JP4702979B2 - Composite particles - Google Patents

Description

【００５９】
表１の結果より、比較例１の平均粒径が３．０μｍより小さい試料Ｎｏ．３０では、被覆厚みが０．０５μｍより薄いものであった。また、比較例２の試料Ｎｏ．３１では、被覆厚みが部分的に不均一で、かつ平均被覆厚みが２μｍを越え、さらに、混合により混合粒子の平均粒径の減少率が１０％を越えガラス層が剥離することが示唆された。また、比較例３の試料Ｎｏ．３２では、被覆厚みが部分的に不均一で、かつ平均被覆厚みが２μｍを越え、また、反応生成物層の厚みが１００ｎｍを越えるものであった。
【００６０】
これに対して、本発明に従う試料Ｎｏ．２〜２９では、いずれも平均粒径３．０μｍ以上、ガラス層の被覆厚みが０．０５〜２μｍ、平均粒径の減少率が１０％以下、反応生成物層厚み１００ｎｍ以下、アスペクト比１．７以下の複合粒子となった。なお、Ｘ線回折測定の結果から、ガラスＡ，Ｂを添加した試料についてはいずれもディオプサイド結晶相の析出が見られた。
【００６１】
次に、表２、３に示す上記表１の複合粒子（表２、３中、表１の試料Ｎｏ．を複合粒子の種類として記載）に対して、平均粒径２μｍの表２、３に示すガラス粉末と、有機バインダ、可塑剤、トルエンを添加し、回転ミルにて１２時間混合してスラリーを調製した後、このスラリーを用いてドクターブレード法により厚さ３００μｍのグリーンシートを作製した。そして、このグリーンシートを１０〜１５枚積層し、５０℃の温度で１０ＭＰａの圧力を加えて熱圧着した。得られた積層体を水蒸気含有／窒素雰囲気中、７００℃で脱バインダ処理を行った後、乾燥窒素中で表２の条件で焼成しガラスセラミックスを得た。
【００６２】
得られたガラスセラミックスについてアルキメデス法に基づき磁器の相対密度を測定し、また、誘電率、誘電損失、抗折強度、熱膨張係数、熱伝導率を以下の方法で評価した。
【００６３】
誘電率、誘電損失については、直径２〜７ｍｍ、厚み２〜２．５ｍｍの形状に切り出し、６０ＧＨｚにてネットワークアナライザー、シンセサイズドスイーパーを用いて誘電体円柱共振器法により行った。測定では、ＮＲＤガイド（非放射性誘電体線路）で、誘電体共振器の励起を行い、ＴＥ₀₂₁またはＴＥ₀₃₁モードの共振特性より、誘電率、誘電損失を算出した。
【００６４】
また、試料を幅４ｍｍ×厚さ３ｍｍ×長さ７０ｍｍの形状に切り出し、ＪＩＳＣ−２１４１の規定に基づいて３点曲げ試験を行った。さらに、室温から４００℃における熱膨張曲線をとり、熱膨張係数を算出した。また、厚み１ｍｍの試料に対してレーザーフラッシュ法により熱伝導率を測定した。
【００６５】
さらに、磁器の研磨面におけるＳＥＭ（走査型電子顕微鏡）写真から面積比率によりセラミックフィラー粒子の平均粒径ｄ、および隣接するセラミックフィラー２０個について最近接するセラミックフィラー５個間の平均距離ｒを求め、ｒ＜０．６ｄの割合を求めた。結果は表２、３に示した。
【００６６】
【表２】

【００６７】
【表３】

【００６８】
表２、３の結果から明らかなように、ガラスを被覆しない粒子を用いた試料Ｎｏ．３３については、セラミックフィラー粒子間の距離のばらつきが大きく、誘電損失が高く、強度が低いものであった。また、ガラスを被覆しない粒子を用いガラス量を減じた試料Ｎｏ．３４では、１０００℃以下にてガラスセラミックスを緻密化することができなかった。さらに、比較例１の平均粒径が３．０μｍより小さい複合粒子を用いた試料Ｎｏ．６３、および比較例２の複合粒子を用いた試料Ｎｏ．６４では、１０００℃の焼成でガラスセラミックスを緻密化させることができず、比較例３の複合粒子を用いた試料Ｎｏ．６５、およびガラスのみを用いた試料Ｎｏ．６６では、セラミックフィラー粒子間の距離のばらつきが大きく、誘電損失が高く、強度、熱伝導率の低いものであった。
【００６９】
これに対して、本発明に従い、上述した複合粒子を用いてガラスセラミックスのセラミックフィラー粒子間の距離を均一に短くした試料Ｎｏ．３５〜６２では、いずれも６０ＧＨｚにおける誘電損失が２０×１０^-4以下、強度２５０ＭＰａ以上、熱伝導率２．５Ｗ／ｍ・Ｋ以上の優れた特性を有するものであった。
【００７０】
【発明の効果】
以上詳述した通り、本発明の複合粒子は、セラミック粉末とガラス粉末とを乾式混合して粒子同士を衝突、接触、摩擦させることにより、強度の高いセラミック粒子表面に均一な厚みのガラス層を被着形成できることから、セラミックフィラーの含有比率を高めた低温焼成磁器を作製することができ、絶縁基板とする配線基板を作製することができる。
【図面の簡単な説明】
【図１】本発明の複合粒子の模式図である。
【図２】本発明の磁器の組織を説明するための模式図である。
【図３】本発明の高周波用磁器を用いた高周波用配線基板の一例である誘電体アンテナを具備する高周波用配線基板の概略断面図である。
【図４】本発明の高周波用磁器を用いた高周波用配線基板の他の一例である半導体素子収納用パッケージの概略断面図である。
【符号の説明】
Ｘ 複合粒子
Ｙ セラミック粒子
Ｚ ガラス層
ｏ ガラスセラミックス
ｐ ガラス相
ｑ セラミックフィラー粒子
ｄ セラミックフィラー粒子の粒径
ｒ 隣接する粒子間の距離
１ 絶縁基板
２、３ 導体層
４ ビアホール
５ 導波管線路
６ 導体層
７ スロット
２０ 高周波用パッケージ
２１ 絶縁基板
２２ 蓋体
２３ キャビティ
２４ 高周波素子
２５、２８ 配線層
２６ アース層
２７、２９ マイクロストリップ線路
３０ スロット孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to composite particles made of ceramic particles coated with glass, and in particular, wiring comprising an insulating substrate that can be co-fired with copper and silver and has an increased proportion of ceramic particles in porcelain. It relates to a substrate.
[0002]
[Prior art]
Conventionally, a method of coating glass on the surface of ceramic particles is known. For example, in Japanese Patent Publication No. 7-502245, the surface of silica particles or the like is coated with a borosilicate glass gel obtained by a sol-gel method, and composite particles dried at a low temperature are produced, and the composite particles are molded and fired. The production of a low dielectric constant substrate is described. In JP-A-6-321615, etc., ceramic particles are coated with a gel glass obtained by a sol-gel method, heated to 600 to 800 ° C. to remove decomposition gas in the glass, A porcelain that is pulverized, shaped into a tape and fired is described. Further, JP-A-61-21961 describes that an alumina / glass composite material can be produced by depositing and melting molten glass on the surface of alumina particles.
[0003]
On the other hand, ceramic wiring boards are widely used in which a wiring layer made of a refractory metal such as tungsten or molybdenum is formed on the surface or inside of an insulating board made of an alumina sintered body. As the frequency band used is shifting to higher frequencies, it is possible to integrally form a wiring layer of a conductor with a low resistance, such as copper, silver, gold, and other low resistance metals as the main component. Is required.
[0004]
In response to this demand, a wiring board using glass ceramics, which is a composite material of glass and ceramics, is being developed as an insulating board for a wiring board. It is described that by using coated ceramic particles, it is possible to eliminate agglomeration and segregation of ceramics and glass, and to produce a porcelain having no structural nonuniformity and no dimensional distortion.
[0005]
[Problems to be solved by the invention]
However, since the glass-coated particles of the above-mentioned JP-T-7-502245 are coated with borosilicate glass gel on the surface of the silica particles, the thickness of the glass coating varies locally with the fluidity of the gel, and the ceramic particles are uniform. In addition, if the sol is simply dried, the coated particles agglomerate with each other. Furthermore, when an organic solvent is added to the composite particles to form a slurry, the coated sol peels off and the organic solvent is removed. As a result of dissolution in the glass, there is a limit to increase the uniform dispersibility of the ceramic filler in the substrate after firing, and there is a problem that structural non-uniformity occurs, and the content of the organic component in the gel glass is There is a problem that the binder removal characteristic is increased and the porcelain cannot be densified at a low temperature.
[0006]
Moreover, in the ceramic particles heat-treated at 600 to 800 ° C. after coating the gel glass as disclosed in JP-A-6-321615, it is necessary to grind the agglomerates of the ceramic particles and the glass after the heat treatment. The glass is peeled off at the interface between the ceramic particles and the glass, and the glass can only be partially coated on the surface of the ceramic particles, or the ceramic particles and the glass are separated, and the glass of the uniform thickness is coated on the surface of the ceramic particles. There was a problem that could not be done. Furthermore, the composite particles tend to have an irregular shape due to the above-mentioned pulverization, and the density of the molded body is reduced, so that the sinterability is lowered or the glass content needs to be increased for densification, and the inclusion of ceramic particles in the porcelain There was a problem that the ratio was low.
[0007]
Further, in the method of depositing and pulverizing glass dissolved on the surface of ceramic particles in JP-A-61-21961, the glass having a uniform thickness is coated on the surface of ceramic particles for the same reason as described above. In addition, there is a problem that the sinterability is lowered and the content ratio of the ceramic particles in the porcelain is low. Further, since the molten glass comes into contact with the surface of the ceramic particles, the surface of the ceramic particles There is a risk that the characteristics of the ceramic particles may change due to the reaction, or the ceramic characteristics may change due to the change of the glass component.
[0008]
Therefore, an object of the present invention is to increase the content ratio of composite particles made of ceramic particles having a uniform coating thickness of glass and ceramic fillers using the same, and in particular, simultaneously with a conductor layer mainly composed of copper or silver. The object is to produce a wiring board using a low-temperature fired porcelain capable of firing as an insulating substrate.
[0009]
[Means for Solving the Problems]
As a result of intensive studies on the above problems, the present inventors have performed dry mixing of ceramic particles and glass particles, and collided, contacted, and rubbed the particles with a high collision force to improve the surface of the ceramic powder. It has been found that a glass layer with a uniform thickness can be deposited on the surface of high ceramic particles.
[0010]
That is, the composite particle of the present invention has an average particle size. 3.0 A composite particle having a surface of a ceramic particle having a thickness of 0.05 to 2 μm and a surface of the ceramic particle of 500 μm or more, and 100 g of water and the composite particle in a cylindrical container having a volume of 500 ml and a diameter of 50 mm When 10 g is added and mixed for 12 hours in a rotary mill at a rotation speed of 50 rotations / minute, the reduction rate of the average particle diameter of the composite particles is 10% or less.
[0011]
Here, there is a reaction product layer of 10 between the ceramic particles and the glass layer. 0 be present in a thickness of less than or equal to nm, approximately spherical with an average aspect ratio of 1.7 or less, and the ceramic particles are Al. ₂ O _Three , SiO ₂ , MgTiO _Three , CaTiO _Three , SrTiO _Three , Cordierite, enstatite, forsterite, steatite, willemite, ZnTiO _Three , Zn ₂ TiO _Four , Diopside, ZrO ₂ MgO, AlN, SiC, Si _Three N _Four It is desirable that at least one selected from the group of
[0012]
The glass layer is made of SiO. ₂ , Al ₂ O _Three , Containing an alkaline earth metal oxide, the glass layer is further B ₂ O _Three It is desirable that the content of PbO and the alkali metal oxide in the glass layer is 10% by weight or less.
[0015]
The glass ceramic of the present invention contains glass and / or crystals precipitated from glass and ceramic particles as a filler, and is a glass ceramic having a relative density of 90% or more, and is a scanning type of a polished surface of the glass ceramic. In the electron micrograph, the distance between the adjacent ceramic particles is such that the ratio of the average particle size of the ceramic particles being 60% or less is 90% or more.
[0016]
Here, the ceramic filler is approximately spherical with an average aspect ratio of 1.7 or less, and the ceramic filler is Al. ₂ O _Three , SiO ₂ , MgTiO _Three , CaTiO _Three , SrTiO _Three , Cordierite, enstatite, forsterite, steatite, willemite, ZnTiO _Three , Zn ₂ TiO _Four , Diopside, ZrO ₂ MgO, AlN, SiC, Si _Three N _Four It is desirable that the main component is at least one selected from the above group, and the content ratio of the ceramic filler is 50% by weight or more.
[0017]
Further, crystals precipitated from the glass are MgTiO. _Three , CaTiO _Three , SrTiO _Three , Cordierite, enstatite, forsterite, steatite, willemite, ZnTiO _Three , Zn ₂ TiO _Four It is desirable to contain at least one selected from the group consisting of diopside, anorthite and slausonite.
[0018]
Furthermore, the wiring board of the present invention is characterized in that the insulating board is formed of the above-mentioned glass ceramics in a wiring board in which a conductive layer comprising copper or silver as a main component and integrated by sintering is formed on the surface of the insulating board. To do.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
In order to produce the composite particles of the present invention, first, ceramic powder and glass powder are prepared.
The ceramic particles include, for example, an oxide, nitride or carbide having an average particle size of 0.35 μm or more, particularly 0.5 to 15 μm, further 1 to 10 μm, more preferably 3 to 8 μm. ₂ O _Three , SiO ₂ , MgTiO _Three , CaTiO _Three , SrTiO _Three , Cordierite, enstatite, forsterite, steatite, willemite, ZnTiO _Three , Zn ₂ TiO _Four , Diopside, ZrO ₂ MgO, AlN, SiC, Si _Three N _Four It is desirable that at least one selected from the group of
[0020]
In addition, the ceramic particles are preferably approximately spherical with an average aspect ratio of 1.7 or less in order to increase the dispersibility of the particles in the slurry and increase the density of the molded body and the porcelain, and the particles do not aggregate. It is desirable to consist of single crystal particles.
[0021]
Examples of the glass include PbO glass, Bi glass, borosilicate glass, alkali borosilicate glass, and aluminoborosilicate glass. ₂ -Al ₂ O _Three It is desirable to include glass containing -RO (R: at least one of alkaline earth elements). Further, boron (B) may be contained in the glass. However, in order to reduce dielectric loss in the high frequency band, the boron content may be ₂ O _Three In terms of conversion, it is preferably 16% by weight or less, particularly 9% by weight or less, and more preferably 1% by weight or less. Furthermore, it is desirable that the content of PbO and the alkali metal oxide in the glass is 10% by weight or less, particularly 1% by weight or less, further 0.1% by weight or less, and further substantially free of these.
[0022]
Further, the softening point of the glass is preferably 600 to 900 ° C, particularly preferably 700 to 850 ° C.
[0023]
The ceramic powder and the glass powder are, for example, 50 to 99% by weight of ceramic powder having an average particle size of 0.35 μm or more, and an average particle size of 0.5 μm or more, particularly the average particle size of the glass powder / the average of the ceramic particles. A glass powder having a particle size ratio of 0.1 to 0.7 and 1 to 50% by weight are blended in a predetermined ratio, and a jet mill, ceramic particles and glass particles are put in a container, and the container is, for example, By mixing by a dry mixing method such as high-speed rotation at 100 rpm or more, the particles of the ceramic particles and the glass particles collide, contact, and rub, and the glass particles are preferentially crushed and have low strength. As a result of part of the glass particles adhering to the surface of the ceramic particles, a glass layer having a uniform thickness can be deposited on the surface of the ceramic particles having high strength.
[0024]
Further, since glass adheres to the surface of the ceramic particles with frictional heat, the glass coated on the surface of the ceramic particles has high adhesion. Therefore, 10 g of the composite particles are added to 100 g of water. When mixed for a period of time, the reduction rate of the average particle size of the powder becomes 10% or less, particularly 5% or less. When a solvent is added to the composite particles and mixed to form a slurry, the coated glass peels off and becomes non-uniform. Can be prevented. That is, when the reduction rate of the average particle diameter exceeds 10%, the glass layer of the composite particles is peeled off when the composite particles are mixed, and the homogeneity of the composite particles is impaired.
[0025]
The specific conditions for the mixing are as follows: 100 g of water and 10 g of composite particles are placed in a roughly cylindrical container with a volume of 500 ml and a diameter of 50 mm, and mixed for 12 hours in a rotary mill at a rotation speed of 50 times / min. The mean particle size obtained by the microtrack method for the particle size of the powder before and after mixing.
[0026]
In particular, as the dry mixing, in the method in which the ceramic particles and the glass particles are put in a container and the container is rotated, the ceramic particles and the glass particles efficiently collide and come into contact with each other by centrifugal force. The surface of the ceramic particles can be modified by a relatively small driving force, the glass layer can be coated on the surface of the ceramic particles, and the ceramic particles can be prevented from being pulverized.
[0027]
The composite particles of the above aspect have an average particle size of 3.0 μm or more, especially 3.0 ~ 19μm and more 3.0 It is set to ˜14 μm, further 3.1 to 12 μm, and the ceramic particle surface is coated with a glass layer having a thickness of 0.05 to 2 μm. That is, the average particle size of the composite particles is 3.0 If it is smaller than μm, the sinterability decreases. , Ma Further, if the coating thickness of the glass layer is smaller than 0.05 μm, the glass cannot be uniformly coated on the surface of the ceramic particles, and if it is thicker than 2 μm, a large amount of the ceramic filler particles in the glass ceramics are uniformly distributed. Cannot be dispersed.
[0028]
The glass layer may be an aggregate of fine particles having an average particle size of 1 μm or less, particularly 0.1 μm or less, and further 0.05 μm or less, or may be formed in a glass shape, or a combination of both. Good.
[0029]
Furthermore, a reaction product layer generated by a reaction between the ceramic particles and the glass layer may be formed, but the dielectric constant, dielectric loss, strength, thermal conductivity due to the reaction product layer may be formed. The thickness of the reaction product layer is preferably 100 nm or less from the viewpoint of preventing such deterioration.
[0030]
A small amount of water and / or an organic binder may be added to increase the activity of the glass surface during the dry mixing.
[0031]
In particular, the composite particles of the above aspect have an average particle size of 3.0 -10 μm, 3.0 ~ 5 . 0 In addition, it is desirable that ceramic particles or glass particles having an average particle diameter of 0.5 μm or less, particularly 0.2 μm or less coexist in the composite particles at a ratio of 10% by weight or less in total. Good.
[0032]
In order to produce a porcelain using the composite particles, an organic binder and a solvent are optionally added to and mixed with the composite particles prepared by dry mixing the ceramic powder and the glass powder. It is molded into a predetermined shape by a known molding method such as a doctor blade method, a calender roll method, a press molding method, an extrusion molding method, or a casting molding method, and is fired at a predetermined temperature of, for example, 1050 ° C. or lower, particularly 1000 ° C. or lower Thus, a glass ceramic densified to a relative density of 90% or more, particularly 95% or more is produced.
[0033]
According to the present invention, as shown in the schematic diagram of FIG. 2, the glass ceramic o of the above aspect contains glass p and / or crystals precipitated from the glass (not shown) and ceramic filler particles q. In addition, in the scanning electron micrograph of the polished surface of the glass ceramic o, the average value of the distances r between the five ceramic filler particles q closest among the adjacent ceramic filler particles q is the value of the ceramic filler particles q. The ratio of 60% or less of the average particle diameter d is 90% or more, particularly 95% or more.
[0034]
The glass ceramic preferably has a ceramic filler particle content of 50% by weight or more, particularly 60% by weight or more. The average particle size of the ceramic filler particles is 0.35 μm or more, particularly 0.5 to 15 μm, further 1 to 10 μm, and further 3 to 8 μm.
[0035]
Furthermore, in order to produce the wiring board of the present invention using the composite particles, an organic binder, a dispersant and a solvent are added to the composite particles prepared by dry-mixing the ceramic powder and the glass powder. For example, after a slurry is produced by mixing for 8 to 12 hours in a ball mill, a green sheet is produced by a doctor blade method, a calender roll method, a press molding method, a rolling method, or the like.
[0036]
Then, after through holes are formed in the green sheet as desired, a conductive paste mainly composed of copper or silver is filled in the through holes. Then, printing is performed on the surface of the green sheet by the screen printing method or the gravure printing method using the metal paste, or a metal foil having a pattern formed on the resin sheet is transferred to a predetermined position on the surface of the green sheet. A wiring circuit layer of the pattern is formed.
[0037]
Thereafter, the plurality of green sheets on which the wiring layers are formed are aligned and laminated and pressure-bonded, and then fired at, for example, 800 to 1050 ° C., particularly 850 to 1000 ° C., to produce a wiring board.
[0038]
Then, electronic components such as semiconductor elements are appropriately mounted on the surface of the wiring board, and connected to the wiring layer so that signals can be transmitted. As a method of connection, the semiconductor element may be directly mounted on the wiring layer and connected, or the semiconductor element may be bonded with an adhesive such as resin of 50 μm, resin such as Ag-epoxy, Ag-glass, Au—Si, metal, ceramics, etc. Is fixed to the surface of the insulating substrate, and the wiring layer and the semiconductor element are connected by wire bonding, TAB tape or the like.
[0039]
Furthermore, on the surface of the wiring board on which electronic components such as semiconductor elements are mounted, a cap made of the same kind of insulating material as that of the insulating substrate, other insulating materials, or a metal having good heat dissipation, and having high electromagnetic shielding properties, Further, it may be joined by an adhesive such as resin or brazing material, whereby the electronic component can be hermetically sealed.
[0040]
In addition, a connection terminal that is electrically connected to the wiring layer of the wiring board and is mounted on the external circuit board may be disposed on the back surface of the wiring board. Note that the connection terminal may have a layer shape or a ball shape.
[0041]
Next, an example of a wiring board obtained by the above method will be described based on a schematic cross-sectional view of a high-frequency wiring board including the dielectric antenna of FIG.
According to the high frequency wiring board of FIG. 3, the pair of conductor layers 2 and 3 are formed at predetermined positions sandwiching the insulating substrate 1 having the predetermined thickness A. In addition, a large number of via holes 4 that are electrically connected to the conductor layers 2 and 3 are provided between the conductor layers 2 and 3. The via holes 4 are formed in two rows with a predetermined interval B with a predetermined interval C in the signal transmission direction, that is, the line forming direction. Although there is no particular limitation on the predetermined thickness A, when used in a single mode, it is desirable that the distance B is about B / 2 or about 2B. The predetermined distance C is based on a cutoff wavelength λc which is a signal wavelength. An electrical wall is formed by being set at a narrow interval, and the signal is confined between the two rows of via holes 4 and 4.
[0042]
Since a TEM wave can propagate between a pair of conductor layers 2 and 3 placed in parallel, if the interval C between the via holes 4 and 4 is greater than or equal to the cutoff wavelength λc, it can propagate even if electromagnetic waves are fed to this line. If the gap C between the via holes 4 and 4 is smaller than the cut-off wavelength λc, the electromagnetic wave is shielded in the direction perpendicular to the transmission line, and the inside of the waveguide line 5 surrounded by the conductor layers 2 and 3 and the via hole 4 It is propagated in the direction of the transmission line while reflecting.
[0043]
Further, according to FIG. 3, the slot 7 is formed in the conductor layer 2 formed on one surface of the waveguide line 5 made of a dielectric, and the high-frequency signal transmitted through the waveguide 5 is transmitted to the slot 7. It is radiated from and acts as a dielectric waveguide antenna. Further, another dielectric waveguide (not shown) is connected to the surface of the slot 7 so as to surround the slot 7, or as shown in FIG. 3, it penetrates the slot 7 and both ends are waveguide lines. 5 A via-hole conductor (not shown) that connects the inside and the conductor layer 6 for the patch antenna may be formed.
[0044]
Furthermore, it is possible to mount a high frequency element or a package (not shown) on which the high frequency element is mounted on the surface of the insulating substrate 1, particularly on the back surface of the conductor layer 6 formation surface.
[0045]
According to the present invention, the main feature is that the insulating substrate 1 is made of the above-described porcelain. Since the dielectric loss in the high frequency band of the porcelain is small, the high frequency signal is not attenuated in the waveguide line 5. Can be transmitted. In addition, the dielectric constant of the high-frequency porcelain is preferably 10 or less from the viewpoint of minimizing the dielectric loss or the conductor loss. From the viewpoint of preventing the mounting portion from being peeled off due to the stress generated due to the difference in thermal expansion from the printed circuit board containing the resin, and preventing the occurrence of cracks, etc., the thermal expansion of the high frequency porcelain from room temperature to 400 ° C. The coefficient is 8 × 10 ^-6 ~ 12x10 ^-6 It is desirable that the variation of the thermal expansion coefficient between the porcelains is 1 × 10 ^-6 It is desirable to be within.
[0046]
Further, another example of the high-frequency wiring board according to the present invention will be described based on a schematic cross-sectional view of the high-frequency package of FIG.
According to FIG. 4, the high-frequency package 20 has a cavity 23 formed by an insulating substrate 21 made of an insulating material and a lid 22, and a high-frequency such as Si, Si—Ge, Ga—As, etc. is formed in the cavity 23. An element 24 is mounted. The lid 22 is preferably made of a material that can prevent leakage of electromagnetic waves between the high-frequency element 24 and the outside.
[0047]
A wiring layer 25 electrically connected to the high frequency element 24 is formed on the surface of the insulating substrate 21. According to the present invention, a high frequency signal of 1 GHz or higher, particularly 20 GHz or higher, 50 GHz or higher, or even 70 GHz or higher is transmitted to the wiring layer 25. Therefore, the shape of the wiring layer 25 is a transmission loss of a high frequency signal. In order to reduce the length, it is preferable that the light source is composed of at least one of a strip line, a microstrip line, a coplanar line, and a dielectric waveguide line. The wiring layer 25 preferably contains any one of copper and silver low-resistance metals, and in particular, these metals are the main components in order to reduce transmission loss of high-frequency signals.
[0048]
In the package 20 of FIG. 4, the wiring layer 25 forms a microstrip line 27 together with the ground layer 26. A wiring layer 28 connected to the external circuit board is formed on the back surface of the insulating substrate 21, and a microstrip line 29 is formed together with the ground layer 26. The wiring layer 25 and the wiring layer 28 are electromagnetically coupled by forming the end portions of the wiring layers 25 and 28 so as to face each other through the slot holes 30 formed in the ground layer 26. A signal with less loss is transmitted between the microstrip line 27 and the microstrip line 29.
[0049]
According to the present invention, the structure of the wiring layer is not limited to the electromagnetic coupling structure described above. For example, the dielectric waveguide line as described above is laminated at the end of the microstrip line 27 in FIG. It is also possible to connect the dielectric waveguide line and the microstrip line 27 by a via-hole conductor that is disposed and penetrates a slot 30 provided in a part of the earth layer 26.
[0050]
4 has a configuration in which the high-frequency element 24 is hermetically sealed with the insulating substrate 21 and the lid body 22. However, the present invention is not limited to this, and the lid body 22 is formed. The high frequency element 24 may be sealed with a resin mold or the like.
[0051]
【Example】
Example 1
Three types of crystallized glass having the following compositions were prepared.
Glass A: SiO ₂ 50% by weight-Al ₂ O _Three 5.5 wt% -MgO 18.5 wt% -CaO 26 wt% (softening point 840 ° C.)
Glass B: SiO ₂ 47.5 wt% -Al ₂ O _Three 4.9 wt% -MgO 16.1 wt% -CaO 11.5 wt% -SrO 20 wt% (softening point 839 ° C.)
Glass C: SiO ₂ 10.4 wt% -Al ₂ O _Three 2.5% by weight-B ₂ O _Three 45.3% by weight—ZnO 35.2% by weight—Li 2 O 6.6% by weight (softening point 780 ° C.)
And the said crystallized glass powder with an average particle diameter of 1.8 micrometers and the ceramic powder of Table 1 with an average particle diameter of 7 micrometers were put in the container, and were mixed at 500 rpm. Al ₂ O _Three Powder, AlN powder, SiO ₂ As the powder, a powder in which 95% or more of the powder is composed of single crystal particles was used.
[0052]
About the obtained composite particles, the average particle diameter was measured by the microtrack method, and the coating thickness of the composite particles and the thickness of the reaction product layer were measured with a TEM (transmission electron microscope) of the particles to obtain 10 particles. The average value of was measured.
[0053]
Further, 100 g of water and 10 g of the composite particles were added into a roughly cylindrical container having a volume of 500 ml and a diameter of 50 mm, and the average particle diameter of the powder after mixing for 12 hours at a rotation speed of 50 times / minute was measured with Microtrac. The reduction rate of the average particle diameter was measured using a method. Further, the aspect ratio of the composite particles was calculated from the SEM photograph by the Luzex analysis method.
[0054]
(Example 2)
As the ceramic filler of the example, Al having an average particle diameter of 15 μm ₂ O _Three Except for using the powder in the ratio of Table 1, composite particles were prepared in the same manner as in the examples and evaluated in the same manner as in the examples (Sample No. 29). The results are shown in Table 1.
[0055]
(Comparative Example 1)
As the ceramic filler of the example, Al having an average particle size of 0.3 μm ₂ O _Three Except for using the powder in the ratio of Table 1, composite particles were prepared in the same manner as in the examples and evaluated in the same manner as in the examples (Sample No. 30). The results are shown in Table 1.
[0056]
(Comparative Example 2)
Water and hydrochloric acid were added to 50 ml of an ethanol solution of tetraethoxysilane for hydrolysis, and then 30 ml of trimethyl borate was added and mixed to prepare a sol solution. To this, Al of the example ₂ O _Three 100 g of powder was added and dried on a hot plate with stirring to produce composite particles, which were evaluated in the same manner as in the example (Sample No. 31). The results are shown in Table 1.
[0057]
(Comparative Example 3)
Example Al ₂ O _Three 100 g of powder and 100 g of borosilicate glass powder having a softening point of 750 ° C. were mixed, heated and melted, and then pulverized to produce composite particles, which were evaluated in the same manner as in the examples (Sample No. 32). The results are shown in Table 1.
[0058]
[Table 1]

[0059]
From the results in Table 1, the average particle size of Comparative Example 1 is 3.0 Sample No. smaller than μm In No. 30, the coating thickness was less than 0.05 μm. In addition, sample No. No. 31, it was suggested that the coating thickness was partially non-uniform, the average coating thickness exceeded 2 μm, and the reduction rate of the average particle size of the mixed particles exceeded 10% by mixing, and the glass layer was peeled off. . In addition, Sample No. In No. 32, the coating thickness was partially non-uniform, the average coating thickness exceeded 2 μm, and the thickness of the reaction product layer exceeded 100 nm.
[0060]
On the other hand, sample no. 2 to 29, all have an average particle diameter 3.0 The composite particles had a thickness of μm or more, a glass layer coating thickness of 0.05 to 2 μm, an average particle size reduction rate of 10% or less, a reaction product layer thickness of 100 nm or less, and an aspect ratio of 1.7 or less. In addition, from the result of the X-ray diffraction measurement, precipitation of the diopside crystal phase was observed in all the samples to which the glasses A and B were added.
[0061]
Next, for the composite particles in Table 1 shown in Tables 2 and 3 (in Tables 2 and 3, the sample No. in Table 1 is described as the type of composite particles), Tables 2 and 3 having an average particle diameter of 2 μm The glass powder shown, an organic binder, a plasticizer, and toluene were added and mixed in a rotary mill for 12 hours to prepare a slurry, and then a green sheet having a thickness of 300 μm was prepared using this slurry by a doctor blade method. And 10-15 sheets of this green sheet were laminated | stacked, the pressure of 10 Mpa was applied at the temperature of 50 degreeC, and the thermocompression bonding was carried out. The obtained laminate was debindered at 700 ° C. in a steam-containing / nitrogen atmosphere, and then fired in dry nitrogen under the conditions shown in Table 2 to obtain glass ceramics.
[0062]
The relative density of the porcelain was measured based on the Archimedes method for the obtained glass ceramics, and the dielectric constant, dielectric loss, bending strength, thermal expansion coefficient, and thermal conductivity were evaluated by the following methods.
[0063]
The dielectric constant and dielectric loss were cut into a shape having a diameter of 2 to 7 mm and a thickness of 2 to 2.5 mm, and the dielectric cylinder resonator method was performed using a network analyzer and a synthesized sweeper at 60 GHz. In the measurement, the NRD guide (non-radiative dielectric line) is used to excite the dielectric resonator, and TE ₀₂₁ Or TE ₀₃₁ The dielectric constant and dielectric loss were calculated from the resonance characteristics of the mode.
[0064]
Further, the sample was cut into a shape of width 4 mm × thickness 3 mm × length 70 mm, and a three-point bending test was performed based on the provisions of JISC-2141. Furthermore, the thermal expansion coefficient from room temperature to 400 ° C. was taken, and the thermal expansion coefficient was calculated. In addition, the thermal conductivity of a sample having a thickness of 1 mm was measured by a laser flash method.
[0065]
Further, from the SEM (scanning electron microscope) photograph on the polished surface of the porcelain, the average particle diameter d of the ceramic filler particles and the average distance r between the five closest ceramic fillers for the 20 adjacent ceramic fillers are determined by the area ratio, A ratio of r <0.6d was determined. The results are shown in Tables 2 and 3.
[0066]
[Table 2]

[0067]
[Table 3]

[0068]
As is clear from the results in Tables 2 and 3, Sample No. using particles not coated with glass. For No. 33, the variation in the distance between the ceramic filler particles was large, the dielectric loss was high, and the strength was low. In addition, sample no. In No. 34, the glass ceramic could not be densified at 1000 ° C. or lower. Furthermore, the average particle size of Comparative Example 1 is 3.0 Sample No. using composite particles smaller than μm. 63 and Sample No. using the composite particles of Comparative Example 2. 64, it was not possible to densify the glass ceramics by firing at 1000 ° C., and sample No. 6 using the composite particles of Comparative Example 3 was used. 65, and sample No. using only glass. In No. 66, the distance between the ceramic filler particles was large, the dielectric loss was high, and the strength and thermal conductivity were low.
[0069]
On the other hand, in accordance with the present invention, sample No. 1 in which the distance between the ceramic filler particles of the glass ceramic was uniformly shortened using the composite particles described above. 35-62, the dielectric loss at 60 GHz is 20 × 10 ^-Four Hereinafter, it had excellent characteristics with a strength of 250 MPa or more and a thermal conductivity of 2.5 W / m · K or more.
[0070]
【The invention's effect】
As described above in detail, the composite particles of the present invention are obtained by dry mixing ceramic powder and glass powder to collide, contact, and rub the particles, thereby forming a glass layer with a uniform thickness on the surface of the ceramic particles with high strength. Since it can be formed by deposition, a low-temperature fired ceramic with an increased content of the ceramic filler can be produced, and a wiring substrate as an insulating substrate can be produced.
[Brief description of the drawings]
FIG. 1 is a schematic view of a composite particle of the present invention.
FIG. 2 is a schematic view for explaining the structure of the porcelain of the present invention.
FIG. 3 is a schematic cross-sectional view of a high-frequency wiring board including a dielectric antenna that is an example of a high-frequency wiring board using the high-frequency porcelain of the present invention.
FIG. 4 is a schematic cross-sectional view of a package for housing a semiconductor element, which is another example of a high-frequency wiring board using the high-frequency porcelain of the present invention.
[Explanation of symbols]
X composite particles
Y ceramic particles
Z glass layer
o Glass ceramics
p glass phase
q Ceramic filler particles
d Particle size of ceramic filler particles
r Distance between adjacent particles
1 Insulating substrate
2, 3 Conductor layer
4 Beer hall
5 Waveguide line
6 Conductor layer
7 slots
20 High frequency package
21 Insulating substrate
22 Lid
23 cavity
24 high frequency element
25, 28 Wiring layer
26 Earth layer
27, 29 Microstrip line
30 slot holes

Claims (13)

A composite particle having an average particle size of 3.0 μm or more and a ceramic particle surface coated with a glass layer having a thickness of 0.05 to 2 μm, and having a volume of 500 ml in a cylindrical container having a diameter of 50 mm When 100 g of water and 10 g of the composite particles are added to and mixed with a rotary mill at a rotation speed of 50 times / min for 12 hours, the average particle size reduction rate of the composite particles is 10% or less. Composite particles.   The composite particle according to claim 1, wherein a reaction product layer is present between the ceramic particle and the glass layer in a thickness of 100 nm or less.   The composite particle according to claim 1, wherein the composite particle has an approximately spherical shape with an average aspect ratio of 1.7 or less. The ceramic particles are Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , CaTiO ₃ , SrTiO ₃ , cordierite, enstatite, forsterite, steatite, willemite, ZnTiO ₃ , Zn ₂ TiO ₄ , diopside, ZrO _{2. 4.} The composite particle according to claim 1, comprising at least one selected from the group consisting of MgO, AlN, SiC, and Si ₃ N ₄ as a main component. 5. The composite particle according to claim 1, wherein the glass layer contains SiO ₂ , Al ₂ O ₃ , and an alkaline earth metal oxide. 6. The composite particle according to claim 1, wherein the glass layer further contains B ₂ O ₃ at a ratio of 16 wt% or less.   The composite particles according to any one of claims 1 to 6, wherein the PbO and alkali metal oxide contents in the glass layer are each 10% by weight or less.   Glass and / or crystal precipitated from glass and ceramic particles as a filler, and a glass ceramic having a relative density of 90% or more, the adjacent ceramic in a scanning electron micrograph of a polished surface of the glass ceramic The glass ceramics characterized in that the distance between the particles is 90% or more at a ratio of 60% or less of the average particle diameter of the ceramic particles.   The glass ceramic according to claim 8, wherein the ceramic filler has a substantially spherical shape with an average aspect ratio of 1.7 or less. The ceramic filler is Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , CaTiO ₃ , SrTiO ₃ , cordierite, enstatite, forsterite, steatite, willemite, ZnTiO ₃ , Zn ₂ TiO ₄ , diopside, ZrO _2. The glass ceramic according to claim 8 or 9, comprising at least one selected from the group consisting of MgO, AlN, SiC, and Si ₃ N ₄ as a main component. Crystals precipitated from the glass are selected from the group consisting of MgTiO ₃ , CaTiO ₃ , SrTiO ₃ , cordierite, enstatite, forsterite, steatite, willemite, ZnTiO ₃ , Zn ₂ TiO ₄ , diopside, anorthite and sulsonite. The glass ceramic according to any one of claims 8 to 10, comprising at least one selected.   The glass ceramic according to any one of claims 8 to 11, wherein a content ratio of the ceramic filler is 50% by weight or more.   A wiring board in which a conductive layer comprising copper or silver as a main component and integrated by sintering is formed on a surface of the insulating board, wherein the insulating board is made of the glass ceramic according to any one of claims 8 to 12. Wiring board.

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