WO2013008919A1 - セラミックス回路基板 - Google Patents
セラミックス回路基板 Download PDFInfo
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- WO2013008919A1 WO2013008919A1 PCT/JP2012/067956 JP2012067956W WO2013008919A1 WO 2013008919 A1 WO2013008919 A1 WO 2013008919A1 JP 2012067956 W JP2012067956 W JP 2012067956W WO 2013008919 A1 WO2013008919 A1 WO 2013008919A1
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- circuit board
- alumina substrate
- alumina
- mass
- ceramic circuit
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
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Definitions
- the present invention relates to a ceramic circuit board using an alumina substrate.
- ceramic circuit boards in which metal plates such as a copper plate, an aluminum plate, and various clad plates are bonded on a ceramic substrate are widely used as circuit substrates such as a power transistor module substrate and a switching power supply module substrate.
- a ceramic substrate an inexpensive and highly versatile alumina (Al 2 O 3 ) substrate, an aluminum nitride (AlN) substrate having electrical insulation and excellent thermal conductivity, or high-strength silicon nitride ( A Si 3 N 4 ) substrate or the like is generally used.
- Al 2 O 3 alumina
- AlN aluminum nitride
- a Si 3 N 4 high-strength silicon nitride
- an alumina substrate is advantageous in that it is inexpensive and highly versatile.
- FIG. 1 is a plan view showing an example of a configuration on the pattern surface side of a ceramic circuit board.
- FIG. 2 is a cross-sectional view taken along line AA of the ceramic circuit board shown in FIG.
- FIG. 3 is a bottom view showing an example of the configuration of the back side of the ceramic circuit board shown in FIG.
- the ceramic circuit board 1 has a metal circuit board 3 such as a copper plate bonded or formed on one surface of the ceramic board 2 and the other surface being the back surface of the ceramic board 2. It is formed by joining a back metal plate 4 such as a copper plate.
- the metal circuit board 3 is composed of various metal plates bonded to the surface of the ceramic substrate 2 or a metal layer formed on the surface of the ceramic substrate 2.
- the direct bonding method is, for example, a method of directly bonding the ceramic substrate 2 and the metal circuit board 3 by generating a eutectic liquid phase at the interface between the ceramic substrate 2 and the metal circuit board 3.
- the direct bonding method will be specifically described by taking as an example the case where the metal circuit board 3 is a copper circuit board.
- a copper circuit board 3 punched into a predetermined shape is placed in contact with a ceramic substrate 2 and heated to generate a eutectic liquid phase such as Cu—Cu 2 O or Cu—O at the bonding interface.
- the wettability between the ceramic substrate 2 and the copper circuit board 3 is enhanced by the crystal phase.
- this eutectic liquid phase is cooled and solidified, the ceramic substrate 2 and the copper circuit board 3 are directly joined together to obtain the ceramic circuit board 1.
- This method is a so-called direct copper bonding method (DBC method: Direct Bonding Copper method).
- the refractory metal metallization method is a method of obtaining the ceramic circuit substrate 1 by integrating the ceramic substrate 2 and the metal circuit layer by baking a refractory metal such as Mo or W onto the surface of the ceramic substrate 2.
- the active metal method is such that, for example, a metal plate 3 such as a copper circuit board is placed on the ceramic substrate 2 via an Ag—Cu brazing material layer containing an active metal such as a group 4A element such as Ti, Zr, and Hf. Is a method of obtaining the ceramic circuit board 1 by integrally bonding the two.
- the bonding strength between the brazing material layer and the copper circuit board 3 is increased by the Cu and Ag components of the brazing material layer, and the bonding between the brazing material layer and the ceramic substrate 2 is performed by the Ti, Zr, and Hf components. Strength increases.
- the ceramic circuit board 1 obtained by the direct bonding method or the active metal brazing method has a high bonding strength between the ceramic substrate 2 and the metal circuit board 3 and has a simple structure. For this reason, the ceramic circuit board 1 is advantageous in that it can be miniaturized and highly mounted, has the effect of shortening the manufacturing process, and can be applied to a large current type or highly integrated semiconductor chip. ing.
- the thickness of the ceramic board 2 is reduced to about 0.25 to 0.38 mm to reduce the thermal resistance.
- a ceramic circuit board 1 that improves the flexibility of the ceramic board 2 and prevents the metal circuit board 3 from peeling off is known.
- an alumina substrate having a purity as high as about 96% is used as the ceramic substrate 2, and this alumina is used.
- Patent Document 1 discloses a ceramic circuit board using a high-purity alumina substrate having a purity of 99.5% or more.
- Patent Document 1 a ceramic circuit board having excellent properties such as strength and Vickers hardness is obtained by setting the alumina purity to 99.8%.
- the ceramic circuit board described in Patent Document 1 can have excellent properties such as strength and Vickers hardness by using an alumina substrate as a high-purity alumina substrate.
- an advantage of selecting and using an alumina substrate from various ceramic substrates is that the alumina substrate is less expensive than an aluminum nitride substrate or a silicon nitride substrate. Since the ceramic circuit board described in Patent Document 1 uses a high-purity alumina substrate as the ceramic substrate, there has been a problem that the merit of the alumina substrate being inexpensive is not fully exhibited.
- the present invention has been made in view of the above circumstances, and an object thereof is to provide a ceramic circuit board excellent in characteristics such as bonding strength and Vickers hardness by using an inexpensive alumina substrate which is not highly pure as a ceramic substrate. To do.
- the inventors of the present application are alumina substrates obtained by cauterization using alumina powder and a sintering aid containing at least silicon oxide as a raw material, and are derived from the sintering aid generated from the sintering aid. It has been found that according to an alumina substrate containing a predetermined amount of components, an alumina substrate having high sinterability, cost reduction, and high Vickers hardness can be obtained. The inventors of the present application have found that a ceramic circuit board having excellent bonding strength can be obtained by using this alumina substrate, and have completed the present invention.
- the ceramic circuit board of the present invention solves the above-mentioned problem.
- the alumina substrate contains 94 to 98% by mass of alumina Al 2 O 3 , And 2 to 6% by mass of a component derived from a sintering aid produced from a sintering aid blended before sintering, and the component derived from a sintering aid is an inorganic oxide containing silicon, Silicon in the binder-derived component is contained in an amount of 0.01 to 1.5% by mass in 100% by mass of the alumina substrate in terms of silicon oxide SiO 2 , and the alumina substrate has a maximum void diameter of 15 ⁇ m or less.
- the void average diameter is 10 ⁇ m or less, and the Vickers hardness is 1300 or more.
- the component derived from the sintering aid is an inorganic oxide further containing calcium, and the calcium in the component derived from the sintering aid is 100 mass by mass in terms of calcium oxide CaO. % Is preferably contained in an amount of 0.001 to 1.5 mass%.
- the sintering aid-derived component is an inorganic oxide further containing magnesium, and magnesium in the sintering aid-derived component is 100 mass of the alumina substrate in terms of mass converted to magnesium oxide MgO. % Is preferably contained in an amount of 0.001 to 1.0 mass%.
- the sintering aid-derived component is an inorganic oxide further containing sodium, and the sodium in the sintering aid-derived component is the alumina substrate in a mass converted to sodium oxide Na 2 O. It is preferable that 0.001 to 0.5% by mass is contained in 100% by mass.
- the alumina substrate preferably has an average crystal grain size of alumina crystal grains of 20 ⁇ m or less.
- Ceramic circuit board of the present invention the alumina substrate, relative to the total number N t of alumina crystal grains observed in the observation range of the unit area 200 [mu] m ⁇ 200 [mu] m by observation of the cross section is observed within the observation range, alumina crystal grains It is preferable that the ratio N A / N t of the number N A of alumina crystal grains in the range of 0.3 A to 1.7 A when the average crystal grain size is A ⁇ m is 70% or more.
- the alumina substrate preferably has 5 to 50 voids per unit area of 100 ⁇ m ⁇ 100 ⁇ m calculated by cross-sectional observation.
- the alumina substrate preferably has a void area ratio, which is a void area ratio calculated by observing a cross section of the alumina substrate, of 20% or less.
- the alumina substrate has a withstand voltage of 15 KV / mm or more.
- the alumina substrate preferably has a thermal conductivity of 20 W / m ⁇ K or more.
- the alumina substrate preferably has a bending strength of 300 MPa or more.
- the metal circuit board is bonded to the alumina substrate by a direct bonding method.
- the metal circuit board is preferably a copper circuit board, and the copper circuit board is preferably bonded to the alumina substrate by a Cu—O eutectic compound.
- the metal circuit board is a copper circuit board, and the copper circuit board preferably contains 0.1 to 1.0% by mass of carbon.
- the curve along the surface of the metal circuit board is It is preferable to have an intricate structure in which the ratio of contact with the curve along the surface irregularities is 95% or more.
- the alumina substrate preferably has a thickness of 0.25 to 1.2 mm.
- the metal circuit board preferably has a thickness of 0.1 to 0.5 mm.
- the cost can be significantly reduced.
- a predetermined amount of the sintering aid-derived component containing silicon is included, characteristics such as bonding strength are high.
- FIG. 2 is a cross-sectional view taken along the line AA of the ceramic circuit board shown in FIG.
- the bottom view which shows an example of the structure of the back surface side of the ceramic circuit board shown in FIG.
- 2 is an SEM photograph of a bonding interface of a ceramic circuit board according to Example 1.
- the ceramic circuit board of the present invention will be described.
- the ceramic circuit board of the present invention is a ceramic circuit board in which a metal circuit board is bonded on an alumina substrate.
- the ceramic circuit board of the present invention is, for example, a ceramic circuit board 1 in which a metal circuit board 3 is bonded on one surface of an alumina substrate 2 as shown in FIG.
- FIG. 1 shows an example in which a back metal plate 4 such as a copper plate is bonded to the other surface of the alumina substrate 2, that is, the surface on the back surface side.
- the ceramic circuit substrate of the present invention is an alumina substrate.
- the metal circuit board 3 may be joined to both surfaces on one surface of 2 and the other surface.
- the alumina substrate contains 94 to 98% by mass of alumina Al 2 O 3 and 2 to 6% by mass of a sintering aid-derived component produced from the sintering aid blended before sintering.
- the alumina substrate used in the present invention is a polycrystal composed of many alumina crystal grains, and the sintering aid-derived component is a glass phase present at the grain boundaries of the alumina crystal grains.
- the total amount of the alumina Al 2 O 3 and the sintering aid-derived component is preferably 100% by mass.
- the sintering auxiliary agent-derived component may contain inevitable impurity components that are components other than the sintering auxiliary component.
- the sintering aid component and the inevitable impurity component will be described in detail later.
- the sintering aid component is a substance obtained by converting Si, Ca, Mg, and Na into the same oxide as the sintering aid. Examples of the sintering aid component include SiO 2 , CaO, MgO, and Na 2 O.
- an inevitable impurity component is the remainder remove
- the inevitable impurity component contained in the sintering aid-derived component may be contained in 100% by mass of the alumina substrate in an amount of 0.5% by mass or less.
- the sintering aid-derived component contained in the alumina substrate is a raw material of the alumina substrate of the present invention, and the sintering aid blended with the alumina powder before sintering became a liquid phase by heat treatment during sintering. Later, it means an inorganic oxide that has solidified into a glass phase.
- the component derived from the sintering aid is contained in the alumina substrate in an amount of 2 to 6% by mass.
- the sintering substrate-derived component contained in the alumina substrate is less than 2% by mass, when the alumina substrate is produced by sintering the mixture containing the alumina powder as a raw material of the alumina substrate and the sintering aid.
- the amount of the sintering aid is too small, the alumina substrate may be insufficiently sintered or the sintering time may be prolonged.
- Patent Document 2 Japanese Patent Laid-Open No. 2005-281063
- the component derived from the sintering aid contained in the alumina substrate exceeds 6% by mass, the amount of the sintering aid is too large when the alumina substrate is produced. Strength tends to decrease.
- the sintering aid-derived component contained in the alumina substrate is an inorganic oxide containing at least silicon.
- Silicon in the binder-derived component is contained in an amount of 0.01 to 1.5% by mass, preferably 0.5 to 1.3% by mass in 100% by mass of the alumina substrate in terms of mass converted to silicon oxide SiO 2 .
- the mass of silicon converted to silicon oxide SiO 2 is 0.01 to 1.5% by mass in 100% by mass of the alumina substrate, the amount of the sintering aid containing silicon is appropriate when the alumina substrate is produced. Therefore, the sinterability is increased, and the sintering time of the alumina substrate is shortened.
- the mass of silicon converted to silicon oxide SiO 2 is less than 0.01% by mass in 100% by mass of the alumina substrate, the action of the sintering aid containing silicon becomes insufficient, and the alumina substrate machine The mechanical strength tends to decrease.
- the mass in terms of silicon oxide, silicon SiO 2 is more than 1.5 mass% in 100 mass% alumina substrate, the thermal conductivity of the alumina substrate tends to decrease.
- the component derived from the sintering aid contained in the alumina substrate is preferably an inorganic oxide further containing calcium in addition to silicon.
- Calcium in the sintering aid-derived component is usually contained in an amount of 0.001 to 1.5% by mass, preferably 0.01 to 1.0% by mass in 100% by mass of the alumina substrate in terms of mass in terms of calcium oxide CaO. .
- the component derived from the sintering aid contained in the alumina substrate is preferably an inorganic oxide further containing magnesium in addition to silicon or silicon and calcium.
- Magnesium in the sintering aid-derived component is usually contained in an amount of 0.001 to 1.0% by mass, preferably 0.01 to 0.5% by mass in 100% by mass of the alumina substrate in terms of the mass converted to magnesium oxide MgO. .
- the sintering aid-derived component contained in the alumina substrate is preferably an inorganic oxide further containing sodium in addition to silicon or at least one element selected from calcium and magnesium and silicon.
- Sodium in the sintering aid-derived component is usually 0.001 to 0.5% by mass, preferably 0.01 to 0.2% by mass in 100% by mass of the alumina substrate in terms of mass converted to sodium oxide Na 2 O. included.
- the sintering aid-derived component is an inorganic oxide further containing at least one element selected from calcium (Ca), magnesium (Mg), and sodium (Na) in addition to silicon (Si).
- the binder-derived component is an inorganic oxide containing only silicon (Si)
- the sintering aid in the state before sintering of the sintering aid-derived component is one or more oxides selected from Ca oxide, Mg oxide, and Na oxide in addition to Si oxide
- it contains further it will become easy to form the glass phase used as a grain-boundary phase.
- the sintering aid-derived component is an inorganic oxide containing all of silicon (Si), calcium (Ca), magnesium (Mg), and sodium (Na)
- the sintering aid-derived component is a homogeneous glass phase. Most preferable because it is very easy to form.
- the substance which converted Si, Ca, Mg, and Na and the compound of these elements into the same oxide as a sintering auxiliary agent among sintering auxiliary agent origin components is called a sintering auxiliary agent component.
- the sintering aid-derived component is an inorganic oxide containing Si, Ca, Mg, and Na, and compounds of these elements, these elements are converted into the same oxide as the sintering aid.
- Certain SiO 2 , CaO, MgO, and Na 2 O are sintering aid components.
- components other than the sintering aid component among the sintering aid-derived components are referred to as inevitable impurity components.
- the alumina crystal grains of the alumina substrate have an average crystal grain size of usually 20 ⁇ m or less, preferably 10 ⁇ m or less. Since the alumina substrate used in the present invention has high sinterability, the average crystal grain size of the alumina crystal grains becomes as small as 20 ⁇ m or less.
- the average and the crystal grain size is the average value of the grain diameter D c calculated from a plurality of alumina crystal grains observed by cross-sectional observation of the alumina substrate as follows. That is, as shown in FIG. 4, when one alumina crystal grain 22 is observed, first, the length of the line segment selected so that the diameter of the alumina crystal grain 22 is the largest is taken as the major axis L1. Next, a vertical line perpendicular to the line segment constituting the major axis L1 and passing through the midpoint of the line segment constituting the major axis L1 is drawn, and the length of the portion representing the diameter of the alumina crystal grain in the vertical line is drawn. The short diameter is L2.
- the (L1 + L2) / 2 to calculate the grain size D c of one of the alumina grains 22. Then, this operation is performed for 100 alumina crystal grains in the field of view of the cross section of the alumina substrate, and the average value of the 100 crystal grain diameters D c is defined as the average crystal grain diameter of the alumina crystal grains.
- the alumina substrate has the following ratio N A / N t which is an index indicating the small variation in the crystal grain size D c of the alumina crystal grains, usually 70% or more, preferably 70 to 95%. variation of the particle diameter D c is small.
- the ratio N A / N t is observed within the observation range with respect to the total number N t of alumina crystal grains observed within the observation range of unit area 200 ⁇ m ⁇ 200 ⁇ m by cross-sectional observation of the alumina substrate. This means the ratio N A / N t of the number N A of alumina crystal grains within the range of 0.3 A to 1.7 A when the average crystal grain size of the crystal grains is A ⁇ m.
- the alumina substrate used in the present invention has a small average crystal grain size of alumina crystal grains of 20 ⁇ m or less and a small variation in the crystal grain size D c of the alumina crystal grains.
- the triple point between the alumina crystal grains is small, the number of voids is small, and the size of the voids is small.
- the triple point between alumina crystal grains means a grain boundary part surrounded by three alumina crystal grains.
- the voids of the alumina substrate are usually voids or depressions generated at the triple point between the alumina crystal grains.
- the alumina substrate has an average void diameter of 10 ⁇ m or less, preferably 5 ⁇ m or less.
- the alumina substrate has a maximum void diameter of 15 ⁇ m or less, preferably 12 ⁇ m or less. A void is formed in the gap between alumina crystal particles. When the maximum diameter of the void exceeds 15 ⁇ m, a region in which the densification is partially insufficient is formed on the alumina substrate, so that the mechanical strength and dielectric strength of the alumina substrate may be reduced.
- the average diameter of the void refers to the average value of the diameter D v of the void calculated from 100 voids observed by cross-sectional observation of the alumina substrate as follows. That is, first, with respect to the cross section of the alumina substrate, an enlarged photograph capable of obtaining an observation range of a unit area of 200 ⁇ m ⁇ 200 ⁇ m or 100 ⁇ m ⁇ 100 ⁇ m was taken and measured so that the diameter of each void existing in the observation range was the largest. the value and individual void diameter D v. Then performed for 100 voids measurements randomly chosen within the observation range of the diameter D v of the void, to define the average value of 100 void of diameter D v and the average diameter of the void.
- the maximum diameter of the voids means the maximum value of the diameter D v of the void calculated from 100 voids observed by cross-sectional observation of the alumina substrate as described above.
- a secondary electron image of an SEM photograph is preferably 250 times or more, and more preferably 500 times or more.
- the alumina crystal may be shed from the cross section.
- degranulation is a phenomenon in which the alumina particles fall off as they are, so that the crystallization of alumina crystal particles and voids can be distinguished in the cross-sectional observation of the alumina substrate.
- the number of voids per unit area 100 ⁇ m ⁇ 100 ⁇ m calculated by cross-sectional observation is usually 5 to 50, preferably 10 to 35.
- the alumina substrate has high strength and high bonding strength with the metal circuit board.
- the bonding strength between the alumina substrate and the metal circuit board is a shape in which the unevenness on the surface of the alumina substrate and the surface of the metal circuit board are complicated, that is, the surface of the metal circuit board is deformed following the unevenness on the surface of the alumina substrate.
- the unevenness on the surface of the alumina substrate is formed by the surface shape of the alumina crystal grains, the surface shape of the component derived from the sintering aid, and the shape of the void.
- the size of the unevenness on the surface of the alumina substrate is usually that of the void. The unevenness due to the shape becomes the largest. For this reason, when the number of voids per unit area of 100 ⁇ m ⁇ 100 ⁇ m is 5 or more on the surface of the alumina substrate, the bonding strength between the alumina substrate and the metal circuit board tends to be high.
- the void number of per unit area 100 [mu] m ⁇ 100 [mu] m calculated by the cross-section observation means the number N v of the voids is calculated as follows. That is, first, an enlarged photograph capable of obtaining an observation range having a unit area of 200 ⁇ m ⁇ 200 ⁇ m or 100 ⁇ m ⁇ 100 ⁇ m is taken for the cross section of the alumina substrate, and the total number N vT of voids existing in the observation range is counted. Next, the total number N vT of voids is converted into the number per 100 ⁇ m ⁇ 100 ⁇ m, and the number N v100 of voids per 100 ⁇ m ⁇ 100 ⁇ m is calculated.
- the unit area of 200 ⁇ m ⁇ 200 ⁇ m includes four parts of the unit area of 100 ⁇ m ⁇ 100 ⁇ m.
- the voids of the number N v100 obtained by converting the total number N vT void at one location of a unit area 200 [mu] m ⁇ 200 [mu] m in number per 100 [mu] m ⁇ 100 [mu] m may be as it is as the number of voids N v.
- the bonding strength with the metal circuit board may be lowered.
- the number of voids per unit area 100 ⁇ m ⁇ 100 ⁇ m calculated by cross-sectional observation of the alumina substrate exceeds 50, surface defects of the alumina substrate occur, and the mechanical strength, insulation withstand voltage, and thermal conductivity of the alumina substrate decrease. It's easy to do.
- the void area ratio which is the void area ratio calculated by observing the cross section of the alumina substrate, is usually 20% or less, preferably 13% or less, more preferably 6% or less. If the void area ratio exceeds 20%, the mechanical strength of the alumina substrate may be lowered.
- the void area ratio means an area ratio RS v of voids is calculated as follows. That is, first, an enlarged photograph capable of obtaining an observation range having a unit area of 200 ⁇ m ⁇ 200 ⁇ m or 100 ⁇ m ⁇ 100 ⁇ m is taken with respect to the cross section of the alumina substrate, and the total area of the voids S vT is obtained by summing the areas of the voids existing in the observation range. Is calculated. Next, a value per 1 ⁇ m 2 obtained by dividing the total area S vT of the voids by the unit area is defined as a void area ratio RS v (%).
- the alumina substrate has a Vickers hardness of 1300 or more.
- the Vickers hardness means the Vickers hardness defined in JIS-R-1610.
- the alumina substrate usually has a withstand voltage of 15 KV / mm or more.
- the withstand voltage is a value calculated by the following method. That is, each ceramic circuit board is immersed in insulating oil (trade name Florinart), electrodes are arranged on metal circuit boards bonded to both surfaces of the ceramic board, and an AC voltage is applied between the electrodes at a rate of voltage increase of 10 kV per minute. Is applied.
- the alumina substrate usually has a thermal conductivity of 20 W / m ⁇ K or more.
- the thermal conductivity means a thermal conductivity measured by a laser flash method according to JIS-R-1611.
- the alumina substrate usually has a bending strength (three-point bending strength) of 300 MPa or more.
- the bending strength (three-point bending strength) means the bending strength defined in JIS-R1601.
- the thickness of the alumina substrate is usually 0.25 to 1.2 mm.
- an alumina substrate can be manufactured by preparing an alumina powder and a sintering aid, performing a slurry adjustment process or a granulation process, performing a molding process, performing a degreasing process, and performing a sintering process. it can.
- the alumina powder has an alumina purity of usually 98% by mass or more, preferably 99.9% by mass or more. When the purity of alumina is 98% by mass or more, the characteristics of the resulting alumina substrate are likely to be good. In addition, when the purity of alumina is 99.9% by mass or more, it is easy to calculate impurities that are contained in alumina powder and function as a sintering aid during sintering. This is preferable because the amount of the auxiliary agent can be easily adjusted.
- the impurity functioning as a sintering aid during sintering means the following sintering aid component impurities.
- the alumina powder usually contains Si, Ca, Mg, Na, or a substance containing other elements as components other than alumina.
- Si, Ca, Mg, and Na, and compounds of these elements are substances composed of the same elements as the sintering aid, so that the sintering aid component impurities That's it.
- substances other than alumina and sintering aid component impurities are referred to as inevitable impurities. Since the sintering aid component impurity is a substance composed of the same elements as the sintering aid, it functions as a sintering aid in the sintering process. For this reason, it is preferable to handle the sintering aid component impurities contained in the alumina powder as part of the sintering aid.
- the mass of the sintering aid component impurity is the mass converted to the sintering aid, and this converted mass is used as the sintering aid.
- a method of making part of the mass is used. Specifically, when the sintering aid component impurities are Si, Ca, Mg, and Na, and compounds of these elements, these are used as the sintering aids SiO 2 , CaO, MgO, and After converting to Na 2 O, the mass of these oxides is handled as the mass of the sintering aid.
- SiO 2 converted from the Si component in the sintering aid component impurities contained in the alumina powder is Ag, and SiO 2 added as a sintering aid to this alumina powder is Bg, the sintering aid
- the total mass of the SiO 2 agent is A + Bg.
- the average particle size of the alumina powder is usually 1 to 4 ⁇ m. Further, if the alumina powder contains 2 to 30% by mass of alumina powder having a particle size of 0.8 ⁇ m or less, the void size of the resulting alumina substrate can be reduced or the number of voids can be reduced. preferable.
- the reason for this is as follows. Voids are generated in the gaps between the alumina crystal grains. An alumina powder containing 2 to 30% by mass of an alumina powder having a particle diameter of 0.8 ⁇ m or less has a moderate distribution of large and small powders. A structure can be adopted in which small alumina powder enters the gap. For this reason, the alumina substrate obtained from the alumina powder having such a structure has a small void size and a small number of voids.
- a sintering aid As a raw material for the alumina substrate, a sintering aid is used in addition to the alumina powder.
- a sintering aid at least silicon oxide (SiO 2 ) is used.
- the sintering aid may contain one or more oxides selected from calcium oxide (CaO), magnesium oxide (MgO), and sodium oxide (Na 2 O) in addition to silicon oxide (SiO 2 ).
- the sintering aid preferably contains all of silicon oxide (SiO 2 ), calcium oxide (CaO), magnesium oxide (MgO) and sodium oxide (Na 2 O).
- a powdery one is used as a sintering aid.
- the sintering aid is mixed with the alumina powder in the subsequent slurry adjustment step or granulation step.
- the total amount of the mixed powder of alumina powder and sintering aid, and the mass M A converted sintering aid component impurities contained in the alumina powder sintering aid, and the mass M S sintering aids 2-6% by mass of M A + M S is contained.
- the ball milling using alumina balls mill in slurry adjusting process after in consideration of the amount M B of the sintering auxiliary component impurities incorporated from the alumina balls mill, determine the amount of sintering aid. That is, the mixed powder of alumina powder and sintering aid, so that the M A + M S + M B contained 2-6% by weight.
- the sintering aid component impurity taken in from the alumina ball mill is the same material as the sintering aid component impurity contained in the alumina powder.
- the slurry adjustment step is a step of preparing a slurry by mixing alumina powder and sintering aid powder.
- the slurry is prepared by adding alumina powder and sintering aid powder in pure water or an organic solvent, and further adding a binder such as PVA (polyvinyl alcohol) or PVB (polyvinyl butyral) as necessary. It can be prepared by pulverizing the alumina powder and the sintering aid powder.
- the balls used in the ball mill are preferably made of alumina. However, alumina balls made of alumina usually have an alumina purity of about 96% and contain a relatively large amount of impurities such as Na, Si, and Ca.
- the sintering powder in the ball mill treatment using the alumina balls, it is preferable to mix the sintering powder with an amount of the sintering aid powder taking into account impurities such as Na, Si, and Ca mixed from the alumina balls into the slurry.
- the above-described slurry adjustment step or the following granulation step is selected and performed.
- the granulation step is a step of mixing and granulating alumina powder and sintering aid powder.
- alumina powder and a sintering aid powder are added to pure water or an organic solvent, and a binder such as PVA (polyvinyl alcohol) or PVB (polyvinyl butyral) is further added if necessary.
- the alumina powder and the sintering aid powder can be pulverized with a wet ball mill and further granulated with a wet granulator.
- the molding step is a step of producing a molded body using the slurry obtained in the slurry adjustment step or the granulated powder obtained in the granulation step.
- molding process produces a plate-shaped molded object, for example using a doctor blade method.
- molding process produces a plate-shaped molded object, for example using a metal mold
- the thickness of the plate-shaped molded body is 1 mm or less, it is preferable to use a doctor blade method.
- a degreasing process is a process of degreasing the obtained plate-shaped molded object.
- the plate-shaped molded body is degreased by heat treatment usually at 400 to 900 ° C.
- a sintering process is a process of sintering the degreased plate-shaped molded object.
- it is usually heat treated at 1200 to 2 to 8 hours, preferably 1200 to 1650 ° C. for 4 to 8 hours, and sintered.
- it can be sintered usually by heat treatment at 1200 to 1700 ° C. for 2 to 5 hours, preferably 1200 to 1650 ° C. for 2 to 5 hours.
- the sintering process may be performed in two stages with different temperature ranges for the heat treatment. For example, after heat treatment at a temperature range of 1450 to 1650 ° C. for 3 to 4 hours, heat treatment may be performed at less than 1450 ° C. for 2 to 3 hours. In this way, since the sintering process does not continue to sinter for a long time at a high temperature, but after sintering for a certain period of time, by sintering at a slightly low temperature, the grain growth of the alumina crystal grains can be suppressed. It becomes easier to control the size and number. As described above, since the main sintering step can reduce the sintering time to 8 hours or less, there is no need to perform a long-time heat treatment sintering step of 20 hours as disclosed in Patent Document 1.
- the reason why the sintering time of the sintering process is short in the present invention is mainly because the total amount of sintering aid powder and sintering aid component impurities in the degreased plate-like molded body is appropriate. It is believed that there is.
- the plate-shaped molded body produced from the slurry or granulated powder and degreased has a sintering aid component impurity contained in the alumina powder in a total amount of 100 mass% of the alumina powder and the sintering aid powder. 2 to 6 mass% of the total amount M A + M S of the mass M A converted into a sintering aid and the mass M S of the sintering aid.
- the plate-shaped molded body produced from the slurry or granulated powder and degreased has an amount M of the sintering aid component impurities taken in from the alumina ball mill.
- the M a + M S + M B, including B has to contain 2-6% by weight.
- the sintering process of a non-high-purity alumina substrate containing 94 to 98% by mass of alumina Al 2 O 3 of the present invention is a high-purity alumina in which M A + M S or M A + M S + M B is less than 2% by mass.
- the sintering temperature can be lowered by about 20 to 50 ° C., and the sintering time can be shortened to 8 hours or less.
- the sintering temperature can be lowered or the sintering time can be shortened, so that growth of alumina crystal grains due to sintering can be suppressed.
- an alumina substrate obtained is alumina crystal grains is reduced, variation of the crystal grain size D c of alumina crystal grains is reduced, it is possible to suppress the occurrence of voids, reducing the size of the generated voids be able to.
- the average crystal grain size of the alumina crystal grains is usually 20 ⁇ m or less, preferably 10 ⁇ m or less
- the ratio N A / N t indicating the variation of the crystal grain size D c is usually 70. % Or more, preferably 70 to 95%.
- the resulting alumina substrate has an average void diameter of 10 ⁇ m or less, preferably 5 ⁇ m or less, and a void area ratio of usually 20% or less.
- the alumina substrate obtained through the above steps is bonded to the metal circuit board.
- a circuit is formed on the metal circuit board bonded to the alumina substrate by appropriately using etching or the like.
- both a metal circuit board on which a circuit is not formed and a metal circuit board on which a circuit is formed are simply referred to as a metal circuit board.
- the obtained alumina substrate is appropriately subjected to a process of removing dust on the surface by a honing process and a process of polishing the surface as a process before being bonded to the metal circuit board.
- the metal circuit board is bonded onto the alumina substrate.
- the metal circuit board is a concept including both a metal circuit board in which a circuit is formed using etching or the like and a metal circuit board in which a circuit is not formed.
- the alumina substrate and the metal circuit board are bonded by a method such as a direct bonding method (DBC method) or an active metal method.
- the direct bonding method refers to, for example, using a reaction in which copper and oxygen of a metal circuit board form a eutectic compound (Cu—O eutectic) to connect the alumina substrate and the metal circuit board. It is a method of joining.
- the active metal method is a method of joining an alumina substrate and a metal circuit board using an active metal joining brazing paste.
- the metal circuit board is bonded to the alumina substrate by a method such as a direct bonding method or an active metal method.
- a metal circuit board is bonded to an alumina substrate by a direct bonding method
- a copper circuit board made of copper is usually used as the metal circuit board. Since the bonding method between the alumina substrate and the metal circuit board is a direct bonding method, the copper circuit board is bonded to the alumina substrate by a Cu—O eutectic compound. The thickness of the copper circuit board is usually 0.1 to 0.5 mm.
- the copper circuit board is preferably made of tough pitch electrolytic copper containing 100 to 1000 ppm by mass of oxygen. By using such a copper circuit board, the bonding strength with the alumina substrate is increased.
- the copper circuit board preferably contains 0.1 to 1.0% by mass of carbon.
- the copper material constituting such a copper circuit board include tough pitch copper and oxygen-free copper. Since carbon functions as a deoxidizer, oxygen in the copper circuit board is moved to the surface of the copper circuit board. In addition, the oxygen that has moved to the surface of the copper circuit board is used to form a Cu—O eutectic compound when performing the direct bonding method. In addition, when the carbon content of the copper circuit board is less than 0.1% by mass, there is no effect of carbon content, and when the carbon content exceeds 1.0% by mass, the carbon content increases too much and the conductivity of the copper circuit board Reduce sex.
- the copper circuit board When a copper circuit board having an oxygen content of less than 100 ppm by mass is used as the copper circuit board, the copper circuit board is bonded to the alumina substrate by forming a copper oxide film on the bonding surface side of the copper circuit board with the alumina substrate. Strength can be increased.
- Examples of a method for forming a copper oxide film on the surface of a copper circuit board include a method of directly oxidizing a copper circuit board by heat treatment, a method of applying a copper oxide powder paste, and the like.
- Direct oxidation method As a method for direct oxidation, for example, a copper oxide film is formed on the surface of a copper circuit board by performing a surface oxidation treatment in which the copper circuit board is heated in the atmosphere at a temperature of 150 to 360 ° C. for 20 to 120 seconds. Is used.
- the copper oxide film has a thickness of usually 1 to 10 ⁇ m, preferably 2 to 5 ⁇ m.
- the thickness of the copper oxide film is less than 1 ⁇ m, the amount of Cu—O eutectic compound generated is reduced, and the unbonded portion between the alumina substrate and the copper circuit board is increased, thereby improving the bonding strength. Becomes smaller.
- the thickness of the copper oxide film exceeds 10 ⁇ m, the effect of improving the bonding strength is small, and the conductive characteristics of the copper circuit board are hindered.
- Method of applying copper oxide powder paste for example, a paste containing copper oxide powder having an average particle diameter of 1 to 5 ⁇ m is used, and the paste is applied on a copper circuit board to have a thickness of 1 to 10 ⁇ m. After the layer is formed, a method of forming a copper oxide film on the surface of the copper circuit board by drying or heat treatment is used.
- the metal circuit board includes copper, aluminum, iron, nickel, chromium, silver, molybdenum, cobalt alone, alloys thereof, and cladding materials thereof. Is used. Among these, a copper plate and an aluminum plate are preferable because of good bonding properties.
- the thickness of the metal circuit board is determined in consideration of the current carrying capacity and the thickness of the alumina substrate. Specifically, when the thickness of the alumina substrate is 0.25 to 1.2 mm, the thickness of the metal circuit board is preferably 0.1 to 0.5 mm. When the thickness of the alumina substrate is 0.25 to 0.38 mm, the thermal resistance is reduced and the heat dissipation of the ceramic circuit board can be improved.
- Examples of the active metal bonding brazing paste used in the active metal method include 15 to 35% by mass of Cu and 1 to 10% by mass of at least one active metal selected from Ti, Zr, and Hf.
- An active metal bonding braze paste prepared by dispersing a bonding composition substantially consisting of Ag in the balance in an organic solvent is used.
- the active metal compounded in the active metal bonding brazing paste improves the wettability and reactivity of the active metal bonding brazing material to the alumina substrate.
- the compounding amount of the active metal in the active metal joining brazing paste is 1 to 10% by mass with respect to 100% by mass of the joining composition contained in the active metal joining brazing paste.
- an Ag—Cu based brazing material containing at least one active metal selected from Ti, Zr and Hf and having an appropriate composition ratio is used, and this Ag—Cu based brazing material is used as an organic solvent.
- a bonding composition paste is prepared by dispersing in, and this bonding composition paste is screen-printed on the surface of the alumina substrate, and a copper plate as a metal circuit board is superimposed on the surface of the alumina substrate, and heated. An alumina substrate and a metal circuit board can be joined.
- the joining interface between the alumina substrate and the metal circuit board has an intricate structure in which the surface of the metal circuit board is deformed along the irregular shape of the surface of the alumina substrate. Specifically, the bonding interface between the alumina substrate and the metal circuit board is a curve along the surface of the alumina substrate when the cross section of the ceramic circuit board is observed.
- the contact ratio (hereinafter referred to as “bonding interface contact ratio”) is usually 95% or more, preferably 99% or more, and more preferably 100%.
- the bonding interface contact ratio is an index indicating the followability of the metal circuit board to the irregularities on the surface of the alumina substrate. For example, when the alumina substrate and the metal circuit board are bonded together without any gap, the bonding interface contact ratio is 100%. Further, when the alumina substrate and the metal circuit board are completely separated, the bonding interface contact ratio is 0%.
- the calculation method of the bonding interface contact ratio is as follows. That is, first, when the cross section of the ceramic circuit board is observed, an enlarged photograph of the bonded cross section is taken.
- the enlarged photograph of the bonded cross section is preferably 1000 times or more.
- the enlarged photograph is taken over a length of 100 ⁇ m at the bonding interface. If a length of 100 ⁇ m cannot be photographed in one field of view, photographing may be performed every 20 to 50 ⁇ m, and a total of 100 ⁇ m may be photographed.
- the length L A of the curve along the unevenness of the surface of the alumina substrate at the bonding interface and the length L M of the curve along the surface of the metal circuit board at the bonding interface are measured. Then, to calculate the L M / L A obtained by dividing the L M with L A as a joining interfacial contact ratio.
- the bonding interface contact ratio tends to decrease when deep voids are exposed on the surface of the alumina substrate. If deep voids are exposed on the surface of the alumina substrate, the bonding ratio of the interface contact tends to decrease because the metal circuit plate is less likely to follow the surface of the alumina substrate when the alumina substrate is bonded to the metal circuit plate. .
- the ceramic circuit board of the present invention there is substantially no exposure of deep voids on the surface of the alumina substrate, and the alumina substrate and the metal circuit board are bonded under specific conditions. The metal circuit board follows and enters.
- the ceramic circuit board of the present invention has a high bonding interface contact ratio of usually 95% or more, and has a structure in which the surface of the alumina substrate and the metal circuit board are intricate, resulting in an anchor effect and high bonding strength. .
- the ceramic circuit board is manufactured by bonding an alumina substrate and a metal circuit board.
- a direct bonding method (DBC method) or an active metal method is used as the method for bonding the alumina substrate and the metal circuit board.
- ⁇ Direct bonding method> In the direct bonding method, first, a copper circuit board as a metal circuit board is disposed on an alumina substrate. When an oxide film (copper oxide film) is formed on the copper plate, the oxide film is disposed on the alumina substrate side. Next, when heated to, for example, 1065 to 1085 ° C. in an inert gas atmosphere, a ceramic circuit board in which a copper circuit board is bonded onto an alumina substrate is obtained.
- active metal method In the active metal method, first, an active metal bonding brazing paste is applied on an alumina substrate by a method such as screen printing. Next, when a metal circuit board is placed on the surface of the alumina substrate on which the active metal bonding brazing material paste is applied and heated, a ceramic circuit board in which the copper circuit board is bonded onto the alumina substrate is obtained.
- the ceramic circuit substrate having the above-described configuration by using an alumina substrate containing 2 to 6% by mass of a sintering aid-derived component, the sinterability and mechanical strength are high, and the properties as a substrate are high.
- the alumina substrate is dense and has few surface defects derived from voids, even when the substrate thickness is reduced, the withstand voltage characteristic is hardly lowered and the occurrence of dielectric breakdown (withstand voltage leak) is suppressed.
- the joint strength of a metal circuit board can be improved by making the surface defect (surface unevenness
- Example 1 Alumina powder composed of ⁇ -alumina crystals having an average particle size of 2.5 ⁇ m (less than 0.8 ⁇ m is 13% by mass) and having a purity of 99.2% by mass (impurity Si content 0.4% by mass, Ca content 0.2% by mass) %, Mg content 0.1% by mass, Na content 0.01% by mass, unavoidable impurities 0.29% by mass).
- As a sintering aid 0.3 mass% of SiO 2 , 0.5 mass% of CaO, 0.4 mass% of MgO, 0.1 mass% of Na 2 O are added, and further an organic binder is added. Each raw material mixture was prepared.
- Each raw material mixture was sheet-formed by a doctor blade method to prepare a plate-like molded body, and this molded body was heated in a vacuum at 800 ° C. for 4 hours for complete degreasing.
- This degreased body was sintered at a temperature of 1580 ° C. for 7 hours to prepare an alumina substrate having a length of 29 mm ⁇ width of 63 mm ⁇ thickness of 0.32 mm.
- Example 2 High-purity alumina powder consisting of ⁇ -alumina crystals with an average particle size of 1.5 ⁇ m (0.8 ⁇ m or less is 25% by mass) and having a purity of 99.99% by mass (impurity Si content 0.002 mass%, Ca content 0. 002 mass%, Mg content 0.001 mass%, Na content 0.001 mass%, unavoidable impurities 0.005 mass%).
- As a sintering aid 1.0 mass% of SiO 2 , 1.0 mass% of CaO, 1.0 mass% of MgO and 0.1 mass% of Na 2 O are added, and an organic binder is further added. Each raw material mixture was prepared.
- Each raw material mixture was sheet-formed by a doctor blade method to prepare a plate-like molded body, and this molded body was heated in a vacuum at 800 ° C. for 4 hours for complete degreasing.
- This degreased body was sintered at a temperature of 1560 ° C. for 6 hours to prepare an alumina substrate having a length of 29 mm ⁇ width of 63 mm ⁇ thickness of 0.32 mm.
- the raw material mixture was adjusted by a ball mill process using alumina balls having a purity of 96%.
- High-purity alumina powder having an average particle size of 1.5 ⁇ m (0.8 ⁇ m or less is 35% by mass) and having a purity of 99.99% by mass (impurity Si amount 0.002% by mass, Ca amount 0. 002 mass%, Mg content 0.001 mass%, Na content 0.001 mass%, unavoidable impurities 0.005 mass%).
- An alumina substrate was prepared in the same manner as in Example 2 except that SiO 2 was not added as a sintering aid.
- Example 2 Alumina powder consisting of ⁇ -alumina crystals with an average particle size of 2.5 ⁇ m (0.8 ⁇ m or less is 1% by mass) and having a purity of 99.2% by mass (impurity Si content 0.4 mass%, Ca content 0.2 mass) %, Mg content 0.1% by mass, Na content 0.01% by mass, unavoidable impurities 0.29% by mass).
- An alumina substrate was prepared in the same manner as in Example 1 except that 3.0% by mass of SiO 2 was added as a sintering aid.
- an enlarged photograph having a unit area of 200 ⁇ m ⁇ 200 ⁇ m was taken, the area of each void in the enlarged photograph was measured, and the number obtained by dividing the total area by 200 ⁇ m ⁇ 200 ⁇ m was defined as the void area ratio. Moreover, the value measured so that a diameter might become the largest about each void was made into the maximum diameter, and the average value for 100 voids was made into the void average diameter. Further, the number of voids was measured at four locations per unit area of 100 ⁇ m ⁇ 100 ⁇ m, and the minimum number and the maximum number were shown.
- the average grain size of the alumina crystal grains is such that the length of the line segment selected so that the diameter of each alumina crystal grain is the largest is the major axis L1, and the vertical axis is drawn from the center of the minor axis L2. And (L1 + L2) / 2 was defined as the particle size (see FIG. 4). This operation was performed 100 grains, and the average value was defined as the average grain diameter. Regarding the variation of the crystal grain size of the alumina crystal grains, the ratio of the crystal grains falling within the range of A ⁇ (0.3 to 1.7) with respect to the average crystal grain size A ⁇ m was obtained.
- FIG. 5 is a SEM photograph of the bonding interface of the ceramic circuit board according to Example 1. As shown in FIG. 5, the metal circuit board (copper circuit board) 3 is in close contact with the surface of the alumina substrate 2 at the interface between the alumina substrate 2 of the ceramic circuit board 1 and the metal circuit board (copper circuit board) 3. .
- the reason why the inevitable impurities are slightly increased in the alumina sintered body is that impurities such as Fe are mixed in the manufacturing process. Similarly, the reason why the amount of SiO 2 slightly increased is that it was mixed in the ball mill process using alumina balls during the manufacturing process.
- the alumina substrate according to this example has good sinterability and exhibits excellent characteristics.
- the alumina substrate of Comparative Example 1 was insufficient in Si amount, so that sufficient sintering was not possible under these sintering conditions, and large voids were generated.
- the alumina substrate of Comparative Example 2 had too much Si content and the sinterability was reduced.
- Examples 3 to 5 What changed the amount of sintering auxiliary agents and sintering conditions was prepared, and the same measurement as Example 1 was performed. The results are shown in Tables 1 and 2 to 3. The raw material powder was the same as that used in Example 1.
- the alumina substrate according to this example showed excellent characteristics even when the sintering time was 8 hours or less.
- Examples 1B to 6B, Comparative Examples 1B to 2B Ceramic circuit boards were prepared using the alumina substrates and copper plates of Examples 1 to 5 and Comparative Examples 1 and 2.
- the copper plate was prepared by heat treatment to form a copper oxide film having a thickness of 5 ⁇ m on the bonding surface side.
- Copper plates (one is a copper plate for a metal circuit board and the other is a back copper plate) are arranged on both sides of the alumina substrate, and are heated by a direct bonding method in a nitrogen atmosphere at 1075 ° C. for 1 minute.
- the copper plate for metal circuit boards was unified with a thickness of 0.3 mm, and the back copper plate with a thickness of 0.4 mm.
- Examples 1B to 5B were prepared with a carbon content in the copper plate in the range of 0.2 to 0.8 mass%, and 6B with no carbon contained (below the detection limit). Next, the metal circuit board of the obtained ceramic circuit board was etched to form the circuit pattern shown in FIG.
- both ends of the circuit pattern surface on the front side are supported by a support span of 30 mm, while a load is applied to one point in the center of the back copper plate on the back side to provide three points.
- the bending strength was measured, and the maximum amount of deflection with respect to the plane including both edges of the alumina substrate was measured.
- the bending strength value of each ceramic circuit board has shown the load value at the time of an alumina substrate fracture
- the maximum amount of deflection was measured as the amount of deflection when the alumina substrate broke. Table 4 shows the measurement results.
- the ceramic circuit board according to this example was found to exhibit excellent characteristics with a maximum deflection of 1.0 mm or more.
- the bonding strength and the bonding interface state of the copper circuit boards of the ceramic circuit boards of Examples 1B to 6B and Comparative Examples 1B to 2B were examined.
- the bonding strength was determined by a peel test.
- As for the bonding interface an enlarged photograph (2000 times) of the bonding interface between the alumina substrate and the copper circuit board is taken. This operation was photographed for 100 ⁇ m of the bonding interface. It was investigated how the copper circuit board was bonded so as to cover the surface irregularities of the alumina substrate at the bonding interface. The results are shown in Table 5.
- Example 1B As can be seen from the table, the ceramic circuit board according to this example was excellent in bonding strength. Further, when Example 1B and Example 6B were compared, Example 1B was superior in bonding strength. This is presumably because oxygen contained in the copper plate moved to the surface of the copper plate and contributed to the Cu—O eutectic reaction by containing a predetermined amount of carbon in the copper plate. Therefore, it is considered that the ratio of the copper circuit board covering the surface irregularities of the alumina substrate at the bonding interface has increased.
- Ceramic circuit board 2 Alumina substrate 3 Metal circuit board (copper circuit board) 4 Back metal plate (back copper plate) 22 Alumina crystal grains
Abstract
Description
金属回路板3は、セラミックス基板2の表面に接合された各種金属板またはセラミックス基板2の表面に形成された金属層からなる。
直接接合法について、金属回路板3が銅回路板である場合を例にとり具体的に説明する。はじめに、セラミックス基板2上に、所定形状に打ち抜いた銅回路板3を接触配置して加熱し、接合界面にCu-Cu2O、Cu-O等の共晶液相を生成させて、この共晶液相によりセラミックス基板2と銅回路板3との濡れ性を高める。次に、この共晶液相を冷却固化させると、セラミックス基板2と銅回路板3とが直接接合することによりセラミックス回路基板1が得られる。この方法は、いわゆる銅直接接合法(DBC法: Direct Bonding Copper法)である。
さらに、活性金属法は、例えば、Ti、Zr、Hf等の4A族元素のような活性を有する金属を含むAg-Cuろう材層を介してセラミックス基板2上に銅回路板等の金属板3を一体に接合することによりセラミックス回路基板1を得る方法である。この活性金属法によれば、ろう材層のCuおよびAg成分によりろう材層と銅回路板3との接合強度が高まる上、Ti、Zr、Hf成分によりろう材層とセラミックス基板2との接合強度が高まる。
また、増大した熱負荷に対処するとともに回路基板の耐久性を向上させた他のセラミックス回路基板1としては、セラミックス基板2として純度が96%程度と比較的純度が高いアルミナ基板を用い、このアルミナ基板に、前記直接接合法または活性金属法により金属回路板3(回路層)を一体に接合したセラミックス回路基板1が知られている。
特許文献1に記載されたセラミックス回路基板は、セラミックス基板として高純度アルミナ基板を用いているため、安価であるというアルミナ基板のメリットを十分に発揮できていないという課題があった。
本発明のセラミックス回路基板は、アルミナ基板上に金属回路板が接合されたセラミックス回路基板である。
本発明のセラミックス回路基板は、たとえば、図1に示されるように、アルミナ基板2の一方の表面上に金属回路板3が接合されたセラミックス回路基板1になっている。
なお、図1には、アルミナ基板2の他方の表面上、すなわち裏面側の表面上に銅板等の裏金属板4が接合されている例を示すが、本発明のセラミックス回路基板は、アルミナ基板2の一方の表面上および他方の表面上の両面に金属回路板3が接合されていてもよい。
アルミナ基板は、アルミナAl2O3を94~98質量%、および焼結前に配合された焼結助剤から生成された焼結助剤由来成分を2~6質量%含む。
本発明で用いられるアルミナ基板は、多くのアルミナ結晶粒からなる多結晶体であり、焼結助剤由来成分は、アルミナ結晶粒の粒界に存在するガラス相である。
焼結助剤由来成分は、後述のように、焼結助剤成分以外の成分である不可避不純物成分を含むことがある。焼結助剤成分および不可避不純物成分については、後に詳述するが、焼結助剤成分とは、Si、Ca、Mg、およびNaを焼結助剤と同じ酸化物に換算した物質である。焼結助剤成分としては、たとえば、SiO2、CaO、MgO、およびNa2Oが挙げられる。また、不可避不純物成分とは、焼結助剤由来成分から焼結助剤成分を除いた残部である。
焼結助剤由来成分中に含まれる不可避不純物成分は、アルミナ基板100質量%中に、0.5質量%以下の量で含まれていてもよい。
アルミナ基板に含まれる焼結助剤由来成分とは、本発明のアルミナ基板の原料として、焼結前にアルミナ粉末とともに配合された焼結助剤が、焼結時の熱処理により液相になった後、固化してガラス相になった無機酸化物を意味する。
アルミナ基板中に含まれる焼結助剤由来成分が、2質量%未満であると、アルミナ基板の原料であるアルミナ粉末と焼結助剤とを含む混合物を焼結させてアルミナ基板を製造する際に焼結助剤の量が少なすぎるため、アルミナ基板の焼結が不十分になったり、焼結時間が長くなったりするおそれがある。なお、アルミナ基板の焼結が不十分になるおそれがある場合は、原料となるアルミナ粉末として特許文献2(特開2005-281063号公報)に示したような高純度アルミナ粉末を用いる必要が生じるため、アルミナ基板の製造コストが高くなる。
結助剤由来成分中のケイ素は、酸化ケイ素SiO2に換算した質量でアルミナ基板100質量%中に0.01~1.5質量%、好ましくは0.5~1.3質量%含まれる。
ケイ素を酸化ケイ素SiO2に換算した質量が、アルミナ基板100質量%中で0.01~1.5質量%であると、アルミナ基板を製造する際にケイ素を含む焼結助剤の量が適切になるため焼結性が高くなり、アルミナ基板の焼結時間が短縮される。
また、ケイ素を酸化ケイ素SiO2に換算した質量が、アルミナ基板100質量%中で1.5質量%を超えると、アルミナ基板の熱伝導率が低下しやすい。
焼結助剤由来成分中のカルシウムは、酸化カルシウムCaOに換算した質量でアルミナ基板100質量%中に通常0.001~1.5質量%、好ましくは0.01~1.0質量%含まれる。
焼結助剤由来成分中のマグネシウムは、酸化マグネシウムMgOに換算した質量でアルミナ基板100質量%中に通常0.001~1.0質量%、好ましくは0.01~0.5質量%含まれる。
焼結助剤由来成分中のナトリウムは、酸化ナトリウムNa2Oに換算した質量でアルミナ基板100質量%中に通常0.001~0.5質量%、好ましくは0.01~0.2質量%含まれる。
すなわち、焼結助剤由来成分の焼結前の状態である焼結助剤が、Si酸化物に加えて、Ca酸化物、Mg酸化物、およびNa酸化物から選ばれる1種以上の酸化物をさらに含むと、粒界相となるガラス相を形成し易くなる。
また、焼結助剤由来成分のうち、焼結助剤成分以外の成分を不可避不純物成分という。
アルミナ基板のアルミナ結晶粒は、平均結晶粒径が、通常20μm以下、好ましくは10μm以下である。本発明で用いられるアルミナ基板は、焼結性が高いため、アルミナ結晶粒の平均結晶粒径が20μm以下のように小さくなる。
すなわち、図4に示されるように1個のアルミナ結晶粒22が観察された場合において、はじめに、アルミナ結晶粒22の直径が最も大きくなるように選んだ線分の長さを長径L1とする。次に、この長径L1を構成する線分に対して垂直でありかつ長径L1を構成する線分の中点を通る垂直線を引き、この垂直線のうちアルミナ結晶粒の直径を表す部分の長さを短径L2とする。さらに、(L1+L2)/2により、1個のアルミナ結晶粒22の結晶粒径Dcを算出する。そして、この作業をアルミナ基板の断面観察の視野内の100個のアルミナ結晶粒について行い、100個の結晶粒径Dcの平均値をアルミナ結晶粒の平均結晶粒径と規定する。
ここで、比率NA/Ntとは、アルミナ基板の断面観察により単位面積200μm×200μmの観察範囲内で観察されるアルミナ結晶粒の全個数Ntに対する、前記観察範囲内で観察され、アルミナ結晶粒の平均結晶粒径をAμmとしたときに0.3A~1.7Aの範囲内にあるアルミナ結晶粒の個数NAの比率NA/Ntを意味する。
アルミナ基板のボイドは、通常、アルミナ結晶粒間の3重点に発生する空隙または窪みである。
アルミナ基板は、ボイドの平均径が10μm以下、好ましくは5μm以下である。
また、アルミナ基板は、ボイドの最大径が15μm以下、好ましくは12μm以下である。ボイドは、アルミナ結晶粒子同士の隙間に形成されるものである。ボイドの最大径が15μmを超えると、アルミナ基板に部分的に緻密化が不十分な領域ができるためアルミナ基板の機械的強度や絶縁耐圧が低下するおそれがある。
すなわち、はじめに、アルミナ基板の断面について、単位面積200μm×200μmまたは100μm×100μmの観察範囲を得られる拡大写真を撮り、この観察範囲内に存在する個々のボイドにつき直径が最も大きくなるように測定した値を個々のボイドの直径Dvとする。次に、このボイドの直径Dvの測定を前記観察範囲内でランダムに選んだ100個のボイドについて行い、100個のボイドの直径Dvの平均値をボイドの平均径と規定する。
アルミナ基板の断面観察で算出される単位面積100μm×100μmあたりのボイドの個数が5~50個であると、アルミナ基板が高強度であるとともに、金属回路板との接合強度が高い。
すなわち、はじめに、アルミナ基板の断面について、単位面積200μm×200μmまたは100μm×100μmの観察範囲を得られる拡大写真を撮り、この観察範囲内に存在するボイドの総数NvTを数える。次に、このボイドの総数NvTを100μm×100μmあたりの個数に換算して100μm×100μmあたりのボイドの個数Nv100を算出する。そして、この100μm×100μmあたりのボイドの個数Nv100の算出を、アルミナ基板の断面の4箇所で行い、この4個のボイドの個数Nv100の平均値をボイドの個数Nvと規定する。
また、アルミナ基板の断面観察で算出される単位面積100μm×100μmあたりのボイドの個数が50個を超えると、アルミナ基板の表面欠陥となり、アルミナ基板の機械的強度、絶縁耐圧や熱伝導率が低下しやすい。
ボイド面積率が20%を超えると、アルミナ基板の機械的強度が低くなるおそれがある。
すなわち、はじめに、アルミナ基板の断面について、単位面積200μm×200μmまたは100μm×100μmの観察範囲を得られる拡大写真を撮り、この観察範囲内に存在するボイドの面積を合計してボイドの総面積SvTを算出する。次に、このボイドの総面積SvTを単位面積で割った1μm2あたりの値をボイド面積率RSv(%)と規定する。
アルミナ基板は、ビッカース硬度が1300以上である。ここで、ビッカース硬度とは、JIS-R-1610に規定されるビッカース硬度を意味する。
アルミナ基板は、絶縁耐圧が、通常15KV/mm以上である。ここで、絶縁耐圧とは、以下の方法より算出される値である。すなわち、各セラミックス回路基板を絶縁油(商品名フロリナート)中に浸漬し、セラミックス基板の両面に接合した金属回路板にそれぞれ電極を配置し、この電極間に毎分10kVの電圧上昇速度で交流電圧を印加する。そして、10pC(ピコクーロン)の電荷量を放電する際の印加電圧を部分放電開始電圧とし、基板の単位厚さ当たりの部分放電開始電圧を絶縁耐圧とする。
アルミナ基板は、熱伝導率が、通常20W/m・K以上である。ここで、熱伝導率とは、JIS-R-1611に準ずるレーザフラッシュ法で測定される熱伝導率を意味する。
アルミナ基板は、抗折強度(3点曲げ強度)が、通常300MPa以上である。ここで、抗折強度(3点曲げ強度)とは、JIS-R-1601に規定される抗折強度を意味する。
次に、アルミナ基板の製造方法について説明する。
アルミナ基板は、たとえば、アルミナ粉末と焼結助剤とを用意した後、スラリー調整工程または造粒工程を行い、成形工程を行い、脱脂工程を行い、焼結工程を行うことにより製造することができる。
アルミナ粉末は、アルミナの純度が、通常98質量%以上、好ましくは99.9質量%以上である。
アルミナの純度が98質量%以上であると、得られるアルミナ基板の特性が良好になりやすい。
また、アルミナの純度が99.9質量%以上であると、アルミナ粉末中に含まれ、焼結時に焼結助剤として機能する不純物の計算が容易になることから、アルミナ粉末とともに混合する焼結助剤の量を調整しやすいため好ましい。ここで、焼結時に焼結助剤として機能する不純物とは、下記の焼結助剤成分不純物を意味する。
本発明において、アルミナ粉末に含まれる物質のうち、Si、Ca、Mg、およびNa、ならびにこれらの元素の化合物は、焼結助剤と同じ元素からなる物質であるため、焼結助剤成分不純物という。
また、アルミナ粉末に含まれる物質のうち、アルミナおよび焼結助剤成分不純物以外の物質を、不可避不純物という。
焼結助剤成分不純物は、焼結助剤と同じ元素からなる物質であるため、焼結工程において焼結助剤として機能する。このため、アルミナ粉末に含まれる焼結助剤成分不純物は、焼結助剤の一部として扱うことが好ましい。
また、アルミナ粉末は、0.8μm以下の粒径のアルミナ粉末を2~30質量%含むものであると、得られるアルミナ基板のボイドサイズを小さくしたり、ボイドの個数を減らしたりすることができるため、好ましい。この理由は以下のとおりである。ボイドはアルミナ結晶粒同士の隙間に発生する。0.8μm以下の粒径のアルミナ粉末を2~30質量%含むアルミナ粉末は、大きな粉末と小さな粉末が適度に分布したものとなることから、焼結前のアルミナ粉末を、大きなアルミナ粉末同士の隙間に小さなアルミナ粉末が入り込む構造にすることができる。このため、このような構造のアルミナ粉末から得られるアルミナ基板は、ボイドサイズが小さくなったり、ボイドの個数が少なくなったりする。
アルミナ基板の原料としては、アルミナ粉末に加えて焼結助剤が用いられる。
焼結助剤としては、少なくとも酸化ケイ素(SiO2)を用いる。焼結助剤は、酸化ケイ素(SiO2)に加えて、酸化カルシウム(CaO)、酸化マグネシウム(MgO)および酸化ナトリウム(Na2O)から選ばれる1種以上の酸化物を含んでいてもよい。
焼結助剤は、酸化ケイ素(SiO2)、酸化カルシウム(CaO)、酸化マグネシウム(MgO)および酸化ナトリウム(Na2O)のすべてを含むと好ましい。
焼結助剤としては、粉末状のものを用いる。
スラリー調整工程は、アルミナ粉末と焼結助剤粉末とを混合してスラリーを調製する工程である。スラリーは、たとえば、純水または有機溶媒中にアルミナ粉末と焼結助剤粉末とを添加し、必要によりさらにPVA(ポリビニルアルコール)、PVB(ポリビニルブチラール)等のバインダを添加した上、湿式ボールミルで、アルミナ粉末および焼結助剤粉末を粉砕することにより調製することができる。
ボールミルで用いられるボールは、アルミナ製であることが好ましい。ただし、アルミナ製のアルミナボールは、通常、アルミナ純度が96%程度であり、Na、Si、Ca等の不純物を比較的多く含む。このため、アルミナボールを用いたボールミル処理では、アルミナボールからスラリーに混入するNa、Si、Ca等の不純物を考慮した量の焼結助剤粉末をアルミナ粉末に配合することが好ましい。
アルミナ基板の製造方法では、上記のスラリー調整工程または下記の造粒工程を選択して行う。
造粒工程は、アルミナ粉末と焼結助剤粉末とを混合して造粒する工程である。
造粒で得られる造粒粉は、たとえば、純水または有機溶媒中にアルミナ粉末と焼結助剤粉末とを添加し、必要によりさらにPVA(ポリビニルアルコール)、PVB(ポリビニルブチラール)等のバインダを添加した上、湿式ボールミルで、アルミナ粉末および焼結助剤粉末を粉砕し、さらに湿式造粒機で造粒することにより作製することができる。
スラリー調整工程または造粒工程を行った後は、成形工程を行う。
成形工程は、スラリー調整工程で得られたスラリー、または造粒工程で得られた造粒粉を用いて、成形体を作製する工程である。
スラリーを用いる場合、成形工程は、たとえば、ドクターブレード法を用いて板状の成形体を作製する。造粒粉を用いる場合、成形工程は、たとえば、金型成型法を用いて板状の成形体を作製する。
板状の成形体の厚さが1mm以下である場合は、ドクターブレード法を用いることが好ましい。
[脱脂工程]
脱脂工程は、得られた板状の成形体を脱脂する工程である。
脱脂工程は、通常400~900℃で熱処理して板状の成形体を脱脂させる。
焼結工程は、脱脂された板状の成形体を焼結させる工程である。
焼結工程は、常圧で焼結させる場合は、通常1200~で2~8時間、好ましくは1200~1650℃で4~8時間熱処理して、焼結させる。
また、0.5MPa以上の加圧下で焼結させる場合は、通常1200~1700℃で2~5時間、好ましくは1200~1650℃で2~5時間熱処理して、焼結させることもできる。
たとえば、温度範囲1450~1650℃で3~4時間熱処理した後、1450℃未満で2~3時間熱処理するようにしてもよい。
このように、焼結工程を、高温で長時間焼結し続けるのではなく、一定時間焼結した後、少し低温で焼結させることにより、アルミナ結晶粒の粒成長を抑制できるため、ボイドのサイズや個数の制御を行い易くなる。
このように、本焼結工程は、焼結時間を8時間以下にすることができるため、特許文献1に示されるような20時間という長時間の熱処理の焼結工程を行う必要がない。
具体的には、得られるアルミナ基板は、アルミナ結晶粒の平均結晶粒径が、通常20μm以下、好ましくは10μm以下となり、結晶粒径Dcのばらつきを示す比率NA/Ntが、通常70%以上、好ましくは70~95%となる。
また、得られるアルミナ基板は、ボイドの平均径が10μm以下、好ましくは5μm以下であり、ボイド面積率が、通常20%以下となる。
得られたアルミナ基板は、金属回路板と接合される前の処理として、適宜、ホーニング加工により表面のごみを除去する処理や、表面を研磨加工する処理が行われる。なお、アルミナ基板と金属回路板との接合方法として直接接合法を用いる場合は、ホーニング加工により表面のごみを除去するだけとすることが好ましい。
金属回路板は、アルミナ基板上に接合される。ここで、金属回路板とは、エッチング等を用いて回路が形成された金属回路板、および回路が形成されていない金属回路板の両方を含む概念である。
ここで、直接接合法(DBC法)とは、たとえば、金属回路板の銅と酸素とが共晶化合物(Cu-O共晶)を形成する反応を利用してアルミナ基板と金属回路板とを接合する方法である。
また、活性金属法とは、活性金属接合ろう材ペーストを用いてアルミナ基板と金属回路板とを接合する方法である。
金属回路板が直接接合法によりアルミナ基板に接合される場合、金属回路板としては、通常、銅からなる銅回路板が用いられる。
アルミナ基板と金属回路板との接合方法が直接接合法であるため、銅回路板は、Cu-O共晶化合物によりアルミナ基板に接合される。
銅回路板は、厚さが、通常0.1~0.5mmである。
炭素は脱酸剤として機能するため、銅回路板中の酸素を銅回路板の表面に移動させる。また、銅回路板の表面に移動した酸素は、直接接合法を行う際のCu-O共晶化合物を形成するために用いられる。
なお、銅回路板の炭素含有量が0.1質量%未満であると炭素含有の効果がなく、炭素含有量が1.0質量%を超えると炭素含有量が増えすぎて銅回路板の導電性を低下させる。
直接酸化する方法としては、たとえば、銅回路板を、大気中において温度150~360℃の範囲で20~120秒間加熱する表面酸化処理を行うことにより、銅回路板の表面に酸化銅膜を形成する方法が用いられる。
酸化銅膜の厚さが1μm未満であると、Cu-O共晶化合物の発生量が少なくなることから、アルミナ基板と銅回路板との未接合部分が多くなるため、接合強度を向上させる効果が小さくなる。
一方、酸化銅膜の厚さが10μmを超えると、接合強度の改善効果が少なく、却って銅回路板の導電特性を阻害することになる。
酸化銅粉末のペーストを塗布する方法としては、たとえば、平均粒径1~5μmの酸化銅粉末を含むペーストを用い、銅回路板の上にペーストを塗布して厚さ1~10μmの酸化銅ペースト層を形成した後、乾燥または熱処理することにより、銅回路板の表面に酸化銅膜を形成する方法が用いられる。
金属回路板が活性金属法によりアルミナ基板に接合される場合、金属回路板としては、銅、アルミニウム、鉄、ニッケル、クロム、銀、モリブデン、コバルトの単体、これらの合金、およびこれらのクラッド材等が用いられる。これらの中、銅板やアルミニウム板は、接合性がよいため好ましい。
活性金属接合ろう材ペーストに配合される活性金属は、アルミナ基板に対する活性金属接合ろう材の濡れ性および反応性を改善する。活性金属接合ろう材ペースト中の活性金属の配合量は、活性金属接合ろう材ペーストに含まれる接合用組成物100質量%に対して1~10質量%とする。
アルミナ基板と金属回路板との接合界面は、金属回路板の表面がアルミナ基板の表面の凹凸形状に沿って変形した入り組んだ構造になっている。具体的には、アルミナ基板と金属回路板との接合界面は、セラミックス回路基板の断面観察を行ったときに、金属回路板の表面に沿った曲線が、アルミナ基板の表面の凹凸に沿った曲線に接する割合(以下、「接合界面接触割合」という)が、通常95%以上、好ましくは99%以上、さらに好ましくは100%である入り組んだ構造になっている。
たとえば、アルミナ基板と金属回路板とが全く隙間がなく接合している場合、接合界面接触割合は100%である。また、アルミナ基板と金属回路板とが完全に剥離している場合、接合界面接触割合は0%である。
すなわち、はじめに、セラミックス回路基板の断面観察を行ったときに、接合断面の拡大写真を撮影する。接合断面の拡大写真は、1000倍以上であることが好ましい。
拡大写真は、接合界面を長さ100μmに亘って撮影する。なお、一視野で長さ100μmを撮影できないときは、20~50μmずつ撮影し、合計で100μm撮影するようにしてもよい。
次に、拡大写真から、接合界面におけるアルミナ基板の表面の凹凸に沿った曲線の長さLAと、接合界面における金属回路板の表面に沿った曲線との長さLMを測定する。
そして、LMをLAで除したLM/LAを接合界面接触割合として算出する。
本発明のセラミックス回路基板では、アルミナ基板の表面に深いボイドが露出することが実質的にない上、アルミナ基板と金属回路板とを特定の条件で接合させているため、アルミナ基板の表面のボイドに金属回路板が追従して入り込む。このため、本発明のセラミックス回路基板は、接合界面接触割合が通常95%以上と高く、アルミナ基板の表面と金属回路板とが入り組んだ構造になっており、アンカー効果が生じて接合強度が高い。
セラミックス回路基板は、アルミナ基板と金属回路板とを接合することにより製造される。アルミナ基板と金属回路板との接合方法は、上記のとおり、たとえば、直接接合法(DBC法)、活性金属法等の方法が用いられる。
直接接合法では、はじめに、アルミナ基板上に、金属回路板としての銅回路板を配置する。銅板に酸化膜(酸化銅膜)を形成した場合は、酸化膜がアルミナ基板側になるように配置する。次に、不活性ガス雰囲気中で、たとえば、1065~1085℃に加熱すると、アルミナ基板上に銅回路板が接合されたセラミックス回路基板が得られる。
活性金属法では、はじめに、アルミナ基板上にスクリーン印刷等の方法で活性金属接合ろう材ペーストを塗布する。次に、アルミナ基板の活性金属接合ろう材ペーストが塗布された面に、金属回路板を配置し、加熱すると、アルミナ基板上に銅回路板が接合されたセラミックス回路基板が得られる。
平均粒径2.5μm(0.8μm以下が13質量%)のα-アルミナ結晶から成り、純度が99.2質量%のアルミナ粉末(不純物Si量0.4質量%、Ca量0.2質量%、Mg量0.1質量%、Na量0.01質量%、不可避不純物0.29質量%)を用意した。
焼結助剤としてSiO2を0.3質量%、CaOを0.5質量%、MgOを0.4質量%、Na2Oを0.1質量%添加し、さらに有機結合剤を添加して原料混合体をそれぞれ調製した。各原料混合体をドクターブレード法によりシート成形して板状の成形体を調製し、この成形体を真空中で800℃で4時間加熱して完全に脱脂した。この脱脂体を温度1580℃で7時間焼結することにより、縦29mm×横63mm×厚さ0.32mmのアルミナ基板を調製した。
平均粒径1.5μm(0.8μm以下が25質量%)のα-アルミナ結晶から成り、純度が99.99質量%の高純度アルミナ粉末(不純物Si量0.002質量%、Ca量0.002質量%、Mg量0.001質量%、Na量0.001質量%、不可避不純物0.005質量%)を用意した。
焼結助剤としてSiO2を1.0質量%、CaOを1.0質量%、MgOを1.0質量%、Na2Oを0.1質量%添加し、さらに有機結合剤を添加して原料混合体をそれぞれ調製した。各原料混合体をドクターブレード法によりシート成形して板状の成形体を調製し、この成形体を真空中で800℃で4時間加熱して完全に脱脂した。この脱脂体を温度1560℃で6時間焼結することにより、縦29mm×横63mm×厚さ0.32mmのアルミナ基板を調製した。
なお、実施例1および実施例2ともに原料混合体の調整は純度96%のアルミナボールを用いたボールミル工程により行った。
平均粒径1.5μm(0.8μm以下が35質量%)のα-アルミナ結晶から成り、純度が99.99質量%の高純度アルミナ粉末(不純物Si量0.002質量%、Ca量0.002質量%、Mg量0.001質量%、Na量0.001質量%、不可避不純物0.005質量%)を用意した。
焼結助剤としてSiO2を添加しない以外は実施例2と同様にして、アルミナ基板を調製した。
平均粒径2.5μm(0.8μm以下が1質量%)のα-アルミナ結晶から成り、純度が99.2質量%のアルミナ粉末(不純物Si量0.4質量%、Ca量0.2質量%、Mg量0.1質量%、Na量0.01質量%、不可避不純物0.29質量%)を用意した。
焼結助剤としてSiO2を3.0質量%添加した以外は実施例1と同様にして、アルミナ基板を調製した。
各アルミナ基板のAl2O3純度、平均結晶粒径、結晶粒径のばらつき、ボイドの面積率、ボイド平均径、ボイドの最大径、ボイドの個数、絶縁耐圧、抗折強度、破壊靭性値、熱伝導率およびビッカース硬度をそれぞれ測定して表1に示す結果を得た。
ボイド率、ボイド平均径、平均結晶粒径および結晶粒径のばらつきはアルミナ基板の断面観察により測定した。
すなわち、単位面積200μm×200μmの拡大写真を撮り、この拡大写真に写る個々のボイドの面積を測定し、合計面積を200μm×200μmで割った数字をボイドの面積率とした。
また、個々のボイドにつき直径が最も大きくなるように測定した値を最大径とし、ボイド100個分の平均値をボイド平均径とした。また、ボイドの個数は単位面積100μm×100μmあたりの個数を4か所分測定し、その最小個数と最大個数を示した。
また、アルミナ結晶粒の平均結晶粒径は、個々のアルミナ結晶粒において直径が最も大きくなるように選んだ線分の長さを長径L1とし、その中心から垂直線を引いたときを短径L2とし、(L1+L2)/2を粒径とした(図4参照)。この作業を100粒行い、その平均値を平均粒径とした。
アルミナ結晶粒のまた、結晶粒径のばらつきは、平均結晶粒径Aμmに対し、A×(0.3~1.7)の範囲に入る結晶粒の割合を求めた。
絶縁耐圧、抗折強度(3点曲げ強度)、熱伝導率、破壊靭性値およびビッカース硬度は、JIS-R-1601(抗折強度)、JIS-R-1607(破壊靭性値)、JIS-R-1610(ビッカース硬度)、JIS-R-1611(熱伝導率)等に記載された方法で求めた。また、絶縁耐圧は、前述の通り、絶縁油(商品名フロリナート)を用いた部分放電開始電圧を用いた方法で行った。
これらの結果を表1~3に示す。
図5は、実施例1に係るセラミックス回路基板の接合界面のSEM写真である。図5に示されるように、セラミックス回路基板1のアルミナ基板2と金属回路板(銅回路板)3の界面において、金属回路板(銅回路板)3はアルミナ基板2の表面に密着している。
焼結助剤量および焼結条件を変えたものを用意し、実施例1と同様の測定を行った。その結果を表1、表2~3に示す。なお、原料粉末は実施例1で用いたものと同じものを用いた。
実施例1~5および比較例1~2のアルミナ基板と銅板を用いて、セラミックス回路基板を調製した。銅板は熱処理して接合面側に厚さ5μmの酸化銅膜を形成したものを用意した。アルミナ基板の両面に銅板(一方が金属回路基板用銅板、もう一方が裏銅板)を配置し、窒素雰囲気中1075℃×1分間加熱して直接接合法により接合した。なお、金属回路板用銅板は厚さ0.3mm、裏銅板は厚さ0.4mmで統一した。また、実施例1B~5Bは銅板中の炭素含有量は0.2~0.8質量%の範囲内のもの、6Bは炭素が含有されていないもの(検出限界以下)のものを用意した。
次に得られたセラミックス回路基板の金属回路板をエッチングして、図1に示した回路パターンを形成した。
次に実施例1B~6B、比較例1B~2Bのセラミックス回路基板の銅回路板の接合強度および接合界面の状態について調べた。接合強度はピール試験により求めた。
また、接合界面は、アルミナ基板と銅回路板の接合界面の拡大写真(2000倍)を撮影する。この作業を接合界面100μm分撮影した。接合界面において、アルミナ基板の表面凹凸をどれだけ覆うように銅回路板が接合されているかを調べた。その結果を表5に示す。
2 アルミナ基板
3 金属回路板(銅回路板)
4 裏金属板(裏銅板)
22 アルミナ結晶粒
Claims (17)
- アルミナ基板上に金属回路板が接合されたセラミックス回路基板において、
前記アルミナ基板は、アルミナAl2O3を94~98質量%、および焼結前に配合された焼結助剤から生成された焼結助剤由来成分を2~6質量%含み、
前記焼結助剤由来成分は、ケイ素を含む無機酸化物であり、前記焼結助剤由来成分中のケイ素は酸化ケイ素SiO2に換算した質量で前記アルミナ基板100質量%中に0.01~1.5質量%含まれ、
前記アルミナ基板は、ボイドの最大径が15μm以下であり、ボイドの平均径が10μm以下であり、ビッカース硬度が1300以上であることを特徴とするセラミックス回路基板。 - 前記焼結助剤由来成分はカルシウムをさらに含む無機酸化物であり、前記焼結助剤由来成分中のカルシウムは酸化カルシウムCaOに換算した質量で前記アルミナ基板100質量%中に0.001~1.5質量%含まれることを特徴とする請求項1記載のセラミックス回路基板。
- 前記焼結助剤由来成分はマグネシウムをさらに含む無機酸化物であり、前記焼結助剤由来成分中のマグネシウムは酸化マグネシウムMgOに換算した質量で前記アルミナ基板100質量%中に0.001~1.0質量%含まれることを特徴とする請求項1または請求項2に記載のセラミックス回路基板。
- 前記焼結助剤由来成分はナトリウムをさらに含む無機酸化物であり、前記焼結助剤由来成分中のナトリウムは酸化ナトリウムNa2Oに換算した質量で前記アルミナ基板100質量%中に0.001~0.5質量%含まれることを特徴とする請求項1ないし請求項3のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、アルミナ結晶粒の平均結晶粒径が20μm以下であることを特徴とする請求項1ないし請求項4のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、断面観察により単位面積200μm×200μmの観察範囲内で観察されるアルミナ結晶粒の全個数Ntに対する、前記観察範囲内で観察され、アルミナ結晶粒の平均結晶粒径をAμmとしたときに0.3A~1.7Aの範囲内にあるアルミナ結晶粒の個数NAの比率NA/Ntが70%以上であることを特徴とする請求項1ないし請求項5のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、断面観察で算出される単位面積100μm×100μmあたりのボイドの個数が5~50個であることを特徴とする請求項1ないし請求項6のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、このアルミナ基板の断面観察により算出されたボイドの面積の比率であるボイド面積率が20%以下であることを特徴とする請求項1ないし請求項7のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、絶縁耐圧が15KV/mm以上であることを特徴とする請求項1ないし請求項8のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、熱伝導率が20W/m・K以上であることを特徴とする請求項1ないし請求項9のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、抗折強度が300MPa以上であることを特徴とする請求項1ないし請求項10のいずれか1項に記載のセラミックス回路基板。
- 前記金属回路板は、直接接合法により前記アルミナ基板に接合されたことを特徴とする請求項1ないし請求項11のいずれか1項に記載のセラミックス回路基板。
- 前記金属回路板は銅回路板であり、この銅回路板はCu-O共晶化合物により前記アルミナ基板に接合されていることを特徴とする請求項1ないし請求項12のいずれか1項に記載のセラミックス回路基板。
- 前記金属回路板は銅回路板であり、この銅回路板は炭素を0.1~1.0質量%含むことを特徴とする請求項1ないし請求項13のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板と前記金属回路板との接合界面は、前記セラミックス回路基板の断面観察を行ったときに、前記金属回路板の表面に沿った曲線が前記アルミナ基板の表面の凹凸に沿った曲線に接する割合が95%以上である入り組んだ構造になっていることを特徴とする請求項1ないし請求項14のいずれか1項に記載のセラミックス回路基板。
- 前記アルミナ基板は、厚さが0.25~1.2mmであることを特徴とする請求項1ないし請求項15のいずれか1項に記載のセラミックス回路基板。
- 前記金属回路板は、厚さが0.1~0.5mmであることを特徴とする請求項1ないし請求項16のいずれか1項に記載のセラミックス回路基板。
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Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014129666A1 (ja) * | 2013-02-25 | 2014-08-28 | 京セラ株式会社 | 電子部品収納用パッケージおよび電子装置 |
CN105142340A (zh) * | 2015-08-31 | 2015-12-09 | 苏州斯尔特微电子有限公司 | 一种电容型陶瓷电路基板 |
WO2017144331A1 (de) * | 2016-02-26 | 2017-08-31 | Heraeus Deutschland GmbH & Co. KG | Kupfer-keramik-verbund |
JP2019511993A (ja) * | 2016-02-26 | 2019-05-09 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅−セラミックス複合材料 |
JP2019511991A (ja) * | 2016-02-26 | 2019-05-09 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅/セラミック複合材 |
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Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
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Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6144757A (ja) * | 1984-08-08 | 1986-03-04 | 太陽誘電株式会社 | アルミナ磁器組成物 |
JPH05301760A (ja) * | 1992-04-24 | 1993-11-16 | Matsushita Electric Works Ltd | アルミナ基板の製造方法 |
JPH10107174A (ja) * | 1996-09-26 | 1998-04-24 | Fuji Electric Co Ltd | 半導体装置用基板およびその製造方法 |
JP2000247729A (ja) * | 1999-02-23 | 2000-09-12 | Ngk Spark Plug Co Ltd | アルミナ基焼結体 |
JP2000277663A (ja) * | 1999-03-26 | 2000-10-06 | Toshiba Corp | 複合基板およびその製造方法 |
JP2000277662A (ja) * | 1999-03-26 | 2000-10-06 | Toshiba Corp | セラミックス回路基板 |
JP2003163425A (ja) * | 2001-11-29 | 2003-06-06 | Kyocera Corp | 配線基板 |
JP2011111365A (ja) * | 2009-11-27 | 2011-06-09 | Kyocera Corp | 不透光性セラミックス焼結体およびこれを用いた操作パネル |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6483512A (en) * | 1987-09-24 | 1989-03-29 | Showa Denko Kk | Low soda alumina |
JPH06172021A (ja) * | 1992-12-04 | 1994-06-21 | Sumitomo Metal Mining Co Ltd | 高電圧厚膜回路用アルミナ基板 |
KR100361113B1 (ko) * | 1994-08-18 | 2003-02-05 | 닛뽕도구슈우도오교오가부시끼가이샤 | 세라믹 히터용 알루미나기 소결재료 |
TW579372B (en) * | 1998-07-29 | 2004-03-11 | Sumitomo Chemical Co | Process for producing alumina sintered body |
-
2012
- 2012-07-13 JP JP2013524002A patent/JP5972875B2/ja active Active
- 2012-07-13 CN CN201280019369.6A patent/CN103492345B/zh active Active
- 2012-07-13 WO PCT/JP2012/067956 patent/WO2013008919A1/ja active Application Filing
- 2012-07-13 KR KR1020137027480A patent/KR101522807B1/ko active IP Right Grant
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6144757A (ja) * | 1984-08-08 | 1986-03-04 | 太陽誘電株式会社 | アルミナ磁器組成物 |
JPH05301760A (ja) * | 1992-04-24 | 1993-11-16 | Matsushita Electric Works Ltd | アルミナ基板の製造方法 |
JPH10107174A (ja) * | 1996-09-26 | 1998-04-24 | Fuji Electric Co Ltd | 半導体装置用基板およびその製造方法 |
JP2000247729A (ja) * | 1999-02-23 | 2000-09-12 | Ngk Spark Plug Co Ltd | アルミナ基焼結体 |
JP2000277663A (ja) * | 1999-03-26 | 2000-10-06 | Toshiba Corp | 複合基板およびその製造方法 |
JP2000277662A (ja) * | 1999-03-26 | 2000-10-06 | Toshiba Corp | セラミックス回路基板 |
JP2003163425A (ja) * | 2001-11-29 | 2003-06-06 | Kyocera Corp | 配線基板 |
JP2011111365A (ja) * | 2009-11-27 | 2011-06-09 | Kyocera Corp | 不透光性セラミックス焼結体およびこれを用いた操作パネル |
Non-Patent Citations (2)
Title |
---|
"Fine Ceramics Jiten Henshu Iinkai", FINE CERAMICS JITEN, 30 April 1987 (1987-04-30), pages 34 * |
"Material Data Base Henshu Iinkai", MATERIAL DATA BASE -MUKI ZAIRYO, 25 January 1989 (1989-01-25), pages 84 - 87 * |
Cited By (20)
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US9756731B2 (en) | 2013-02-25 | 2017-09-05 | Kyocera Corporation | Package for housing electronic component and electronic device |
WO2014129666A1 (ja) * | 2013-02-25 | 2014-08-28 | 京セラ株式会社 | 電子部品収納用パッケージおよび電子装置 |
CN105142340A (zh) * | 2015-08-31 | 2015-12-09 | 苏州斯尔特微电子有限公司 | 一种电容型陶瓷电路基板 |
US11021407B2 (en) | 2016-02-26 | 2021-06-01 | Heraeus Deutschland GmbH & Co. KG | Copper/ceramic composite |
WO2017144331A1 (de) * | 2016-02-26 | 2017-08-31 | Heraeus Deutschland GmbH & Co. KG | Kupfer-keramik-verbund |
CN108698945A (zh) * | 2016-02-26 | 2018-10-23 | 贺利氏德国有限两合公司 | 铜-陶瓷复合物 |
JP2019511992A (ja) * | 2016-02-26 | 2019-05-09 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅−セラミックス複合材料 |
JP2019511993A (ja) * | 2016-02-26 | 2019-05-09 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅−セラミックス複合材料 |
JP2019511991A (ja) * | 2016-02-26 | 2019-05-09 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅/セラミック複合材 |
JP2019513664A (ja) * | 2016-02-26 | 2019-05-30 | ヘレウス ドイチュラント ゲーエムベーハー ウント カンパニー カーゲー | 銅−セラミック複合材 |
CN111164059B (zh) * | 2017-09-28 | 2023-02-03 | 京瓷株式会社 | 发光元件安装用基板及具备其的发光元件安装用电路基板、以及发光元件模块 |
CN111164059A (zh) * | 2017-09-28 | 2020-05-15 | 京瓷株式会社 | 发光元件安装用基板及具备其的发光元件安装用电路基板、以及发光元件模块 |
JP2022087102A (ja) * | 2017-11-29 | 2022-06-09 | ロジャーズ ジャーマニー ゲーエムベーハー | 金属半製品を製造する方法、金属-セラミック基板を製造する方法および金属-セラミック基板 |
JP2021503433A (ja) * | 2017-11-29 | 2021-02-12 | ロジャーズ ジャーマニー ゲーエムベーハーRogers Germany GmbH | 金属半製品を製造する方法、金属−セラミック基板を製造する方法および金属−セラミック基板 |
JP7337987B2 (ja) | 2017-11-29 | 2023-09-04 | ロジャーズ ジャーマニー ゲーエムベーハー | 金属半製品を製造する方法および金属-セラミック基板を製造する方法 |
US11183819B2 (en) | 2018-10-03 | 2021-11-23 | Ngk Spark Plug Co., Ltd. | Spark plug |
CN110994361A (zh) * | 2018-10-03 | 2020-04-10 | 日本特殊陶业株式会社 | 火花塞 |
JP2020057559A (ja) * | 2018-10-03 | 2020-04-09 | 日本特殊陶業株式会社 | スパークプラグ |
WO2022230220A1 (ja) * | 2021-04-28 | 2022-11-03 | 富士電機株式会社 | 半導体装置 |
WO2024053619A1 (ja) * | 2022-09-05 | 2024-03-14 | Ngkエレクトロデバイス株式会社 | セラミック基板、及びこれを備えた半導体装置用基板 |
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KR20130135965A (ko) | 2013-12-11 |
JP5972875B2 (ja) | 2016-08-17 |
CN103492345A (zh) | 2014-01-01 |
JPWO2013008919A1 (ja) | 2015-02-23 |
CN103492345B (zh) | 2016-04-06 |
KR101522807B1 (ko) | 2015-05-26 |
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