JP2001358431A - Wiring board manufacturing method and wiring board using the same - Google Patents

Abstract

(57) [Problem] To reduce the number of manufacturing steps and improve the yield without lowering the wiring density and reliability, and to significantly reduce the cost. A conductive circuit can be formed by selectively graphitizing a specific portion of a resin surface layer using high energy beam irradiation and forming a conductive film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-cost, high-density multi-layer printed wiring board used in the manufacture of consumer mounting equipment, a communication ATM switch, and the like, and a multi-chip module board for a workstation, a personal computer, and the like. The present invention relates to a wiring board and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become higher in performance and smaller in size and higher in function, printed wiring boards on which various electric components such as LSIs are mounted are required to have further improved performance. In order to cope with high integration of LSI and light and thin electronic devices, technology development of wiring boards with high wiring density and high reliability is required. Wiring boards are developed by electronic device manufacturers, substrate manufacturers, material manufacturers. And so on.

Under these circumstances, miniaturization of wiring and cost reduction are major issues, and various companies are conducting research for reducing the diameter and cost of interlayer connection holes by various methods. .

A typical example is disclosed in Japanese Patent Application Laid-Open No.
For example, a build-up method as disclosed in Japanese Patent Publication No. 90-90 is mentioned. This technology applies a photosensitive insulating material to the surface layer of a printed wiring board on which the surface conductor layer has been patterned, forms a via hole by exposing and developing, and then obtains an adhesive force with copper. Then, a base conductive film is formed on the entire surface of the roughened insulating film.

Then, a conductor circuit is formed by electroplating, and this is repeated to form a multilayer, and finally, a through-plated through hole is formed. Further, a method of manufacturing a multilayer wiring board (hereinafter, referred to as a second conventional technique) which aims at forming a higher-density wiring with respect to the above-described manufacturing method is disclosed in Japanese Unexamined Patent Application Publication No. Hei 8 -83982. In this prior art, as shown in FIG. 6, the connection between the upper layer wiring and the lower layer wiring is achieved by utilizing the space on the via connected via the stud via, thereby achieving high wiring density. It comprises the following steps.

(1) An insulating film 45 is formed on a core substrate 44 provided with a conductor circuit 43 having a stud via 42. (2) The surface of the insulating film is polished to expose the head of the stud via. (3) The insulating film The surface is chemically or physically roughened to form a roughened surface 46. (4) A base conductive film 47 is formed on the roughened surface. (5) A conductive circuit 48 is formed by electroplating. After the stud vias 49 are formed, the above steps of removing the underlying conductive film are repeated to produce a multilayer wiring structure.

Further, in recent years, a technique of pressing a resin film with a copper foil on a core substrate has attracted attention. In this technology, a copper film as an upper wiring layer is formed at the same time as forming an interlayer insulating film by arranging a resin film with copper foil on the core substrate or above and below the core substrate so that the copper foil faces outward. The most significant feature is that the process is greatly shortened and the cost is reduced by being formed thereon. As an example of a method for manufacturing such a wiring board,
Japanese Patent Application Laid-Open No. 10-4271 (hereinafter referred to as a third prior art) is disclosed, and FIG.
The step consisting of (g) is shown.

(A) A semi-cured thermosetting resin 53 with copper foil is placed on a core substrate 52 provided with a through hole 50 and a conductor circuit 51 so that the copper foil is on the outside, and laminated by thermocompression bonding to form an insulating film. (B) The copper foil portion is etched and removed into the hole shape 54 of the non-through connection hole. (C) The resin layer exposed from the fine hole 54 of the copper foil etched and removed into the hole shape of the non-through connection hole is laser-processed. Irradiation removes the conductive circuit of the core substrate to a position where it is almost exposed, and forms a non-through connection hole 55. (d) Strongly removes the resin residue 56 after laser processing remaining on the side surface and the bottom of the non-through connection hole 55. (E) After the plating catalyst is applied, the conductor circuit 58 on the core substrate 57 and the conductor 60 on the resin layer 59 provided thereon are electrically connected by panel plating. (F) The resin layer 61 Upper A multilayer structure by repeating the steps of the foil forming the upper conductor circuit 62 by etching away (g) above (a) ~ (f)

[0009]

According to the first prior art in which the layers are connected by a photo via, the via hole is formed by exposure and development, so that a special device is not required and the cost is low. There is a problem.

The first problem is that the film thickness is limited. A via hole for interlayer connection is formed by exposure and development of a photosensitive resin. However, if the interlayer insulating film thickness changes, the amount of transmitted light greatly changes and a stable via shape cannot be formed, so strict film thickness control is essential. The thickness cannot be changed according to the specifications.

As a result, the film thickness is inevitably limited to a certain range, and the insulating film used in this technique is limited to a photosensitive resin, so that the thickness of the insulating film is smaller than that of a thermosetting resin. And has poor heat resistance and insulation reliability.

The second problem is related to the roughening of the insulating film. In the method of bonding the insulating film and the conductor wiring, an adhesive force is obtained by an anchor effect by roughening the insulating film surface, but the state of the insulating film surface is not necessarily constant, and the in-plane distribution, and Since there is variation among resin lots, it is difficult to obtain a stable roughened surface, and it is difficult to always maintain an adhesive strength of 1 kN / m or more.

In the second prior art, the wiring can be formed above the stud via wiring, so that the wiring density can be increased as compared with the method of forming a photo via. In addition, insulating materials include
Since no photosensitivity is required, a wide range of materials with better insulation reliability can be selected at appropriate times.The film thickness is not limited by the material, and a wide range can be set according to the electrical characteristics. Problem.

The third problem is that the process is complicated. First
In the prior art, the interlayer connection wiring and the upper wiring are formed in a single plating step, but in the second prior art, these are formed separately.

Since the steps of photography are used to form the wiring, these steps are performed twice so that the positional accuracy and the resolution are improved. On the other hand, the steps of mask alignment, exposure and development are performed twice. Process becomes complicated,
Prolong the time.

A fourth problem is a method of bonding the insulating film and the conductor wiring. The method of bonding the insulating film and the conductor wiring in the second prior art is the same as that in the first prior art, and the above-mentioned problem described in the first prior art is not solved at all.

The third conventional technique solves the problem of adhesion between the insulating film and the conductor wiring which is common to the first and second conventional techniques as described above, by a technique of thermocompression bonding of a resin-coated copper foil. Is being planned. Conductive wiring obtained by selectively etching the copper foil for thermocompression bonding of the copper foil on the semi-cured resin to be the interlayer insulating film is stably and firmly adhered to the insulating film.

However, the introduction of a new technique of forming a non-through connection hole by laser processing has caused another problem described below.

That is, the processing residue on the side wall and bottom of the non-through connection hole. In laser processing, the thermal decomposition products of the interlayer insulating film remain on the side walls and bottom of the non-through connection hole, and a layer degraded by heat is formed inside the hole, so the connection reliability and insulation reliability In order to form a wiring board having a high density, it is necessary to surely remove them.

Further, there is a problem related to the adhesive strength between the interlayer insulating film and the conductor wiring. In the first and second prior arts, the interlayer insulating film, the upper conductor wiring, and the insulating film on the wall surface of the non-through connection hole are roughened in order to form a conductor for interlayer connection. Was.

On the other hand, in the third prior art, the adhesive strength between the interlayer insulating film and the upper conductor wiring is obtained by a method of thermocompression bonding of a resin-coated copper foil, so that the adhesive strength of the upper wiring is 1 kN. / M can be secured stably. However, in order to form a conductor in the non-through connection hole, it is necessary to obtain an adhesive force by roughening the side wall portion of the non-through connection hole as in the first and second prior arts. With respect to the location where the conductor is formed in the hole, there is no improvement with respect to the first and second prior arts.

The roughening step is to solve the first problem and the second problem at once by removing the resin residue and forming a dense roughened surface.

However, in order to solve the above problems at the same time, detailed examination of the roughening conditions is required. In the third prior art, no detailed description is given of the roughening conditions. Therefore, we examined the roughening process.

When the roughening time is short, the residual ratio of the deteriorated resin on the wall surface and the hole bottom is high. Conversely, when the roughening time is long, the resin is deteriorated despite the separation of the interface between the hole bottom and the wall surface. The remaining resin still remained. The resin carbonized by such laser irradiation is strongly adhered and cannot be quickly removed by roughening.

We further confirmed the altered state of the carbonized resin by Raman analysis and found that
^{In the} vicinity of ^-1 , absorption of carbon, which is considered to be caused by the graphite structure, was detected with extremely high intensity.

Japanese Patent Laid-Open No. 5-51205 discloses that laser processing can form an oxidation-resistant graphitized layer on the surface of a composite material using an epoxy resin as a matrix.
This is supported by the description in the publication. Therefore, unlike the fact described in the third prior art, the resin deteriorated by the laser irradiation is easily removed by a roughening liquid which is a strong oxidizing agent. I can't. Thus, the third conventional technique is an advanced technique that can surely increase the density as compared with the above-described conventional technique. However, as described above, the third related art has an unprecedented new problem.

In addition, there are two common problems of the first to third prior arts. As a first problem, in order to remove the deteriorated insulating film layer and stably obtain the adhesive strength between the insulating film and the conductor wiring, the alkali normality of the roughening solution, the concentration of potassium permanganate, the temperature, etc. Strict management is required.

In the prior art described above, the roughening step is still indispensable, and it is impossible to bond the conductor unless the surface of the insulating film is roughened. For this reason, in the above-mentioned prior art, there are many problems related to the roughening process, and the process requires the most manufacturing cost.

The second problem is a problem relating to via connection reliability. The lower conductor wiring surface layer of the via bottom exposed after the formation of the via by the photolithography process in the first prior art, after the formation of the stud via wiring pattern in the second prior art, and after the roughening process in the third prior art, Due to the effects of the residual cleaning of the chemical solution in the resist etching step, the roughening step, the catalyst applying step, and the formation of the oxide film, etc., the adhesive force between the via formed by electroless or electroplating and the lower conductor wiring is stably secured. It is difficult.

[0030]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has conducted experiments on laser processing conditions for producing carbon. As a result, laser irradiation was performed under appropriate conditions. , The amount of carbon increases significantly,
In addition, it was found that a carbon film was formed only on the resin surface layer at a specific location. Based on this finding, we have found a technique for effectively using a carbonized film graphitized under the above laser processing conditions as a conductive film. If the laser processing technology based on the experimental results can be introduced into a conventional method for manufacturing a wiring board, the roughening step can be omitted, and the above problem can be solved at once.

First, a non-penetrating connection hole is provided by irradiating the insulating film with a high energy beam, and at the same time, the resin surface on the side surface and the hole bottom of the non-penetrating connection hole is made conductive to establish electrical connection between layers. The second step is a technique for manufacturing a high-density multilayer wiring board including a step of simultaneously forming a non-through connection hole forming pattern and other conductive circuits. The present invention relates to a method for manufacturing a wiring board which achieves lower cost by further improving reliability and shortening the process.

The above-mentioned problem is solved by the following method for manufacturing a wiring board.

The entire steps of the first method of manufacturing a wiring board according to the present invention will be described.

FIG. 1 is a schematic explanatory view of a first method of manufacturing a wiring board according to the present invention. A first method for manufacturing a wiring board according to the present invention will be described with reference to FIG.

A resin film 4 with a copper foil is placed above the core substrate 1 provided with the conductor circuit 2 and the through hole 3 on one or both sides, or in a state where the core substrate is sandwiched therebetween, and then heat-pressed to form the resin film in the through hole. A step of filling the resin and forming an insulating film (step b), and a step of simultaneously etching and removing the copper foil on the insulating film into the hole shape 5 of the non-penetrating connection hole and simultaneously forming the other conductor circuits 6 (step b) c) and irradiating a high energy beam from the upper portion of the insulating film which has been etched and removed to the hole shape 5 of the non-through connection hole, thereby forming the non-through connection hole 7 and simultaneously forming the insulation film on the side and bottom of the non-through connection hole. (Step d) of graphitizing and forming the conductive film 8 and a step (step e) of repeating steps b to d to form a multilayer.

The high energy beam used in step (d) can be a laser or a plasma flame, but the most effective means is a versatile laser suitable for practical use.

Further, in order to graphitize an organic substance,
It is difficult to carbonize the resin of the YAG laser because of its different absorption wavelength, and the carbon dioxide laser is most suitable for easily adjusting the degree of graphitization.

The most advanced technology as compared with the first to third prior arts of the present invention is, first, that it has no roughening step. In the related art, the roughening step is an essential step in order to obtain an adhesive force between the insulating film (organic substance) and a conductor (metal) that is a different material.

However, in the present invention, the side surface of the non-penetrating connection hole is one in which the surface layer of the insulating film is transformed into carbon amorphous by the laser treatment and made conductive. For this reason, since the insulating film and the conductive film are integrated, it is not necessary to obtain an adhesive force by roughening.

Further, in the conductive film according to the present invention, as shown in FIG. 5, the copper electrification rate decreases as going from the surface to the inside of the insulating film, and the gradient becomes gentle.

The higher the conductivity, the more the conductive film becomes a structure composed of only carbon, and the higher the hardness and the more brittle the conductive film. That is, the surface layer is the hardest and brittle film. However, as the conductivity gradually decreases, the composition and the resin strength approach the same as those of the insulating film, and the resin is eventually integrated with the insulating film.

For this reason, even if a heat cycle test is performed, the resin strength changes gradually from the conductive part to the insulating part, so that the resin peels off at the boundary between the conductive part and the insulating part due to the difference in linear expansion coefficient. High reliability can be obtained without any trouble. As a result, the roughening step, the catalyst applying step, and the plating step can be omitted, and the steps can be greatly simplified.

According to the present invention, the deteriorated resin layer is not removed and the deteriorated resin layer is used as a conductor connection circuit between layers. For this reason, in the first and second prior arts, the reliability is reduced due to the variation of the roughened surface, and as in the third prior art, the via bottom resin residue after the roughening,
Insufficient adhesion of organic substances and insufficient removal of the oxide film due to insufficient cleaning of the chemical solution will not cause a connection failure, and the bonding is so strong that it cannot be removed by roughening, so that reliable reliability can be secured.

The processing conditions by the above laser processing are as follows. When the laser output of the beam is 0.05 J / cm ² or less, the progress of graphitization of the deteriorated resin is insufficient, the conductivity is very small, and the insulation of the deteriorated layer is insulated. The resistance value was 10 ⁸ Ω or more. Further, when processing is performed with a beam laser output of 20 J / cm ² or more, graphitization proceeds to the periphery of the non-penetrating connection hole, and the quality of the insulating film is deteriorated. For this reason, the energy density of the laser beam varies depending on the size and shape of the hole diameter, but the most appropriate condition is 0.05 J / cm or more and 20 J / cm ² or less in any processing. .

In the third prior art, the step of patterning the hole shape of the non-through connection hole in the copper foil by etching and the step of forming other conductive circuits by etching are separate steps. In the invention, since the conductive film is formed simultaneously with the formation of the non-through connection hole by laser processing, both steps can be performed simultaneously.

As a result, the number of steps is reduced, and a lower cost printed wiring board is obtained.

Further, in order to further enhance the reliability of the conductive film formed by irradiating the high energy beam, the conductive film may be used as a base conductive film, and the surface of the base conductive film may be plated.

When a conductive film is formed by an electroplating method, a step of patterning a copper foil into a non-through connection hole by etching and a step of forming another conductive circuit by etching cannot be performed at the same time.
Although the number of steps is larger than the number of steps described above, there is a great advantage that the roughening step and the step of forming the underlying conductive film can be omitted, which leads to more reliable improvement as compared with the related art.

In the case where the conductive film is formed by electroless plating, the conductive film can be formed only in the non-through hole in which the underlying graphite conductive film is selectively formed. Similarly to the method, the step of patterning the copper foil into the hole shape of the non-through connection hole by etching and the step of forming another conductor circuit by etching can be performed simultaneously.

The entire process of the second manufacturing method by electroplating and the third manufacturing method by electroless plating according to the present invention will be described.

FIG. 2 is a schematic illustration of a second method of manufacturing a wiring board by electroplating according to the present invention. Hereinafter, a method for manufacturing a wiring board according to the present invention will be described with reference to FIG.

A resin film 12 with a copper foil is placed on an upper part of a core substrate 11 provided with a conductor circuit 9 and a through hole 10 on one or both sides, or in a state sandwiching the core substrate.
A step of filling the resin into the through-holes and forming an insulating film by thermocompression bonding (step b); and forming a non-penetrating connection hole forming pattern on the copper foil on the insulating film. A step (step c) of etching the upper copper foil at the connection hole formation location, and irradiating a high energy beam from above the exposed insulating film by etching to form the non-through connection hole 13 and at the same time the non-through connection hole Graphite the insulating film on the side and the bottom of the hole
Forming a conductive pattern 15 on the substrate after the laser irradiation by electroplating (step e); patterning a wiring pattern on the copper foil of the substrate; (Step f) of forming the conductor circuit 16 by the above-described method, and a step (step g) of repeating the steps b to f to form a multilayer.

In addition to the second manufacturing method, the most common method for forming a conductive film in step (e) is to deposit plating from above the underlying conductive film. In the case of wiring, or when a pattern wiring is provided around the substrate and a lead line is provided from the wiring end to the pattern wiring, the lower-layer conductor pattern wiring is exposed from the substrate end, and the exposed lower-layer conductor pattern wiring end is exposed. From the substrate by electroplating. This plating method fills the non-through holes, so that more reliable reliability can be obtained.

The method of connecting the lower conductor wiring and the upper conductor wiring by depositing plating from the bottom of the non-through hole and filling the non-through hole by electroplating from the lower conductor pattern wiring in the second manufacturing method described above is shown. 3 is shown.

The steps will be described below. A resin film 21 with a copper foil is placed on the core substrate 17 provided with a conductor circuit 19 including a pattern wiring 18 and a through hole 20 on one or both sides, or sandwiching the core substrate. And filling the resin into the through-holes and forming an insulating film by heating and pressure bonding (step b), and etching and removing the copper foil on the insulating film into the hole shape 22 of the non-through connection hole. And forming a non-penetrating connection hole 24 by irradiating a high-energy beam from the upper portion of the insulating film etched and removed to the hole shape 22 of the non-penetrating connection hole. At the same time, the insulating film on the side and bottom of the non-through connection hole is graphitized to form the underlying conductive film 25 (step d). A step of exposing 26 a part of the underlying conductor pattern wiring, depositing plating from a part of the underlying conductor pattern wiring exposed by the electroplating method, and filling the non-through hole with a conductor 27 (step e); (Step f).

Next, FIG. 4 is a schematic explanatory view of a third method of manufacturing a wiring board by the electroless plating method according to the present invention.

A resin film 31 with a copper foil is placed above a core substrate 30 provided with a conductor circuit 28 and a through hole 29 on one or both sides, or a state in which the core substrate is sandwiched, and is heated and press-bonded. Step of filling resin and forming insulating film (step b)
And removing the copper foil on the insulating film by etching into the hole shape 32 of the non-through connection hole and simultaneously forming the other conductive circuit 33 (step c); Irradiating a high-energy beam from above the formed insulating film to form the non-penetrating connection hole 34 and, at the same time, graphitize the insulating film on the side surface and the bottom of the non-penetrating connection hole to form the underlying conductive film 35 (process). d) and a step of applying a conductive film 36 only to the non-through hole wall surface and hole bottom by electroless plating on the substrate after the laser irradiation (step e).
And steps of repeating steps b to e to form a multilayer (step f)
Consists of

In the third manufacturing method, since the plating film is not formed on the copper foil on the insulating film, the thickness of the copper foil on the insulating film does not change from the initial film thickness. Processing is possible.

As described above, according to the present invention, stable reliability can be ensured by omitting the roughening step which has caused the most reduction of reliability in the conventional manufacturing method, and the steps can be shortened and the cost can be reduced. This is a method of manufacturing a wiring board which enables the above.

As described above, in the first prior art to the third prior art, the adhesive force between the resin layer and the wiring layer obtained by the unevenness of the roughened surface is very unstable. In the prior art, non-through connection hole resin residues formed by laser processing must be removed by desmear treatment or the like using a strong alkaline oxidizing agent solution, and higher insulation reliability and connection reliability than before can be expected. Absent.

According to the present invention, it is not necessary to bond the copper foil by roughening the surface of the insulating film, and since the surface of the insulating film is made conductive, the conductive film formed on the resin surface gradually goes from the resin surface to the inside. As the conductivity decreases, the resin characteristics gradually change from the characteristics of amorphous carbon to the original characteristics of the resin. In particular, since the linear expansion coefficient gradually changes from carbon to the linear expansion coefficient of the insulating film, it can sufficiently cope with a rapid thermal change, which leads to improvement in reliability over the prior art.

As described above, the above object can be achieved by applying the above-described wiring board manufacturing technology according to the present invention.

[0063]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a wiring board according to the present invention will be described with reference to examples and comparative examples.

Table 1 summarizes the resin film maker with copper foil used in Examples and Comparative Examples, the conductive film forming method, and the test results.

[0065]

[Table 1]

Example 1 A 10 cm square resin film with copper foil (resin thickness 80 μm) was placed above and below a 10 cm square FR-4 core substrate provided with through holes of φ300 μm and wiring on both sides.
m, copper foil thickness 12 μm: Hitachi Chemical Co., Ltd. MCF-600
0E), a pressure increasing rate of 30 kg / cm ² / min, and a temperature increasing rate of 5.3 ° C./mi under a condition of a vacuum degree of 50 Torr.
Then, the temperature was raised to 180 ° C. and maintained for 60 minutes in this state, and then cooled to room temperature, thereby simultaneously filling the through holes with the resin and forming an insulating film.

Next, a dry film resist (Photec HS930, manufactured by Hitachi Chemical Co., Ltd.) is applied to the insulating film forming substrate.
30 μm) were laminated, and non-through connection holes φ150 μm and φ100 μm connecting between the layers and other wiring patterns were exposed, developed, and patterned.

Next, an etching solution (Meltec:
A process alkaline etching solution), remove by spray etching, perform high-pressure cleaning with ammonia water, and then peel off the dry film resist with a 3 wt% aqueous solution of NaOH to form non-through connection holes φ150 μm and φ
The surface of the insulating film was exposed at a specific portion for forming 100 μm, and at the same time, another conductor circuit was formed.

Next, the non-through holes of φ150 μm and φ100 μm were formed at the non-through connection hole formation portions above the insulating film exposed by the above-mentioned etching using, for example, a carbon dioxide laser at an energy density of 0.23 J / cm ² . φ15
0 μm, pulse width 12/8/3 μs, number of shots 1/1
/ 1, φ100 μm, pulse width 10/5/2 μs, number of shots 1/1/1, irradiate laser light to form a non-through connection hole, and at the same time, graphitize the resin surface of the hole bottom and the wall surface of the hole to conduct. A film was formed.

When a continuity test was performed on all the interlayer connection holes on the substrate prepared above, it was confirmed that 95% of the interlayer connection holes were connected. In addition, the temperature 65
As a result of conducting an insulation reliability test under the conditions of a temperature of 95 ° C., a humidity of 95%, and an applied voltage of 100 V, the insulation resistance at 95% after 500 hours was 10 ¹² Ω or more.

[Embodiment 2] An insulating film was formed in the same manner as in Embodiment 1, and φ150 μm and φ
Etching was performed to form a 100 μm non-through connection hole.

Next, using a carbon dioxide laser, non-through holes of φ150 μm and φ100 μm were formed in the non-through connection holes formed on the upper portion of the insulating film exposed by the above etching, with an energy density of 0.23 J / cm ² , specifically φ150 μm.
m, pulse width 12/8/3 μs, number of shots 1/1 /
By irradiating a laser beam having a diameter of 1, 100 μm, a pulse width of 10/5/2 μs, and the number of shots 1/1/1,
Non-through connection holes were formed, and the resin surface of the hole bottoms and hole wall surfaces was graphitized to form a base conductive film.

Next, after passing through a catalyst applying step and a flash plating step, electroplating was performed under the conditions of ² A / dm ² to form a conductive film having a thickness of 20 μm on the bottom and the wall surface of the non-through hole. Next, the above-mentioned dry film resist was again laminated on the above-mentioned insulating film forming substrate, the wiring pattern was patterned, and then the same etching was performed using the above-mentioned etching solution to form an upper conductor circuit.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that all the interlayer connection holes were connected. In addition, the temperature 6
As a result of conducting an insulation reliability test under the conditions of 5 ° C., humidity of 95%, and applied voltage of 100 V, a 95% interlayer connection insulation resistance value after 500 hours was 10 ¹² Ω or more.

[Embodiment 3] In the same manner as in Embodiment 1, the insulating film is formed, the upper copper foil is etched into the shape of a non-through hole, and another conductor circuit is formed. Then, the non-through hole is formed by laser processing. An underlying conductive film was formed. Next, the pH of the electroless plating solution was adjusted to 12.5, and a high-speed electroless plating was performed at 80 ° C./150 min to form a conductive film having a thickness of 5 μm on the bottom and the wall surface of the non-through hole.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that 100% of the interlayer connection holes were connected. In addition, the temperature 6
As a result of conducting an insulation reliability test under the conditions of 5 ° C., 95% humidity, and applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

Example 4 An insulating film was formed on the upper and lower sides of a 10 cm square FR-4 core substrate provided with a through hole of φ300 μm and solid wiring on both sides according to Example 3, and the upper copper foil was formed into a non-through hole shape. Etching and other conductive circuits were formed, and then a non-through hole was formed by laser processing, and at the same time, a base conductive film was formed.

Next, the lower conductor wiring was exposed from the end of the substrate, and plating was deposited from the bottom of the non-through hole by electroplating under the condition of ² A / dm ² from this end to fill the non-through hole with a conductor. .

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that 100% of the interlayer connection holes were connected. In addition, the temperature 6
As a result of conducting an insulation reliability test under the conditions of 5 ° C., 95% humidity, and applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

Example 5 A resin film with a 10 cm square copper foil (resin thickness 80 μm) was placed above and below a 10 cm square FR-4 core substrate provided with through holes of φ300 μm and wiring on both sides.
m, copper foil thickness 12 μm: Matsushita Electric Works R-0880)
And a pressure increase rate of 5 under the condition of a vacuum degree of 50 Torr.
kg / cm ² / min, the thermocompression bonding at a heating rate of 2.4 ° C. / min were performed. When the temperature reached 130 ° C., the pressure was increased to 30 kg / cm ² / min, the temperature was increased to 3.75 ° C./min while maintaining the degree of vacuum, and the temperature was further increased to 170 ° C. Next, this state is maintained for 10 minutes, the degree of vacuum is reduced to normal pressure, and the temperature is maintained at 170 ° C. for 50 minutes.
After cooling to room temperature, resin filling in the through holes and an insulating film were simultaneously formed.

Next, the surface of the insulating film was exposed to the non-penetrating connection holes φ150 μm and φ100 μm at the specified portions of the upper copper foil by the same method as in Example 1 on the substrate on which the insulating film was formed. Formed.

Next, a carbon dioxide laser was used to form an energy density of 0.3 J /
A non-penetrating connection hole was formed by irradiating a laser beam of cm ² , and the resin surface layer of the hole bottom and the hole wall surface was graphitized to form a conductive film.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that 90% of the interlayer connection holes were connected. In addition, the temperature 65
As a result of an insulation reliability test performed under the conditions of a temperature of 95 ° C., a humidity of 95%, and an applied voltage of 100 V, an insulation resistance value of 90% after 500 hours was 10 ¹² Ω or more.

[Example 6] A resin film with a copper foil: F in which an insulating film of Matsushita was used in Example 5 by the same method as in Example 5.
Resin filling in a through hole and an insulating film were simultaneously formed above and below the R-4 core substrate.

Then, the insulating film surface is exposed in a specific shape of the upper copper foil in a hole shape of non-through connection holes φ150 μm and φ100 μm by etching, and a non-through connection hole is formed using a carbon dioxide laser under the same conditions as in Example 5. At the same time as the hole bottom,
The resin surface of the hole wall surface was graphitized to form a conductive film.

Next, on the above-mentioned substrate, the above-mentioned Embodiment 2 was described.
After the same process as described above, 2A / d
The entire surface was subjected to panel plating under the condition of m ² to form a plating film of 20 μm, and then the upper conductor circuit was formed by etching under the same conditions as in Example 2.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that connection was established in all the interlayer connection holes. further,
As a result of conducting an insulation reliability test under the conditions of a temperature of 65 ° C., a humidity of 95% and an applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

[Example 7] A resin film with copper foil: an insulating film of Matsushita was formed on the upper and lower sides of the FR-4 core substrate simultaneously with resin filling in through holes and an insulating film by the same method as in Example 5.
Non-penetrating connection hole φ1 by etching in specific part of upper copper foil
The surface of the insulating film was exposed in a hole shape of 50 μm and φ100 μm, an upper conductor circuit was formed, a non-through connection hole was formed by a carbon dioxide laser, and at the same time, the resin surface of the hole bottom and the wall surface of the hole was graphitized to form a conductive film.

Then, high-speed electroless plating was performed on the substrate under the conditions of Example 3 to form a conductive film having a thickness of 5 μm on the bottom and the wall surface of the non-through hole.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that connection was established in all the interlayer connection holes. further,
As a result of conducting an insulation reliability test under the conditions of a temperature of 65 ° C., a humidity of 95% and an applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

Example 8 A resin film with a 10 cm square copper foil (resin thickness: 80 μm, copper foil thickness: 18 μm: APL-4001HF, Sumitomo Bakelite Co., Ltd.) was placed above and below the core substrate similar to the core substrate described in Example 1. Is installed, and the degree of vacuum is 50T.
Under the condition of orr, the temperature was raised at a rate of 2.75 ° C./min.
Heated to ° C. When the temperature reached 70 ° C, the pressure was increased to 30 kg / cm ² / min and the temperature was increased to 4.3 ° C / min while maintaining the degree of vacuum, and the temperature was further increased to 150 ° C. Next, the temperature was maintained at 150 ° C. for 20 minutes, then cooled to room temperature, and the resin filling in the through holes and the insulating film were simultaneously formed.

Next, the surface of the insulating film is exposed to the non-through connection holes φ150 μm and φ100 μm at the specified portion of the upper copper foil by the same method as in the first embodiment, and another conductor circuit is simultaneously formed on the insulating film forming substrate. A non-penetrating connection hole was formed by irradiating a carbon dioxide laser beam having an energy density of 0.35 J / cm ² by etching, and the bottom surface of the hole and the resin surface layer of the hole wall were graphitized to form a conductive film.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that 93% of the interlayer connection holes were connected. In addition, the temperature 65
As a result of an insulation reliability test performed under the conditions of a temperature of 95 ° C., a humidity of 95%, and an applied voltage of 100 V, an interlayer connection insulation resistance of 93% after 500 hours was 10 ¹² Ω or more.

[Example 9] A resin film with a copper foil by the same method as in Example 5: F using an insulating film of Matsushita in Example 5
Resin filling in a through hole and an insulating film were simultaneously formed above and below the R-4 core substrate.

Next, the insulating film surface is exposed in a specific shape of the upper copper foil in a hole shape of non-through connection holes φ150 μm and φ100 μm by etching, and a non-through connection hole is formed using a carbon dioxide laser under the same conditions as in Example 5. At the same time as the hole bottom,
The resin surface of the hole wall surface was graphitized to form a conductive film.

Next, the entire surface was plated on the above-mentioned substrate by electroplating under the same conditions as described in Example 2.
After forming a plating film having a thickness of 20 μm, an upper conductor circuit was formed by etching.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that connection was established in all the interlayer connection holes. Furthermore, as a result of an insulation reliability test performed under the conditions of a temperature of 65 ° C., a humidity of 95%, and an applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours were 10 ¹² Ω or more.

Example 10 A resin film with copper foil was formed by the same method as in Example 8, and an insulating film of Matsushita was formed on the upper and lower sides of the FR-4 core substrate by simultaneously filling the resin in the through holes and forming the insulating film. Exposing the insulating film surface to non-penetrating connection holes φ150μm and φ100μmμm by etching in specific part of copper foil, forming upper layer conductor circuit, forming non-penetration connection holes by carbon dioxide laser and resin surface of hole bottom and hole wall surface at the same time Was graphitized to form a conductive film.

Then, high-speed electroless plating was performed on the substrate under the conditions of Example 3 to form a conductive film having a thickness of 5 μm on the bottom and the wall surface of the non-through hole.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that connection was established in all the interlayer connection holes. further,
As a result of conducting an insulation reliability test under the conditions of a temperature of 65 ° C., a humidity of 95% and an applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

Example 11 A bisphenol skeleton epoxy resin, an aromatic amine curing agent and a short fibrous boric acid having an average diameter of 0.7 μm and an average thickness of 16 μm in the same parts by weight were coated on a copper foil mat surface having a thickness of 5 μm. An epoxy composition consisting of aluminum and having a thickness of 20 such that the short fibers are oriented in the same direction.
A resin-coated copper foil was prepared by curtain coating to 0 μm.

These two sheets were superposed on each other so that the orientation direction of the short fibers was perpendicular to the surface, set in a vacuum press, and set at 10 Torr.
Applying an adhesive pressure of 35 kg / cm ² while exhausting at 7 ° C.
The temperature of the hot plate was raised to 170 ° C. at a rate of / min. 170
After holding at 60 ° C./60 min, the mixture was cooled at a rate of 5 ° C./min to take out a 350 μm-thick double-sided copper-clad laminate. Next, using a carbon dioxide laser, an energy density of 0.69 J / cm ² and a diameter of 150 μm (pulse width 12
/ 8/3 μs, number of shots 7/3/3), φ100 μm
(Pulse width 10/5/2 μs, number of shots 7/3/3)
And the surface of the resin on the wall surface of the through-hole was graphitized to form a conductive film.

Next, the entire surface was plated on the substrate by electroplating under the same conditions as described in Example 2,
After forming a μm plating film, an upper conductor circuit was formed by etching.

A continuity test was performed on all the interlayer connection holes on the substrate prepared above, and it was confirmed that connection was established in all the interlayer connection holes. further,
As a result of conducting an insulation reliability test under the conditions of a temperature of 65 ° C., a humidity of 95% and an applied voltage of 100 V, all the interlayer connection insulation resistance values after 500 hours showed 10 ¹² Ω or more.

[Comparative Example 1] The resin film with copper foil described in Example 1 was used, and the resin was filled in the through-hole on the same core substrate as in Example 1 by the same method as described in Example 1. At the same time, an insulating film was formed, and the upper copper foil portion of the substrate was removed by etching into a non-through connection hole shape.

Next, fine holes (φ150 μm and φ100 μm) in the copper foil etched and removed into the hole shape of the non-through connection hole.
μm), a non-through connection hole was formed in the resin layer exposed to carbon dioxide laser under conditions of an energy density of 0.15 J / cm ² .

Then, in order to remove the altered layer on the side surface of the non-through connection hole and the resin residue at the bottom of the hole, a roughened solution of a potassium permanganate solution under strong alkali was used at 80 ° C./6 mi.
After roughening under the condition of n, a palladium catalyst is applied to the entire surface, a base conductive film is formed on the entire surface of the substrate, and the entire surface is plated by electroplating (2 A / dm ² ). The upper conductor circuit was formed by etching according to the above method.

A continuity test was performed on all the interlayer connection holes on the substrate prepared as described above, and a connection failure of 23% was confirmed. Observation of the via cross section of a part of the connection failure portion using an optical microscope revealed that the bottom of the via hole had a thickness of 0.2 μm.
Resin residue of a certain degree was confirmed.

Further, an insulation reliability test was carried out under the conditions of a temperature of 65 ° C., a humidity of 95% and an applied voltage of 100 V with respect to an interlayer connection having a good connection of 77%.
% Of the interlayer connection insulation resistance is 50% of which is 10 ¹² Ω
Despite the above, the other 50% were at least 10 ⁸ Ω.

[Comparative Example 2] The resin film with copper foil described in Example 5 was used, and the through-hole was formed on the same core substrate as that used in Example 5 by the same method as described in Example 5. And an insulating film were simultaneously formed.

Next, similarly to the method described in the fifth embodiment, the upper copper foil portion of the substrate is removed by etching into non-through connection holes (φ150 μm and φ100 μm).
An upper conductor circuit was formed. A non-penetrating connection hole was formed with a carbon dioxide laser at an energy density of 0.10 J / cm ² .

Next, in order to remove the degenerated layer on the side surface of the non-through connection hole and the resin residue on the bottom of the hole, the surface was roughened under the same conditions as in Comparative Example 1 and then subjected to high-speed electroless plating at 80 ° C./1.
Under a condition of 2 hours, a 24 μm plating film was formed.

When a continuity test was performed on all the interlayer connection holes on the substrate prepared above, a connection failure of 28% was confirmed. Observation of the via cross section of a part of the connection failure portion by an optical microscope revealed that blisters occurred in the plating film formed by electroless plating at the bottom of the via hole. Furthermore, an insulation reliability test was performed under the conditions of a temperature of 65 ° C., a humidity of 95%, and an applied voltage of 100 V with respect to a good interlayer connection of 72%. As a result, a 50% interlayer connection insulation resistance value after 500 hours was obtained. Although it showed 10 ¹² Ω or more, the other 1
8% indicates 10 ⁸ Ω or more, and 4% is short-circuited.

[0114]

As described in detail above, it has become possible to effectively utilize the carbonized film formed by laser processing and to make the resin surface layer of the hole bottom and the wall surface conductive simultaneously with the formation of the non-through connection hole. As a result, the roughening step can be omitted, and since the formed conductive film is firmly bonded to the insulating film, it is possible to ensure reliability and to realize a significant cost reduction. It has become possible.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a wiring board according to a first embodiment.

FIG. 2 is a process chart showing a method for manufacturing a wiring board according to a second embodiment.

FIG. 3 is a process chart showing another example of the method for manufacturing a wiring board according to the second embodiment.

FIG. 4 is a process chart showing a method for manufacturing a wiring board according to a third embodiment.

FIG. 5 is a cross-sectional view of a non-through connection hole in which a conductive film is formed on a surface layer of an insulating film by laser processing.

FIG. 6 is a process chart showing an example of a method for manufacturing a wiring board according to a second conventional technique.

FIG. 7 is a process chart showing an example of a method for manufacturing a wiring board according to a third conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core board, 2 ... Conductor circuit, 3 ... Through hole, 4 ...
Resin film with copper foil, 5 ... non-through connection hole shape, 7 ...
Non-through connection hole, 8: conductive film, 9: conductor circuit, 10: through hole, 11: core substrate, 12: resin film with copper foil, 13: non-through connection hole, 14: underlying conductive film, 15: conductive film 16 conductor circuit, 17 core substrate, 18 pattern wiring, 19 conductor circuit, 20 through hole, 21
Resin film with copper foil, 22: conductive circuit, 23: non-through connection hole forming pattern, 24: non-through connection hole, 25: underlying conductive film, 26: exposed lower layer conductor pattern wiring, 27: non-through connection hole conductor 28: conductor circuit, 29: through hole, 30: core substrate, 31: resin film with copper foil, 32
... non-through connection hole forming pattern, 33 ... conductor circuit, 34 ...
Non-through connection hole, 35: underlying conductive film, 36: conductive film, 37
... core substrate, 38 ... lower conductor circuit, 39 ... insulating film, 40
... A conductive part of the resin on the wall surface of the non-through hole, 41 ... A resin conductive part on the bottom of the non-through hole, 42 ... Stud via, 43 ... Conductor circuit, 44 ... Core substrate, 45 ... Insulating film, 46 ... Roughened surface , 4
7: Underlying conductive film, 48: Conductor circuit, 49: Stud via, 50: Through hole, 51: Conductor circuit, 52: Core substrate, 53: Resin film with copper foil, 54: Non-through connection hole forming pattern, 55: Non-through connection hole, 56: Resin residue after laser processing, 57: Core substrate, 58: Conductor, 59: Resin layer, 60: Conductor, 61: Resin layer, 62: Conductor circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/46 H05K 3/46 B // B23K 101: 42 B23K 101: 42 (72) Inventor Takashi Kashimura Kanagawa 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Japan Inside Hitachi, Ltd.Production Technology Laboratory (72) Inventor Takehiko Hasebe 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd.Production Technology Laboratory (72) Inventor K Masayuki I, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Production Technology Research Laboratory (72) Inventor Isamu Tanaka 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Production Technology Laboratory (72) Inventor Kinhide Yamaguchi 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture, Hitachi, Ltd. Makio Watanabe 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Hitachi, Ltd.Communications Division 4E068 AF01 AF02 DA11 DB10 5E343 AA02 AA15 AA17 BB04 BB16 BB24 BB71 DD33 DD43 DD69 EE32 ER16 GG02 AGG12A AA15 AA26 AA32 AA35 AA43 CC04 CC09 CC32 CC55 CC58 DD02 DD12 DD32 DD44 DD48 EE06 EE13 EE14 EE18 EE33 EE35 EE38 FF02 FF04 FF07 FF13 FF14 GG15 GG17 GG18 GG22 GG23 GG27 GG28 HH11H31

Claims (9)

[Claims] 1. A method of manufacturing a wiring board, comprising forming a graphitized conductor in which a specific portion of a resin surface layer is selectively graphitized by irradiating a high energy beam as at least a part of a wiring structure. Method. 2. A conductive film is formed by irradiating a high-energy beam and graphitizing a specific portion of a resin surface layer, and a plating film serving as a wiring conductor is formed using the conductive film as a power supply. Manufacturing method of wiring board. Wherein said resin surface layer graphitized, and the energy density of the energy beam required to form the conductive film, 0.05 J / cm ² or more, and characterized in that 20 J / cm ² or less according Item 3. The method for manufacturing a wiring board according to item 1 or 2. 4. A non-penetrating connection hole is formed at a predetermined position of a resin film by irradiating a high energy beam, and a conductive film is formed by graphitizing the bottom and side surfaces of the non-penetrating connection hole. A method of manufacturing a wiring board, wherein the wiring board is connected to an upper-layer conductor wiring provided on the resin film. 5. A method for manufacturing a multilayer wiring board, comprising: (1) forming a conductor circuit by etching a conductor formed on a copper-clad laminate or an interlayer insulating film; (3) forming an etching resist on the copper foil and patterning a conductive circuit pattern including a pattern for forming a non-through connection hole on the laminate formed in the step; After that, a step of etching and removing the copper foil that is not covered with the etching resist (4) A beam is selectively irradiated to a specific portion of the exposed resin upper portion to form a non-through connection hole, Forming a conductive film on the bottom and side surfaces of the through-holes; and repeating the above steps (1) to (4). 6. The copper-clad laminate is a substrate provided with a through hole which is electrically connected to a predetermined place in advance, and the resin film is laminated and bonded by filling the through hole with a resin and forming an insulating film. 6. The method according to claim 5, wherein the steps (a) and (b) are performed collectively. 7. A conductive film is formed on the bottom and side surfaces of the non-through hole provided in the multilayer wiring board, and then the conductive film is formed from the bottom of the non-through hole connected to the lower conductor wiring located on the upper part of the multilayer wiring board. 6. The method according to claim 5, wherein a plating film to be a wiring conductor is formed on the conductive film. 8. The resin according to claim 1, wherein said resin has a molecular weight of 70% to 90%.
The method for producing a wiring board according to claim 1, wherein the composition is a composition containing the following benzene ring. 9. A wiring board manufactured by using the method for forming a conductor circuit according to claim 1.