JP5132387B2 - Multilayer wiring board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multilayer wiring board suitable as various circuit boards and high-frequency wiring boards, and a method for manufacturing the same.

  As a material for forming an insulating layer that constitutes various wiring substrates such as a package for housing a semiconductor element such as an IC or LSI, or a hybrid integrated circuit device in which various electronic components are mounted in addition to the semiconductor element, electrical insulation is used. Alumina ceramics are used because of their excellent properties such as properties and chemical stability, and tungsten (W) and molybdenum having a melting point higher than the firing temperature of alumina (about 1600 ° C.) as the material for forming the wiring layer (Mo) is used.

  However, in recent years, lower wiring resistance is required than tungsten and molybdenum, and low resistance metals such as gold (Au), silver (Ag), and copper (Cu) are attracting attention as a material for forming a wiring layer. Therefore, glass ceramics that can be fired at about 900 ° C., which is lower than the melting point of these low-resistance metals, have been used as an insulating layer corresponding to this (see Patent Document 1 and Patent Document 2).

  A wiring board having such a glass ceramic insulating layer is generally obtained by forming a green sheet by forming a slurry prepared using a glass ceramic raw material powder, an organic binder, and a solvent by a sheet forming method such as a doctor blade method. After punching through holes, etc. in the green sheet, and filling the through holes with a paste for through conductors containing conductor powder, a predetermined wiring pattern is screened on the green sheet using the same conductor paste for wiring layers. It is produced by printing by thick film technique such as printing method, laminating a plurality of obtained green sheets, pressurizing and laminating, then heating this laminate to remove the binder and then firing. It was.

  Here, since gold, silver, and copper, which are low resistance metals, generally start shrinking at a lower temperature than glass ceramics, the adhesive strength between the through conductor and the insulating layer is weak, and a gap is formed at the interface between them. In addition, moisture such as a plating solution enters from the surface of the substrate through the gap, and the through conductor protrudes from the surface of the substrate (hereinafter referred to as via protrusion), which causes problems in mounting components. There is a problem of end.

On the other hand, glass powder such as lead borosilicate glass, borosilicate glass, zinc borosilicate glass, lithium silicate glass, and silica (SiO ₂ ) is added to the paste for through conductor (copper metallized composition). It has been proposed to improve the adhesion strength between the through conductor and the insulating layer and reduce the via protrusion by bringing the shrinkage behavior closer to that of glass ceramics (see Patent Document 3).
JP 63-301405 A Japanese Patent Laid-Open No. 1-112605 Japanese Patent Laid-Open No. 11-16418

  However, if the glass powder as described in Patent Document 3 is contained in the through conductor paste, a gap is also formed at the interface between the conductor component and the glass in the through conductor after firing. Even if the formation of a gap at the interface between the through conductor and the insulating layer is suppressed, if a gap is formed at the interface between the conductor component and the glass in the through conductor, a plating solution or the like is passed through the gap inside the substrate. Moisture may enter. While higher reliability is required for electronic components, it is necessary to suppress the formation of a gap at the interface between the conductor component and the glass in the through conductor.

  The present invention has been made in view of the above circumstances, and provides a highly reliable multilayer wiring board in which via protrusion from the substrate surface is reduced and moisture intrusion into the board is suppressed, and a method for manufacturing the same. For the purpose.

According to the present invention, an insulating substrate formed by laminating a plurality of glass ceramic insulating layers, and a glass ceramic insulating layer constituting at least a surface layer of the insulating substrate are provided, and a through conductor paste is fired. and penetrations conductor obtained, in the multilayer wiring board having a 40 the via conductor paste, gold, and metal powder of silver and mainly composed of any one of copper, the Si in terms of SiO ₂ 60 mass%, Al is 5 to 15 mass% in terms of Al ₂ O ₃ , Ca is 10 to 20 mass% in terms of CaO, Ba is 15 to 25 mass% in terms of BaO, and rare earth elements are 1 to 8 in terms of oxide And glass powder containing by mass%.

  Here, the rare earth element is preferably at least one of Y and La.

The present invention also includes a step of producing a plurality of glass ceramic green sheets, and a glass ceramic green sheet disposed at least on the surface of the laminate when the laminate of the plurality of glass ceramic green sheets is produced. A hole is formed, and in the through-hole, a metal powder mainly containing any one of gold, silver and copper, 40 to 60% by mass of SiO ₂ , and 5 to 15% by mass of Al ₂ O ₃ the CaO 10 to 20 wt%, a BaO 15-25 wt%, a step of filling the via conductor paste and a 1-8 wt% content Suruga Las powder of rare earth oxide, the penetrating into the through hole A step of arranging a glass ceramic green sheet filled with a conductive paste at least on the surface layer to produce a laminate of the plurality of glass ceramic green sheets; and the laminate It is characterized in that and a step of firing the.

Here, it is preferable to use at least one of Y ₂ O ₃ and La ₂ O ₃ as the rare earth oxide.

According to the multilayer wiring board of the present invention, 40 to 60 wt% through conductor Si in terms of SiO _2, 5 to 15 wt% of Al in terms _{of Al} 2 _{O 3,} 10 to 20 wt% of Ca in terms of CaO, By including glass containing 15 to 25% by mass of Ba in terms of BaO and 1 to 8% by mass of rare earth elements in terms of oxide, the glass transition point of the glass contained in the through conductor becomes 720 to 760 ° C., Since the shrinkage behavior of the paste for through conductors as the through conductor and the glass ceramic green sheet as the glass ceramic insulating layer can be matched, the formation of gaps at the interface between the through conductor and the glass ceramic insulating layer is suppressed. At the same time, the via protrusion can be reduced. Further, the glass powder contained in the through conductor has a coefficient of thermal expansion at 30 to 300 ° C. of 6 × 10 ⁻⁶ / ° C. or more, and becomes a conductor component contained in the fired through conductor, and the fired through hole Suppresses the formation of gaps at the interface between the conductor component and glass in the through conductor after firing because the stress caused by the difference in thermal expansion from the glass powder that becomes the glass contained in the conductor is reduced. can do. Therefore, it is possible to realize a highly reliable multilayer wiring board in which moisture penetration is suppressed.

Further, according to the method of manufacturing the multilayer wiring board of the present invention, a through conductor paste for forming the through conductor, gold, and any metal powder of silver and copper, the SiO ₂ 40 to 60 wt% A glass powder containing 5 to 15% by mass of Al ₂ O ₃ , 10 to 20% by mass of CaO, 15 to 25% by mass of BaO and 1 to 8% by mass of rare earth oxide, and which does not precipitate crystals by firing. The glass transition point of the glass contained in the through-conductor paste is set to 720 to 760 ° C., and the difference in shrinkage behavior between the through-conductor paste and the glass ceramic green sheet can be reduced. By setting the thermal expansion coefficient of the powder to 6 × 10 ⁻⁶ / ° C. or higher, it is possible to reduce the stress caused by the difference in thermal expansion between the metal powder and the glass powder. Therefore, it is possible to suppress the formation of a gap at the interface between the through conductor and the glass ceramic insulating layer and at the same time reduce the via protrusion. In addition, since it is possible to suppress the formation of a gap at the interface between the conductor component and the glass in the through conductor, it is possible to obtain a highly reliable multilayer wiring board in which moisture penetration is suppressed.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic longitudinal sectional view showing an embodiment of a multilayer wiring board according to the present invention. In the multilayer wiring board shown in FIG. 1, a plurality of glass ceramic insulating layers 1a, 1b, 1c, 1d, and 1e are laminated. An insulating substrate 1, a wiring layer 2 formed on the surface and inside of the insulating substrate 1, and a through conductor 3 formed in glass ceramic insulating layers 1a and 1e constituting at least the surface layer of the insulating substrate 1. It has.

  In FIG. 1, various electronic components 4 such as ICs, filters, capacitors, etc. are mounted on the upper surface of the multilayer wiring board, and wiring formed on the surface (upper surface) by wire bonding or flip chip mounting (not shown). It is electrically connected to the layer (connection terminal). Further, a protective sealing resin 5 is provided so as to cover the upper surface of the multilayer wiring board. Although not shown, the obtained multilayer wiring board is mounted on an external circuit board (printed board), and the wiring layer (connection terminal) formed on the lower surface and the connection terminal of the external circuit board (printed board) are soldered or the like It is electrically connected via a brazing material or a conductive adhesive. However, the present invention is not limited to the form illustrated in FIG.

  An insulating substrate 1 formed by laminating a plurality of glass ceramic insulating layers 1a to 1e is made of glass powder alone or a mixture of glass powder and ceramic powder to form a glass ceramic green sheet, and then gold, silver, copper, etc. It consists of a glass ceramic sintered body obtained by firing at a temperature lower than the melting point of the low resistance metal, and contains various crystals and glass.

  Crystals include alumina, zirconia, quartz, cristobalite, cordierite, mullite, spinel, garnite, enstatite, forsterite, anorthite, slausonite, serdian, diopside, montericite, akermanite, willemite and its solid solution, substitution A derivative etc. can be illustrated and a plurality of crystals may coexist. From the viewpoint of improving the bending strength, it is preferable to employ alumina, zirconia, forsterite, enstatite, spinel, anorthite, slausonite, and serdian, and alumina, zirconia, forsterite, and serdian are particularly preferable. In addition, forsterite, enstatite, quartz, cristobalite, cordierite, mullite are preferable, and forsterite, quartz, cordierite are particularly preferable in terms of reducing transmission loss of high-frequency signals by lowering the dielectric constant. .

  These crystals may be originally added as ceramic powder (raw material powder), may be precipitated from glass powder during firing, or may be a reaction product of ceramic powder and glass powder. .

Examples of the glass powder include silicate glass, borosilicate glass, boric acid glass, and phosphoric acid glass. Alkali metal oxidation is performed on network forming oxides such as SiO ₂ , B ₂ O ₃ , and P ₂ O _5. Products, alkaline earth metal oxides, modified oxides such as ZnO and rare earth oxides, intermediate oxides such as Al ₂ O ₃ , ZrO ₂ and TiO ₂ or transition metal oxides are appropriately selected and added. is there.

  A glass ceramic green sheet is prepared by adjusting the glass powder alone or a combination of glass powder and ceramic powder as described above, specifically by adjusting the glass powder within the range of 30 to 100 mass% and the ceramic powder of 0 to 70 mass%. Thus, it is possible to obtain a sintered glass ceramic body having characteristics (mechanical characteristics, thermal characteristics, dielectric characteristics, etc.) according to the use by firing at a temperature of 800 to 1000 ° C.

  The wiring layer 2 is formed on the surface and inside of the insulating substrate 1 and is screen-printed or gravure-printed using a conductive paste containing a metal powder mainly composed of any one of gold, silver and copper. It may be formed by a metal foil transfer method or a plating method.

  Further, the through conductor 3 formed in at least the glass ceramic insulating layers 1a and 1e constituting the surface layer is made of the same metal powder as any one of gold, silver and copper similar to the wiring layer 2 as a main component. It is formed using the paste for penetrating conductors which contains, and has as a main component any one in gold | metal | money, silver, and copper.

And this penetration conductor 3 is 40-60 mass% in Si ₂ conversion, Al is 5-15 mass% in Al ₂ O ₃ conversion, Ca is 10-20 mass% in CaO conversion, and Ba is BaO conversion. It is important that the glass contains 15 to 25% by mass and 1 to 8% by mass of rare earth elements in terms of oxides.

The through conductors 3, 40 to 60 wt% of Si in terms of SiO _2, 5 to 15 wt% of Al in terms _{of Al} 2 _{O 3,} 10 to 20 wt% of Ca in terms of CaO, of Ba in terms of BaO 15-25 By including glass containing 1% by mass and 1% by mass of rare earth elements in terms of oxides, the glass transition point of the glass contained in the through conductor becomes 720 to 760 ° C. The difference in shrinkage behavior between the paste for through conductors to be the through conductors 3 and the glass ceramic green sheets to be the glass ceramic insulating layers 1a and 1e can be reduced. As described above, the glass ceramic green sheet in which glass powder alone or a combination of glass powder and ceramic powder is appropriately combined is sintered at a firing temperature of 800 ° C. to 1000 ° C. Is within the above range, the difference in shrinkage behavior can be reduced. As a result, it is possible to realize a multilayer wiring board in which the formation of a gap at the interface between the through conductor and the glass ceramic insulating layer is suppressed and the via protrusion is reduced. Moreover, the thermal expansion coefficient in 30-300 degreeC of the glass contained in a penetration conductor becomes more than 6 * 10 < ^-6 > / degreeC, and the metal powder used as the conductor component contained in the through conductor after baking, and the through conductor after baking Since the stress generated by the difference in thermal expansion with the glass powder contained in the glass is reduced, it is possible to suppress the formation of a gap at the interface between the conductor component and the glass.

  The through conductor 3 after firing preferably contains 2 to 20 parts by weight of glass with respect to 100 parts by weight of any one of gold, silver and copper, and substantially from glass. Precipitated crystals do not exist. Here, being substantially absent means that the amount is such that a diffraction peak derived from the crystal is not observed in X-ray diffraction.

  From the viewpoint of production cost, the rare earth element is preferably at least one of Y and La.

In the multilayer wiring board shown in FIG. 1, the through conductors 3 are formed so as to penetrate all the glass ceramic insulating layers 1a, 1b, 1c, 1d, and 1e, and all the through conductors 3 are made of Si. 40 to 60% by mass in terms of SiO ₂ , 5 to 15% by mass in terms of Al ₂ O ₃ , 10 to 20% by mass in terms of CaO, 15 to 25% by mass in terms of BaO, and rare earth elements Although it is desirable to include glass containing 1 to 8% by mass in terms of oxide, in the present invention, Si is 40 in terms of SiO ₂ in the through conductor 3 formed in at least the glass ceramic insulating layers 1a and 1e constituting the surface layer. 60 wt%, 5 to 15 wt% of Al in terms _{of Al} 2 _{O 3,} 10 to 20 wt% of Ca in terms of CaO, 15 to 25 wt% of Ba in terms of BaO, in terms of oxide of rare earth elements As long as it contains a glass containing 8 wt%.

  The composition of the glass contained in the through conductor 3 after sintering can be performed by using an X-ray probe microanalysis (TEM-EPMA) attached to a transmission electron microscope, fluorescent X-ray analysis (XRF), or the like. . The glass transition point of the glass can be determined by differential thermal analysis (DTA).

  Next, the manufacturing method of the multilayer wiring board of this invention is demonstrated.

  First, a plurality of glass ceramic green sheets are produced. The glass ceramic green sheet contains at least a glass powder, and the glass powder and a ceramic powder appropriately selected for obtaining desired characteristics as necessary are used as a raw material powder, an organic resin binder suitable for the raw material powder, After adding a solvent or the like, mixing is performed to obtain a slurry. From the obtained slurry, a glass ceramic green sheet is produced by a desired forming means such as a doctor blade method, a calender roll method, a rolling method or the like.

  Next, when a laminated body of a plurality of glass ceramic green sheets is produced, a through-hole is formed in the glass ceramic green sheet disposed on at least the surface layer of the laminated body, and the through-hole paste is filled in the through-hole. .

Via conductor paste, gold, and one metal powder one of silver and copper, the SiO ₂ 40 to 60 wt%, the _Al 2 _{O 3} 5 to 15 wt%, 10 to 20 wt% of CaO, A glass powder containing 15 to 25% by mass of BaO and 1 to 8% by mass of rare earth oxide and not crystallized by firing is weighed at a desired mixing ratio, and an appropriate organic resin binder, solvent, etc. After the addition, it was obtained by mixing.

  The through-conductor paste contains a glass powder that does not precipitate crystals by firing. If the glass powder precipitates crystals during firing, the firing shrinkage of the through-conductor paste simultaneously with crystallization This is because the shrinkage behavior difference between the paste for penetrating conductor and the glass ceramic green sheet cannot be reduced.

  Thus, the shrinkage | contraction behavior of the paste for penetration conductors can be controlled by selecting appropriately the glass powder added to the paste for penetration conductors. The glass powder is not particularly limited as long as it does not precipitate crystals upon firing. Examples thereof include silicate glass, borosilicate glass, borate glass, and phosphate glass, and those added with rare earth oxides. It is done.

Then, the glass powder is a SiO ₂ 40 to 60 wt%, the _Al 2 _{O 3} 5 to 15 wt%, the CaO 10 to 20 wt%, 15 to 25 wt% of BaO, 1 to 8 weight rare earth oxides % Content is important.

Here, the glass powder, SiO ₂ is 40 to 60 wt%, _Al 2 _{O 3} from 5 to 15 wt%, CaO 10 to 20 wt%, BaO 15 to 25 wt%, rare earth oxide 1-8 When deviating from the mass% range, the glass transition point exceeds the range of 720 to 760 ° C., and the difference in shrinkage behavior between the paste for penetrating conductors and the glass ceramic green sheet increases. As a result, a gap is formed at the interface and the via protrusion becomes large. In addition, the thermal expansion coefficient at 30 to 300 ° C. does not satisfy 6 × 10 ⁻⁶ / ° C. or more, and the thermal stress generated by the difference in thermal expansion between the metal powder and the glass powder increases when the temperature is lowered during firing. It becomes difficult to suppress the formation of a gap at the interface between the conductor component and the glass.

In particular, when the rare earth oxide content in the glass powder is less than 1% by mass, the coefficient of thermal expansion at 30 to 300 ° C. may not satisfy 6 × 10 ⁻⁶ / ° C. or more, and is less than 8% by mass. If the amount is too large, crystallization of the glass occurs, so that firing shrinkage is hindered, and the shrinkage behavior of the paste for penetrating conductor and the glass ceramic green sheet may be deviated. The content of the rare earth oxide is preferably 3 to 6% by mass.

  The thermal expansion coefficient can be obtained by measuring a minute dimensional change at the time of temperature rise by thermomechanical analysis (TMA).

The use of at least one of Y ₂ O ₃ and La ₂ O ₃ as the rare earth oxide is desirable in that a via hole conductor paste can be produced at a relatively lower cost than other rare earth oxides.

As other components, network forming oxides other than SiO ₂ such as B ₂ O ₃ and P ₂ O ₅ , alkali metal oxides, alkaline earth metal oxides other than CaO and BaO, modified oxides such as ZnO, ZrO ₂ Further, an intermediate oxide such as TiO ₂ or a transition metal oxide may be appropriately selected and added to such an extent that the characteristics are not impaired.

  Furthermore, you may add at least 1 sort (s) chosen from the group of Sb, As, F, N, and S as an oxide or another compound. The compound of these elements functions as a defoaming agent for glass, can reduce the void of the glass in the through conductor, and can reduce the resistance value of the through conductor.

  The addition amount of the glass powder is preferably 2 to 20 parts by mass, particularly 5 to 15 parts by mass with respect to 100 parts by mass of the conductor component, and if it is less than 2 parts by mass, the paste for penetrating conductor and the glass ceramic The effect of reducing the difference in shrinkage behavior with the green sheet may be insufficient, and when the amount is more than 20 parts by mass, the resistance of the through conductor may be too high.

  Next, on a desired glass ceramic green sheet, a conductor pattern to be a wiring layer is formed by screen printing or gravure printing using a conductor paste containing a metal powder mainly composed of any one of gold, silver and copper. Form by the method. This conductor paste is preferably made to have a different viscosity by making the organic binder, the organic solvent, and their amounts different from those of the through conductor paste. This conductor pattern may be formed by a metal foil transfer method or a plating method.

  Next, a glass ceramic green sheet in which the through-hole paste is filled in the through hole is arranged at least on the surface layer to produce a laminate of a plurality of glass ceramic green sheets. Specifically, a plurality of glass ceramic green sheets are aligned and pressed and laminated using a thermocompression bonding method or a laminating aid.

  Finally, the laminate is fired.

  Here, in order to remove the organic resin binder component blended for molding from the laminate, when gold or silver is used as the conductor component of the through conductor paste, the laminate is heated to about 500 ° C. in the atmosphere. The temperature is raised so that there is no delamination of the laminated interface, the temperature is kept at around 500 ° C. as necessary, then the temperature is raised again to around 900 ° C. in the atmosphere, and the maximum temperature of firing is 0.2 to 10 hours. In particular, the multilayer wiring board of the present invention is obtained by baking for 0.5 to 5 hours.

  On the other hand, when copper is used as the conductor component of the paste for through conductors, the temperature is raised to about 700 ° C. in a nitrogen atmosphere so as not to peel off the laminated interface of the laminate, and if necessary, at about 700 ° C. The multilayer wiring board of the present invention is obtained by holding and subsequently heating again to around 900 ° C. in a nitrogen atmosphere and firing at the highest firing temperature for 0.2 to 10 hours, particularly 0.5 to 5 hours. .

  In addition, the 1st glass ceramic green sheet containing the 1st glass powder from which a glass transition point differs, and the 2nd glass ceramic green sheet containing the 2nd glass powder are produced, a through-hole is formed in each, and this penetration After filling the holes with the above paste for through conductors and forming a wiring layer using the conductor paste, the first glass ceramic green sheets and the second glass ceramic green sheets are alternately laminated, and the same as above The multilayer wiring board of the present invention can also be obtained by baking.

  Since the glass transition points of the glass powders contained in the first glass ceramic green sheet and the second glass ceramic green sheet are different, the first glass ceramic green sheet and the second glass ceramic green sheet are subjected to firing shrinkage start temperature and firing. Different shrinkage end temperatures. Therefore, when these are alternately laminated and fired, the shrinkage in the planar direction can be suppressed mainly by shrinking in the laminating direction, and a multilayer wiring board with high dimensional accuracy can be obtained. However, on the other hand, since the shrinkage in the plane direction is suppressed, gap formation at the interface between the through conductor and the glass ceramic insulating layer, increase in via protrusion, and gap generation at the interface between the conductor component in the through conductor and glass are generated. Since it becomes remarkable, the manufacturing method of the present invention is effective for solving these problems.

  Glass raw material powder is weighed and mixed so as to have the composition shown in Table 1 after being heated and melted and rapidly cooled, then heated and melted and rapidly cooled, and then glass having an average particle diameter of 2 μm by ball milling. A powder was prepared. In addition, in Table 1, while showing the mass ratio when the whole is 100 mass%, the glass transition point and thermal expansion coefficient of each glass powder were also shown.

  In addition, a bulk body that has been rapidly cooled and removed without pulverizing the ball mill and cut and ground to a size of 5 × 5 × 10 mm is heat-treated in the atmosphere at 900 ° C. for 1 hour. Then, a pulverized sample was prepared, and the presence or absence of precipitated crystals was measured using powder X-ray diffraction (XRD). The results are shown in Table 1.

  On the other hand, metal powder having an average particle diameter of 5 μm of the type shown in Table 2 was prepared.

  And according to Table 2, the said glass powder and the said metal powder were weighed, and the paste for penetrating conductors was produced by selecting and adjusting suitably the organic binder which consists of methacrylic resin, an organic solvent, and a dispersing agent.

Next, SiO ₂ —Al ₂ O ₃ —MgO—CaO-based glass powder and alumina powder are appropriately selected and adjusted, and the raw material powder is weighed and mixed with an organic binder composed of a methacrylic resin, a plasticizer and a solvent. The obtained slurry was molded by a doctor blade method so that the thickness of the fired glass ceramic insulating layer was 100 μm, and a glass ceramic green sheet was obtained.

  A through hole is formed in the glass ceramic green sheet using a laser processing machine so that the diameter after firing becomes 100 μm, and the through conductor paste is filled in the through hole by a screen printing method. A wiring pattern was formed on the green sheet by a screen printing method using a conductor paste containing the same conductor component as that of the through conductor paste.

  When a predetermined number of glass ceramic green sheets thus produced are aligned and laminated by thermocompression bonding, and gold or silver is used for the through-conductor paste and the conductor paste, 2 at 500 ° C. in the atmosphere. After performing the binder removal treatment by holding the time, a multilayer wiring board was obtained in the atmosphere at 900 ° C. for 1 hour. On the other hand, when copper is used for the paste for through conductors and the conductor paste, the binder removal treatment is performed by holding at 700 ° C. for 2 hours in water vapor containing nitrogen, and then at 900 ° C. in water vapor containing nitrogen. A multilayer wiring board was obtained under conditions of 1 hour.

  In addition, as a sample shape of the obtained multilayer wiring board, the length is 35 mm, the width is 35 mm, and the thickness is 800 μm (8 layers of the green sheets are laminated). A total of 100 conductors were arranged in 10 rows and 10 rows at 300 μm intervals when viewed from above, and a wiring layer was arranged on the surface so as to completely cover the conductors.

  The obtained multilayer wiring board is immersed in a fluorescent flaw detection liquid for 2 hours under reduced pressure, 30 μm is removed from the surface by dry polishing, and then irradiated with ultraviolet light to determine whether the fluorescent flaw detection liquid has entered the through conductor. The results are shown in Table 2.

  Moreover, the shape of the multilayer wiring board is measured using a three-dimensional shape measuring machine with respect to an arbitrary through conductor of the obtained multilayer wiring board, and the flat portion of the multilayer wiring board is used as a base line, which is the highest than that line. The height difference from the part was measured as a via protrusion, and the results are shown in Table 2. In addition, the result shown in Table 2 calculated | required those average values by making n number into 5 (5 pieces), and made 10 micrometers or less pass.

  Furthermore, as a comparative sample, samples prepared by the same method as described above were prepared according to Tables 1 and 2, and the same evaluation was performed (Sample Nos. 1, 5, and 16-18).

As is apparent from Table 2, the sample No. corresponding to the scope of the present invention. 2～4,6～15,19～22 is in the through conductor paste, a SiO ₂ 40 to 60 wt%, the _Al 2 _{O 3} 5 to 15 wt%, 10 to 20 wt% of CaO, the BaO 15 It contains ~ 25 mass%, rare earth oxide 1-8 mass%, and contains glass powder that does not precipitate crystals by firing, so the shrinkage behavior difference between the paste for through conductors and the glass ceramic green sheet can be reduced In addition, since the stress caused by the difference in thermal expansion between the metal powder and the glass powder can be reduced, it was possible to produce a multilayer wiring board having no penetration of moisture in the through conductor and having small via protrusions.

  On the other hand, the sample No. 5 outside the scope of the present invention in which the rare earth oxide content in the glass powder is less than 1%. No. 1 and a sample no. No. 16 has a low glass transition point, and the penetration of the zygote liquid was confirmed at the interface between the through conductor and the glass ceramic insulating layer, and the via protrusion was 10 μm or more. And sample no. For No. 16, since the coefficient of thermal expansion was small, it was confirmed that the grouting liquid entered the interface between the conductor component and the glass in the through conductor.

  In addition, the sample No. in which the content of the rare earth oxide in the glass powder is more than 8% by mass outside the scope of the present invention. In No. 5, crystallization occurred, and the penetration of the zygote liquid was confirmed at the interface between the through conductor and the glass ceramic insulating layer, and the via protrusion became 10 μm or more.

And the sample No. in which the composition of the glass powder greatly deviates from outside the range. In No. 17, crystallization occurred, and the penetration of the zygote liquid was confirmed at the interface between the through conductor and the glass ceramic insulating layer, and the via protrusion became 10 μm or more.
Zaiguro liquid intrusion occurred, and the via protrusion became large.

  In addition, Sample No. which does not contain glass powder in the through conductor paste. In No. 18, the difference in shrinkage behavior between the through-conductor paste and the glass ceramic green sheet was increased, and the penetration of zygrote was confirmed at the interface between the through-conductor and the glass ceramic insulating layer, and the via protrusion was 10 μm or more. .

It is a schematic longitudinal cross-sectional view which shows one Embodiment of the multilayer wiring board of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation base | substrate 1a, 1b, 1c, 1d, 1e Glass ceramic insulation layer 2 Wiring layer 3 Through-conductor

Claims (4)

Penetrations the plurality of glass ceramic insulating layer is obtained by firing the insulating substrate are laminated, is provided in the glass ceramic insulating layer constituting at least a surface layer of the insulating substrate, and the via conductor paste In a multilayer wiring board provided with a conductor,
The through-conductor paste is
A metal powder mainly composed of any one of gold, silver and copper;
40-60 wt% of Si in terms of SiO _2, 5 to 15 wt% of Al in terms _{of Al} 2 _{O 3,} 10 to 20 wt% of Ca in terms of CaO, 15 to 25 wt% of Ba in terms of BaO, rare earth elements And a glass powder containing 1 to 8% by mass in terms of oxide.   The multilayer wiring board according to claim 1, wherein the rare earth element is at least one of Y and La. Producing a plurality of glass ceramic green sheets;
When producing a laminate of the plurality of glass ceramic green sheets, a through-hole is formed in the glass ceramic green sheet disposed on at least the surface layer of the laminate, and the through-hole is made of gold, silver, and copper. a metal powder mainly composed of any one, a SiO ₂ 40 to 60 wt%, the _Al 2 _{O 3} 5 to 15 wt%, 10 to 20 wt% of CaO, 15-25 wt% of BaO, rare earth a step of filling the oxide 1-8 mass% content Suruga Las powder and via conductor paste containing,
A step of producing a laminated body of the plurality of glass ceramic green sheets by disposing at least a glass ceramic green sheet filled with the through conductor paste in the through holes on a surface layer;
Method for manufacturing a multilayer wiring board, characterized in that and a step of firing the laminate. Method for manufacturing a multilayer wiring board according to claim 3, characterized by using at least one of Y ₂ O ₃ and La ₂ O ₃ as the rare earth oxide.

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