JP2002141662A - Wiring board manufacturing method - Google Patents

Abstract

(57) Abstract: Provided is a method of manufacturing a wiring board for the purpose of improving insulation reliability and insulating film characteristics and forming fine wiring. SOLUTION: By uniformly embedding copper fine powder in a film shape on the surface of an insulating film, the adhesive strength between the insulating film and the wiring is improved, and a stable adhesive force is obtained.

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 production of consumer mounting equipment, a communication ATM switch, and the like, and further relates to a wiring relating to a multi-chip module board such as a workstation and a personal computer. The present invention relates to a method for manufacturing a substrate.

[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 have been required to have higher performance.
For this reason, in order to cope with the high integration of LSI and the miniaturization and lightness of electronic equipment, the technical development of wiring boards with high wiring density and high reliability has been developed by electronic equipment manufacturers, substrate manufacturers,
It is performed by all related companies such as material manufacturers.

In order to obtain high reliability along with miniaturization of wiring, it is important to improve the bonding strength between the wiring and the insulating film and to maintain stable bonding strength. For this reason, generally, an organic filler or an inorganic filler is mixed into a resin, the cured insulating film surface is roughened with a roughening solution such as a permanganic acid solution under strong alkali, and the filler is dissolved from the insulating film surface. Alternatively, a method of bonding the wiring and the insulating film by an anchor effect by dropping and forming irregularities on the surface has been performed.

As a method of mixing an organic filler into an insulating material, Japanese Patent Application Laid-Open No. 2-8283 discloses a heat-resistant resin which is soluble in an uncured heat-resistant resin which is hardly soluble in an oxidant. A method of dispersing resin coarse particles and fine powder, heating and curing, then roughening the surface of the insulating film by roughening, forming irregularities (first conventional technique), and in JP-A-2-8281, uncured Pseudo particles for anchor formation, in which a cured resin fine powder with an average particle diameter of 0.8 μm or less is attached to the surface of a heat-resistant resin powder with an average particle diameter of 10 μm or less in the heat-resistant resin, are further dispersed. A method aimed at forming a surface (second conventional technique), and as a method utilizing the difference in solubility with respect to a roughening solution, cellulose or a derivative thereof is mixed into an epoxy resin insulating material, and after curing, roughening is performed. When applied, cellulose elutes and forms irregularities JP-5 method is to
No. 308194 (third prior art). In addition, compared to the method using the fine powder mixed insulating layer described above,
As a further developed method, an insulating film of two layers is provided, and fine powder soluble in acid is sprayed on the upper uncured insulating film, and then the insulating film is cured. The upper portion of the insulating film is polished, and the exposed fine powder is dissolved and removed with an acid to form a concave portion.
No. 4216 (fourth prior art). Also,
In JP-A-6-224529, after a conductive paste is applied on an insulating film by a printing method, a surface roughening treatment is performed to remove a surface region binder of the copper paste, thereby exposing copper particles. Then, a method of improving the adhesive strength by applying copper plating to the exposed copper particle surface is disclosed.
(Fifth prior art).

On the other hand, in addition to the above-described roughening method by a chemical method, a method of laminating a sheet-like insulating film has been proposed as a method of obtaining an adhesive force between the insulating film and the wiring.

[0006] In Japanese Patent Application Laid-Open No. 6-260760, a copper-clad adhesive sheet using an insulating material soluble in an aqueous alkaline solution is laminated, and a surface copper foil is laminated by repeating a process of forming wiring by selective etching. A method is disclosed in which the outermost layer is formed by removing a copper foil at a position of a blind via hole by etching, and then dissolving an insulating film with an alkaline aqueous solution to expose a conductive circuit pattern (sixth prior art). Further, Japanese Patent Application Laid-Open No. 7-45948 discloses a method for improving the adhesion between a copper wiring and an insulating film by providing a metal thin film on an insulating film by sputtering and applying copper plating on the metal thin film. (Seventh prior art). Further, as a method for obtaining an adhesive force between an insulating film and a wiring, there is disclosed a technique relating to a surface treatment of a copper foil, in which a compound chelator such as triazole having a complex formation is applied to a copper foil and then bonded to an uncured insulating film. No. 60-218485 (eighth prior art).

[0007]

FIG. 2 shows an example of the first, second and third prior arts. The process will be described in detail. An insulating material 15 in which organic fillers or inorganic fillers are dispersed is applied to a core substrate 13 (a) on which horizontal wirings 14 and vertical wirings 14 for interlayer connection are formed, and a step of curing (b) polishing (C) roughening the surface of the insulating film with a strong alkaline oxidizing agent to dissolve or drop the filler dispersed in the insulating film, thereby forming irregularities on the insulating film surface Step (d) Step of forming an underlying conductive film 17 (e) Step of forming a wiring layer 18 by electrolytic copper plating (f) Step of removing the underlying conductive film (g) Step of applying an insulating material 19 (h) This is a manufacturing method of forming a multilayer by repetition.

In the above-mentioned prior art, an insulating film in which an organic filler soluble in an oxidizing agent is dispersed is roughened by an oxidizing agent under a strong alkali to secure an adhesive force between the insulating film and the wiring. The organic filler is easily aggregated, and it is difficult to re-disperse the once aggregated filler. Since the re-agglomerated pseudo-particles form a coarse roughened shape, fine wiring cannot be formed.

[0009] Further, a pinhole is easily generated in the concave portion formed by dissolving the reaggregated filler in the insulating resin. Furthermore, since an oxidizing agent is used under a strong alkali, the material of the insulating film is limited, and there is a limit to the reduction in thickness in consideration of the thickness of the roughened layer.

In the fourth prior art, a two-layer insulating film is provided, a suspension in which a filler such as calcium carbonate soluble in acid is dispersed is sprayed on an uncured upper insulating film, and the suspension is cured and polished. Since the filler is dissolved by the aqueous solution to form a roughened surface, the probability of occurrence of pinholes is reduced as compared with the first to third conventional techniques. However, since the two coating steps and the polishing step are performed, the accuracy of the film thickness is reduced, and the variation in the film thickness is increased, so that the electrical characteristics are reduced. Further, it is impossible to further reduce the thickness.

The fifth technique is a method in which a copper paste is applied to an upper portion of an insulating film, and then the resin in the copper paste is degraded or dissolved by an oxidizing agent or the like, so that only copper particles adhere to the surface of the insulating film. . In this case, the copper particle content of the copper paste is considered to be higher than that of the binder, and the deterioration of the resin by the oxidizing agent is quick, and it is difficult to control the surface area. If the deterioration of the resin surface progresses too much, the strength of the resin surface becomes weak, the adhesive strength with the wiring is reduced, and the reliability is reduced.

As described above, the method of obtaining the adhesive force between the wiring and the insulating film by roughening the surface by a chemical method using an oxidizing agent is not always uniform because the insulating material is a mixture. Therefore, it is difficult to always obtain a good roughened surface, and the adhesive strength tends to vary. In addition, since wiring is formed on the roughened surface deteriorated by the oxidizing agent,
This may cause a decrease in insulation reliability.

On the other hand, the sixth technique for laminating a copper-clad adhesive sheet is considered to provide stable adhesive strength and good insulation reliability. However, since the method for forming the wiring is limited and the wiring is formed by etching, a fine wiring cannot be formed. Further, in the seventh conventional technique in which a metal foil film is formed on an insulating film by sputtering, a sufficient adhesive strength cannot be obtained despite high cost. In addition, in the eighth prior art in which surface treatment is performed on copper foil, since the wiring is formed by etching as in the sixth prior art, an improvement in wiring density cannot be expected, and an amine-based triazole compound is used. Doing so causes a decrease in insulation reliability. in this way,
Various attempts have been made so far to improve the adhesive strength between the insulating film and the wiring, but by obtaining the adhesive strength in any of the above conventional techniques, heat resistance, linear expansion coefficient,
Characteristics such as electric characteristics and mechanical characteristics were deteriorated, and a sufficient effect as an insulating film could not be obtained. In addition, with the conventional method, there is a limit in thinning and wiring density in response to the demand for lighter and smaller electronic devices, and it will be difficult to respond in the future. The present invention relates to a method for manufacturing a wiring board which ensures high reliability of a wiring board and enables fine wiring to be formed, and has an adhesive force between an insulating film and a wiring without sacrificing the above-described characteristics and the like. It is intended to provide a technology that leads to not only improvement of the cost but also low cost and improvement of the yield.

[0014]

In order to solve the above problems, it is necessary to obtain a stable adhesive force between the insulating film and the wiring,
Insulation reliability is ensured and fine wiring can be formed.
The technology must be applicable to thinning. The present invention relates to a method for bonding an insulating film and a wiring for solving the above-mentioned problem, and the above-mentioned problem is achieved by the following method for manufacturing a wiring board.

An example of a method of manufacturing a wiring board by a method of bonding an insulating film and wiring according to the present invention will be described. FIG. 1 is a schematic explanatory view of a method for manufacturing a wiring board according to the present invention. The method of manufacturing a wiring board according to the present invention will be described with reference to FIG.

Wiring horizontal to substrate by etching
2, a step (b) of applying an insulating material 3 on a substrate 1 on which a stud via 2 perpendicular to the substrate is formed by electrolytic copper plating with a dispenser (b) and 42 mirror-finished dies in a closed space After setting the above substrate with scissors and defoaming at room temperature or below the temperature at which curing heat is generated according to the state of the material, the temperature is increased under pressure or hydrostatic pressure, and the curing heat is calculated from the temperature at which curing heat is generated. Step (c) of forming an uncured insulating film 5 in which a curing reaction is promoted for a certain time within a temperature range in which the maximum is maximized, and a mold release agent 6 is applied on one surface, and copper fine powder 7 is sprayed. Step c described above in the mirror polishing mold 4
The step (d) of installing the uncured insulating film-formed substrate formed in step (d) and again, curing under a pressure or hydrostatic pressure at a temperature not lower than the temperature at which the curing calorific value becomes the maximum, the insulating film 9 and the underlying copper electrode film (E) and the horizontal wiring 11 by electroplating, and the step (f) of forming the stud via 11 and the step of removing the underlying conductive film other than the wiring (g) and (g) on the wiring substrate It comprises a laminating step (h) in which the insulating material 12 is applied and the steps (b) to (g) are repeated.

In the step (d), the insulating film is softened by heating the insulating film, and the head of the via and the copper fine powder come into contact with each other due to the weight of the copper fine powder itself. But,
Depending on the insulating material, the softened state at the time of heating differs, so that the via head may not be able to contact the copper fine powder. in this case,
A step of exposing the via head by polishing is required between the steps (c) and (d) (c ′).

If a gap is formed between the copper fine particles of the formed underlying conductive film after the step (e), a step (e ′) of applying the flash plating 10 is required as a repair method.

As the resin used as the insulating material, any of a thermosetting resin and a thermoplastic resin can be applied. Since the resin is not treated with a chemically strong oxidizing agent under a strong alkali, the resin is not damaged and is not roughened. There is no need to consider the resin strength of the surface. In addition, when roughening has been performed by a chemical method, an insulating material having a high glass transition temperature has a high resin strength and is difficult to roughen the resin surface. The temperature was limited to 150 ° C, and heat resistance had to be sacrificed.

However, in the bonding method according to the present invention, an insulating material can be selected regardless of the glass transition temperature.

As the thermosetting resin, epoxy resin, phenol resin and BT resin are preferable.
Epoxy resins such as A, bisphenol F skeleton, biphenyl skeleton, naphthalene skeleton, alicyclic, phenol novolak, and hydroxyphenyl skeleton, and modified products thereof for imparting flexibility are suitable. On the other hand, the curing agent is preferably a phenolic resin and its derivatives, dicyandiamide, acid anhydride, isocyanate, aliphatic amine, alicyclic amine, and aromatic amine. Heat-curable amines are most preferred. The combination of these epoxy resins and curing agents is
It is desirable to select according to the characteristics of the wiring board to be used. The accelerator may be any of a tertiary amine, imidazole and phosphine, and is determined by a suitable shell life and a combination of an epoxy resin and a curing agent.

As the thermoplastic resin, polyester resin, polyphenylene ether resin, polyarylate and polyterephthalene ether are preferable, and from the viewpoint of heat resistance of the base substrate and molding conditions, the softening point is preferably in the range of 180 ° C. to 220 ° C. . When such a thermoplastic resin is used, since the melt viscosity during molding is high, the resin molded into a sheet or the resin in the form of a pellet is placed on a substrate and applied under pressure or hydrostatic pressure, depending on the application method using a dispenser. Is suitable.

A filler may be mixed with these insulating resins for the purpose of improving electrical characteristics (dielectric constant and dielectric loss), reducing linear expansion coefficient (α), and suppressing thermosetting shrinkage. The content of the filler is the volume content
When 30 to 80% is preferably 30% or less, there is no effect of the above purpose, and when it is 80% or more, when bonding fine copper powder on the insulating film, a gap is easily generated between particles due to the effect of filler. It causes a decrease in yield. As the type of filler, silica exhibiting a low dielectric constant, potassium titanate, and potassium borate are preferable, and the shape is preferably spherical powder or needle-like from the viewpoint of fluidity and dispersibility, and the average particle diameter is 0. .
1-5 μm is preferred. However, considering the formation of fine wiring, the range of 0.2 to 2 μm is most appropriate. Fira is
Fluidity, dispersibility, and insulating film characteristics of the insulating film material change depending on the shape, the average particle size, and the content thereof.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of manufacturing a wiring board according to the present invention for improving the adhesive strength between an insulating film and a wiring will be described with reference to examples. Tables 1 and 2 show the amounts and structural formulas of the insulating materials used in the examples and comparative examples. Tables 3, 4, and 5 show the results of measuring the adhesive strength (peel strength) of the insulating film and the wiring, the results of forming the wiring, and the results of the insulation reliability test of the examples and the comparative examples, respectively.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

Example 1 A kneaded product of a solid epoxy insulating material shown in Table 1-1 was modified so that the temperature at the tip of the needle did not decrease. A dispenser device (SHOTMASTER-2D) was used.
S: Musashi Engineering Co., Ltd.) and 10 ³ poise based on the melt viscosity measurement results shown in FIG. 3 on a 10 cm square FR-4 base substrate with wiring formed on both sides as shown in FIG. 1- (a). ~Ten
It was applied on both sides within the range of ⁴ poise. After placing this substrate between the mirror polishing molds and performing sufficient degassing at 65 ° C, under the condition of a temperature rise rate of 5 ° C / min, under a hydrostatic pressure of an adhesive pressure of 0.65 MPa and an air pressure of 0.5 MPa, It was heated to a temperature of 160 ° C. immediately before the heat generation value of curing shown in FIG. 3 was maximized, and held for 10 minutes. 10 in this state
After cooling to 0 ° C., it was taken out from between the mirror-finished polishing dies to form an uncured insulating film.

A fluorine-based release agent (Daifree 6010: manufactured by Daikin Co., Ltd.) is applied to one surface of the two mirror-polished mold surfaces, and a copper fine powder (Wako Pure Chemical Industries, Ltd.) is applied to the surface of the mold. ): Kawasaki Steel Corp .: Average particle size 0.2 μm) is sprayed evenly, and the mold surface with the copper fine powder adhered is scissors so as to be in contact with the insulating film surface. The temperature was raised under the same conditions as above, and the temperature was maintained at 180 ° C. for 1 hour. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces.

Next, a thin copper plating is applied on the underlying conductive film by flash plating, and a current density of 2 A / dm ² is applied.
Copper plating was performed under the following conditions. As a result, it is possible to form a wiring having a line / space of 50 μm / 50 μm, and the bonding strength between the underlying conductive film and the insulating film is> 10
It was 00 N / m. In addition, temperature 65 ° C, humidity 95%, applied voltage 100V
As a result of an insulation reliability test performed under the following conditions, the insulation resistance value after 500 hours was> 10 ¹² .

Example 2 A kneaded product of a dicyandiamide-cured liquid epoxy insulating material shown in Table 1-2 was applied to both surfaces of a wiring shown in FIG. 1- (a) by a dispenser device (SHOTMASTER-2DS, manufactured by Musashi Engineering). 10cm square F formed
It was applied on both sides of the R-4 base substrate. Since the melt viscosity of the epoxy insulating material shown in FIG. 4 was <10 ³ poise at 25 ° C., it was applied at 25 ° C. with the highest viscosity.

This substrate was placed between the mirror polishing dies,
After degassing sufficiently at ℃, at a heating rate of 5 ℃ / min, under the hydrostatic pressure of adhesive pressure 0.65MPa, air pressure 0.5MPa,
The temperature immediately before the curing heat generation shown in FIG. 4 is maximized: 150 ° C.
And held for 20 minutes.

After being cooled to 100 ° C. in this state, it was taken out from between the mirror polishing dies to form an uncured insulating film.

A fluorine-based release agent is applied to one surface of the two mirror-polished molds, and a copper fine powder (Wako Pure Chemical Industries, Ltd.) is applied to the mold surface.
(Kawasaki Iron & Steel Co., Ltd .: average particle size 0.2 μm) was sprayed uniformly to adhere copper fine powder. The mold surface was scissors in contact with the insulating film surface, degassed, heated at a rate of 5 ° C./min under the conditions described above, and kept at 180 ° C. for 2 hours. After cooling to 100 ° C. under hydrostatic pressure, the resultant was taken out from between the mirror polishing dies, and a 50 μm-thick insulating film and a base conductive film were simultaneously formed on both surfaces. Next, thin copper plating is applied on the underlying conductive film by flash plating, and the current density is 2A.
The electrolytic copper plating was performed under the condition of / dm ² . As a result, it was possible to form a wiring having a line / space of 50 μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. Insulation reliability test was conducted under the conditions of temperature 65 ° C, humidity 95%, and applied voltage 100V.
The insulation resistance after time showed> 10 ¹² .

Example 3 A kneaded product of an acid anhydride-cured liquid epoxy insulating material shown in Table 1-3 was dispensed with a dispenser device.
(SHOTMASTER-2DS: manufactured by Musashi Engineering)
The wiring shown in FIG. 1A was applied at 25 ° C. on both sides of a 10 cm square FR-4 base substrate formed on both sides. The application conditions and the curing conditions were determined from the measurement results of the melt viscosity and the heat generated by curing in the same manner as in [Example 2].

After the application, insert scissors between the mirror polishing molds, and apply at 25 ° C.
After sufficiently degassing with, at a heating rate of 5 ° C / min,
Under hydrostatic pressure of adhesive pressure 0.65MPa, air pressure 0.5MPa, 120
C./30 min. Then, after raising the temperature to 150 ° C,
After holding for 5 minutes, in this state, it was cooled to 100 ° C., taken out from between the mirror-polished dies, and an uncured insulating film was formed.

A fluorine-based release agent is applied to one surface of the two mirror-polished molds, and a copper fine powder (Wako Pure Chemical Industries, Ltd.) is applied to the mold surfaces.
(Kawasaki Iron & Steel Co., Ltd .: average particle size 0.2 μm) was sprayed uniformly to adhere copper fine powder. The mold surface was scissors in contact with the insulating film surface, degassed, heated at a rate of 5 ° C./min under the same conditions as above, and kept at 160 ° C. for 2 hours. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces. Next, thin copper plating is performed on the underlying conductive film by flash plating, and the current density is reduced.
Electroless copper plating was performed under the conditions of ² A / dm ² . As a result, it was possible to form a wiring having a line / space of 50 μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. Insulation reliability test was conducted under the conditions of temperature 65 ° C, humidity 95%, and applied voltage 100V.
The insulation resistance after time showed> 10 ¹² .

Example 4 A kneaded mixture of the pulverized thermoplastic insulating material shown in Table 1-4 was placed between mirror-surface polishing dies, and
After deaeration at 0 ° C., the sheet was held at 150 ° C./10 min under a hydrostatic pressure of an adhesive pressure of 0.65 MPa and an air pressure of 0.5 MPa, cooled to 100 ° C., and two supply sheets were prepared. A supply sheet, a release agent is applied on both sides of the FR-4 base substrate shown in FIG. 1- (a) shown in FIG. And then kept at 150 ° C./30 min under hydrostatic pressure. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces. Next, thin copper plating was performed on the underlying conductive film by flash plating, and electrolytic copper plating was performed at a current density of 2 A / dm ² . As a result, it is possible to form a wiring having a line / space of 50 μm / 50 μm,
The bonding strength between the underlying conductive film and the insulating film is> 1000 N / m
Met. Further, an insulation reliability test was performed under the conditions of a temperature of 65 ° C. and a humidity of 95% and an applied voltage of 100 V. As a result, the insulation resistance value after 500 hours was> 10 ¹² .

Example 5 A pulverized thermoplastic resin insulating film material shown in Table 1-5 was placed between mirror polishing dies, and
After deaeration at 0 ° C., the sheet was held at 180 ° C. for 10 minutes under a hydrostatic pressure of an adhesive pressure of 0.65 MPa and an air pressure of 0.5 MPa, cooled to 100 ° C., and two supply sheets were prepared. Next, a supply sheet was set in the same manner as in the above [Example 4], heated to 180 ° C., sufficiently deaerated, and then kept at 180 ° C./30 min under hydrostatic pressure. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces. Next, polishing was performed on the surface of the formed uncured film to expose the upper portion of the via wiring. Next, thin copper plating was performed on the underlying conductive film by flash plating, and then electrolytic copper plating was performed at a current density of 2 A / dm ² . As a result, it was possible to form a wiring having a line / space of 50 μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. Also the temperature
As a result of performing an insulation reliability test under the conditions of 65 ° C. and 95% humidity and an applied voltage of 100 V, the insulation resistance value after 500 hours was> 10 ¹² .

Example 6 A kneaded product of a solid epoxy insulating material having heat resistance shown in Table 1-6 was applied by a dispenser in the same manner as described in Example 1 above, and after deaeration at 80 ° C. After raising to 180 ° C under hydrostatic pressure,
After holding at 80 ° C./20 min and cooling to 100 ° C., it was taken out from between the molds to form an uncured film. Then, in the same manner as described in the above [Example 1], the fine copper powder was squeezed into a uniformly dispersed mold, degassed, and then subjected to hydrostatic pressure at 220 ° C./1.5 hr.
Heated. Next, after cooling to 100 ° C., it was taken out from between the molds, and a base conductive film and a 50 μm insulating film were simultaneously formed on both surfaces. Ultra-thin copper plating was performed on the underlying conductive film by flash plating, and electrolytic copper plating was performed under the conditions of a current density of 2 A / dm ² . As a result, line / space 50μ
m / 50 μm wiring can be formed.
The adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. Further, an insulation reliability test was performed under the conditions of a temperature of 65 ° C. and a humidity of 95% and an applied voltage of 100 V. As a result, the insulation resistance value after 500 hours was> 10 ¹² .

[Example 7] Table 1 in which the filler content was increased by 10 vol% as compared with the insulating material described in [Example 1] above.
The kneaded product of the solid epoxy insulating material shown in -7 was applied by a dispenser in the same manner as in the above [Example 1], and after degassing, heated at 160 ° C./10 min under hydrostatic pressure to obtain 10
After cooling to 0 ° C., it was taken out from between the molds to form an uncured film. Then, by the same method as described above [Example 1], the copper fine powder was squeezed into a mold uniformly dispersed,
After degassing, the mixture was heated under a hydrostatic pressure at 180 ° C./1.0 hr. Then 10
After cooling to 0 ° C., the film was taken out from between the molds, and a base conductive film and a 50 μm insulating film were simultaneously formed on both surfaces. A thin copper plating is applied on this underlying conductive film by flash plating.
Electroless copper plating was performed under the conditions of a current density of 2 A / dm ² . As a result, it was possible to form a wiring having a line / space of 50 μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. The temperature is 65 ° C and the humidity is 95
As a result of an insulation reliability test performed under the condition of a% applied voltage of 100 V, the insulation resistance value after 500 hours was> 10 ¹² .

Example 8 A kneaded mixture of the pulverized thermoplastic insulating material shown in Table 1-4 was placed between mirror-surface polishing dies.
After degassing at 0 ° C., two supply sheets were prepared, kept at 150 ° C./10 min under a hydrostatic pressure of an adhesive pressure of 0.65 MPa and an air pressure of 0.5 MPa, and cooled to 100 ° C. Supply sheets are placed on both sides of a 10 cm square FR-4 base substrate shown in Fig. 1- (a), then a release agent is applied, and copper fine powder (Culox6030: average particle size 3 µm, Culox Techno
logies, Inc) in the order of the mold in which it was sprayed, heated to 150 ° C, sufficiently degassed, and then crushed under hydrostatic pressure for 15 minutes.
It was kept at 0 ° C./30 min. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces. Next, thin copper plating was performed on the underlying conductive film by flash plating, and electrolytic copper plating was performed at a current density of 2 A / dm ² .
As a result, it was possible to form a wiring having a line / space of 50 μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. The temperature is 65 ° C
As a result of performing an insulation reliability test under a condition of 95% humidity and an applied voltage of 100 V, the insulation resistance value after 500 hours was> 10 ¹² .

[Embodiment 9] The epoxy solid insulating film material described in the above [Embodiment 1] was coated on both sides of a base substrate by a dispenser under the same conditions. Next, as shown in FIG. 5, an 8 cm square Teflon frame was set on both sides of the substrate, and then scissors were inserted between the mirror polishing dies, and sufficiently deaerated at 65 ° C. 160 ℃ at 5 ℃ / min
And held for 10 minutes. After cooling to 100 ° C. in this state, it was taken out from between the mirror-polished dies to form an uncured insulating film.

In the same manner as described above, a fluorine-based mold release agent was applied to one surface of the two mirror-finished molds, and then copper fine powder was sprayed on the mold surfaces so as to be uniform. Next, again, after installing an 8 cm square Teflon frame on both surfaces on the uncured insulating film, scissors from both sides so that the mold surface with the copper fine powder adhered to the insulating film surface, and after sufficient degassing, The temperature was raised under the same conditions as described above, and the temperature was maintained at 180 ° C. for 1 hour. 100 in this state
After cooling down to ℃, remove from the mirror polishing mold
A 50 μm insulating film and a base conductive film were simultaneously formed on both surfaces. Next, thin copper plating was performed on the underlying conductive film by flash plating, and electrolytic copper plating was performed at a current density of 2 A / dm ² . As a result, the line / space 50 μm / 5
It was possible to form a 0 μm wiring, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m.
The 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. As a result, the insulation resistance after 500 hours was> 1
0 ¹² was indicated.

Example 10 The liquid insulating film material of the above Example 2 was coated on both sides of a base substrate by a dispenser under the same conditions. Then, on both sides of the substrate 8cm
After installing the square Teflon frame, insert the scissors between the mirror-polished molds, perform sufficient degassing at 25 ° C, pressurize and hold at 150 ° C / 20min at a temperature rise rate of 5 ° C / min. did. After cooling to 100 ° C. in this state, it was taken out from between the mirror-polished dies to form an uncured insulating film.

In the same manner as described above, a fluorine-based release agent was applied to one surface of the two mirror-polished molds, and then copper fine powder was sprinkled on the mold surfaces so as to be uniform. Then, again, after placing an 8 cm square Teflon frame on both surfaces of the uncured insulating film, scissors the mold surface with the copper fine powder in contact with the insulating film surface, after sufficient degassing, the same as above The temperature was raised under the conditions described above, and the temperature was maintained at 180 ° C. for 2 hours. After cooling to 100 ° C. in this state, it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces.

A thin copper plating was performed on the underlying conductive film by flash plating, and an electrolytic copper plating was performed under the conditions of a current density of 2 A / dm ² . As a result, the line / space 50
It was possible to form a wiring of μm / 50 μm, and the adhesive strength between the underlying conductive film and the insulating film was> 1000 N / m. Further, an insulation reliability test was performed under the conditions of a temperature of 65 ° C. and a humidity of 95% and an applied voltage of 100 V. As a result, the insulation resistance value after 500 hours was> 10 ¹² .

[Example 11] A supply sheet of the thermoplastic epoxy insulating material shown in the above-mentioned [Example 4] was prepared in the same manner, and then a 10 cm square FR-4 base substrate shown in FIG. A supply sheet and a release agent were applied to both sides as shown in FIG.
After heating to ℃, perform sufficient degassing, then pressurize to 150 ℃ / 3
Held for 0 min. Next, after cooling to 100 ° C., it was taken out from between the mirror polishing dies, and an insulating film and a base conductive film having a thickness of 50 μm were simultaneously formed on both surfaces. The substrate on which the insulating film was formed was subjected to flash plating and electrolytic copper plating by the method described above, and wiring was formed on the insulating film. As a result, a wiring having a line / space of 50 μm / 50 μm can be formed, and the adhesive strength between the underlying conductive film and the insulating film is:
It was 1000 N / m. The temperature is 65 ° C, the humidity is 95%, the applied voltage is 10
As a result of an insulation reliability test performed under the condition of 0 V, the insulation resistance value after 500 hours was> 10 ¹² .

[Comparative Example 1] The above description [Example 1] A solid insulating film material was applied on both sides of a base substrate by a dispenser under the same conditions. This substrate is sandwiched between mirror polishing dies and scissors are sufficiently deaerated at 65 ° C., and then maintained at 160 ° C./30 min under hydrostatic pressure under the same conditions as described in [Example 1] above. Cured. After cooling to 100 ° C in this state,
Remove from the mirror polishing mold and 180 in a fine oven
C./1 hour post-curing was performed to form an insulating film. The insulating film is
By changing the film thickness, two types of substrates of 100 μm and 50 μm were formed. These insulating films were immersed in a potassium permanganate solution at 80 ° C./40 min in the presence of a strong alkali to roughen the insulating film surface. This roughened surface was subjected to flash plating to form a base conductive film. Next, electrolytic copper plating was performed under the conditions of ² A / dm ² to form a wiring. As a result, an insulating film having a thickness of 100 μm was capable of forming a wiring having a line / space of 50 μm / 50 μm. However, an insulating film having a thickness of 50 μm was excessively roughened on the surface of the insulating film. The surface unevenness is severe,
The limit was line / space 100 μm / 100 μm. The adhesive strength between the insulating film and the wiring was> 1000 N / m for a 100 μm-thick insulating film, whereas the resin strength of the resin surface of the 50 μm-thick insulating film was increased due to the progress of roughening. Because of the decrease, it was 500 N / m. Along with this, an insulation reliability test was performed by the same test method as in the above example, and as a result, 100 μm was obtained.
The insulation resistance of the m-thick insulation film after 500 hours was> 10 ¹² , but the insulation resistance of the 50-μm-thick insulation film decreased to> 10 ⁸ after 200 hours, and after 250 hours Was short-circuited, and the resistance was> 10 ² .

[Comparative Example 2] The epoxy insulating material described in the above [Example 3] was applied to a substrate and cured under the same conditions as in [Example 3]. The thickness of the insulating film is changed to 100 μm
And two types of 50 μm substrates. Put these insulating films in potassium permanganate solution in the presence of strong alkali at 80 ℃ / 10mi
After immersion, the roughening had progressed to the inside of the insulating film.
After the roughening, flash plating was performed to form a base conductive film. Next, electrolytic copper plating was performed under the conditions of ² A / dm ² to form a wiring. Line / space 50μ for all insulating films
Although it was possible to form a wiring of m / 50 μm, the irregularities on the roughened surface were transferred, and the irregularities on the electroplating film surface were severe. Further, the adhesive strength between the underlying conductive film and the insulating film was <300 N / m in all cases. In addition, as a result of performing an insulation reliability test by the same test method as the above-mentioned example,
Short circuit in less than an hour.

Comparative Example 3 A supply sheet was prepared from the epoxy insulating material described in the above [Example 5] under the same conditions as in [Example 5], and an insulating film was formed on a base substrate. The thickness of the insulating film was changed, and two types of substrates of 100 μm and 50 μm were formed. After exposing the upper portion of the via wiring by polishing, these insulating films were immersed in a potassium permanganate solution at 80 ° C. for 15 minutes in the presence of a strong alkali to perform roughening.
These insulating films were roughened to the inside, and the surface of the insulating film was dissolved because it did not have a crosslinked structure, and was severely deteriorated. For this reason, it has been impossible to perform the wiring formation on the insulating film, the adhesion test between the underlying conductive film and the insulating film, and the insulation reliability test.

[Comparative Example 4] The epoxy insulating material described in the above [Example 6] was applied on a substrate under the same conditions as in [Example 6], and was sandwiched between mirror-finished polishing dies. After degassing, the mixture was heated under hydrostatic pressure at 200 ° C. for 30 minutes, cooled to 100 ° C., and then taken out from between the molds. This substrate was further cured in a fine oven at 220 ° C. for 1 hour to form a 50 μm insulating film. Then, as in [Comparative Example 1], at 80 ° C./45 mi
After n-roughening, the roughened surface was subjected to flash plating to form a base conductive film. Next, electrolytic copper plating was performed under the conditions of ² A / dm ² to form a wiring. As a result, as for the insulating film, it was possible to form a line / space wiring of 100 μm / 100 μm, but the wiring of 50 μm / 50 μm was
When the underlying conductive film was peeled, the wiring was peeled from the insulating film. Further, since the resin strength was high, the roughening did not easily proceed, and it was difficult to form a good roughened surface. Therefore, the adhesive strength between the underlying conductive film and the insulating film was <250 N / m. . Also,
As a result of performing an insulation reliability test by the same test method as that of the above example, short-circuit occurred in 350 hours.

[Comparative Example 5] The epoxy insulating material described in the above [Example 7] was applied on a substrate under the same conditions as in [Example 7], and was sandwiched between mirror-finished molds, and was sufficiently heated at 65 ° C. After degassing, heating at 160 ° C./30 min under hydrostatic pressure and cooling to 100 ° C., the product was taken out from between the molds. This substrate was further cured in a fine oven at 180 ° C. for 1 hour to form a 50 μm insulating film. Then, as in [Comparative Example 1], at 80 ° C / 40 min
On the roughened surface, the progress of the roughening was rapid due to the increase in the filler, and the etching amount of the insulating film was 10 μm or more.
It was as large as 13 μm, and the surface unevenness was severe. This roughened surface was subjected to flash plating to form a base conductive film. Next, electrolytic copper plating was performed under the conditions of ² A / dm ² to form a wiring. As a result, the insulation film has a line / space of 100μ.
Although it was possible to form a wiring of m / 100 μm,
The unevenness of the roughened surface was remarkably transferred to the upper part of the wiring. The adhesive strength between the underlying conductive film and the insulating film was <500 N / m, and the insulation reliability test was performed by the same test method as in the above example.

[0056]

As described in detail above, a general chemical bonding method for bonding a wiring and an insulating film is not suitable for resins such as heat-resistant resins and thermoplastic resins. Is also limited, so that the insulating material is limited. In addition, reducing the thickness of the insulating film in this method lowers the insulating reliability, so that there is a limit to thinning. However, by applying the method for manufacturing a wiring board according to the present invention, the selection range of the resin and the setting range of the content of the filler are widened, so that the material is switched to a material having a higher glass transition temperature than the conventional insulating film material. And heat resistance can be improved. In addition, regardless of the filler content, the adhesive strength between the wiring and the insulating film and insulation reliability can be ensured.By increasing the filler content compared to the conventional case, the linear expansion coefficient (α) of the insulating film can be increased. It becomes possible to approach α of the copper foil, and it is possible to reduce the occurrence of internal stress due to a temperature difference. Further, since the filler aggregates do not fall off due to the roughening by the oxidizing agent, no pinholes are generated, the yield is improved, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a process chart showing an example of a conventional wiring board manufacturing method for obtaining an adhesive force between an insulating film and a wiring by using a chemical method.

FIG. 2 is a process chart showing a method of manufacturing a printed wiring board for obtaining an adhesive force between an insulating film and a wiring by forming a copper fine powder layer on the surface of the insulating film according to the present invention.

FIG. 3 shows a curing heat generation curve and a melt viscosity curve of the solid epoxy insulating material shown in Table 1-1.

FIG. 4 shows a curing heat generation curve and a melt viscosity curve of the liquid epoxy insulating material shown in Table 1-2.

FIG. 5 is a configuration diagram when a thermosetting resin insulating film is molded under pressure.

FIG. 6 is a configuration diagram when a thermoplastic resin insulating film is molded under pressure.

[Explanation of symbols]

1 ... Core substrate, 2 ... First wiring layer, 3 ... Insulating material, 4 ... Mirror polishing mold, 5 ... Uncured insulating film, 6 ... Release agent, 7 ... Copper fine powder, 8
... underlying conductive film of copper fine powder, 9 ... cured insulating film, 10 ... underlying conductive film by electroless plating, 11 ... second wiring layer, 12 ... uncured insulating film, 13 ... core substrate, 14 ... first wiring layer , 15: filler-containing insulating film, 16: roughened surface, 17: underlying conductive film, 18: second wiring layer, 19: filler-containing insulating material, 20: mirror-finished polishing mold,
21: Teflon frame, 22: Copper fine powder, 23: Uncured thermosetting resin insulating film, 24: Core substrate, 25: Wiring layer, 26: Mirror polishing mold, 27: Thermoplastic resin supply sheet, 28: Teflon Frame, 29
... copper fine powder, 30 ... core substrate, 30 ... wiring layer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshihide Yamaguchi, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Manufacturing Research Laboratory, Hitachi, Ltd. (72) Takashi Kashimura 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address Co., Ltd., Hitachi, Ltd.Production Technology Research Laboratory (72) Inventor Hidetaka Shigi 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Co., Ltd.Production Technology Research Laboratory Hitachi, Ltd. (72) Makio Watanabe Totsuka, Yokohama-shi, Kanagawa Prefecture 216 Totsuka-cho, Ward, Hitachi, Ltd.Communications Division (72) Inventor Masayuki Keii 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture, Ltd.Hitachi Manufacturing Co., Ltd. (72) Inventor Hiroi Nakayama, Kanagawa Prefecture 216 Totsuka-cho, Totsuka-ku, Yokohama-shi F-term in Hitachi, Ltd. Communications Division 5E346 AA03 AA0 4 AA12 AA15 AA29 AA32 BB01 CC09 CC13 CC32 DD03 DD22 FF23 FF27 GG01 GG28 HH07 HH08 HH18

Claims (7)

[Claims] 1. A step of uniformly spreading metal fine powder particles on an uncured insulating film or a heated and melted insulating film provided on a substrate without gaps, and further proceeds with curing of the insulating film. A step of forming an underlying conductive film by solidification by cooling or by cooling; a step of forming a horizontal wiring and an interlayer connection wiring layer by plating; . 2. An uncured insulating film or an insulating film that is heated and melted between a release agent-coated mirror polishing mold in which metal fine powder particles are uniformly spread without gaps in the base conductive film forming step. Is installed and the insulating film is cured by heating or
A method for manufacturing a wiring board, comprising forming an underlying conductive film by cooling and solidifying. 3. A method for manufacturing a wiring board, wherein the insulating film and the underlying conductive film are formed by heating under pressure or hydrostatic pressure. 4. When the insulating film material described above is a thermosetting resin, the uncured insulating film when the metal fine particles are bonded is within a temperature range from the curing heat generation starting temperature to the maximum curing heat generation amount. A method of manufacturing a wiring board, characterized by being an insulating film formed by heating in (1). 5. In the case where the insulating film material is a thermoplastic resin, after the supply sheet is prepared, the material is melted at a temperature in a range of 1,000,000 poise to 100,000 poise by the method according to claim 2. A method for manufacturing a wiring board, comprising bonding fine particles onto an insulating film. 6. A method for manufacturing a wiring board, wherein the average particle size of the metal fine powder particles spread on the insulating film is 0.1 to 5 μm. 7. A method for manufacturing a wiring board, wherein when a gap is formed between metal fine particles by the method according to claim 2, thin plating is performed on the surface of the conductive film underlying the metal fine particles.