JP2005101300A - Ceramic package and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and thin ceramic package which is fired simultaneously with metallization and is unbroken easily even if it is sealed hermetically. <P>SOLUTION: The ceramic package comprises: an insulating substrate 1 having a substrate bottom part 1a for mounting an electric element 4 on the surface and a substrate bank part 1b provided integrally with the substrate bottom part 1a on the outer circumference thereof; a conductor layer 2 provided in the insulating substrate 1 and/or on the surface thereof; and a metallization layer 3a provided at a part of the substrate bank part 1b in order to bond a cover 8. The insulating substrate 1 is composed of an alumina sintered body containing 6 mass% or more of sintering acid and having a finish porcelain strength of 650 MPa or above. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a ceramic package in which electrical elements such as vibrators and semiconductor elements are mounted and sealed secretly by a lid such as a lid, in particular, an ultra-small and ultra-thin with a height of 0.6 mm or less. The present invention relates to a ceramic package and a manufacturing method thereof.

  In recent years, along with the high integration of semiconductor elements and the miniaturization of electronic components, various electronic devices have been miniaturized and enhanced in function. Along with this, miniaturization of the ceramic package on which the electric element is mounted is required, and for example, a ceramic package miniaturized to about 3 mm in outside size, 2 mm in width, and about 0.8 mm in height is disclosed (for example, Patent Documents). 1).

  Recently, however, the package is required to be further reduced in size so that it can be applied to an ultra-small and ultra-thin product represented by an IC card having a height of 0.6 mm or less. In such an ultra-small and ultra-thin ceramic package, the width of the substrate bank portion and the thickness of the substrate bottom portion of the insulating substrate are reduced. Therefore, the ceramic package has high strength so that these parts are not damaged by the joining of the lid. It is becoming necessary.

In order to solve this problem, it is proposed to realize a high-strength alumina substrate having a thickness of 0.25 to 0.35 mm and a strength of 55 kgf / mm ² or more by using high-purity alumina having a purity of 99% or more. (For example, refer to Patent Document 2).

  However, this high-purity and high-strength alumina substrate has a high alumina purity of 99% by mass or more, and when metallization is formed by simultaneous firing, the bonding strength of metallization is low. Therefore, in order to obtain metallization with high bonding strength, it is necessary to bake after sintering a conductive component composed mainly of Mo and an active metal such as Mn, Ti, etc., which increases the process and increases the cost. was there. In addition, since magnesium oxide used as a sintering aid is a fine powder, there is a problem in that secondary agglomeration tends to occur during slurry preparation, a sintering defect tends to occur, and the strength decreases.

Therefore, it is proposed that a conductor layer is formed on an alumina compact with 4% by mass or more of a sintering aid and fired to perform firing and metallization at the same time to realize an alumina substrate at low cost. (For example, see Patent Document 3).
JP 2001-196485 A JP 2000-7425 A Japanese Patent Laid-Open No. 2000-277762

  However, the alumina sintered body described in Patent Document 3 can be metallized by simultaneous firing. However, since the sintering aid is contained in an amount of 4% by mass or more, the strength is low at 400 MPa or less, and the hermetic sealing is performed. When the lid and the ceramic package are bonded to each other, there is a problem that the insulating substrate is broken by the thermal stress generated by the difference in thermal expansion coefficient among the insulating substrate, the metallized layer, the brazing material, and the lid. In particular, a ceramic package that is fired simultaneously with a conductor is not subjected to processing such as polishing, and is used as it is baked, so that there are many sources of destruction on the product surface, and there is a problem that it is easily broken during sealing.

  Accordingly, the present invention is to provide a small and thin ceramic package that can be fired simultaneously with metallization and is not easily broken even if hermetically sealed, and a method for manufacturing the same.

  The ceramic package of the present invention includes a substrate bottom portion for mounting an electric element on the surface, a substrate bank portion integrally provided on the outer periphery of the substrate bottom portion, and an interior and / or surface of the insulation substrate. In a ceramic package comprising a conductor layer provided on a metal layer and a metallized layer provided on a part of the substrate bank portion for bonding a lid, the insulating substrate contains a sintering aid of 6% by mass or more. And an alumina sintered body having a baked porcelain strength of 650 MPa or more.

In particular, the insulating substrate contains Mn at a ratio of 2 to 8% by mass in terms of Mn ₂ O ₃ , Si at 1 to 6% by mass in terms of SiO ₂ , and Mg at a rate of 0.1 to 1% by mass in terms of MgO. ₂ / MgO is preferably composed of an alumina sintered body having a content ratio of 5 to 15.

  Moreover, it is preferable that the width | variety of the said board | substrate bank part is 0.1-0.3 mm, the thickness of the said board | substrate bottom part is 0.1-0.3 mm, and the height of the whole package is 0.3-0.6 mm.

The method for producing a ceramic package of the present invention is the sum of alumina powder and Mn ₂ O ₃ powder having an average particle diameter of 1.3 μm or less, SiO ₂ powder and magnesium carbonate powder having an average particle diameter of 3 to 5 μm as a sintering aid. After forming a conductor layer and a metallized layer on a green sheet having a composition of 5 to 15 in terms of SiO ₂ / MgCO ₃ in terms of SiO ₂ / MgO, using a conductor paste, The green sheets are appropriately laminated and then fired so that the baked porcelain strength is 650 MPa or more.

The Mn ₂ O ₃ powder is 2 to 8% by mass, the SiO ₂ powder is 1 to 6% by mass, the magnesium carbonate is 0.1 to 1% by mass in terms of MgO, and the content ratio of SiO ₂ / MgO is 5 It is preferably ~ 15.

In the present invention, by controlling the particle size of MgCO ₃ as a sintering aid and controlling the ratio of SiO ₂ / MgO, it is possible to obtain a dense sintered body with good dispersion of Mn and Mg components. It is possible to obtain an alumina insulating substrate with a baked porcelain strength of 650 MPa or more. By using this as a package, it can be fired simultaneously with metallization, and a lid is bonded for hermetic sealing. Even if it is small and thin ceramic packages that are hard to break, especially small and / or thin ceramic packages that can be built into IC cards or the like can be realized at low cost.

Further, the insulating substrate contains Mn at a ratio of 2 to 8 mass% in terms of Mn ₂ O ₃ , Si at 1 to 6 mass% in terms of SiO ₂ , and Mg at a ratio of 0.1 to 1 mass% in terms of MgO, and SiO ₂ Since it comprises an alumina sintered body having a content ratio of / MgO of 5 to 15, high strength can be stably obtained.

  Further, the width of the substrate bank portion is 0.1 to 0.3 mm, the thickness of the substrate bottom portion is 0.1 to 0.3 mm, and the height of the entire package is 0.3 to 0.6 mm. By setting the dimensions to be small, it is possible to more effectively prevent the thermal stress destruction of the insulating substrate and further reduce the volume of the package.

In addition, the ceramic package manufacturing method of the present invention includes alumina powder and a sintering aid, Mn ₂ O ₃ powder having an average particle diameter of 1.3 μm or less, SiO ₂ powder, and magnesium carbonate powder having an average particle diameter of 3 to 5 μm. The conductor layer and the metallized layer were deposited using a conductor paste on a green sheet having a total content of 6% or more and a SiO ₂ / MgCO ₃ content ratio of 5 to 15 in terms of SiO ₂ / MgO. Thereafter, the green sheets are appropriately laminated, and then fired so that the baked porcelain strength becomes 650 MPa or more, but is sintered at a low temperature while suppressing grain growth, and 6% by mass or more of a sintering agent is added. However, a sintered body with higher density and higher dispersion can be realized, and an alumina sintered body having a strength of 650 MPa or more can be obtained.

In particular, the Mn ₂ O ₃ powder is 2 to 8% by mass, the SiO ₂ powder is 1 to 6% by mass, the magnesium carbonate is 0.1 to 1% by mass in terms of MgO, and the content ratio of SiO ₂ / MgO is 5 Since it is -15, high intensity | strength can be achieved more stably.

  The ceramic package of this invention is demonstrated using figures. FIG. 1 shows an example of a ceramic package according to the present invention. FIG. 1 (a) is a schematic cross-sectional view of the ceramic package, and FIG. 1 (b) shows an electronic component such as a vibrator or a semiconductor element inside. It is sectional drawing of the ceramic package which mounts an electrical element and was covered with the cover body.

  The ceramic package is made of an alumina sintered body, and includes an insulating substrate 1 including a substrate bottom 1a and a substrate bank 1b, a conductor layer 2 provided on the substrate bottom 1a, and a ring formed on the substrate bank 1b. The upper metallized layer 3a is provided.

  The insulating substrate 1 includes a substrate bottom portion 1a and a substrate bank portion 1b, and the substrate bank portion 1b is integrally provided on the outer periphery of the substrate bank portion 1a. The conductor layer 2 includes a surface conductor layer 2a provided on the surface of the substrate bottom 1a, a back conductor layer 2c provided on the back for electrical connection with the outside, a surface conductor layer 2a and a back conductor layer 2c. In order to connect the two, an internal conductor layer 2b formed inside the substrate bottom 1a.

  The ceramic package of the present invention is used by placing electronic components and semiconductor elements inside and sealing them with a lid. For example, as shown in FIG. An electronic component 4a and a semiconductor element 4b connected to the provided conductor layer 2 are provided.

  The electronic component 4a is electrically connected to the conductor layer 2 using a conductive adhesive 5a. As the electronic component 4a, at least one of a crystal oscillator, a dielectric, a resistor, a filter, and a capacitor can be used. The semiconductor element 4b is connected to the conductor layer 2 by wire bonding.

  The metal lid 8 is joined to a ceramic package and hermetically sealed in order to protect the electronic component 4a and the semiconductor element 4b. Further, the metal lid 8 is formed by optionally forming a plating layer 3b on the surface of the metallized layer 3a deposited on the upper surface of the substrate bank portion 1b, and using a brazing material 6 such as eutectic Ag-Cu. And joined by a method such as seam welding.

  In the ceramic package of the present invention, it is important that the sintered porcelain strength of the alumina sintered body constituting the insulating substrate 1 is 650 MPa or more, and when the lid 8 made of metal or the like is sealed or during secondary mounting. It is difficult to break even when thermal stress is applied, or it is possible to effectively prevent breakage due to an impact during handling or use. In particular, in order to further enhance such effects, the baked porcelain strength is preferably 670 MPa or more, more preferably 680 MPa or more, and more preferably 700 MPa or more.

  In addition, the intensity | strength in this invention shows the measured value by a 3 point | piece bending strength test, and can be evaluated using the sample of thickness 3mm, width 4mm, and length 40mm. However, the tension surface is a value measured at room temperature in accordance with JIS R1601, with no processing. The baking strength is the strength measured on the surface of the test piece where the maximum stress is applied unprocessed, and the strength after polishing is the strength measured after polishing the surface where the maximum stress of the test piece is applied. is there.

  In addition, it is important that the crystal grain size of the insulating substrate 1 is 0.8 to 1.8 μm. By controlling the crystal grain size, there is an effect of preventing the stress from being concentrated and becoming a fracture source and maintaining a high strength. According to the present invention, a strength of 650 MPa or more can be obtained by setting the crystal grain size in a small range as described above. In particular, in order to enhance the above effect, 1 to 1.5 μm is preferable.

  Furthermore, it is important that the insulating substrate 1 contains alumina as a main component and contains 6% by mass or more of a sintering aid. By containing 6% by mass or more of sintering aid, metallization and simultaneous firing can be performed.

  The main component alumina is preferably 90% by mass or more, particularly 90 to 94% by mass, and more preferably 91 to 94% by mass. Thereby, it becomes easy to set the strength to 650 MPa while maintaining the insulating property of the insulating substrate 1 and the adhesion between the insulating substrate 1 and the conductor layer 2.

As the second component, Mn oxide _(Mn 2 _{O 3)} 2~8% by weight in terms of, in particular 3 to 8% by weight, even 3-6% by weight, the proportion of 2-4 wt%, more preferably It is preferable to contain. This is because the Mn component acts as a sintering aid, facilitates low-temperature firing at 1350 to 1500 ° C., and does not excessively precipitate MnAl ₂ O ₄ , so that densification can be facilitated.

Further, Mn ₂ O ₃ preferably has an average particle diameter of 0.3 to 1.3 μm, particularly 0.4 to 1.0 μm, and more preferably 0.4 to 0.8 μm. When such a powder is used, the green sheet has good moldability, can prevent Mn aggregation, and improve the dispersion of the auxiliary component.

As a third component, 1-6 wt% of Si in terms of SiO _2, in particular 2 to 5 wt%, more preferably in a proportion of 3-5 wt%. When SiO ₂ is present in such a ratio, a liquid phase contributing to sinterability is generated and densification is promoted, and MnAl ₂ O ₄ is easily crystallized, so that high strength is easily obtained.

As a 4th component, it is preferable to contain Mg in the ratio of 0.1-1 mass% in conversion of MgO, especially 0.15-1.0 mass%, Furthermore, 0.2-0.5 mass%. MgO has the effect of suppressing the grain growth of alumina crystal particles, and by uniformly dispersing, a uniform sintered body having a small alumina particle diameter can be obtained. It is difficult to occur, and a crystal phase of MnAl ₂ O ₄ is easily generated, and high strength can be realized.

According to the invention, it is important that the content ratio of SiO ₂ / MgO is 5-15. By precipitating the Mg—Si compound, it is possible to suppress the aggregation of the Mn—Si compound that causes the porcelain stain and the strength reduction, and to easily increase the strength. In particular, 5-10 are preferable.

  Moreover, in order to improve the simultaneous sintering property of the insulating substrate 1 and the conductor layer 2, if desired, at least one of Ca, Sr, and Ba is used as the fifth component in an amount of 3% by mass or less in terms of oxide. May be included in proportions. Furthermore, if desired, a metal such as W or Mo may be included as a sixth component in a proportion of 2% by mass or less as a component for blackening the sintered body. In the present invention, the sintering aid means the second to sixth components.

At least the second and third components are present at the grain boundaries of the alumina crystal particles, and it is preferable that all or a part of Mn as the second component among these components is present as MnAl ₂ O _4. . When Mn ₂ O ₃ added as a sintering aid is precipitated as MnAl ₂ O ₄ , the bending strength of the sintered body can be increased.

  According to the present invention, the width d of the substrate bank portion 1b shown in FIG. 1A is 0.1 to 0.3 mm, the thickness D of the substrate bottom portion 1a is 0.1 to 0.3 mm, and the package The height T is preferably 0.3 to 0.6 mm. By setting the dimensions as described above, the strength of the alumina sintered body that is the insulating substrate 1 can be taken into consideration, so that the metal body 10 can be more effectively prevented from being damaged by thermal stress at the time of sealing. The volume of can be made smaller. In particular, when the height of the package is 0.6 mm or less, it can be easily applied to an IC card or the like as an ultra-small and ultra-thin ceramic package on which the electronic component 4a and / or the semiconductor element 4b are mounted.

  The adhesive strength of the metallized layer 3a to the alumina sintered body constituting the insulating substrate 1 is preferably 49N or more, particularly 68N or more, and more preferably 98N or more. Thus, by setting the adhesive strength to 49 N or more, the reliability of the connection with the metal terminal and the reliability against the thermal stress due to the thermal cycle after sealing are improved, and the metallized layer 3a formed in a ring shape with the insulating substrate 1 Can be prevented, and the airtightness of the ceramic package can be sufficiently maintained.

In order to improve the baking strength, it is important to uniformly distribute the crystal grain size of the alumina sintered body constituting the insulating substrate 1 within a certain range. That is, by setting the average crystal grain size to 1.8 μm or less, particularly 1.5 μm or less, it is possible to improve the baking strength and the strength after polishing. In addition, by setting the average crystal grain size to 0.8 μm or more, particularly 1 μm or more, aggregation can be prevented and strength can be improved by uniform dispersion. For this purpose, a method can be employed in which the average particle diameter of the MgCO ₃ raw material powder for the sintering aid is set to a specific value.

  Furthermore, the porosity of the insulating substrate 1 is preferably 4% or less, particularly 3.5% or less, and more preferably 3% or less. By increasing the porosity, it is possible to suppress a decrease in strength.

  The porosity can be measured by the Archimedes method, and the average crystal grain size can be measured by the intercept method.

  The adhesive strength is measured by forming a 2 mm x 25 mm conductor layer on the surface of the alumina sintered body, applying electroless Ni plating, joining the metal fittings using silver brazing, and peeling off the metal fittings. The load was measured. The obtained load value was defined as the adhesive strength.

  The thermal conductivity of the insulating substrate 1 releases heat at the time of sealing out of the system and can also reduce the temperature difference in the insulating substrate, thereby preventing destruction at the time of sealing more effectively. It is preferably 15 W / mK or more, particularly 20 W / mK or more, and more preferably 25 W / mK or more.

  The Young's modulus of the insulating substrate is preferably 325 GPa or less because it tends to absorb thermal stress by deformation and prevent destruction more effectively.

  The conductor layer 2 seals the lid or can be connected to various metal terminals, and forms a metallization having a strong adhesive force with the insulating substrate, so that W and / or Mo are the main components and alumina is 10 It is preferable to contain not more than 8% by mass, particularly not more than 8% by mass.

  The lid 8 is preferably made of an Fe—Ni—Co alloy because thermal expansion is close to that of alumina, thermal stress generated during sealing is reduced, and the insulating substrate 1 is less likely to break during sealing.

  Such an alumina package has a feature of high strength and is difficult to be destroyed even if it is small or thin. Therefore, it can be suitably used not only for an IC card but also for an electronic device such as a portable information terminal.

  Next, a method for producing the ceramic package of the present invention will be specifically described.

  First, an alumina powder having an average particle size of 0.5 to 2.5 μm, particularly 1.0 to 2.0 μm is prepared as a raw material powder. By setting the average particle size to 0.5 μm or more, the sheet formability can be secured and the cost of the powder can be prevented from increasing. Moreover, by setting it as 2.5 micrometers or less, the densification by baking at 1500 degrees C or less can be accelerated | stimulated, and sintering can be made easy. Moreover, in order to prevent strength reduction due to impurities, the purity of the alumina powder is preferably 99% or more.

Further, it is important to first add Mn ₂ O ₃ powder having an average particle size of 1.3 μm or less as a sintering aid. By setting the thickness to 1.3 μm or less, dispersion of the Mn component can be improved and densification can be promoted. In particular, sheet formability can be easily ensured by setting the lower limit of the average particle diameter to 0.4 μm or more. Furthermore, in order to avoid impurities, the purity is preferably 99% or more.

It is also important to add SiO ₂ powder as the _second sintering aid. The purity is preferably 99% or more, and the average particle size is preferably 0.5 to 3 μm. In particular, it is preferable to use molten SiO ₂ . When SiO ₂ produced by melting is used, the density is high, and it becomes easy to obtain denser sintering, and high strength is easily achieved.

Furthermore, it is important to use MgCO ₃ powder having an average particle diameter D ₅₀ of 3 to 5 μm as the third sintering aid. MgCO ₃ powder having an average particle diameter in such a range is easy to disperse uniformly, suppresses the crystal growth of alumina crystal particles during sintering, and has fine and evenly distributed alumina crystals. You can get a body.

Is less than the average particle diameter D ₅₀ 3 [mu] m, tend to powder aggregation because fine powder is increased, becomes poor dispersion in the slurry, the appearance of cracks defect occurs during the green sheet produced. On the other hand, if it exceeds 5 μm, MgO particles become a source of destruction and the strength decreases. In particular, from 3.5 to 4.5 μm is preferable for sheet formability and stable high strength. The purity of the MgCO ₃ powder is preferably 99% or more in order to avoid impurities and increase the dispersibility of Mg.

_Then, it is important that the content ratio of SiO 2 / MgCO ₃ is formulated to be 5 to 15 at _SiO 2 / MgO terms. By adding SiO ₂ and MgCO ₃ at such a ratio, the precipitation of the Mg—Si compound is suppressed, and the aggregation of the Mn—Si compound, which causes the porcelain stain and the strength reduction, is suppressed, and the strength is increased to 650 MPa or more. Can be realized.

  Mn, Si, and Mg may be added as carbonates, nitrates, acetates, and the like that can form oxides by firing in addition to the above powder.

These components are ₂ to 8% by mass of Mn ₂ O ₃ powder, 1 to 6% by mass of SiO ₂ powder, and 0.1 to 1% by mass of MgCO ₃ powder in terms of MgO with respect to the alumina powder. Addition is preferable in order to enhance sinterability and promote densification. Furthermore, 2-4 mass% of Mn ₂ O ₃ powder, 2-4 mass% of SiO ₂ powder, and MgCO ₃ powder may be added at a ratio of 0.1-0.6 mass% to the alumina powder. preferable.

  If desired, as a fifth component, at least one of Ca, Sr, and Ba is 3% by mass or less in terms of oxide, and as a sixth component, a metal powder or oxide of a transition metal such as W or Mo You may add powder as a coloring component in the ratio of 2 mass% or less in metal conversion.

  Furthermore, Zr, Hf, etc., which are well-known methods for improving strength and fracture toughness, may be added as appropriate.

  An organic binder is appropriately added to the mixed powder, and then a green sheet for producing an insulating substrate is produced by a known forming method such as a press method, a doctor blade method, a rolling method, and an injection method. For example, an organic binder or a solvent is added to the mixed powder to prepare a slurry, and then a green sheet is formed by a doctor blade method. Alternatively, an organic binder is added to the mixed powder, and a green sheet having a predetermined thickness can be produced by press molding, rolling molding, or the like.

  If desired, a via hole having a diameter of 50 to 250 μm can be formed on the green sheet by a micro drill, a laser, or the like.

  For the green sheet thus produced, a conductor paste is formed on each green sheet by a method such as screen printing and gravure printing, and if desired, the conductor paste is filled in the via hole, Printing is applied in a ring shape to form a metallized layer.

  The conductor paste preferably uses W and / or Mo as a conductor component and alumina powder added thereto at a ratio of 10% by mass or less, particularly 8% by mass or less. This enhances the adhesion between the alumina sintered body and the conductor layer 2 while keeping the conduction resistance of the conductor layer 2 low, and can prevent the occurrence of defects such as lack of plating. In addition, in order to improve adhesion, the same composition powder as the oxide ceramic component forming the insulating substrate may be added instead of the alumina powder, and an oxide such as Ni is added in an amount of 0.05 to 2% by mass. It is also possible to add in proportions.

  Thereafter, it is important that the green sheet on which the conductive paste is printed is aligned and laminated and pressure-bonded, and then the laminated body is fired so that the firing porcelain strength is 650 MPa or more. For example, it is heated at a temperature rising rate of 150 ° C./h or more from at least 1000 ° C. to the highest firing temperature, fired in a non-oxidizing atmosphere of 1350 to 1500 ° C., and the cooling rate to 1000 ° C. is 250 ° C./h or less. It can bake on the conditions to do.

  When the rate of temperature increase is less than 150 ° C./h between 1000 ° C. and the maximum firing temperature, the liquid phase generation in the low temperature liquid phase region at the time of temperature increase becomes uneven and the grain growth of alumina is biased As a result, bending strength tends to decrease. In particular, in order to further increase the strength, it is preferable that the rate of temperature rise is 180 ° C./h or more, and further 200 ° C./h or more.

  It is also important to fire at 1350-1500 ° C. When the temperature is lower than 1350 ° C., the densification is insufficient and the bending strength may not reach 650 MPa. When the temperature is higher than 1500 ° C., W and / or Or sintering of Mo itself advances and there exists a tendency for the adhesive strength with an alumina to become weak. The firing temperature is particularly preferably 1350 to 1450 ° C. in order to improve mechanical and electrical reliability.

The cooling rate from the holding temperature immediately after the end of firing to 1000 ° C. is preferably 250 ° C./h or less. If it exceeds 250 ° C./h, MnAl ₂ O ₄ is difficult to be crystallized and remains as an amorphous substance, so that the bending strength tends to decrease. The cooling rate is particularly preferably 200 ° C./h or less from the viewpoint of further increasing the strength.

  The firing atmosphere is preferably a non-oxidizing atmosphere so that the metal is not oxidized. Specifically, it is preferable to use nitrogen or a mixed gas of nitrogen and hydrogen. In degreasing the organic binder, a non-oxidizing atmosphere containing hydrogen and nitrogen and having a dew point of + 30 ° C. or lower, particularly 25 ° C. or lower is desirable. Note that an inert gas such as argon may be mixed in the atmosphere as desired.

  The metallized layer 3a and the conductor layer 2 can be improved in adhesion at the time of bonding by forming a plating layer made of at least one of Ni, Co, Cr, Au and Cu as desired.

  The ceramic package manufactured by such a method can be fired simultaneously with metallization, and can be suitably used as a small ceramic package having a strength of 650 MPa or more.

  Finally, the electronic component 4a and / or the semiconductor element 4b are mounted inside the insulating substrate 1, electrically connected to the conductor layer 2, and the surface of the metallized layer 3a formed in a ring shape. A semiconductor in which the electronic component 4a and / or the semiconductor element 4b are hermetically sealed by joining the metal lid 18 to the insulating substrate 1 by seam welding with the brazing material 9 through the plating layer 3b covered with A device can be obtained.

With respect to alumina powder having a purity of 99% or more and an average particle diameter of 1.5 μm, Mn ₂ O ₃ powder having a purity of 99% or more and the average particle diameter shown in Table 1, purity 99% or more and the average particles shown in Table 1 A molten SiO ₂ powder having a diameter of 99% or more and a MgCO ₃ powder having an average particle diameter of 3.6 μm and a MoO ₃ powder having a purity of 99% or more and an average particle diameter of 0.7 μm were prepared.

After mixing these raw material powders in the proportions shown in Table 1, an acrylic binder as a molding organic resin (binder) and toluene are mixed as a solvent to prepare a slurry, and then the thickness is determined by a doctor blade method. A 150 μm green sheet was prepared. In Table 1, the MgCo ₃ content is shown not as the MgO equivalent value but as the MgCO ₃ content value.

  The obtained green sheets were laminated to a predetermined thickness, degreased in an open air + 25 ° C nitrogen-hydrogen mixed atmosphere, and subsequently heated from 1000 ° C to a firing maximum temperature of 1370 ° C at 180 ° C / h. After firing for 48 minutes in a nitrogen-hydrogen mixed atmosphere with a dew point of + 25 ° C. as the firing temperature, the temperature was lowered to 1000 ° C. at 180 ° C./h.

  The porosity of the obtained sintered body was measured by Archimedes method, and the strength was measured at room temperature based on JIS R1601. The test piece is a beam having a thickness of 3 mm, a width of 4 mm, and a length of 40 mm. The test piece used for the baking strength is measured while the surface to which the maximum stress is applied is left unprocessed. A sample was prepared by polishing the surface to which is applied.

  Further, the Young's modulus was measured at room temperature based on JIS R1602, and the thermal conductivity was measured at room temperature by a laser flash method.

  On the other hand, 94% by mass of Mo powder having an average particle size of 2.6 μm, 6% by mass of alumina powder having an average particle size of 1.5 μm, an acrylic binder and acetone as a solvent were mixed to prepare a conductor paste.

  The green sheet produced in the same manner as above is punched to form a via hole having a diameter of 100 μm, and the via paste is filled in the via hole by a screen printing method. And it was printed and applied in a ring shape. In addition, the green sheet in which the ring-shaped metallization was formed was removed by punching the part that houses the electronic component.

The conductor paste has a purity of 99% or more, 95% by mass of Mo powder having an average particle size of 0.7 μm, 4.6% by mass of alumina powder having an average particle size of 1.5 μm, and Mn ₂ O _{3 having} an average particle size of 1.0 μm. The composition was composed of 0.2% by mass of the powder and SiO ₂ powder having an average particle diameter of 1.0 μm.

  The green sheets thus produced were aligned and laminated and pressed to produce a laminate. Thereafter, this laminated molded body was degreased in a nitrogen-hydrogen mixed atmosphere at a dew point of + 25 ° C., then degreased in a nitrogen-hydrogen mixed atmosphere at an open-air + 25 ° C., and subsequently at a temperature rising rate of 180 ° C./h. The temperature was raised from 1000 ° C. to a firing maximum temperature of 1370 ° C., firing at a firing maximum temperature of 1370 ° C. for 48 minutes in a nitrogen-hydrogen mixed atmosphere with a dew point of 25 ° C., and then cooled to 1000 ° C. at 180 ° C./h.

  Next, electrolytic Ni plating was applied to the surfaces of the conductor layer and metallization layer on the surface of the insulating substrate, and further 0.2 μm Au plating was applied to the surface. A metal lid having a thickness of 0.2 mm made of an Fe—Ni—Co alloy was joined to the metallized layer by seam welding using a eutectic Ag—Cu brazing material, and hermetically sealed.

The obtained samples were checked for metallization peeling and cracks on the insulating substrate with a 40 × microscope, and for each result, the case where there was no metallization peeling or cracking was evaluated as ○, and other cases were evaluated as x. It was. Further, the hermetic sealing property was evaluated by the He leak method. In the He leak method, after being held in a 0.41 MPa He pressurized atmosphere for 2 hours, the He leak method is taken out, and the amount of He gas detected in a vacuum atmosphere is measured to obtain 1 × 10 ⁻¹⁰ MPa · cm ³ / sec or less. ○ A value exceeding 5 × 10 ⁻⁹ MPa · cm ³ / sec was evaluated as ×, and the result is shown in Table 1.

本発明の試料Ｎｏ．１〜１５は、いずれも焼上げ強度が６５０ＭＰａ以上、研磨後の強度も６５０ＭＰａ以上であった。外観異常は観察されず、Ｈｅリーク試験でも見られず、封止状態も良好であった。 In addition, the adhesive strength of the metallized layer to the insulating substrate is a peeling load when a metal wire is formed using 2 mm x 5 mm, electroless Ni plating is applied, and then the metal fitting is joined using silver solder, and the metal fitting is peeled off. Was measured. The results are shown in Table 1.

Sample No. of the present invention. 1 to 15 all had a baking strength of 650 MPa or more, and the strength after polishing was 650 MPa or more. Appearance abnormality was not observed, He leak test was not observed, and the sealing state was good.

On the other hand, Sample No. which does not contain MgCO ₃ and is outside the scope of the present invention. 16 and 17 had a baking strength of 440 MPa or less. Sample No. No. 16 had no appearance abnormality, but an abnormality was found in the He leak test, and the sealing state was poor. Furthermore, sample no. No. 17 had cracks and an abnormal appearance.

An example of the ceramic package of this invention is shown, (a) is a schematic sectional drawing of a ceramic package, (b) is a schematic sectional drawing of the ceramic package of the state which mounted the electric element inside and joined the cover body. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 1a ... Substrate bottom part 1b ... Substrate bank part 2 ... Conductor layer 2a ... Surface conductor layer 2b ... Back conductor layer 2c ... Inner conductor layer 3a ... Metallized layer 3b ... plated layer 4 ... electric element 4a ... electronic component 4b ... semiconductor element 5a ... conductive adhesive 5b ... wire bonding 6 ... brazing material 8 ... Metal lid d ... Substrate bank width D ... Substrate bottom thickness T ... Package height

Claims (5)

An insulating substrate comprising a substrate bottom for mounting electrical elements on the surface, and a substrate bank integrally provided on the outer periphery of the substrate bottom; and a conductor layer provided on the inside and / or surface of the insulating substrate; And a ceramic package comprising a metallization layer provided on a part of the substrate bank portion for joining the lid, wherein the insulating substrate contains 6% by mass or more of a sintering aid, and the average crystal grain size is A ceramic package comprising an alumina sintered body having a firing ceramic strength of 650 MPa or more at 0.8 to 1.8 μm. Wherein including a dielectric substrate and Mn 2 to 8% by mass _Mn 2 _{O 3} in terms, 1-6 wt% of Si in terms of SiO _2, the Mg in a proportion of 0.1 to 1 wt% in terms of MgO, _SiO 2 / The ceramic package according to claim 1, wherein the ceramic package is made of an alumina sintered body having a MgO content ratio of 5 to 15. The width of the substrate bank portion is 0.1 to 0.3 mm, the thickness of the substrate bottom portion is 0.1 to 0.3 mm, and the height of the entire package is 0.3 to 0.6 mm. Item 3. A ceramic package according to item 1 or 2. Average particle diameter of 1.3μm or less of _Mn 2 _{O 3} powder as the alumina powder and the sintering aid, SiO ₂ powder and the average particle diameter is contained more than 6 wt% in total of magnesium carbonate powder 3 to 5 [mu] m, SiO ₂ / content ratio of MgCO ₃ is the green sheet having the composition of 5-15 at SiO 2 / _MgO conversion, after the conductive layer and the metallization layer using a conductive paste deposited formed by stacking the green sheets as appropriate, accordingly A method for producing a ceramic package, characterized in that firing is performed later such that the baked porcelain strength is 650 MPa or more. The Mn ₂ O ₃ powder is 2 to 8% by mass, the SiO ₂ powder is 1 to 6% by mass, the magnesium carbonate is 0.1 to 1% by mass in terms of MgO, and the content ratio of SiO ₂ / MgO is 5 to 15 The method of manufacturing a ceramic package according to claim 10, wherein:

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