JP5404470B2 - Glass ceramic wiring board - Google Patents

Description

  The present invention relates to a glass ceramic wiring board having a low-resistance wiring layer mainly composed of copper, which is applied to a package for housing a semiconductor element or a high-frequency module board used in the field of mobile communication.

  FIG. 5 is a schematic cross-sectional view showing a glass ceramic wiring board. 6 is an enlarged cross-sectional view of a region A surrounded by a broken line in the schematic cross-sectional view of the glass-ceramic wiring board of FIG. FIG. 7 is an enlarged plan view of a region A surrounded by a broken line in the schematic cross-sectional view of the glass ceramic wiring board of FIG.

  The glass ceramic wiring board B includes an insulating substrate 101 in which a plurality of glass ceramic insulating layers 111, 112, 113, and 114 are laminated, a through conductor 103 that passes through the glass ceramic insulating layers 111, 112, 113, and 114, and an insulating substrate. An internal wiring layer 104 formed inside 101 and a surface wiring layer 105 formed on upper and lower surfaces which are main surfaces of the insulating substrate are provided.

  In such a glass ceramic wiring board B, the surface wiring layer 105a on the upper surface side of the surface wiring layers 105 formed on the upper and lower surfaces of the insulating substrate 101 serves as a wiring layer for mounting semiconductor elements, electronic components, and the like. On the other hand, the lower surface side surface wiring layer 105b serves as a wiring layer for forming connection terminals 106 for connection to an external circuit board. A ceramic film is formed as a protective layer 107 for increasing the metallization strength of the surface wiring layer 105 from the peripheral edge 105c of the surface wiring layer 105 formed on the upper and lower surfaces of the insulating substrate 101 to the surface 101c of the surrounding insulating substrate 101. Is formed to cover a part of the surface wiring layer 105.

  Such a glass ceramic wiring board B uses a glass ceramic material as the insulating substrate 101, and the through conductor 105, the internal wiring layer 104 and the surface wiring layer 105 have a low melting point and a low resistance copper. The insulating base 101, the through conductor 103, the internal wiring layer 104, and the surface wiring layer 105 are integrated by simultaneous firing (see, for example, Patent Documents 1 to 5).

  The glass-ceramic wiring board obtained in this way is free from defects such as voids on the surface substrate in order to improve moisture resistance, and has the purpose of improving the connection reliability with semiconductor elements and external circuit substrates. There is a demand for a glass-ceramic wiring board having high metallization strength of the layer 105 and high flatness of the substrate surface.

Such a glass ceramic wiring board B is manufactured by the following processes. First, after forming a glass ceramic green sheet containing a glass ceramic material as a main component, through holes are formed in the glass ceramic green sheet, and a conductive paste is filled. Next, the conductor paste is printed on the main surface of the glass ceramic green sheet in which the through-holes are filled with the conductor paste to form each conductor pattern that becomes the internal wiring layer 104 or the surface wiring layer 105. Here, a ceramic pattern including a glass component and a filler component is printed on the peripheral portion 105c of the conductive pattern to be the surface wiring layer 105 and the surface of the surrounding glass ceramic green sheet, and the ceramic pattern that becomes a ceramic film after firing Form. Next, a laminated body is formed by laminating a plurality of glass ceramic green sheets on which the conductor patterns to be the through conductor 103, the internal wiring layer 104, and the surface wiring layer 105 are formed, and then the laminated body is subjected to predetermined conditions. The base body of the multilayer wiring board is formed by firing. Next, the glass ceramic wiring board B can be obtained by forming a plating film on the surface of the surface wiring layer 105 formed on the surface of the element body of the multilayer wiring board.

JP 2004-231454 A JP-A-10-190178 JP 2003-163427 A JP 2009-238884 A JP 2009-206233 A

  However, in the glass-ceramic wiring board B disclosed in the above publication, spots called black sesame occur on the protective layer 107 covering the peripheral edge portion 105 c of the surface wiring layer 105, or the surface wiring of the protective layer 107. The appearance that the components of the ceramic sheet used to cover the product during firing adhere to the surface of the protective layer 107 covering the surface 101c of the insulating base 101 located around the peripheral edge portion 105c of the layer 105. There was a problem that defects were likely to occur. In order to deal with such a problem, a method for selecting a ceramic wiring substrate body immediately after firing by appearance inspection and a method for polishing a portion having a poor appearance for minor ones have been adopted so far. .

  In addition, the spots called black sesame are diffused in the protective layer 107, copper, which is a conductive material forming the surface wiring layer 105, during the baking in manufacturing the multilayer wiring board B, and the etching solution is used during the plating process. The reason is that the components of the ceramic sheet adhere to the surface of the protective layer 107 that covers the surface 101c of the insulating substrate 101. The components of the protective layer 107 partially melt during firing. This is due to the reaction with the components of the ceramic sheet placed on the upper surface.

  The present invention has been made in view of the above circumstances, and there is no defect such as a void in the protective layer covering the surface wiring layer, the surface wiring layer has high metallization strength and flatness, and is formed on the surface of the insulating substrate. Glass ceramic wiring that has no spots called black sesame on the protective layer side that covers the peripheral edge of the surface wiring layer formed, and that does not adhere components of the ceramic sheet to the surface of the protective layer covering the surface of the insulating substrate An object is to provide a substrate.

The multilayer wiring board of the present invention partially covers a ceramic insulating layer, a surface wiring layer formed on the surface of the ceramic insulating layer, a peripheral portion of the surface wiring layer, and the ceramic insulating layer around it. A protective wiring layer, wherein the protective layer in a portion covering the surface wiring layer has a SiO ₂ filler of 27.7 to 31.7% by mass and chromium oxide of 1%. 0.0 to 1.2% by mass, ₂ to 31.0% by mass of SiO ₂ in the balance, 5.0 to 7.0% by mass of Al ₂ O _3, and 1.0 to 2.0% of CaO %, BaO 14.0-16.0 mass%, MgO 13.0-16.0 mass%, SrO 0.5-1.5 mass% and ZrO 0.5-0.8 mass% A glass component, and partially covering the ceramic insulating layer That said protective layer comprises 27.7 to 31.7 wt% of SiO ₂ filler, and 1.0 to 1.2 mass% of chromium oxide, the SiO ₂ to the remainder from 32.0 to 34.0 wt% Al ₂ O ₃ is 6.5 to 8.0 mass%, CaO is 9.0 to 12.0 mass%, BaO is 15.0 to 18.0 mass%, and SrO is 1.5 to 3.0 mass%. % Glass component.

  In the glass-ceramic wiring board, the outer shape of the surface wiring layer is preferably circular, and the protective layer is preferably formed concentrically with respect to the center of the surface wiring layer.

  In the glass ceramic wiring board, the width W of the protective layer covering the surface wiring layer is preferably 4% ≦ W / D ≦ 13% with respect to the diameter D of the surface wiring layer. .

  According to the glass ceramic wiring board of the present invention, the surface of the substrate is free from defects such as voids, the surface wiring layer has a high metallization strength and flatness, and covers the periphery of the surface wiring layer formed on the surface of the insulating substrate. On the layer side, there can be obtained a glass-ceramic wiring board having no spots called black sesame and having no ceramic sheet components attached to the surface of the protective layer covering the surface of the insulating substrate.

It is a schematic sectional drawing of one Embodiment of the glass-ceramic wiring board of this invention. It is an enlarged view of the area | region A enclosed with the broken line shown in FIG. It is a top view of the area | region A enclosed with the broken line shown in FIG. 1, and is a structure where the protective layer is arrange | positioned concentrically with respect to the surface wiring layer. It is a top view which shows the other structure of the arrangement | positioning which a protective layer does not have a concentric position with respect to a surface wiring layer. It is a schematic sectional drawing of one Embodiment of the conventional glass ceramic wiring board. It is an enlarged view of the area | region B enclosed with the broken line shown in FIG. FIG. 6 is a plan view of a region B surrounded by a broken line shown in FIG. 5, in which the protective layer is concentrically arranged with respect to the surface wiring layer.

  Hereinafter, an embodiment of a ceramic wiring board of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an embodiment of the glass ceramic wiring board of the present invention. FIG. 2 is an enlarged view of a region A surrounded by a broken line shown in FIG.

  A glass ceramic wiring board A shown in FIG. 1 includes an insulating substrate 1 in which a plurality of glass ceramic insulating layers 11, 12, 13, and 14 are laminated, and surface wiring layers 2 and 3 provided on the main surface of the insulating substrate 1. It has. The main surface of the insulating substrate 1 is the surface of the widest area of the insulating substrate 1 and refers to the upper and lower surfaces shown in FIG.

The insulating base 1 is formed by laminating a plurality of glass ceramic insulating layers 11, 12, 13, and 14. The glass ceramic insulating layers 11, 12, 13, and 14 are formed of glass ceramics. For example, the glass ceramic insulating layers 11, 12, 13, and 14 have a high thermal expansion coefficient (13 × 10 ⁻⁶ / ⁶ ) excellent in secondary mounting reliability with a printed wiring board (motherboard). Glass ceramics containing quartz having a main crystal of [15 ° C. to 15 × 10 ⁻⁶ / ° C.] are employed. In addition, since quartz has a low relative dielectric constant in the vicinity of room temperature, it has an advantage that transmission signal attenuation in a high frequency region can be suppressed and transmission loss due to signal delay can be reduced. In addition to quartz, crystals such as serdian and enstatite may exist in the insulating substrate 1, and the presence of these crystals also contributes to an improvement in the thermal expansion coefficient of the insulating substrate 1.

A surface wiring layer (ball pad portion) 2 is provided on the main surface of the insulating base 1, and an internal wiring layer 4 is provided inside the insulating base 1. Further, a protective layer 231 and a protective layer 232 are formed adjacent to each other on the same plane in the peripheral portion of the surface wiring layer 2. Here, the protective layer 231 formed on the peripheral portion of the surface wiring layer 2 is a film made of glass ceramic whose sinterability is enhanced in order to ensure the plating property, while the protective layer 232 is the main layer. In addition, it is a glass ceramic film with reduced reactivity in order to suppress an excessive reaction with a component of a ceramic sheet (hereinafter referred to as a setter) used to cover a product which is a glass ceramic wiring board during firing. A plurality of plating layers (Pd plating layer 21, Ni plating layer 22, and Au plating layer 23) are formed on the upper side of the surface wiring layer 2 (on the side opposite to the insulating substrate 1 side).

Here, the protective layer 231 covering the surface wiring layer 2 includes 27.7 to 31.7% by mass of silica (SiO ₂ ) filler and 1.0 to 1 of chromium oxide (Cr ₂ O ₃ ). .2% by mass and the remaining glass component, and the composition of the glass component is 28.0 to 31.0% by mass of SiO ₂ and 5.0 to 7.0 mass of Al ₂ O _3. %, CaO 1.0-2.0 mass%, BaO 14.0-16.0 mass%, MgO 13.0-16.0 mass%, SrO 0.5-1.5 mass% and It contains 0.5 to 0.8% by mass of ZrO.

The protective layer 232 partially covering the glass ceramic insulating layers 11, 12, 13, and 14 includes 27.7 to 31.7% by mass of SiO ₂ filler and 1.0 to 1 of chromium oxide. 0.1% by mass and the remaining glass component, and the composition of the glass component is 32.0 to 34.0% by mass of SiO ₂ and 6.5 to 8.0% by mass of Al ₂ O _3. %, CaO 9.0 to 12.0 mass%, BaO 15.0 to 18.0 mass% and SrO 1.5 to 3.0 mass%.

As a result, the metallization strength of the surface wiring layer 2 is 5 kgf / mm ² or more and the flatness is 80 μm or less, and on the protective layer 231 side covering the peripheral edge of the surface wiring layer 2 formed on the surface of the insulating substrate 1, It is possible to obtain a glass-ceramic wiring board A having no spots called sesame and having no setter component adhered to the surface of the protective layer 232 covering the surface of the insulating substrate 1.

  Moreover, in the glass ceramic wiring board A of this embodiment, when the composition of the glass phase contained in the protective layer 231 coated on the surface wiring layer 2 is in the above range, the protective layer 231 is sintered by the diffusion of copper. Deterioration can be suppressed, erosion of the glass etching solution and copper etching can be prevented, and the plating property can be improved. Here, improving the plating property means a state in which there are no spots such as black sesame after plating a conductor layer such as the surface wiring layer 2.

  Moreover, when the composition of the glass phase contained in the protective layer 232 that partially covers the glass ceramic insulating layers 11, 12, 13, and 14 is within the above range, the excessive reaction between the product and the setter is suppressed. It is possible to prevent the setter from adhering, and at the same time, it is possible to suppress coarse voids generated due to the decrease in the sinterability of the protective layer covering the insulating layer. The glass phase contained in the protective layer 231 and the protective layer 232 is amorphous, and there is almost no recrystallization from the raw glass powder.

  On the other hand, when the content of chromium oxide contained in the protective layer 231 covering the surface wiring layer 2 is less than 1.0% by mass, the protective layer 23 is printed on the surface wiring layer 2. In addition, since the green coloring is weakened, it is difficult to print on the surface wiring layer 2 with high accuracy, and there is a possibility that strength deterioration may occur due to printing failure of the protective layer 23.

  On the other hand, when the content of chromium oxide is more than 1.1% by mass, green spots are generated on the protective layer 231 due to poor dispersion of the ink paste due to excessive pigment, and poor appearance due to adhesion of ceramic components from the setter. May be incurred.

When the content of silica (SiO ₂ ) is less than 27.7% by mass, the protective layer 231 covered with the surface wiring layer 2 is easily sintered, so that setter adhesion is likely to occur. At the same time, the behavior of firing shrinkage between the surface wiring layer 2 and the protective layer 23 is not matched, and there is a possibility that voids or voids are generated between the surface wiring layer 2 and the protective layer 23.

On the other hand, when the mass of silica (SiO ₂ ) is greater than 31.7% by mass, the liquid phase of the glass is insufficient with respect to the surface area of the silica (SiO ₂ ) powder, which is a filler. As the sinterability of the protective layer 23 decreases, black sesame is likely to occur after plating.

When the content of SiO ₂ in the glass component is less than 28.0% by mass, when the content of Al ₂ O ₃ is less than 5.0% by mass, the content of CaO is more than 2.0% by mass The BaO content is less than 14.0% by mass, the MgO content is more than 16% by mass, the SrO content is less than 0.5% by mass, and the ZrO ₂ content. Is less than 0.5% by mass, the flatness is impaired and the warpage is increased to 80 μm or more.

On the other hand, when the content of SiO ₂ in the glass component is more than 31.0% by mass, when the content of Al ₂ O ₃ is more than 7.0% by mass, the content of CaO is less than 1% by mass. The BaO content is more than 16.0% by mass, the MgO content is less than 13% by mass, the SrO content is more than 1.5% by mass, and the ZrO2 content is When the amount is more than 0.8% by mass, the sinterability of the protective layer 231 covering the surface wiring layer 2 is lowered, and thus black sesame appearing after plating is likely to occur on the surface of the protective layer 231. .

  Further, the protective layer 232 partially covering the glass ceramic insulating layers 11, 12, 13, and 14 also has a reduced metallization strength of the protective layer 231 when the chromium oxide content is less than 1.0 mass%. On the other hand, when the mass of chromium oxide is more than 1.1% by mass, there is a risk of appearance failure due to adhesion of the ceramic component from the setter.

When the content of silica (SiO ₂ ) is less than 27.7% by mass, the protective layer 232 is easily sintered excessively, so that setter adhesion is likely to occur.

On the other hand, when the mass of silica (SiO ₂ ) is more than 31.7% by mass, the sinterability of the protective layer 232 is reduced, so that coarse voids are easily formed on the substrate surface. Sesame is likely to occur.

When the content of SiO ₂ in the glass component is less than 32.0% by mass, when the content of Al ₂ O ₃ is less than 6.5% by mass, the content of CaO is more than 12.0% by mass. In the case where the BaO content is less than 15.0% by mass, the MgO content is more than 16% by mass, and the SrO content is less than 1.5% by mass, all are flat. The degree of warpage is increased and warping is increased to 80 μm or more, and adhesion of setters is likely to occur.

On the other hand, when the content of SiO ₂ in the glass component is more than 34.0% by mass, when the content of Al ₂ O ₃ is more than 8.0% by mass, the content of CaO is more than 9.0% by mass. When the content of BaO is more than 18.0% by mass and when the content of SrO is more than 3.0% by mass, the sinterability of the protective layer 232 is reduced and coarse voids are formed. Since it becomes easy to generate | occur | produce, it will become easy to generate | occur | produce the black sesame which appears on the surface of the protective layer 232 after plating.

Further, in the glass ceramic wiring board A, since the insulating substrate 1 is sintered at a temperature of 1000 ° C. or lower, the main component of the surface wiring layer 2 is low melting point and low resistance copper. Here, the surface wiring layer 2 may contain other metals, oxides, ceramics, and the like as long as electrical resistance and thermal conductivity are not deteriorated.

The glass ceramic insulating layer 11, 12, 13, 14 constituting the insulating substrate 1, SiO ₂ 30 to 50 _wt%, B 2 _{O 3} is 5 to 15 wt%, _Al 2 _{O 3} is 8.0 mass %, MgO 10.0 to 25% by mass, CaO 0.5 to 3% by mass, BaO 10 to 25% by mass, SrO 0.5 to 2.0% by mass and ZrO ₂ 0.5 to ₂ %. It is good that it is mass%.

  The surface wiring layer 2 provided on the surfaces of the glass ceramic insulating layers 11, 12, 13, and 14 constituting the insulating base 1 is composed of 94.9 to 95.8% by mass of copper, and 3.2 to 4 .2% by mass of glass phase and 0.5 to 1.4% by mass of fused silica phase should be included, and the internal wiring layer 4 should have the same composition.

Further, the glass phase contained in the surface wiring layer 2 has Si of 48.0 to 51.0% by mass in terms of SiO ₂ and Al of Al ₂ O, when the total of the components contained therein is 100% by mass. ₃ to 9.8 to 10.2% by mass, Mg to 0.1 to 0.3% by mass in terms of MgO, Ca to 14.0 to 16.0% by mass in terms of CaO, and Ba to 21.O in terms of BaO. It is good that it is 0-24.0 mass% and Sr is 2.4-3.0 mass% in conversion of SrO. In addition, the glass phase contained in the surface wiring layer 2 is the one in which the amorphous glass as the raw material remains, and the content of each component is the same as the glass composition of the raw material.

  When the ratio of each component contained in the glass phase of the surface wiring layer 2 is in the above range, unevenness of the main surface of the glass ceramic wiring board (insulating base 1) due to fluctuations in shrinkage behavior is suppressed. Further, since glass is appropriately present on the surface included in the surface wiring layer 2, oxidation of the surface included in the surface wiring layer 2 is suppressed, and generation of an oxide film (copper oxide) is suppressed. . As a result, the formation (Pd adsorption) of the Pd plating layer 21 performed after etching the copper, which is the metal component contained in the surface wiring layer 2, becomes favorable, and further the formation of the Ni plating layer 22 and the Au plating layer 23 later. Will be good.

  Here, as for the composition of the protective layer 23, for example, a sample to be analyzed is cut and this cross section is polished, and an image is analyzed by a scanning electron microscope (SEM). It can be calculated by separating the fillers and determining the area ratio. Further, the content of each component contained in the glass phase can be calculated by performing energy dispersive X-ray spectroscopic analysis (EDS) on a part of the glass phase in a spot manner.

  Also, the composition of the surface wiring layer 2 is obtained by the same method. In this case, first, copper and glass phase are separated on the screen of the observed structure, and the area ratio is obtained. Further, the content of each component contained in the glass phase is obtained by performing energy dispersive X-ray spectroscopic analysis (EDS) on a part of the glass phase in a spot manner.

  A Pd plating layer 21, a Ni plating layer 22, and an Au plating layer 223 are formed in this order from the insulating substrate 1 side on the surface of the surface wiring layer 2 constituting the ceramic wiring board A of this embodiment to form the plating layer 22. Has been. This plating layer is formed for the purpose of preventing the surface wiring layer 2 from being oxidized and improving the bonding strength with the mounted component.

  3 is a plan view of a region A surrounded by a broken line shown in FIG. 1, and has a structure in which the protective layer is concentrically arranged with respect to the surface wiring layer. FIG. 4 is a plan view showing another structure in which the protective layer is not positioned concentrically with respect to the surface wiring layer.

  In the ceramic wiring board A of this embodiment, the outer shape of the surface wiring layer 2 is circular, and the protective layer 23 formed on the surface of the surface wiring layer 2 is at the center of the surface wiring layer 2. On the other hand, it is desirable to form it concentrically. When the outer shape of the surface wiring layer 2 is circular and the protective layer 23 is formed concentrically with respect to the center of the surface wiring layer 2, there is an advantage that the metallization strength of the surface wiring layer 2 can be increased. . Here, the protective layer 23 formed on the peripheral portion of the surface wiring layer 2 is formed concentrically with respect to the center of the surface wiring layer 2, as shown in FIG. The width W of the peripheral portion occupied by the protective layer 231 is the same as that of the diameter D. On the other hand, the state that the protective layer 23 formed on the peripheral portion of the surface wiring layer 2 is not concentric with the center of the surface wiring layer 2 is a surface conductor as shown in FIG. With respect to the diameter D of the layer 2, the width W of the peripheral edge occupied by the protective layer 231 is different from that of the circumferential surface and has different widths W 1 and W 2.

  In the ceramic wiring board A of this embodiment, the width W of the protective layer 23 formed on the surface of the surface wiring layer 2 is 4% ≦ W / D ≦ 13% with respect to the diameter D of the surface wiring layer 2. It is desirable that When the width W of the protective layer covering the surface wiring layer 2 with respect to the diameter D of the surface wiring layer 2 has a relationship of 4% ≦ W / D ≦ 13%, the warp of the ceramic wiring board A is reduced to 70 μm or less. There is an advantage that the flatness can be increased.

  In addition, the measuring method of curvature (flatness) is measured using the laser displacement meter with respect to the main surface of the element | base_body of the ceramic wiring board after baking.

  The metallization strength of the surface wiring layer 2 is measured using a tensile tester (“MODEL-1310DW” manufactured by AIKO ENGINEERING) on a pattern for strength measurement by bonding a Cu pin using eutectic solder. Determine the breaking strength by pulling.

  The presence or absence of coarse voids in the protective layer 232 is determined by performing a red check test on the body of the glass ceramic wiring board after firing. The red check test is a method of immersing a sample to be evaluated in a red-based solution and then confirming the discoloration of the sample after washing. The presence or absence of existing voids can be confirmed. If a colored portion is seen after the red check test, it is determined here that there is a void.

  Next, a method for manufacturing a ceramic wiring board will be described.

  First, glass powder and a ceramic filler for preparing a glass ceramic green sheet are prepared.

The glass powder, a SiO ₂ 35 to 45 _wt%, the B 2 _{O 3} 5 to 10 wt%, the _Al 2 _{O 3} 6 to 10 wt%, the MgO 15-25 wt%, 1-3 mass CaO %, BaO 17 to 23% by mass, SrO 0.5 to 2% by mass and ZrO ₂ 0.5 to 1.5% by mass powder having an average particle size of 2.0 to 5.0 μm is used. This glass is a crystalline glass on which celsian and enstatite are precipitated by firing.

As the ceramic filler, SiO ₂ (quartz), which is a crystal extremely effective for increasing the thermal expansion, is used. The average particle size of the ceramic filler is preferably 3.5 to 5.0 μm, and the specific surface area is preferably 1.5 to ^2.5 cm ² / g.

Next, a glass ceramic green sheet is produced by mixing 60 to 70% by mass of glass powder, 30 to 40% by mass of ceramic filler, and 0.9 to 1.3% by mass of chromium oxide. Specifically, an appropriate organic binder and organic solvent are mixed with a mixture of glass powder, ceramic filler, and chromium oxide (total 100 mass%) 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, a through hole is formed in the obtained glass ceramic green sheet by punching or laser processing. The through hole is filled with a conductor paste for a through conductor containing copper powder as a main component.

  Also, on the desired glass ceramic green sheet, a conductive pattern for the surface wiring layer or the internal wiring layer is formed by screen printing or gravure printing using a wiring layer conductive paste containing copper powder as a main component. To do.

  Next, a protective layer pattern to be the protective layer 231 covering the surface wiring layer 2 is formed on the peripheral portion of the conductor pattern for the surface wiring layer 2 by screen printing using a protective layer paste. .

  Next, the glass ceramic insulating layers 11, 12, 13, and 14 are partially applied around the protective layer pattern that becomes the protective layer 231 covering the surface wiring layer 2, using a protective layer paste. A pattern for the covering protective layer 232 is formed.

  Here, the conductive paste for forming the surface wiring layer 2 and the internal wiring layer 4 has an average particle size of 1.6 to 2. 5 with respect to 100 parts by mass of copper powder having an average particle size of 4.5 to 5.5 μm. 3.5 to 4.5 parts by mass of 0 μm glass powder, 0.5 to 2.0 parts by weight of fused silica having an average particle size of 1.0 to 1.5 μm as filler, and an average particle size of 2.0 to 5. It is prepared by adding a predetermined amount of an organic binder and an organic solvent to a mixture obtained by adding 2.5 to 4.0 parts by weight of 0 μm cuprous oxide.

Wherein the composition of the glass powder added to the conductor paste, Si is from 48.0 to 51.0 wt% in terms of SiO _2, 9.8 to 10.2 wt% of Al is in terms _{of Al} 2 _{O 3,} Mg is MgO 0.1 to 0.3% by mass in terms of Ca, 14.0 to 16.0% by mass in terms of CaO, 21.0 to 24.0% by mass in terms of BaO, and 2.4 in terms of SrO. It is preferable that it is -3.0 mass%.

Next, the paste for the protective layer 231 that covers the surface of the surface wiring layer 2 contains 27.7 to 31.7% by mass of SiO ₂ filler having an average particle size of 2.0 to 4.0 μm, and chromium oxide. An organic binder, an organic solvent, etc. are added to a mixed powder composed of 67.3 to 71.2% by mass of glass powder having an average particle size of 3.0 to 4.0 μm and 1.0 to 1.2% by mass. And kneaded. Here glass powder of SiO ₂ 28.0 to 31.0 wt%, Al2 O3 and 5.0 to 7.0 mass%, the CaO 1.0 to 2.0 wt%, a BaO from 14.0 to 16. It is composed of 0 mass%, MgO 13.0 to 16.0 mass%, SrO 0.5 to 1.5 mass%, and ZrO 0.5 to 0.8 mass%. Here, as for the glass component contained in the paste for protective layers 231, what has a glass transition point of 670-690 degreeC is desirable.

If the content of the SiO ₂ filler contained in the paste for the protective layer 231 is less than 27.7% by mass, the protective layer 231 that covers the surface wiring layer 2 is likely to be excessively sintered. Of the surface wiring layer 2 and the protective layer 23 become incompatible with each other, which may cause voids and voids between the surface wiring layer 2 and the protective layer 23. .

On the other hand, when the mass of silica (SiO ₂ ) is greater than 31.7% by mass, the liquid phase of the glass is insufficient with respect to the surface area of the silica (SiO ₂ ) powder, which is a filler. When the sinterability of the protective layer 23 is lowered, there is a possibility that black sesame is likely to occur after plating.

  When the content of chromium oxide contained in the paste for the protective layer 231 is less than 1.0% by mass, the protective layer 231 is excessively sintered and adhesion of setters is often observed.

  On the other hand, when the content of chromium oxide is more than 1.1% by mass, the sinterability of the protective layer 231 decreases, and black sesame appearing after plating on the surface of the protective layer 231 is likely to occur.

When the content of SiO ₂ is less than 28.0% by mass, it becomes difficult for the glass to form a three-dimensional network structure, so that the viscosity of the glass may be lowered. On the other hand, when the content of SiO ₂ is more than 31.0% by mass, the glass skeleton becomes firm, but conversely, the liquidus temperature of the glass is excessively increased. There is a risk that the density will be low, and black sesame and red check plating will be deteriorated.

When the content of Al ₂ O ₃ is less than 5.0% by mass, the cross-linking effect between atoms is weakened, and it becomes difficult to match the shrinkage behavior of the insulator and the conductor due to the decrease in the glass liquidus temperature. Therefore, there is a risk that warping will increase. On the other hand, when the content of Al ₂ O ₃ is more than 7% by mass, the cross-linking effect of Al ₂ O ₃ which is a network modification oxide is strengthened, the viscosity of the glass is increased, and the reactivity with the conductor is decreased, thereby protecting the protective layer. As the denseness of the material deteriorates, black sesame is easily generated on the surface.

  When the content of MgO is less than 13.0% by mass, the chemical durability of the glass is lowered, and thus the plating property may be lowered. On the other hand, when the content of MgO is more than 16% by mass, a complex oxide such as forsterite is precipitated in a small amount, and the amount of shrinkage of the protective layer 23 is likely to vary. May grow.

  When the content of CaO is less than 1.0% by mass, the chemical durability of the glass is deteriorated and at the same time the cross-linking structure is strengthened, so that the reactivity with the surface wiring layer 2 is lowered, and the denseness of the protective layer 23 is reduced. Therefore, black sesame is likely to be generated on the surface of the protective layer 231. On the other hand, when the content of CaO is more than 2.0% by mass, the viscosity at the high temperature range in the firing is lowered, and the shrinkage start temperature of the surface wiring layer 2 is likely to change to a low temperature. The unevenness of the main surface of the substrate 1 is increased, and the flatness may be increased.

When the content of BaO is less than 14.0% by mass, the glass structure becomes unstable and the viscosity of the glass phase tends to decrease, so that the unevenness of the main surface of the insulating substrate 1 may be increased. On the other hand, when the content of BaO is more than 16.0% by mass, elements such as Al ₂ O ₃ and SiO ₂ are precipitated, and the amount of shrinkage during firing increases, resulting in flatness of the substrate surface. May increase.

  If the SrO content is less than 0.5% by mass, the chemical durability of the glass is lowered, and the viscosity of the glass tends to be lowered. On the other hand, when the SrO content is more than 1.5% by mass, a composite oxide containing SrO is likely to be generated in the glass phase, so that the shrinkage behavior of the protective layer 231 may change and the flatness may increase. There is.

When the content of ZrO ₂ is less than 0.5% by mass, the viscosity of the glass tends to decrease, so that the unevenness of the main surface of the insulating substrate 1 may increase. On the other hand, the content of ZrO ₂ is 0.
. If the amount is more than 8% by mass, the chemical durability of the glass itself is increased, but the liquidus temperature of the glass is increased, so that the density of the protective layer 231 is decreased and black sesame is likely to be generated. is there.

Next, in the protective layer paste to be coated on the glass ceramic insulating layers 11, 12, 13, and 14, 27.7 to 31.7 mass% of SiO ₂ filler having an average particle size of 2.0 to 4.0 μm. And an organic binder in a mixed powder composed of 1.0 to 1.2% by mass of chromium oxide and 67.3 to 71.2% by mass of glass powder having an average particle size of 1.0 to 2.0 μm, An organic solvent or the like is added and kneaded. The glass powder SiO2 of 32.0 to 34.0 wt%, the _Al 2 _{O 3} 6.5 to 8.0 wt%, the CaO 9.0-12.0 mass%, a BaO 15.0 to 18 0.0 mass% and SrO are comprised from 1.5-3.0 mass%. Here, the glass component contained in the paste for the protective layer 232 preferably has a glass transition point of 645 to 777 ° C. That is, in the present invention, the glass transition point of the glass component contained in the protective layer 232 paste is made higher than that of the glass component contained in the protective layer 231 paste. desirable. In addition, as for the protective layer 23 which comprises the glass-ceramic wiring board A of this embodiment, the composition after baking hardly changes from the composition at the time of preparation. Therefore, even after firing, the glass transition point of the glass component contained in the protective layer 231 covering the surface wiring layer 2 is Tg1, and the glass ceramic insulating layers 11, 12, 13, and 14 are partially covered. When the glass transition point of the glass component contained in the layer 232 is Tg2, the relationship Tg1 <Tg2 is satisfied.

  On the other hand, when the content of chromium oxide is less than 1.0% by mass, the protective layer 232 is excessively sintered and adhesion of setters is often observed.

  On the other hand, when the content of chromium oxide is more than 1.1% by mass, the firing property of the protective layer 232 is reduced, so that coarse voids are likely to be generated on the surface of the protective layer 231 and black that appears after plating is formed. Sesame is likely to occur.

When the content of silica (SiO ₂ ) as a filler is less than 27.7% by mass, the protective layer 232 is easily sintered excessively, so that setter adhesion is likely to occur.

On the other hand, when the mass of silica (SiO ₂ ) as the filler is more than 31.7% by mass, the sinterability of the protective layer 232 is reduced, so that coarse voids are likely to be formed on the substrate surface. Later, black sesame is likely to occur.

About the glass component contained in the paste for protective layers 232, since the glass becomes difficult to form a three-dimensional network structure when the content of SiO ₂ is less than 32.0% by mass, the viscosity of the glass decreases. Therefore, there is a risk of reaction with silica (SiO 2) as a filler. On the other hand, when the content of SiO ₂ exceeds 34.0% by mass, the skeleton of the glass becomes strong, but conversely, the liquidus temperature of the glass is excessively increased, so that the surface of the insulating substrate is coarse. There is a risk of voids.

When the content of Al ₂ O ₃ is less than 6.5% by mass, the temperature at which the liquid phase of the glass decreases, so that the shrinkage behavior of the glass ceramic insulating layers 11, 12, 13, 14 and the protective layer 232 is reduced. There is a possibility that the flatness of the substrate will be increased due to the failure to match. On the other hand, when the content of Al ₂ O ₃ is more than 8.0% by mass, the viscosity of the glass increases, and the reactivity with silica (SiO ₂ ) as a filler decreases, so that the denseness of the protective layer 232 is reduced. This makes it difficult to generate coarse voids on the surface of the protective layer 232.

Even when the CaO content is less than 9.0% by mass, the filler silica (SiO
₂ ) The reactivity with ₂ ) decreases, so that the protective layer 232 becomes difficult to be densified, and coarse voids are likely to be generated on the surface of the protective layer 232. On the other hand, when the content of CaO is more than 12.0% by mass, the viscosity of the glass at a high temperature range is lowered, so that there is a possibility that it easily reacts with the setter.

  When the content of BaO is less than 15.0% by mass, the viscosity of the glass is lowered. Therefore, the main surface of the insulating substrate 1 including the protective layer 232 can be easily uneven, and the flatness may be increased. On the other hand, when the content of BaO is more than 16.0% by mass, the liquidus temperature of the glass is increased, so that the sinterability of the protective layer 232 is lowered and coarse voids are likely to be generated. .

  If the content of SrO is less than 1.5% by mass, the viscosity of the glass tends to be lowered, so that the reactivity with the insulating substrate 1 is increased and the unevenness of the substrate surface is increased, so that the flatness is increased. There is a fear. On the other hand, when the content of SrO is more than 3.0% by mass, the liquidus temperature of the glass rises, so that coarse voids are easily generated in the protective layer 232.

  Next, the through hole is filled with the conductive paste for the through conductor, the conductor pattern for the internal wiring layer or the surface wiring layer is formed on the main surface, and the peripheral portion of the conductor pattern for the surface wiring layer and its periphery A laminate is prepared by laminating a plurality of glass ceramic green sheets each having a protective layer pattern formed thereon, and pressure laminating them using a thermocompression bonding method or a laminating aid.

  Next, the obtained laminate is fired. Firing is performed by degreasing by holding at a temperature of 700 to 750 ° C. for 1 to 5 hours in a nitrogen atmosphere, and then for 1 to 2 hours at a temperature of 850 ° C. to 900 ° C. in a nitrogen atmosphere.

  Next, the body of the glass ceramic wiring board obtained by firing is subjected to a surface treatment using an etching solution such as sulfuric acid and ammonium persulfate, for example, and the surface wiring layer formed on the body of the glass ceramic wiring board The oxide film (copper oxide) on the surface is removed. Thereafter, a glass etching process is performed using, for example, acidic ammonium fluoride, and the glass on the surface is removed.

  Finally, a plating process is performed on the first wiring layer to form a Pd plating layer, a Ni plating layer, and an Au plating layer. In addition, water washing, alkali degreasing, acid treatment, etc. are suitably performed between each immersion process.

  By the manufacturing method described above, the protective layer 23 covering the surface wiring layer 2 has no defects such as voids, the surface wiring layer 2 has high metallization strength and flatness, and is formed on the surface of the insulating substrate 1. Glass ceramic wiring that has no spots called black sesame on the side of the protective layer 231 that covers the peripheral edge of the surface wiring layer 2 and that has no setter attached to the surface of the protective layer 232 that covers the surface of the insulating substrate 1 A substrate can be obtained.

As the glass powder, a glass powder having the composition shown in Table 1 and a ceramic filler made of SiO ₂ were prepared and weighed and mixed so as to have the ratio shown in Table 3. The average particle size of the glass powder was 3.5 μm, and the average particle size of the filler body was 3.5 μm.

  To this mixture, an organic binder containing isobutyl methacrylate as the main chain and toluene as a solvent was added, dibutyl phthalate was added as an organic solvent, and mixed well to prepare a slurry, and then a glass ceramic having a thickness of 125 μm by a doctor blade method. A green sheet was produced.

  After the through hole was formed in the obtained glass ceramic green sheet by punching, the through hole was filled with a conductive paste for the through hole. The conductor paste for through-holes was prepared by adjusting the viscosity by adding an acrylic binder and terpineol to copper powder.

  Next, a conductor pattern for an internal wiring layer or a conductor pattern for a surface wiring layer was formed on the surface of a glass ceramic green sheet filled with a conductor paste for through holes. The conductor paste for forming the conductor pattern for the internal wiring layer or the conductor pattern for the surface wiring layer is composed of glass powder having the composition shown in Table 2, copper powder, cuprous oxide, and fused silica in the proportions shown in Table 3. The viscosity is adjusted by adding an acrylic binder and terpineol thereto. In addition, the average particle diameter of the copper powder contained in the conductor paste for the surface wiring layer was 5 μm, and the average particle diameter of the glass powder was 1.8 μm. Moreover, the average particle diameter of the copper powder contained in the conductor paste for the internal wiring layer was 2 μm, and the average particle diameter of the glass powder was 1.5 μm.

  A plurality of glass ceramic green sheets formed with the conductor pattern thus formed were aligned and 20 layers were laminated by thermocompression bonding to produce a laminate.

  Next, after degreasing in a nitrogen atmosphere containing water vapor under the conditions of a temperature of 725 ° C. and a holding time of 3 hours, the maximum temperature was 860 ° C. and the holding time was 1 hour in the nitrogen atmosphere. The main firing was performed under the conditions, and an element body of a glass ceramic wiring board having a size of 45 mm in length, 45 mm in width, and 2 mm in thickness was produced. The surface wiring layer formed on the surface of the body of the glass ceramic wiring board had a circular shape in plan view, and its diameter was 0.8 μm.

  Further, regarding the arrangement of the protective layer coated on the surface wiring layer with respect to the surface wiring layer having a circular shape in plan view, the protective layer coated on the surface wiring layer with respect to the surface wiring layer is concentric (FIG. 3). As shown in FIG. 4, the protective layer coated on the surface wiring layer was displaced from the position of the concentric circle (FIG. 4). In addition, the protective layer coated on the surface wiring layer was manufactured by changing the width W of the protective layer with respect to the diameter of the surface wiring layer.

  Finally, the obtained body of the glass ceramic wiring board is etched with ammonium persulfate for 30 seconds to remove the oxide film (copper oxide) on the surface of the surface wiring layer. The glass phase on the surface of the first layer was removed by etching the element using acidic ammonium fluoride.

  Next, a Pd plating layer, an Ni plating layer, and an Au plating layer are formed in this order on the first layer formed on the surface of the etched glass ceramic wiring board body, thereby completing the glass ceramic wiring board. I let you. In these platings, the base body of the glass ceramic wiring board is immersed in a Pd plating bath for 90 seconds, then immersed in a Ni plating bath for 18 minutes, and finally immersed in an Au plating bath for 5 minutes. Pd plating layer, Ni plating layer, Au plating layer) were formed.

  The following measurements were performed on the multilayer wiring board obtained by the above method.

  First, composition analysis was performed on the protective layer coated on the surface wiring layer formed on the surface of the insulating substrate and the protective layer coated on the glass ceramic insulating layer. Specifically, in a sample after firing, energy dispersive X-ray spectroscopic analysis (EDS) is performed on a part of each glass phase in a spot manner, so that each element contained in the glass phase is contained in terms of oxide. The amount was determined. Table 4 shows the composition of the protective layer coated on the surface wiring layer, and Table 5 shows the composition of the protective layer coated on the glass ceramic insulating layer. In this case, it was confirmed that the content of each component was the same as the glass composition as the raw material.

  Further, the width W of the protective layer covering the surface wiring layer was measured. Specifically, the maximum diameter of the surface wiring layer and the width W of the protective layer covering the surface wiring layer were measured using an optical microscope and a three-dimensional image recognition device.

  In addition, the metallization strength of the surface wiring layer was evaluated. Specifically, eutectic solder balls having a diameter of 0.6 mmΦ were melted on the surface of the surface wiring layer after plating at 250 ° C. × 1 min for soldering. Thereafter, the flux used for placing the substrate with the solder balls on the solder balls was washed with clean-through (cleaning agent) for about 10 minutes, washed, washed with water, and the strength was measured with a bond tester. Measurement conditions were such that the tension rate of the clamp was 83 μm / second.

  Further, the adhesion of the setter was observed with a binocular microscope at a magnification of 10 to 100 times.

  As for the plating property, the protective layer covering the surface wiring layer was immersed in the red check solution for about 5 seconds, washed with water, and then binocular microscope. The presence or absence of red check liquid residue was observed.

  Moreover, the flatness of the main surface of the insulating substrate was evaluated. Specifically, the height of the main surface was measured every 5 mm in length and width using a laser displacement meter in a 40 mm square area on one main surface, and the difference between the maximum value and the minimum value was obtained.

  In addition, when the crystal phase in the insulating substrate was identified by X-ray diffraction (XRD), it was found that all samples had the highest quartz content, followed by celsian and enstatite. confirmed. These results are shown in Table 6.

As is clear from the results in Table 6, the samples of the present invention (Sample Nos. 1, 8, 21, 27, and 37 to 42) have no defects such as voids on the substrate surface, and the metallization strength of the surface wiring layer is 5 .1 kgf / mm ² or more, warpage of the substrate is 75 μm or less and the flatness is high, and there is no spot called black sesame on the protective layer side covering the peripheral portion of the surface wiring layer formed on the surface of the insulating substrate. In addition, the setter component did not adhere to the surface of the protective layer covering the surface of the insulating substrate.

  In the sample of the present invention, when the protective layer coated on the surface wiring layer with respect to the surface wiring layer is concentric (sample Nos. 1, 8, 21, and 27), the composition of the protective layer is the same. The metallization strength was higher than that of the samples (sample Nos. 37 to 42) in which the positions of the protective layers were not concentric.

  In particular, a sample in which the position of the protective layer is a concentric circle and the width W of the protective layer covering the surface wiring layer with respect to the maximum diameter of the surface wiring layer is 4 to 9% (sample Nos. 1, 8, 21 and In No. 27), the warpage was as small as 66 μm compared to the samples (sample Nos. 41 and 42) in which the width W of the protective layer covering the surface wiring layer with respect to the maximum diameter of the surface wiring layer was 3% and 15%.

On the other hand, sample No. which is outside the scope of the present invention. In 2-7, 9-20, 22-26, and 28-36, there is a defect such as a void on the substrate surface, the metallization strength of the surface wiring layer is lower than 5.1 kgf / mm ² , or the substrate warp The surface of the protective layer that is larger than 75 μm, has spots called black sesame on the protective layer side that covers the periphery of the surface wiring layer formed on the surface of the insulating substrate, or covers the surface of the insulating substrate There was adhesion of setter components to the surface.

DESCRIPTION OF SYMBOLS 1 ... Insulating base | substrate 11, 12, 13, 14 ... Glass ceramic insulating layer 2 ... Surface wiring layer (ball pad part)
21 ... Pd plating layer 22 ... Ni plating layer 23 ... Au plating layer 23 ... Protective layer 231 ... Protective layer 232 for covering the surface wiring layer ... Glass ceramic insulating layer Protective layer 4 ... internal wiring layer 5 ... through conductor

Claims (3)

A ceramic insulating layer; a surface wiring layer formed on the surface of the ceramic insulating layer; and a protective layer partially covering the peripheral portion of the surface wiring layer and the ceramic insulating layer around the periphery. In the ceramic wiring board, the protective layer covering the surface wiring layer is composed of 27.7-31.7% by mass of SiO ₂ filler and 1.0-1.2% by mass of chromium oxide. And the balance is 28.0 to 31.0% by mass of SiO ₂ , 5.0 to 7.0% by mass of Al ₂ O ₃ , 1.0 to 2.0% by mass of CaO, and 14.0 to BaO. A glass component containing 16.0% by mass, MgO 13.0 to 16.0% by mass, SrO 0.5 to 1.5% by mass and ZrO 0.5 to 0.8% by mass. , and the said protective layer that the ceramic insulating layer is partially coated, SiO Filler and a 27.7 to 31.7 weight percent, and 1.0 to 1.2 mass% of chromium oxide, the SiO ₂ from 32.0 to 34.0 wt% to the remainder, the _Al 2 _{O 3} 6. 5 to 8.0% by mass, CaO 9.0 to 12.0% by mass, BaO 15.0 to 18.0% by mass and SrO 1.5 to 3.0% by mass. A glass-ceramic wiring board, characterized in that   2. The glass ceramic wiring board according to claim 1, wherein the outer shape of the surface wiring layer is circular and the protective layer is formed concentrically with respect to the center of the surface wiring layer. . 3. The glass ceramic according to claim 2, wherein a width W of the protective layer covering the surface wiring layer is 4% ≦ W / D ≦ 13% with respect to a diameter D of the surface wiring layer. Wiring board.

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