JP5803453B2 - Glass ceramic dielectric material and glass ceramic dielectric - Google Patents

Description

  The present invention relates to a material for glass ceramic dielectrics that can be used for the production of glass ceramic dielectrics used for semiconductor wiring boards, circuit boards, and the like and can be sintered at a temperature of 1000 ° C. or lower.

  Semiconductor wiring boards, circuit boards, and the like are generally composed of a dielectric substrate and conductors or electrodes formed on or inside the dielectric substrate. A wiring board, a circuit board, etc. are produced as follows, for example. First, a binder, a plasticizer and a solvent are added to ceramic powder as a raw material to prepare a slurry. Next, the slurry is formed into a green sheet by a doctor blade method. Thereafter, the green sheet is dried and cut to a predetermined size, and then mechanical processing is performed to form a through hole, and a metal material that becomes a conductor or an electrode is printed on the surface of the through hole and the green sheet. Subsequently, a plurality of green sheets are laminated and integrated by thermocompression bonding.

  Conventionally, an alumina ceramic dielectric obtained by sintering alumina powder has been generally used as a dielectric substrate. Here, since the alumina ceramic dielectric has a high sintering temperature of about 1600 ° C., it is necessary to use tungsten, which is a refractory metal, as a conductor material. However, tungsten has a problem of low electrical conductivity and large conductor loss. In addition, the alumina ceramic dielectric has a disadvantage that the dielectric constant is as high as about 10 and the signal processing speed of the semiconductor becomes slow.

  In order to solve the above-mentioned problems of alumina ceramic dielectrics, low temperature sintered dielectrics such as glass ceramic dielectrics have been developed in recent years. The glass-ceramic dielectric can be generally produced by sintering borosilicate glass powder and alumina powder at a relatively low temperature of, for example, 1000 ° C. or less. Therefore, there is an advantage that silver or copper having a low melting point and low conductor loss can be used as a conductor material. Moreover, it has the characteristic that it has a dielectric constant lower than the alumina ceramic dielectric material of about 4-8 (for example, refer patent document 1 and 2).

Japanese Patent Laid-Open No. Sho 62-113758 JP-A-9-295827

  The glass ceramic dielectric using borosilicate glass powder as a raw material has a problem that when the green sheet is formed, the change in slurry viscosity with time is large and the thickness of the green sheet tends to vary. Moreover, since the fluidity | liquidity of the slurry was low, there existed a problem that it was inferior to leveling property and it was difficult to obtain a smooth green sheet.

  In view of the above, the present invention is a glass-ceramic dielectric material made of borosilicate glass powder as a raw material, and is less likely to cause a change in the viscosity of the slurry during green sheet molding, and has high fluidity and excellent leveling properties. Another object of the present invention is to provide a glass ceramic dielectric material.

  In the present invention, 49.9 to 89.9% by mass of borosilicate glass powder, 10 to 50% by mass of alumina powder and / or quartz powder, and 0% of aluminum borate powder and / or silica borate compound powder. The present invention relates to a glass ceramic dielectric material characterized by containing 1 to 4% by mass.

  As a result of various investigations, the present inventors have found that when an appropriate amount of aluminum borate powder and / or silica borate compound powder is added to a mixture of borosilicate glass powder and alumina powder and / or quartz powder, slurry is formed. It has been found that the change in viscosity with time is small, the fluidity is high, and the leveling property is remarkably improved. Although the details of the mechanism for obtaining the effect are unknown, the aluminum borate powder and / or the silica borate compound powder act on the interface between the borosilicate glass powder and the organic component such as an organic solvent to improve fluidity. I guess that.

Secondly, in the glass ceramic dielectric material of the present invention, the aluminum borate powder is 2Al ₂ O ₃ · B ₂ O ₃ or 9Al ₂ O ₃ · 2B ₂ O ₃ and the silica borate compound powder is B ₂ SiO ₅ , NaBSi ₃ O ₈ , NaBSi ₂ O ₅ (OH) ₂ or KBSi ₂ O ₆ is preferred.

Third, the glass ceramic dielectric material of the present invention is a borosilicate glass having a glass composition of mass%, SiO ₂ 60 to 85%, B ₂ O ₃ 10 to 20%, RO (R is Mg, Ca Sr or Ba) 0 to 20% and R ′ ₂ O (R ′ is Li, Na or K) preferably 0.1 to 3%.

  Fourth, the glass ceramic dielectric material of the present invention is preferably in the form of a green sheet.

  Fifthly, the present invention relates to a glass-ceramic dielectric characterized by sintering any one of the glass-ceramic dielectric materials.

  When the glass ceramic dielectric material of the present invention is used, the viscosity of the slurry hardly changes during green sheet molding, and the fluidity is high and the leveling property can be improved.

  The glass ceramic dielectric material of the present invention comprises 49.9 to 89.9% by mass of borosilicate glass powder, 10 to 50% by mass of alumina powder and / or quartz powder, and aluminum borate powder and / or boron. It contains 0.1 to 4% by mass of acid silica-based compound powder.

  Borosilicate glass powder is a main component of a glass ceramic dielectric material, and is a component that achieves a low dielectric constant and enables low-temperature sintering. The content of the borosilicate glass powder is preferably 49.9 to 89.9% by mass, 60 to 85% by mass, particularly 65 to 80% by mass. If the content of the borosilicate glass powder is too small, the porosity of the glass ceramic dielectric increases and the strength tends to decrease. On the other hand, if the content of the borosilicate glass powder is too large, the excess glass component that has not been sintered is raised on the surface of the glass ceramic dielectric, and the adhesive strength between the wiring material and the glass ceramic dielectric is reduced. There is a tendency that the wettability of the solder with respect to the surface of the glass ceramic dielectric is lowered, and a problem that the solder is not placed on the surface of the glass ceramic dielectric occurs.

The borosilicate glass powder, in mass% as a glass _{composition, SiO 2 60~85%, B 2} O 3 10~20%, RO (R is Mg, Ca, Sr or Ba) 0 to 20% and R _'2 O (R ′ is Li, Na, or K) It is preferable to contain 0.1 to 3%. The reason for limiting the glass composition in this way will be described below. In the following description of the content of each component, “%” represents “mass%” unless otherwise specified.

SiO ₂ is a main component of borosilicate glass and is a component that forms a glass skeleton. The content of SiO ₂ is preferably 60 to 85%, particularly 65 to 80%. When the content of SiO ₂ is too small, chemical durability tends to decrease. On the other hand, if the content of SiO ₂ is too large, low-temperature sintering and the sintering temperature becomes higher (e.g., 1000 ° C. or less) tend to become difficult.

B ₂ O ₃ is a component that lowers the viscosity. The content of B ₂ O ₃ is preferably 10 to 20%, particularly preferably 16 to 20%. If the content of B ₂ O ₃ is too small, there is a tendency for low-temperature sintering becomes difficult sintering temperature becomes high. On the other hand, when the content of B ₂ O ₃ is too large, chemical durability tends to decrease.

  RO is a component that lowers the melting temperature. The total RO content is preferably 0 to 20%, 0.1 to 15%, particularly preferably 1 to 10%. When there is too much content of RO, it will become difficult to vitrify or it will become difficult to sinter because fluidity | liquidity falls.

R ′ ₂ O is a component that lowers the melting temperature. The total content of R ′ ₂ O is preferably 0.1 to 3%, particularly preferably 1 to 2.5%. If the content of R ′ ₂ O is too small, it is difficult to obtain the above effect. On the other hand, when R 'content _{2 O} is too large, the volume resistivity tends to be inferior in insulating properties decrease.

In addition to the above components, Al ₂ O ₃ as a component for stabilizing glass, ZnO as a component for facilitating vitrification, and CuO, CeO ₂ , Sb ₂ as components for suppressing coloring due to Ag used as wiring. O ₃ or SnO, TiO ₂ or ZrO ₂ or the like as a component for improving chemical resistance (acid resistance or alkali resistance) may be contained up to 30% in total.

  Alumina powder and quartz powder are components that improve the mechanical strength of the glass ceramic dielectric. In particular, since quartz powder has a low dielectric constant of about 3.5, the effect of lowering the dielectric constant of the glass ceramic dielectric is great, and it is easy to improve the signal processing speed when a wiring board or circuit board is used. Alumina powder and quartz powder may contain only one or both. The total content of the alumina powder and the quartz powder is preferably 10 to 50% by mass, particularly 20 to 40% by mass. When the content of the alumina powder and / or the quartz powder is too small, the mechanical strength of the glass ceramic dielectric tends to decrease. On the other hand, if the content of alumina powder and / or quartz powder is too large, the content of borosilicate glass powder is relatively small and sintering becomes insufficient, resulting in a large porosity of the glass ceramic dielectric. As a result, the mechanical strength tends to decrease.

The aluminum borate powder and the silica borate compound powder are components that improve fluidity and stabilize the viscosity when the glass ceramic dielectric material of the present invention is slurried. The aluminum borate powder and the silica borate compound powder may contain either one or both. The total content of the aluminum borate powder and the silica borate compound powder is preferably 0.1 to 4% by mass, particularly 1 to 3.5% by mass. If the content of the aluminum borate powder and / or the silica borate compound powder is too small, it is difficult to obtain the above effect. On the other hand, when the content of the aluminum borate powder and / or the silica borate compound powder is too large, the porosity of the glass ceramic dielectric increases and the mechanical strength tends to decrease. Examples of the aluminum borate _{powders, 2Al 2 O 3 · B 2 O} 3 and _{9Al 2 O 3 · 2B 2 O} 3. Specific examples of the silica borate compound powder include B ₂ SiO ₅ , NaBSi ₃ O ₈ , NaBSi ₂ O ₅ (OH) ₂ and KBSi ₂ O ₆ .

The size of each powder described above is not particularly limited, but if it is too large, the porosity of the glass-ceramic dielectric increases and the mechanical strength tends to decrease, whereas if it is too small, the handleability tends to be inferior. is there. Therefore, the average particle diameter _{(D 50)} of the respective powders is 0.01 to 100 [mu] m, 0.1 to 50 [mu] m, and particularly preferably a 1 to 10 [mu] m. Here, the average particle diameter (D ₅₀ ) is a value measured by a laser diffraction scattering method.

  In addition to the above powder, the glass ceramic dielectric material of the present invention contains zircon powder, titania powder, zirconia powder, etc. for the purpose of improving the properties such as thermal expansion coefficient, toughness, dielectric constant, chemical resistance, etc. It doesn't matter.

  The glass ceramic dielectric of the present invention is formed by sintering the glass ceramic dielectric material. The dielectric constant of the glass ceramic dielectric of the present invention is preferably 3 to 8, particularly 3.5 to 7.

  Below, an example of the detailed manufacturing method of the glass-ceramic dielectric material of this invention is demonstrated.

  First, after preparing a glass raw material so that it may become a desired glass composition, it fuse | melts at 1300-1650 degreeC, for example. After the molten glass is formed into a thin plate shape by, for example, a water-cooled roller, the formed body is pulverized to obtain a borosilicate glass powder.

  Alumina powder and / or quartz powder and aluminum borate powder and / or silica borate compound powder are mixed with borosilicate glass powder, and a predetermined amount of binder, plasticizer and solvent are added to form a slurry. Prepare. Here, as the binder, for example, polyvinyl butyral resin and methacrylic acid resin can be used. As the plasticizer, for example, dibutyl phthalate can be used. As the solvent, for example, toluene and methyl ethyl ketone can be used.

  Next, the slurry is formed into a green sheet by a doctor blade method. Thereafter, the green sheet is dried and cut to a predetermined size, and then mechanical processing is performed to form a through hole, and a metal material that becomes a conductor or an electrode is printed on the surface of the through hole and the green sheet. Subsequently, a plurality of green sheets are stacked and integrated by thermocompression bonding. Further, by firing the laminated green sheet, a multilayer substrate dielectric having an insulating layer made of glass ceramic can be obtained.

  The glass ceramic dielectric material and glass ceramic dielectric of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

  Tables 1 and 2 show examples of the present invention (sample Nos. 1-4 and 8-14) and comparative examples (samples No. 5-7, 15 and 16).

(1) Production of Borosilicate Glass Powder First, glass materials prepared so as to have the composition shown in the table were put into a platinum crucible and melted at 1600 ° C. for 3 to 6 hours. Next, the molten glass was formed into a thin plate shape by a water-cooled roller. Further, the compact was coarsely crushed by a ball mill, and then alcohol was added and wet pulverized to obtain a borosilicate glass powder having an average particle diameter of 3 μm.

(2) Production of Green Sheet for Glass Ceramic Dielectric Fabrication For borosilicate glass powder, alumina powder or quartz powder (average particle size: 3 μm each) and aluminum borate powder or silica borate compound powder (average particle size) : 1 μm each). To 100 parts by weight of the obtained mixed powder, 10 parts by weight of polyvinyl butyral resin, 2 parts by weight of dibutyl phthalate and 50 parts by weight of toluene were added and mixed for 24 hours to prepare a slurry. Next, the slurry was molded into a sheet by the doctor blade method, dried, and cut into 10 cm squares to obtain green sheets.

  The thickness of 100 green sheets thus obtained was measured, and the difference between the maximum value and the minimum value was evaluated as thickness variation.

(3) Fabrication and characteristic evaluation of glass ceramic dielectric A predetermined number of the obtained green sheets were laminated and fired at 900 ° C. to obtain a sintered body (glass ceramic dielectric). The obtained glass ceramic dielectric was evaluated or measured for sinterability, dielectric constant at 1 MHz and bending strength by the following methods. The results are shown in Tables 1 and 2.

  For sinterability, oil-based magic ink was applied to the surface of the glass ceramic dielectric, wiped off with gauze, the ink did not remain (= densely sintered) ○, the ink remained (= insufficiently dense) A sample) was marked with x.

  The dielectric constant was measured using an LCR meter.

  The bending strength was evaluated according to a three-point bending strength measurement based on JIS R1601.

  As is apparent from the table, Examples No. Each of the samples 1-4 and 8-14 had a slurry viscosity as low as 8 Pa · s or less, and the thickness variation of the green sheet was as small as 6 μm or less. Moreover, since a dense sintered body was obtained, the bending strength was as high as 120 MPa or more.

  On the other hand, No. which is a comparative example. Sample No. 5 contains neither aluminum borate powder nor silica borate compound powder, so the slurry viscosity is as high as 25 Pa · s, and the change over time is large, so the thickness variation of the green sheet is as large as 13 μm. It was. No. Samples 6, 7, 15 and 16 contain too much alumina powder, aluminum borate powder or silica borate compound powder, so the sintered body is not densified and the bending strength is as low as 75 MPa or less. It was.

  The glass ceramic dielectric material of the present invention can be used as an electronic component material such as a semiconductor package or a multilayer chip component in addition to a dielectric such as a multilayer substrate dielectric.

Claims (4)

49.9 to 89.9 wt% of borosilicate glass powder, alumina powder and / or quartz powder 10 to 50 wt%, and, Ruga Las ceramics containing aluminum borate Powder 0.1-4 wt% A dielectric material , in which borosilicate glass is glass composition by mass%, SiO ₂ 60 to 85%, B ₂ O ₃ 10 to 20%, RO (R is Mg, Ca, Sr or Ba) 0 A glass-ceramic dielectric material comprising 20% and R ′ ₂ O (R ′ is Li, Na or K) 0.1 to 3% . Glass ceramic dielectric material according to claim 1, wherein the aluminum borate powder is _{2Al 2 O 3 · B 2 O} 3 or _{9Al 2 O 3 · 2B 2 O} 3. Glass ceramic dielectric material according to claim 1 or 2, characterized in that a green sheet. Glass ceramic dielectric, characterized in that formed by sintering a glass ceramic dielectric material according to any one of claims 1-3.