JP2009206135A - Multilayer wiring board, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board which is free from breaking, and has nearly rectangularly sectioned wiring of ≤30 μm in line width with a high aspect ratio (a value obtained by dividing a thickness by a line width) in a ceramic insulating layer, and to provide a manufacturing method thereof. <P>SOLUTION: The multilayer wiring board includes an insulating base formed by layering a plurality of ceramic insulating layers and the nearly rectangularly sectioned wiring made of conductor paste in the ceramic insulating layer, wherein the line width of the wiring is ≤30 μm in plan view and the value obtained by dividing the thickness by the width of the wiring is 0.7 to 2.0. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a multilayer wiring board having fine wiring suitable for a package for housing semiconductor elements, a hybrid integrated circuit device, and the like, and a method for manufacturing the same.

  In multi-layer wiring boards that are applied to semiconductor element storage packages that mount semiconductor elements such as ICs and LSIs, and hybrid integrated circuit devices on which various electronic components are mounted, wiring is required for miniaturization and higher performance. Since it is necessary to form it with high density, miniaturization of wiring is required.

In order to satisfy this requirement, for example, a method using a photosensitive resin film (photoresist) is known as a method for manufacturing a multilayer wiring board for forming a fine wiring having a line width of 30 μm or less. Specifically, after a photosensitive resin film is formed on the surface of the resin film, exposure is performed by irradiating with i-line (wavelength 365 nm) through a photomask having a light-shielding film having the same pattern as that of the wiring. By developing with an aqueous solution or the like, the photosensitive resin film is penetrated to form a groove formed by the photosensitive resin film and the resin film. Next, the conductor paste is filled into the groove with a blade or the like and dried, and then the photosensitive resin film is removed with an alkaline aqueous solution to form a dried conductor paste on the resin film. Then, the method is such that the conductor paste dried body formed on the resin film is transferred to a ceramic green sheet, and the ceramic green sheet to which the conductor paste dried body is transferred is laminated and fired (see, for example, Patent Document 1). ).
Japanese Patent Laid-Open No. 7-122839

  Here, in the method of manufacturing a multilayer wiring board described in Patent Document 1, if the line width of the wiring is reduced, the wiring resistance increases. Therefore, the wiring resistance does not increase when the line width is reduced. Therefore, it is necessary to increase the thickness of the wiring. That is, it is necessary to increase the aspect ratio (the value obtained by dividing the thickness by the line width).

  However, if a dried conductor paste with a high aspect ratio (thickness divided by line width) is to be formed on the resin film by this method, the dried conductor paste is removed when the photosensitive resin film is removed with an alkaline aqueous solution. This collapsed and this caused the disconnection of the finally produced multilayer wiring board. Therefore, the wiring formed on the conventional multilayer wiring board has an aspect ratio (a value obtained by dividing the thickness by the line width) of about 0.4 to 0.5 at most.

  The present invention has been made in view of the above circumstances, and there is no disconnection, and a wiring having a substantially rectangular shape with a section having a line width of 30 μm or less and a high aspect ratio (a value obtained by dividing the thickness by the line width) is formed inside the ceramic insulating layer. It is an object of the present invention to provide a multilayer wiring board having the same and a manufacturing method thereof.

  The present invention includes an insulating base formed by laminating a plurality of ceramic insulating layers, and a wiring having a substantially rectangular cross section formed by a conductive paste inside the ceramic insulating layer, and the line width of the wiring in plan view Is a multilayer wiring board characterized in that a value obtained by dividing the thickness of the wiring by the line width is 0.7 or more and 2.0 or less.

  Further, the present invention provides a process for forming a photosensitive resin film on one main surface of a resin film via an adhesive resin film, and a wiring formation that penetrates the photosensitive resin film by performing an exposure process and a development process. After forming the groove, the step of filling the groove with a conductive paste and drying, and after exposing the photosensitive resin film again, removing the photosensitive resin film to produce a film with a dried conductor paste And applying the ceramic slurry so as to cover the conductor paste dried body and the adhesive resin film of the film with the conductor paste dried body and drying, and then removing the resin film and the adhesive resin film to remove the conductor paste. A process for producing a ceramic green sheet with a dried body and a ceramic ceramic sheet with a dried conductor paste by laminating a plurality of ceramic green sheets with the dried conductor paste A method for producing a multilayer wiring board having a step of producing a green sheet laminate and a step of firing the ceramic green sheet laminate with a dried conductor paste, measured using SAICAS of the dried conductor paste The manufacturing method of the multilayer wiring board is characterized in that the strength is 8 to 50 N / m.

  Further, the present invention provides a process for forming a photosensitive resin film on one main surface of a resin film via an adhesive resin film, and a wiring formation that penetrates the photosensitive resin film by performing an exposure process and a development process. After forming the groove, the step of filling the groove with a conductive paste and drying, and after exposing the photosensitive resin film again, removing the photosensitive resin film to produce a film with a dried conductor paste And pressing the ceramic green sheet so as to cover the dried conductor paste and the adhesive resin film to transfer the dried conductor paste to the ceramic green sheet, and then the resin film and the adhesive resin film. Removing the ceramic green sheet with the dried conductor paste, and laminating a plurality of the ceramic green sheets with the dried conductor paste. A method for producing a multilayer wiring board, comprising: producing a ceramic green sheet laminate with a dried conductor paste; and firing the ceramic green sheet laminate with a dried conductor paste, A method for producing a multilayer wiring board, wherein the strength measured using SAICAS is 8 to 50 N / m.

  Furthermore, the present invention provides a wiring obtained by sintering the conductor paste dry body in the above manufacturing method, wherein the line width in plan view is 30 μm or less, and the value obtained by dividing the thickness of the wiring by the line width is 0. It is a manufacturing method of a multilayer wiring board characterized by forming so that it may become .7 or more and 2.0 or less.

  According to the multilayer wiring board of the present invention, there is no disconnection or short circuit, and the cross section having a line width of 30 μm or less and a high aspect ratio (a value obtained by dividing the thickness by the line width) has a substantially rectangular shape inside the ceramic insulating layer. Since a multilayer wiring board can be realized, it is possible to increase the density and resistance of the wiring.

  Further, according to the method for producing a multilayer wiring board of the present invention, a photosensitive resin film is formed on one main surface of the resin film via an adhesive resin film, and subjected to an exposure process and a development process, and the photosensitive film is formed. After forming a groove for wiring formation penetrating through the resin film, filling the groove with the conductor paste and drying, the photosensitive resin film is again exposed, and then the photosensitive resin film is washed with an alkaline aqueous solution. When the film is removed to produce a film with a dried conductor paste, it is possible to suppress the occurrence of peeling and collapse of the dried conductor paste. Further, when the photosensitive resin film is removed, even if the dried conductor paste remains on the photosensitive resin film, the remaining dried conductor paste can be easily removed. Therefore, highly accurate fine wiring having a substantially rectangular cross section can be formed.

  Hereinafter, an embodiment of the present invention will be described.

  The present invention includes an insulating base formed by laminating a plurality of ceramic insulating layers, and a wiring having a substantially rectangular cross section formed by a conductive paste inside the ceramic insulating layer, and the line width of the wiring in plan view Is a multilayer wiring board characterized in that a value obtained by dividing the thickness of the wiring by the line width is 0.7 or more and 2.0 or less.

The insulating base is a laminate of a plurality of ceramic insulating layers. The ceramic insulating layer is formed of a crystallized glass or an amorphous glass that precipitates crystals such as quartz, cristobalite, cordierite, mullite, anorthite, serzian, spinel, garnite, willemite, dolomite, petalite, and the like, and SiO _2. , Al ₂ O ₃ , ZrO _{2 and} other inorganic fillers are used as raw materials, and an organic binder, an organic solvent, etc. are added to these mixtures to produce a ceramic slurry, and then a sheet is obtained by a doctor blade method, a rolling method, a pressing method, etc. It is obtained by molding into a shape and firing.

  A wiring formed of a conductive paste containing a metal powder, an organic binder, and an organic solvent is provided inside the ceramic insulating layer. Here, the inside of the ceramic insulating layer means that the wiring is formed inside one ceramic insulating layer, and does not exclude what is formed facing the boundary between adjacent ceramic insulating layers. Absent.

  As the metal powder, low-resistance Cu powder or Ag powder is preferable, and Cu powder is most desirable in order to suppress a decrease in reliability due to migration of metal components. The average particle size of the metal powder is preferably 0.5 μm or more from the viewpoint of various properties (viscosity and strength during drying) of the conductor paste, and 5 μm or less from the viewpoint of forming a wiring having a line width of 30 μm or less.

  In the present specification, the “average particle diameter” means the particle diameter d50 at which the cumulative curve becomes 50% when the cumulative curve is obtained with the total volume of the powder group as 100%. The particle size distribution of the powder can be measured using, for example, a Microtrac particle size distribution measuring apparatus X-100 (manufactured by Nikkiso Co., Ltd.) using a laser diffraction / scattering method.

  As the organic binder, for example, isobutyl methacrylate resin, methyl methacrylate resin or the like is used. The mixing ratio of the organic binder in the conductor paste is 2 to 12 parts by mass with respect to 100 parts by mass of the metal powder.

  As the organic solvent, for example, terpineol, dibutyl phthalate (DBP), toluene, acetone or the like is used. The mixing ratio of the organic solvent in the conductor paste is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the metal powder.

  Here, the strength measured using SAICAS (Surface And Interfacial Cutting Analysis System manufactured by Daipura Wintes Co., Ltd.) of the dried conductor paste is 8 to 50 N / m, which produces the multilayer wiring board of the present invention. It is important. The state where the conductor paste is dried refers to a state where the organic solvent has blown out from the conductor paste, in other words, a state where the proportion of the organic solvent is substantially 0% by mass. SAICAS is a device that can measure the peel strength and shear strength of an adherend, and can be measured by cutting and peeling from the surface of the adherend to the interface at a very low speed with a sharp cutting blade made of diamond. The peel strength is obtained as a horizontal force applied to the cutting edge (horizontal force per blade width), and the shear strength is obtained based on the cutting theory. In the present invention, the dried conductor paste obtained by drying the conductor paste corresponds to the adherend, and the strength in the present invention is the peel strength (N / m) measured using a device called SAICAS. is there. Specifically, the same conductive paste dry body as that used for manufacturing the multilayer wiring board is formed on the adhesive resin film formed on one main surface of the resin film so that the thickness is 10 μm or more. In addition, it is separately formed for measurement so as to have a width exceeding the blade width (for example, 1 mm) in plan view, and the SAICAS cutting blade (for example, the blade width of 1 mm) is positioned within the thickness range from the surface of the conductor paste dry body ( For example, it is a measured value when moved in the horizontal direction at a depth of 4 μm. In the measurement of the strength of the dried conductor paste, the dried conductor paste is not limited to being formed on the adhesive resin film formed on one main surface of the resin film.

  In order to set the strength to 8 to 50 N / m, the molecular weight of the organic binder is an important factor in combination with the mixing ratio of the organic binder. That is, the mixing ratio of the organic binder in the conductor paste is set to 2 to 12 parts by mass with respect to 100 parts by mass of the metal powder, and the molecular weight of the organic binder is set to 50,000 to 700,000. Can be set to 8 to 50 N / m. For example, when an organic binder having a molecular weight of 50,000 is used, the mixing ratio of the organic binder needs to be 8 to 12% by mass with respect to 100% by mass of the metal powder. Further, when the mixing ratio of the organic binder is 6% by mass with respect to 100% by mass of the metal powder, the molecular weight of the organic binder needs to be 150,000 to 700,000. The molecular weight of the organic binder is appropriately adjusted depending on the polymerization initiator. Moreover, ceramic powder and glass powder may be added to this conductor paste as needed, and the mixing ratio when these powders are added is based on 100 parts by mass of metal powder and ceramic powder (glass powder). The organic binder and the organic solvent may be mixed in the above ratio with respect to 100 parts by mass.

  In general, as a method for forming a wiring using a conductive paste, a method of screen printing using a plate making made of a metal mesh is known. In this method, the stringiness of the conductor paste used is important. That is, it is necessary to keep the bonding state between the organic binders or between the organic binder and the metal powder moderately, and to make the passage through which the conductive paste passes through the plate making good, and the conductive paste for satisfying this requirement The strength measured with SAICAS in the dry state is about 4 N / m.

  On the other hand, in the present invention, by adjusting the molecular weight of the organic binder and the mixing ratio of the organic binder, the bonding state between the organic binders or between the organic binder and the metal powder can be strengthened, so that the strength of 8 to 50 N / m was obtained.

  By producing a multilayer wiring board with such a conductor paste by the method described later, the cross-sectional shape is substantially rectangular, the line width in plan view is 30 μm or less, and the value obtained by dividing the thickness by the line width is 0.00. A multilayer wiring board having wirings of 7 or more and 2.0 or less inside the ceramic insulating layer is obtained. In particular, a multilayer wiring board having wiring whose thickness is divided by line width is 0.7 or more and 2.0 or less is obtained.

  Here, the cross-sectional shape of the wiring being substantially rectangular means that the cross-sectional shape has corners at the four corners, and the angle of each corner is in the range of 80 to 95 degrees. This shape can be formed by a manufacturing method in which a photosensitive resin film is formed on a resin film, which will be described later, and exposure and development processes are performed.

  Moreover, the value obtained by dividing the thickness of the wiring by the line width is 0.7 or more and 2.0 or less, not a total value obtained by laminating a plurality of layers of the dried conductor paste, but a layer of dried conductor paste. Value. What is obtained by stacking can be distinguished by confirming whether the cross-sectional shape of the wiring does not have a substantially rectangular shape, or whether or not there is a boundary between layers.

  In practice, the line width of the wiring is preferably 10 μm or more, and the effect of the above-described configuration can be obtained when the line width is 10 μm or more and 30 μm or less.

  When the strength measured using SAICAS of the dried conductor paste is 8 to 50 N / m, the line width is 30 μm or less, and the value obtained by dividing the thickness by the line width is 0.7 or more and 2.0 or less. When forming a wiring, even if a load is applied to the conductor paste dry body when removing the photosensitive resin film with an alkaline aqueous solution, the occurrence of peeling and collapse of the conductor paste dry body can be suppressed, and disconnection can be suppressed. it can. On the other hand, when the above-mentioned strength is 50 N / m or less, even if the dried conductor paste remains on the photosensitive resin film when the photosensitive resin film is removed with an alkaline aqueous solution, the remaining dried conductor paste Therefore, it is possible to form a highly accurate fine wiring having a substantially rectangular cross section. In addition, if the conductor paste dry body remaining on the photosensitive resin film cannot be removed cleanly and remains as a burr, Cu and Ag diffuse when the ceramic green sheet and the conductor paste dry body are simultaneously fired. Then, there is a possibility that the adjacent wirings are connected at a level that is not apparent in appearance, and a short circuit may occur, but this problem can be solved when the strength is 50 N / m or less.

  In addition, the organic substance contained in the conductor paste can be specified by gas chromatograph (GC) analysis. Specifically, the qualitative analysis of the organic substance can be performed by baking the conductor paste and analyzing the gas generated at this time. In particular, when a quantitative analysis is desired, a sample whose amount is known in advance can be analyzed again by gas chromatograph (GC), and a calibration curve can be drawn from the intensity ratio. Moreover, the inorganic substance (metal, ceramic, glass) contained in the conductor paste can be qualitatively analyzed and quantitatively analyzed by ICP (Inductively Coupled Plasma) emission spectroscopic analysis.

  The molecular weight of the organic binder in the conductor paste is determined by diluting the conductor paste with an organic solvent, removing inorganic solid components (metal, inorganic filler, etc.) in the paste with a filter pass, etc. It can be identified by chromatographic (GPC) analysis.

  Next, a method for manufacturing the above multilayer wiring board will be described.

  As shown in FIG. 1, the manufacturing method of the multilayer wiring board of the present invention is as follows. First, an adhesive resin film 2 is dried on one main surface of a transparent and flexible resin film 1 such as polyethylene terephthalate (PET) and dried to 3 μm. It forms by the doctor blade method so that it may become a thickness, and also the photosensitive resin film 3 is formed on the main surface of the adhesive resin film 2 by the same method as the adhesive resin film 2.

  The adhesive resin film 2 is used to adhere the photosensitive resin film 3 to the adhesive resin film 2 and suppress the peeling of the photosensitive resin film 3 during development processing or the like. Among acrylic resins, butyl having a low glass transition temperature is used. It is preferable to form an acrylate or the like by a doctor blade method by dissolving it in an organic solvent such as toluene, isopropyl alcohol (IPA) or acetone. The adhesive strength of the adhesive resin film 2 is desirably in the range of 1 mN / mm to 15 mN / mm with respect to the photosensitive resin film 3, and the photosensitive resin film 3 is resin in the middle of the process by setting it to 1 mN / mm or more. It can prevent peeling from the film 1, and can peel without giving a big load at the time of peeling the photosensitive resin film 3 finally by setting it as 15 mN / mm or less. The adhesive strength is measured by forming the adhesive resin film 2 on the resin film 1 and forming the photosensitive resin film 3 (positive photoresist) on the surface of the adhesive resin film 2 by the doctor blade method. After drying for 2 hours at a temperature of 2 ° C. to produce a multilayer film, a 180 ° peel strength test between the photosensitive resin film / adhesive resin film using a tensile / compression test apparatus (STA-1150 manufactured by Orientec Co., Ltd.) is used. Specifically, the above value is obtained by cutting the multilayer film into a size of 15 mm wide × 100 mm long, pulling at a speed of 300 mm / min, and reading the load when the photosensitive resin film is completely peeled, 15 mm The intensity per width is shown.

  The photosensitive resin film 3 may be formed by a doctor blade method using a liquid photosensitive resist dissolved in an organic solvent, or may be formed by thermocompression bonding a film-like dry film resist with a laminator. .

  Next, as shown in FIG. 2, an exposure process and a development process are performed to form a wiring forming groove 4 penetrating the photosensitive resin film 3 in the photosensitive resin film 3. Specifically, an exposure process using i-line (wavelength 365 nm) is performed using a photomask 7 having a thickness of about 1.6 mm on which a light-shielding film having the same pattern as the wiring is formed, and an alkaline aqueous solution (for example, 1% concentration) A groove 4 for wiring formation formed by the photosensitive resin film 3 and the resin film 1 having the adhesive resin film 2 is developed with a sodium hydroxide aqueous solution) and penetrates the photosensitive resin film 3. Form.

  Next, as shown in FIG. 3, the above-mentioned conductor paste 5 a is filled into the wiring forming groove 4 formed in the photosensitive resin film 3. The filling of the conductor paste 5a into the groove 4 for forming the wiring is, for example, a urethane rubber squeegee, preferably using a sword squeegee. The filling method can be performed manually, but it is more desirable to use a screen printer or the like in order to appropriately control the pressure. Thereafter, the conductor paste 5a is dried at 60 to 100 ° C. for about 1 to 3 hours to obtain a conductor paste dried body 5b.

  Then, after exposing the photosensitive resin film 3 again, the photosensitive resin film 3 is removed to produce a film 6 with a dried conductor paste. For removing the photosensitive resin film 3, for example, a method of dissolving the photosensitive resin film 3 using an alkaline aqueous solution (for example, a 2% concentration sodium hydroxide aqueous solution) is used.

  At this time, when the strength measured using SAICAS of the conductor paste dried body 5b in the film 6 with a conductor paste dried body is 8 to 50 N / m, the photosensitive resin film 3 is removed with an alkaline aqueous solution. Further, it is possible to suppress peeling and collapse of the dried conductor paste 5b and to suppress the generation of burrs.

  Furthermore, as shown in FIG. 4, the ceramic slurry 8a is applied to a desired thickness by a doctor blade method so as to cover the conductor paste dried body 5b and the adhesive resin film 2 of the film 6 with a conductor paste dried body. Then, after the ceramic slurry 8a is dried to obtain a green sheet 8b, the resin film 1 is peeled off together with the adhesive resin film 2 to remove them, thereby producing a ceramic green sheet 9 with a dried conductor paste.

  In addition, after separately preparing a ceramic green sheet and thermally bonding the wiring forming surface of the film 6 with the dried conductor paste to the surface of the separately prepared ceramic green sheet, the resin film 1 is attached to the adhesive resin film 2 together. The ceramic green sheet 9 with a dried conductor paste may be produced by peeling and transferring the dried conductor paste to a ceramic green sheet.

Here, the green sheet 8b in the ceramic green sheet 9 with a dried conductor paste is formed by mixing, for example, crystallized glass or amorphous glass and an inorganic filler such as SiO ₂ , Al ₂ O ₃ , or ZrO _2. Is obtained. Other examples of the inorganic filler include corundum (α alumina), forsterite, zirconia, and magnesia. Moreover, in the case of crystallized glass, what precipitates crystals, such as quartz, cristobalite, cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, and petalite, can be exemplified. A glass ceramic composition is prepared by mixing crystallized glass or amorphous glass and the above inorganic filler (ceramic component), and an organic binder or the like is added to the mixture to prepare a ceramic slurry to be a ceramic green sheet. It is formed by forming into a sheet by a blade method, a rolling method, a pressing method or the like.

  In addition, the ceramic green sheet 9 with the dried conductor paste is processed by vias using a micro drill, an infrared laser, or the like in addition to the wiring formation by the above-described method, and the above-described conductor paste 5a is embedded in the vias by a screen printing method. Wiring formation is also performed.

  A plurality of obtained ceramic green sheets 9 with dried conductor paste are laminated to produce a ceramic green sheet laminated body with dried conductor paste, and the ceramic green sheet laminated body with dried conductor paste is, for example, 400 to 800 in a nitrogen atmosphere. After the organic binder has disappeared at 1 ° C. for 1 to 3 hours, the multilayer wiring substrate can be obtained by firing at 800 to 1000 ° C. in a nitrogen atmosphere for 1 to 2 hours, for example.

  According to the method for manufacturing a multilayer wiring board described above, unlike the wiring formed by the screen printing method, the cross section is substantially rectangular, the line width in plan view is 30 μm or less, and the thickness is divided by the line width. A multilayer wiring board having wiring with a value of 0.7 or more and 2.0 or less inside the ceramic insulating layer can be obtained.

  When screen printing is used for wiring formation, the cross-sectional shape of the wiring is a kamaboko shape in which the upper surface is curved and an acute angle portion is formed at the corner portion on the lower surface side, and the electric charge concentrates on the acute angle portion so that the specific resistance and The electrical characteristics such as transmission loss (S21) of the high-frequency signal may be deteriorated. However, according to the above-described manufacturing method of the multilayer wiring board, a wiring having a substantially rectangular cross section and a thicker thickness is formed. Therefore, electrical characteristics such as specific resistance and high-frequency signal transmission loss (S21) can be improved.

  That is, the multilayer wiring board can be reduced in size and performance.

An adhesive resin film mainly composed of butyl acrylate is formed on a PET film as a resin film by a doctor blade method so that the thickness after drying becomes 3 μm, and then a photosensitive resin film is formed on the surface of the adhesive resin film. The positive photoresist (PMER LA900PM manufactured by Tokyo Ohka Kogyo Co., Ltd.) was formed into a film at a drying temperature of 110 ° C. so that the thickness after drying was 20 μm by the doctor blade method. Then, using a photomask having a light-shielding film having the same pattern as that of the wiring, exposure is performed at 1000 mJ / cm ² from the photosensitive resin film side by an i-line irradiator, and development processing is performed with a 1% by mass aqueous sodium hydroxide solution. A groove for wiring formation was formed in a type photoresist (PMER LA900PM manufactured by Tokyo Ohka Co., Ltd.).

  Table 1 shows isobutyl methacrylate resins having the molecular weights shown in Table 1 as organic binders with respect to 100 parts by mass of mixed powder composed of 98% by mass of Cu powder having an average particle size of 2 μm and 2% by mass of borosilicate glass powder. While adding at a ratio, 20 parts by mass of α-terpineol as an organic solvent was added and mixed with a three-roll mill to prepare a conductor paste. The produced conductor paste was filled into a wiring formation groove formed in a positive photoresist using a squeegee.

  Thereafter, the filled conductor paste was dried at a temperature of 80 ° C., and then a positive photoresist, which is a photosensitive resin film, was dissolved in a 2% aqueous sodium hydroxide solution. A film with a dried conductor paste was obtained by dissolving the positive photoresist.

  And after apply | coating a ceramic slurry on the film with a conductor paste dry body by a doctor blade method and drying at 80 degreeC, after peeling PET film as a resin film in which the adhesive resin film was formed on the upper surface, conductor paste A ceramic green sheet with a dried body was obtained.

The ceramic slurry at this time was prepared by kneading 100 parts by mass of ceramic powder, 15 parts by mass of an organic binder (isobutyl methacrylate), and 70 parts by mass of toluene with a ball mill for 24 hours. The ceramic powder was a mixture of SiO ₂ as an inorganic filler and amorphous borosilicate glass, and the average particle size of this mixed raw material powder was 2 μm. As the glass composition, SiO ₂ was 40 mass%, B ₂ O ₃ was 10 mass%, BaO was 40 mass%, Al ₂ O ₃ was 5 mass%, and CaO was 5 mass%.

  And 5 layers of the said ceramic green sheet with a conductor paste dried body was thermocompression-bonded at 10 MPa and 50 degreeC, and the ceramic green sheet laminated body with a conductor paste dried body was produced. The obtained ceramic green sheet laminate with the dried conductor paste was burned off at 750 ° C. for 3 hours in a nitrogen atmosphere and then fired at 950 ° C. for 1 hour in a nitrogen atmosphere. A multilayer wiring board was obtained.

  In the manufacturing process of the multilayer wiring board, the conductor paste dried body was peeled or collapsed, or the wiring in the obtained multilayer wiring board was broken or short-circuited. The results are shown in Table 1.

  In Table 1, Sample No. The wiring of No. 1 is L (line width) / S (interval) = 50/50 μm. The wirings 2 to 20 were L (line width) / S (interval) = 20/20 μm, and the amount of paste embedded was adjusted so that the wiring thickness was close to the thickness of the positive photoresist.

  In Table 1, the strength of the conductor paste is the same as the conductor paste dried body used for the production of the multilayer wiring board, and the adhesive resin formed on one main surface of the resin film is prepared. A SAICAS cutting blade (blade width 1 mm) is separately formed on the film to have a thickness of 15 μm and a 2 cm square in plan view at a position 4 μm deep from the surface of the dried conductor paste. It is a measured value when moved in the horizontal direction.

  From the results of Table 1, within the scope of the present invention, in the wiring having a line width of 30 μm or less (20 μm), the value obtained by dividing the wiring thickness by the line width is 0.7 or more and 2.0 or less (0.9, 1 0.0, 1.5, 2.0), and it can be seen that there is no disconnection or short circuit.

  On the other hand, it is outside the scope of the present invention, and the sample No. It can be seen that in 1 to 5, the value obtained by dividing the thickness of the wiring by the line width cannot be 0.7 or more, or the wiring is broken due to peeling or collapse. In addition, Sample No. with a strength of the dried conductor paste exceeding 50 N / m. 15 shows that a burr is formed, causing a short circuit in the wiring.

It is explanatory drawing of the manufacturing method of the multilayer wiring board of this invention, Comprising: The state with the photosensitive resin film formed in the main surface of the resin film through the adhesive resin film is shown. It is explanatory drawing of the manufacturing method of the multilayer wiring board of this invention, Comprising: (a) has shown the state which has exposed the photosensitive resin film, (b) has shown the groove | channel for wiring formation in the photosensitive resin film. The formed state is shown. It is explanatory drawing of the manufacturing method of the multilayer wiring board of this invention, (a) has shown the state by which the conductor paste was filled in the groove | channel for wiring formation formed in the photosensitive resin film, (b) The film with the conductor paste dry body produced by removing the photosensitive resin film | membrane shown to (a) is shown. It is explanatory drawing of the manufacturing method of the multilayer wiring board of this invention, Comprising: (a) has shown the state by which the ceramic slurry was apply | coated to the film with a conductor paste dry body, (b) is the resin film shown to (a) And a ceramic green sheet with a dried conductor paste produced by removing the adhesive resin film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resin film 2 ... Adhesive resin film 3 ... Photosensitive resin film 4 ... Groove 5a ... Conductive paste 5b ... Conductive paste dry body 6 ... With conductive paste dry body Film 7 ... Photomask 8a ... Ceramic slurry 8b ... Green sheet 9 ... Ceramic green sheet with dried conductor paste

Claims (4)

An insulating substrate formed by laminating a plurality of ceramic insulating layers; and a wiring having a substantially rectangular cross section formed by a conductive paste inside the ceramic insulating layer, wherein the wiring has a line width of 30 μm or less in plan view A multilayer wiring board, wherein a value obtained by dividing the thickness of the wiring by the line width is 0.7 or more and 2.0 or less. A step of forming a photosensitive resin film on one main surface of the resin film through an adhesive resin film, and an exposure process and a development process were performed to form a groove for forming a wiring penetrating the photosensitive resin film. Then, a step of filling the groove with a conductive paste and drying, a step of exposing the photosensitive resin film again, and then removing the photosensitive resin film to produce a film with a dried conductor paste, After applying and drying the ceramic slurry so as to cover the conductor paste dried body and the adhesive resin film of the film with the conductor paste dried body, the resin film and the adhesive resin film are removed, and the ceramic green with the conductor paste dried body is removed. A step of producing a sheet, and a plurality of ceramic green sheets with dried conductor paste are laminated to form a ceramic green with dried conductor paste A multilayer wiring board manufacturing method comprising a step of producing a laminate and a step of firing the ceramic green sheet laminate with a dried conductor paste, which is measured using SAICAS of the dried conductor paste A method for producing a multilayer wiring board, wherein the strength is 8 to 50 N / m. A step of forming a photosensitive resin film on one main surface of the resin film through an adhesive resin film, and an exposure process and a development process were performed to form a groove for forming a wiring penetrating the photosensitive resin film. Thereafter, a step of filling the groove with a conductive paste and drying, a step of exposing the photosensitive resin film again, and then removing the photosensitive resin film to produce a film with a dried conductor paste, and a conductor A ceramic green sheet is pressed to cover the dried paste and the adhesive resin film, and the conductive paste dried body is transferred to the ceramic green sheet, and then the resin film and the adhesive resin film are removed to dry the conductor paste. A process for producing a ceramic green sheet with a body, and a plurality of ceramic green sheets with a dried conductor paste are laminated to form a conductor paste A method for producing a multilayer wiring board comprising a step of producing a ceramic green sheet laminate with a dried body and a step of firing the ceramic green sheet laminate with a dried conductor paste, wherein SAICAS of the dried conductor paste is obtained. The manufacturing method of the multilayer wiring board characterized by the intensity | strength measured using being 8-50 N / m. The wiring obtained by sintering the dried conductor paste has a line width of 30 μm or less in plan view, and the value obtained by dividing the thickness of the wiring by the line width is 0.7 or more and 2.0 or less. 4. The method for manufacturing a multilayer wiring board according to claim 2, wherein the multilayer wiring board is formed.

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