JP2006137618A - Dielectric ceramic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric ceramic substrate which is obtained by burning the powder mixture of dielectric materials and glass, hardly generates damage due to chipping when cutting and has high flexural strength. <P>SOLUTION: The dielectric ceramic substrate 1 is obtained by burning the layered material which is prepared by layering a hardly chipping material layer 3 comprising the powder mixture of dielectric materials and glass consisting mainly of an amorphous one on both sides of a high-strength material layer 2 comprising the above powder mixture in which glass is mainly a crystalline one. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dielectric ceramic substrate obtained by firing a mixture of dielectric powder and glass powder.

  In mobile communication devices such as mobile phones and mobile communication terminals that have become widespread in recent years, miniaturization and high performance of high-frequency circuit components used in these devices are required due to demands for miniaturization.

  For high-frequency circuit boards, instead of conventional modules that have surface-mounted capacitors and inductors on printed circuit boards, capacitors with a pattern of capacitors and inductors are formed and laminated on a dielectric ceramic substrate so that they can be miniaturized. It is becoming.

  In addition, such a dielectric ceramic substrate has been used as a semiconductor package substrate on which a semiconductor element is mounted. By using a ceramic ceramic material such as alumina and a glass ceramic material that can be fired at a low temperature as a material used for manufacturing such a dielectric ceramic substrate, it becomes possible to fire at a low temperature of about 900 ° C. .

  As the dielectric ceramic substrate, generally, a mother substrate is manufactured, and the mother substrate is cut into individual dielectric ceramic substrates. However, conventionally, there has been a problem that the substrate is easily damaged by chipping during cutting. In addition, when a material which does not easily cause chipping is used, there is a problem that the bending strength of the substrate after firing becomes low and is insufficient.

  In Patent Document 1, in a composite laminated ceramic component having a structure in which a conductor layer is formed and laminated on a laminated surface of a high dielectric constant layer and a low dielectric constant layer, the interface between the low dielectric constant layer and the high dielectric constant layer is peeled or each layer is separated. In order to suppress cracks occurring in the substrate, it has been proposed to form the low dielectric constant layer from a mixed material of ceramic powder and amorphous glass.

  In Patent Document 2, in the manufacture of ceramic electronic components such as a ceramic multilayer substrate or a multilayer capacitor element manufactured by firing a ceramic green sheet at a low temperature, the glass ceramic substrate green sheet is sandwiched between dummy green sheets and fired. It has been proposed to remove the dummy green sheet.

In Patent Document 3, in the composite multilayer electronic component, in order to enhance the bondability between different material layers and make it difficult to generate cracks, on both sides of the functional layer mainly composed of amorphous glass having a softening point of 800 ° C. or lower, It has been proposed to provide a base layer composed mainly of crystallized glass and oxide ceramic.
Japanese Patent Laid-Open No. 10-106880 Japanese Patent Laid-Open No. 11-157945 JP 2001-351827 A

  An object of the present invention is to provide a dielectric ceramic substrate which is less likely to be damaged by chipping and has a high bending strength when cutting.

  The present invention relates to a dielectric ceramic substrate obtained by firing a mixture of dielectric powder and glass powder, which is a high-strength material comprising a mixture of dielectric powder using crystalline glass as a main component as glass powder A low chipping material layer made of a mixture of a dielectric powder using amorphous glass as a main component as a glass powder is disposed on both sides of the layer to form a laminate, which is obtained by firing the laminate. Yes.

  According to the present invention, a laminate having a low chipping material layer disposed on both sides of a high strength material layer is fired to form a dielectric ceramic substrate, so that it is difficult to cause damage due to chipping during cutting and has a high bending strength. It can be a body ceramic substrate.

  Examples of the dielectric powder used in the present invention include alumina, spinel, willemite and the like, and alumina is particularly preferably used.

In the present invention, the crystalline glass powder used for the high-strength material layer is a crystalline glass powder that precipitates a diopside crystal phase (Ca (Mg, Al) (Si, Al) ₂ O ₆ ) after firing. Is preferably used. Examples of such crystalline glass powder include those containing SiO ₂ , CaO and MgO as main components.

  In the high strength material layer and the low chipping material layer, the mixing ratio of the dielectric powder and the crystalline glass powder or the amorphous glass powder is the weight ratio of the dielectric powder: the crystalline glass powder or the amorphous glass powder, It is preferably in the range of 20:80 to 45:55.

The composition of the crystallizable glass powder in the present _invention, SiO 2 30 to 60 wt%, preferably CaO15~35 wt%, and MgO25~45 wt%.

  In the present invention, the low chipping material layer is mainly composed of the dielectric powder and the amorphous glass powder. The low chipping material layer preferably contains an anorthite phase after firing. As the amorphous glass powder, borosilicate glass is preferably used.

  In the dielectric ceramic substrate of the present invention, the low chipping material layer is disposed on both sides of the high strength material layer. The total thickness of the low chipping material layers provided on both sides is preferably 10% to 90% of the total thickness after firing, and more preferably about 20% to 80%. If the thickness of the low chipping material layer becomes too thin, the effect of reducing damage due to chipping may not be sufficiently obtained. On the other hand, if the thickness of the low chipping material layer is too thick, the thickness of the high strength material layer is relatively thin, so that the bending strength may be too low.

  In the present invention, a low chipping material layer is disposed on both sides of the high-strength material layer to form a laminate, and this laminate is fired to obtain a dielectric ceramic substrate. Although a calcination temperature is not specifically limited, It is preferable that it is about 800 to 900 degreeC. The firing time at the maximum temperature is preferably about 0.5 hours to 10 hours, more preferably 1 hour to 5 hours. The maximum temperature during firing is preferably set to a temperature higher than the crystallization start temperature of the crystalline glass powder.

  In the present invention, the high strength material layer and the low chipping material layer are preferably produced as green sheets. The green sheet of the high-strength material layer can be prepared by mixing a crystalline glass powder and a dielectric powder in a solution containing a binder to produce a slurry, and producing a green sheet from this slurry. The low chipping material layer can be prepared by mixing an amorphous glass powder and a dielectric powder in a solution containing a binder to produce a slurry, and a green sheet can be produced from this slurry. Thus, the dielectric ceramic substrate of the present invention can be obtained by laminating green sheets and firing the pressure-bonded ones.

  In the dielectric ceramic substrate of the present invention, a wiring layer may be formed inside and / or on the surface thereof. By forming such a wiring layer, a capacitor or inductor pattern can be formed on the ceramic substrate.

  The semiconductor package substrate of the present invention uses the dielectric ceramic substrate of the present invention. The dielectric ceramic substrate of the present invention can be used as a semiconductor package substrate on which a semiconductor element is thus placed.

  The present invention is obtained by firing a laminated body in which a low chipping material layer is disposed on both sides of a high strength material layer, and a low chipping material layer having excellent chipping resistance is provided on the outside. Therefore, damage due to chipping hardly occurs during cutting. Moreover, since the high strength material layer with high mechanical strength is provided inside, it has high bending strength.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to a following example.

[Production of high-strength material layer green sheet]
450 g of α-alumina powder (average particle diameter 3 μm) and 550 g of crystalline glass powder (SiO ₂ 50 wt%, CaO 20 wt%, MgO 30 wt%, average particle diameter 3 μm, softening point 750 ° C., crystallization start temperature 800 ° C.) In addition, 450 g of isopropanol (IPA), 300 g of butyl acetate, 20 g of olefin maleic acid copolymer dispersion, 120 g of polyvinyl acetate binder, and 50 g of acrylic binder were pulverized with a ball mill for 4 hours and mixed.

  The obtained slurry was formed into a green sheet having a thickness of 100 μm using a doctor blade device. This sheet was cut out to a size of 100 mm × 100 mm to obtain a sheet A.

[Preparation of green sheet with low chipping material layer]
α-alumina powder (average particle size 3 μm) 450 g, amorphous glass powder (SiO ₂ 40 wt%, B ₂ O ₃ 35 wt%, Al ₂ O ₃ 15 wt%, CaO 10 wt%, average particle size 3 μm, softening 550 g of a point 700 ° C), 450 g of isopropanol (IPA), 300 g of butyl acetate, 20 g of an olefin maleic acid copolymer dispersion, 120 g of a polyvinyl acetate binder, and 50 g of an acrylic binder were pulverized with a ball mill for 4 hours and mixed.

  The obtained slurry was formed into a green sheet having a thickness of 50 μm using a doctor blade device. This sheet was cut out to a size of 100 mm × 100 mm to obtain a sheet B.

(Production of laminate)
Example 1
Two sheets A were superposed, and one sheet B was placed on each of the upper and lower sides of the sheets A and laminated, and these were pressed to form a laminate.

(Comparative Example 1)
Two sheets of the sheet B were superposed, and one sheet A was placed on each of the upper and lower sides of the sheet B and laminated, and this was pressure-bonded to obtain a laminate.

(Comparative Example 2)
Two sheets A were superposed to form a laminate.

(Comparative Example 3)
Four sheets B were superposed to form a laminate.

[Baking of laminate]
A test piece of 25 mm × 25 mm (for chipping evaluation) and a test piece of 50 mm × 5 mm (for bending strength evaluation) were cut out from the laminates of Example 1 and Comparative Examples 1 to 3, and each was at 900 ° C. for 2 hours. Firing was performed to obtain each dielectric ceramic substrate.

  In Example 1, a dielectric ceramic substrate 1 in which a low chipping material layer 3 was disposed on both sides of a high-strength material layer 2 was obtained as shown in FIG.

[Measurement of chipping width]
About each baking sample of Example 1 and Comparative Examples 1-3, the chipping width which generate | occur | produces in the case of a cutting | disconnection was measured. As a dicing blade, a disco resin blade (model number 800, thickness 0.15 mm) was used, and cutting was performed by moving the blade relative to the sample as shown in FIG. Specifically, cutting was performed on the sample (dielectric ceramic substrate) 1 while moving the blade 4 in the direction of arrow B relative to the sample 1 while rotating the blade 4 in the direction of arrow A. The feed speed of the blade 4 was 20 mm / second, and the rotation speed of the blade 4 was 30000 rpm. Further, cutting was performed while supplying cutting water at a flow rate of 1.0 liter / min.

  The chipping width (chipping width) generated during cutting was read with an optical microscope. The measurement results are shown in Table 1.

[Measurement of bending strength]
About each baked sample of Example 1 and Comparative Examples 1-3, in accordance with JIS R1601 (Japanese Industrial Standard: bending strength test method of fine ceramics) (however, the thickness of the sample is not limited thereto) The bending strength (3-point bending strength) was measured. The measurement results are shown in Table 1.

[Measurement of X-ray diffraction pattern]
About each baking sample of Example 1 and Comparative Examples 1-3, the X-ray-diffraction (XRD) pattern was measured. Table 1 shows peaks observed by X-ray diffraction.

  As shown in Table 1, it can be seen that the dielectric ceramic substrate of Example 1 according to the present invention has a small chipping width and a high bending strength. In Comparative Example 1 in which the high strength material layers are arranged on both sides of the low chipping material layer, the bending strength is high, but the chipping width is large. Further, in Comparative Example 2 in which only the high-strength material layer is laminated, the chipping width is large. Further, in Comparative Example 3 in which only the low chipping material layer is laminated, the chipping width is small, but the bending strength is low.

  Further, as is apparent from Table 1, in the dielectric ceramic substrate according to the present invention, alumina, diopside, anorthite, and an amorphous phase are confirmed by X-ray diffraction.

  As described above, according to the present invention, by providing the low chipping material layer on both sides of the high strength material layer, it is possible to obtain a dielectric ceramic substrate which is hardly damaged by chipping and has a high bending strength.

  3 and 4 are an exploded perspective view and a perspective view showing an embodiment of the multilayer ceramic substrate of the present invention. As shown in FIG. 3, an electrode layer 7 made of silver is formed on the dielectric layer 6. By laminating and firing such a dielectric layer 6, a dielectric ceramic substrate 5 having a wiring layer provided inside and / or on the surface as shown in FIG. 4 is obtained. The dielectric ceramic has a length of 0.3 mm to 10 mm, a width of 0.3 mm to 10 mm, and a thickness of 0.3 mm to 5 mm.

  5 and 6 are an exploded perspective view and a perspective view showing a semiconductor package substrate which is an embodiment of the multilayer ceramic substrate of the present invention. As shown in FIG. 5, an electrode layer 7 made of silver is formed on the dielectric layer 6. An appropriate wiring pattern of the electrode layer 7 is formed on the dielectric layer 6 and laminated so that the electrode layer is on the outer surface, whereby the semiconductor package substrate 8 shown in FIG. 6 is obtained. The semiconductor package substrate has a length of 0.3 mm to 30 mm, a width of 0.3 mm to 30 mm, and a thickness of 0.3 mm to 5 mm.

  By using the dielectric ceramic material of the present invention as the material of the dielectric layer 6, as described above, a multilayer ceramic substrate, a semiconductor package substrate or the like that can be fired at a low temperature and has a high bending strength can be obtained.

Sectional drawing which shows the dielectric material ceramic substrate according to this invention. The schematic diagram which shows the arrangement | positioning state of the braid | blade and sample in a chipping evaluation test. 1 is an exploded perspective view of a multilayer ceramic substrate of one embodiment according to the present invention. 1 is a perspective view of a multilayer ceramic substrate of one embodiment according to the present invention. FIG. The disassembled perspective view of the semiconductor package board | substrate of one Example according to this invention. The perspective view of the semiconductor package board | substrate of one Example according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dielectric ceramic substrate 2 ... High-strength material layer 3 ... Low chipping material layer 4 ... Blade 5 ... Multilayer ceramic substrate 6 ... Dielectric layer 7 ... Electrode layer 8 ... Semiconductor package substrate

Claims (6)

A dielectric ceramic substrate obtained by firing a mixture of dielectric powder and glass powder,
On both sides of a high-strength material layer made of a mixture with the dielectric powder using crystalline glass as a main component as the glass powder, the dielectric powder using amorphous glass as a main component as the glass powder A dielectric ceramic substrate obtained by arranging a low chipping material layer made of a mixture to form a laminate and firing the laminate.   The dielectric ceramic substrate according to claim 1, wherein the dielectric powder is alumina.   3. The dielectric ceramic substrate according to claim 1, wherein the high-strength material layer includes a diopside crystal phase after firing.   The dielectric ceramic substrate according to claim 1, wherein the low chipping material layer includes an anorthite phase.   The dielectric ceramic substrate according to claim 1, wherein a wiring layer is provided inside and / or on the surface. A package substrate for a semiconductor comprising the dielectric ceramic substrate according to claim 1.

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