formed on the interlayer resin insulating layer as a plating lead to thicken the conductor circuit. Electroplating film thickness is 5-30μ
m is preferred. At this time, the via hole opening may be filled with electroplating to form a filled via structure.

(9) After forming the electroplating film, the plating resist is peeled off, and the electroless plating film existing under the plating resist and the intermediate layer are removed by etching to form an independent conductor circuit. . It is desirable to use copper plating as the electroplating. Examples of the etchant include sulfuric acid-hydrogen peroxide aqueous solution, ammonium persulfate, sodium persulfate, persulfate aqueous solution such as potassium persulfate, ferric chloride, aqueous solution of cupric chloride, hydrochloric acid,
Nitric acid, hot dilute sulfuric acid and the like can be mentioned. Alternatively, a roughened surface may be formed simultaneously with etching between conductor circuits using an etching solution containing the above-described cupric complex and an organic acid.

(10) Thereafter, the above steps (2) to (9) are repeated to provide an upper conductor circuit of an upper layer, a solder resist layer is provided on the uppermost layer, and a solder bump is provided by opening the solder resist layer. Thereby, for example, a six-layer double-sided multilayer printed wiring board having three layers on one side is obtained. Hereinafter, description will be made based on embodiments.

[0040]

EXAMPLES (Example 1) (1) A copper-clad laminate in which 18 μm copper foil 8 is laminated on both surfaces of a substrate 1 made of a glass epoxy resin or a BT (bismaleimide-triazine) resin having a thickness of 1 mm. It was used as a starting material (see FIG. 1 (a)). First, the copper-clad laminate is drilled, and then a plating resist is formed. Then, the substrate is subjected to an electroless copper plating process to form through holes 9, and the copper foil is patterned in a conventional manner. Then, an inner copper pattern (lower conductive circuit) 4 was formed on both surfaces of the substrate.

(2) The substrate on which the lower conductive circuit 4 is formed is washed with water and dried, and then an etching solution is sprayed on both surfaces of the substrate by spraying, so that the surface of the lower conductive circuit 4 and the land surface of the through hole 9 and the inner wall are formed. And by etching
The roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 1B). A mixture of 10 parts by weight of an imidazole copper (II) complex, 7 parts by weight of glycolic acid, 5 parts by weight of potassium chloride, and 78 parts by weight of ion-exchanged water was used as an etching solution.

(3) A resin filler 10 containing a cycloolefin resin as a main component is applied to both sides of the substrate by using a printing machine to fill the space between the lower-layer conductor circuits 4 or the inside of the through hole 9 and heat the resin. Drying was performed. That is, by this step, the resin filler 10 is filled between the lower conductor circuits 4 or in the through holes 9 (see FIG. 1C).

(4) One surface of the substrate after the treatment of the above (3) is subjected to belt sanding using a belt polishing paper (manufactured by Sankyo Rikagaku Co., Ltd.) to form the surface of the lower conductor circuit 4 and the land surface of the through hole 9 Was polished so that the resin filler 10 did not remain, and then buffed to remove the scratches caused by the belt sander polishing. Such a series of polishing was similarly performed on the other surface of the substrate. Then, the filled resin filler 10 was cured by heating (see FIG. 1D).

In this manner, the surface layer portion of the resin filler 10 filled in the through holes 9 and the like and the roughened layer 4a on the upper surface of the lower conductor circuit 4 are removed to smooth both surfaces of the substrate, and the resin filler 10 and the lower layer are removed. A wiring board was obtained in which the side surfaces of the conductive circuit 4 were firmly adhered through the roughened surface 4a, and the inner wall surface of the through hole 9 was tightly adhered to the resin filler 10 through the roughened surface 9a.

(5) Next, the same etching solution as the etching solution used in (2) is sprayed onto both surfaces of the substrate after the treatment in (4), and the lower conductor circuit once flattened is sprayed. By etching the surface of the lower conductor circuit 4 and the land surface of the through hole 9, roughened surfaces 4a and 9a were formed on the entire surface of the lower conductor circuit 4 (see FIG. 2A).

(6) Next, on both surfaces of the substrate having undergone the above steps,
A pressure of 5 kg / c while heating a thermosetting type cycloolefin resin sheet having a thickness of 50 μm to a temperature of 50 to 150 ° C.
Vacuum compression lamination was performed at m ² to provide an interlayer resin insulating layer 2 made of a cycloolefin-based resin (see FIG. 2B). The degree of vacuum during vacuum compression was 10 mmHg.

(7) Next, using a CO ₂ gas laser having a wavelength of 10.4 μm, the cycloolefin resin was used under the conditions of a beam diameter of 5 mm, a top hat mode, a pulse width of 50 μsec, a mask hole diameter of 0.5 mm, and three shots. A via hole opening 6 having a diameter of 80 μm was formed in the interlayer resin insulating layer 2 made of (see FIG. 2C). Thereafter, a desmear treatment was performed using oxygen plasma.

(8) Next, SV manufactured by Japan Vacuum Engineering Co., Ltd.
Plasma treatment was performed using −4540 to roughen the surface of the interlayer resin insulating layer 2 (see FIG. 2D). At this time, argon gas was used as the inert gas, and the power was 200
Plasma treatment was performed for 2 minutes under the conditions of W, gas pressure 0.6 Pa, and temperature 70 ° C.

(9) Next, after replacing the argon gas inside using the same apparatus, sputtering using a Ni—Cu alloy as a target was performed at a pressure of 0.6 Pa, a temperature of 80 ° C., a power of 200 W, and a time of 5 minutes. Under the conditions, the Ni—Cu alloy layer 12 was formed on the surface of the polyolefin-based interlayer resin insulating layer 2. At this time, the thickness of the formed Ni—Cu alloy layer 12 was 0.2 μm (see FIG. 3A).

(10) A commercially available photosensitive dry film is adhered to both surfaces of the substrate after the above treatment, a photomask film is placed, and after exposure at 100 mJ / cm ² ,
It was developed with 0.8% sodium carbonate to form a pattern of the plating resist 3 having a thickness of 15 μm (see FIG. 3B).

(11) Next, electroplating was performed under the following conditions to form an electroplating film 13 having a thickness of 15 μm (FIG. 3).
(C)). This means that the electroplating film 13 has been used to thicken the portion that will be the conductor circuit 5 and fill the portion that will be the via hole 7 with plating in the steps described later. The additive in the electroplating aqueous solution is Capparaside HL manufactured by Atotech Japan.

[Electroplating aqueous solution] sulfuric acid 2.24 mol / l copper sulfate 0.26 mol / l additive 19.5 ml / l [electroplating conditions] current density 1 A / dm ² hours 65 minutes temperature 22 ± 2 ° C

(12) Then, the plating resist 3 is made of 5% Na
After stripping and removing with OH, the Ni—Cu alloy layer 12 existing under the plating resist 3 is dissolved and removed by etching using a mixed solution of nitric acid, sulfuric acid and hydrogen peroxide, and the electrolytic copper plating film 13 is removed. The conductor circuit 5 (including the via hole 7) having a thickness of 16 μm and the like was formed (FIG. 3).
(D)).

(13) Subsequently, the above steps (5) to (13) were repeated to form a further upper layer conductive circuit.
(See FIGS. 4A to 5B).

(14) Next, a cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) to a concentration of 60% by weight was used. 46.67 parts by weight of an oligomer for imparting properties (molecular weight: 4000), 15 parts by weight of a bisphenol A type epoxy resin (trade name: Epicoat 1001 manufactured by Yuka Shell Co., Ltd.) dissolved in methyl ethyl ketone, and 15 parts by weight of an imidazole curing agent ( (Shikoku Chemicals, trade name: 2E4MZ-CN)
6 parts by weight, 3 parts by weight of polyfunctional acrylic monomer (trade name: R604, manufactured by Nippon Kayaku Co., Ltd.), which is a photosensitive monomer, and polyvalent acrylic monomer (trade name: DP, manufactured by Kyoei Chemical Co., Ltd.)
E6A) 1.5 parts by weight and 0.71 part by weight of a dispersion antifoaming agent (manufactured by San Nopco, trade name: S-65) in a container,
A mixed composition was prepared by stirring and mixing, and 2.0 parts by weight of benzophenone (manufactured by Kanto Kagaku) as a photopolymerization initiator and Michler's ketone (manufactured by Kanto Kagaku) as a photosensitizer were added to the mixed composition. Add 0.2 parts by weight and adjust viscosity to 25 ° C
To obtain a solder resist composition (organic resin insulating material) adjusted to 2.0 Pa · s. 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. Rotor N at 4,6 rpm
o. According to 3.

(15) Next, the above-mentioned solder resist composition is applied to both sides of the multilayer wiring board in a thickness of 20 μm,
After performing a drying process under the conditions of 20 ° C. for 20 minutes and 70 ° C. for 30 minutes, a 5 mm-thick photomask on which a pattern of the opening of the solder resist is drawn is brought into close contact with the solder resist layer, and an ultraviolet ray of 1000 mJ / cm ² is applied. Exposure with DM
Development was performed with a TG solution to form an opening having a diameter of 200 μm. Then, at 80 ° C. for 1 hour, and at 100 ° C. for 1 hour.
The solder resist layer was cured by performing a heat treatment under the conditions of 1 hour at 120 ° C. and 3 hours at 150 ° C., and the solder pad portion was opened, and the thickness was 20 μm.
Of the solder resist layer (organic resin insulating layer) 14 was formed.

(16) Next, a solder resist layer (organic resin
The substrate on which the insulating layer (14) was formed was coated with nickel chloride (2.3).
× 10^-1mol / l), sodium hypophosphite (2.8
× 10 ^-1mol / l), sodium citrate (1.6 ×
10^-1mol / l) and pH = 4.5
Immersion in a plating solution for 20 minutes, and a 5 μm thick
A nickel plating layer 15 was formed. In addition, the board
Potassium gold cyanide (7.6 × 10^-3mol / l), salt
Ammonium iodide (1.9 × 10^-1mol / l), quenched
Sodium acid (1.2 × 10^-1mol / l), phosphorus hypophosphite
Sodium acid (1.7 × 10^-1mol / l)
Immerse in a plating solution at 80 ° C for 7.5 minutes,
0.03 μm thick gold plating layer on the Kell plating layer 15
No. 16 was formed.

(17) Thereafter, a solder paste is printed on the openings of the solder resist layer 14 and reflowed at 200 ° C. to form solder bumps (solder bodies) 17.
A multilayer wiring printed board having the solder bumps 17 was manufactured (see FIG. 5C).

The dielectric constant, dielectric loss tangent, and peel strength of the obtained multilayer printed wiring board were measured.
Heat treatment test for 8 hours and 1 at -55 ° C to 125 ° C
000 heat cycle tests were performed. Then, after the heat treatment test and after the heat cycle test, peeling between the interlayer resin insulating layer and the lower conductive circuit and the resistance change rate of the via hole portion were measured. The results are shown in Table 1 below.

(Example 2) In the same manner as in Example 1 except that the conductor circuit was not etched in the step (5) and the interlayer resin insulating layer was not roughened in the step (8). Thus, a multilayer printed wiring board was manufactured. And
The same tests and evaluations as in Example 1 were performed on the obtained multilayer printed wiring board. The results are shown in Table 1 below.

(Comparative Example 1) A thermosetting linear polyolefin resin (manufactured by Sumitomo 3M, trade name: 1592) was used as a resin for forming an interlayer resin insulating layer.
A multilayer printed wiring board was manufactured in the same manner as in Example 1.
Then, the same tests and evaluations as in Example 1 were performed on the obtained multilayer printed wiring board. The results are shown in Table 1 below.

[0062]

[Table 1]

As is clear from the results shown in Table 1, the multilayer printed wiring board of the example has a small resistance change ratio between the conductor circuit and the via hole even after the heating test and the heat cycle test. While no peeling was observed between the conductor circuit and the interlayer resin insulating layer, the multilayer printed wiring board of the comparative example had a large rate of change in resistance or peeled off after the test.

[0064]

As described above, the multilayer printed wiring board of the present invention uses a cycloolefin resin as the interlayer resin insulating layer, so that the dielectric constant and the dielectric loss tangent are small. Even when signals are used, signal delays and signal errors are unlikely to occur, and mechanical properties such as rigidity are excellent, so the reliability of the connection between conductor circuits is high, and the conductor circuits and interlayer resin insulation layers should be used. Also has excellent adhesion.

In the method for manufacturing a multilayer printed wiring board according to the present invention, the interlayer resin insulating layer is formed by laminating a cycloolefin-based resin sheet on a conductive circuit, so that it is not necessary to use a solvent or the like, and Is simplified, and a multilayer printed wiring board can be easily manufactured.

[Brief description of the drawings]

FIGS. 1A to 1D are longitudinal sectional views showing a part of a manufacturing process of a multilayer printed wiring board according to the present invention.

FIGS. 2A to 2D are longitudinal sectional views showing a part of a manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 3A to 3D are longitudinal sectional views showing a part of a manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 4A to 4C are longitudinal sectional views showing a part of a manufacturing process of the multilayer printed wiring board of the present invention.

FIGS. 5A to 5C are longitudinal sectional views showing a part of a manufacturing process of the multilayer printed wiring board of the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 interlayer resin insulating layer 3 plating resist 4 lower conductive circuit 4a roughened surface 5 upper conductive circuit 6 opening for via hole 7 via hole 8 copper foil 9 through hole 9a roughened surface 10 resin filler 12 Ni-Cu alloy layer 13 Electroplating film 14 Solder resist layer 15 Nickel plating film 16 Gold plating film 17 Solder bump

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Motoo Asai 1-1, Ibigawa-cho, Ibi-gun, Gifu Prefecture Inside the Ogaki-Kita Plant of Ibid Co., Ltd. (72) Inventor Kenichi Shimada 1-1, Ibigawa-cho, Ibi-gun, Gifu Prefecture F-term in Ogaki Kita Plant (reference) 5E346 AA06 AA12 AA15 AA23 AA43 BB01 CC08 CC32 CC37 CC54 DD02 DD03 DD17 DD24 DD33 DD47 EE33 EE35 EE38 FF14 GG15 GG17 GG27 GG28 HH05 HH06 HH07 HH11

Claims (6)

[Claims] 1. A multilayer printed wiring board in which a conductive circuit and a resin insulating layer are sequentially formed on a substrate and these conductive circuits are connected via via holes, wherein the resin insulating layer is made of a cycloolefin resin. A multilayer printed wiring board, comprising: 2. The multilayer printed wiring board according to claim 1, wherein the dielectric constant of the resin insulating layer at 1 GHz is 3.0 or less, and the dielectric loss tangent is 0.01 or less. 3. The multilayer according to claim 1, wherein the cycloolefin-based resin is a homopolymer or a copolymer of a monomer composed of 2-norbornene, 5-ethylidene-2-norbornene, or a derivative thereof. Printed wiring board. 4. The multilayer printed wiring board according to claim 1, wherein the cycloolefin-based resin is a thermosetting cycloolefin-based resin. 5. A method for manufacturing a multilayer printed wiring board, comprising: forming a conductive circuit and a resin insulating layer on a substrate in order, and connecting the conductive circuits through via holes. A method for producing a multilayer printed wiring board, wherein an interlayer resin insulating layer is formed by laminating a film made of a cycloolefin-based resin under vacuum. 6. After forming an interlayer resin insulating layer from a cycloolefin resin on a conductive circuit formed on a substrate,
6. The method for manufacturing a multilayer printed wiring board according to claim 5, wherein a via hole opening is formed by irradiating the interlayer resin insulating layer with laser light.