JP2005101467A - Ceramic package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic package which is not cracked even under high temperature high humidity. <P>SOLUTION: The ceramic package comprises: an insulating substrate consisting of a bottom part for surface mounting an electric element and a bank part provided integrally at the outer circumference of the bottom part; a conductor layer provided in the insulating substrate and/or on the surface thereof; and a metal bonding layer provided at least a part of the bank part in order to bond a cover wherein the bottom part is warped to project to the cover side. Preferably, the bank part has a minimum height of 0.5 mm or less and a width of 0.1-0.3 mm, and the bottom part has a thickness of 0.1-0.3 mm. Furthermore, the warp X at the bottom part is preferably 0<X≤15 μm, and the warp Y at the bottom part after the cover is bonded to the metal bonding layer is preferably 0<Y≤10 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a ceramic package in which electronic elements and / or semiconductor elements are mounted and hermetically sealed by a lid such as a lid, in particular, a height of 0.5 mm or less and a bank portion width of 0.3 mm or less. It relates to ultra-small and ultra-thin ceramic packages.

  In recent years, along with the high integration of semiconductor elements and the miniaturization of electrical components, various electronic devices have been miniaturized and enhanced in function. In particular, downsizing of ceramic packages for housing electronic components mounted on information form terminals such as mobile phones and mobile personal computers, and small electronic devices such as navigation systems or mobile game machines is strictly required.

  In response to these requirements, for example, a ceramic package that houses electronic devices or mounts passive components at the same time as semiconductor devices requires a small and thin size with an outer size of 3 mm, a width of 2 mm, and a height of about 0.8 mm. (For example, refer to Patent Document 1).

  However, there is a demand for further downsizing of the package in order to be mounted on an ultra-small and ultra-thin electronic device represented by an IC card. In such an ultra-small and ultra-thin ceramic package, the electronic element is sealed with a lid to protect it from moisture in the atmosphere.

  For example, a ceramic package has been proposed in which a crystal oscillator is mounted inside, sealed with a lid, and the crystal resonator is protected from the outside air (see, for example, Patent Document 2).

FIG. 3 shows a conventional example of such a ceramic package, which comprises a substrate bottom 51a having a surface wiring conductor 52a, an internal wiring conductor 52b and a terminal electrode 52c, and a substrate bank 51b having a metal bonding layer 53a. A quartz oscillator (not shown) is mounted inside the insulating substrate 51, and a lid 59 is joined via a brazing material 56.
JP 2001-196485 A JP 2002-203921 A

  However, in the ceramic package described in Patent Document 1, the lid body 59 is contracted in the V direction because the lid body 59 composed of a metal or the like having a higher thermal expansion coefficient than the ceramic constituting the insulating substrate 51 is joined. At the same time, tensile stress is generated in the substrate bottom 51a in the W direction, warping occurs so that the opposite side of the lid 59 is convex, and the residual stress is maximized at point A which is the apex of the convex portion, and cracks occur. Is likely to occur. In particular, when the insulating substrate 51 has low corrosion resistance to water, the problem is not particularly noticeable immediately after manufacture, but in a high temperature and high humidity environment such as the rainy season, corrosion progresses with time, and the ceramic package cracks. Has occurred, resulting in a short product life.

  Accordingly, an object of the present invention is to provide a ceramic package in which cracks do not occur even under high temperature and high humidity.

  The ceramic package of the present invention is provided on an insulating substrate including a substrate bottom portion for surface-mounting an electric element and a substrate bank portion integrally provided on the outer periphery of the substrate bottom portion, and on the inside and / or the surface of the insulating substrate. And a metal bonding layer provided for bonding a lid to at least a part of the substrate bank portion, and the substrate bottom is warped so as to be convex toward the lid. It is characterized by this.

  It is preferable that the minimum height of the substrate bank portion is 0.5 mm or less, the width of the bank portion is 0.1 to 0.3 mm, and the thickness of the substrate bottom portion is 0.1 to 0.3 mm.

  It is preferable that the warpage amount X of the substrate bottom portion satisfies 0 <X ≦ 15 μm.

  It is preferable that the warp amount Y of the substrate bottom after joining the lid to the metal joining layer is 0 <Y ≦ 10 μm.

  The maximum residual stress at the bottom of the substrate after joining the lid is preferably 250 MPa or less.

In the present invention, when the lid is joined to the ceramic package, the residual stress caused by the difference in the coefficient of thermal expansion affects the water corrosion and crack generation of the ceramic package, that is, the presence of water vapor and the residual stress combined with the occurrence of cracks. Based on the knowledge that the extension is promoted, the warpage in the direction opposite to the direction in which the residual stress is applied to the bottom of the substrate is formed in advance, and the residual stress generated when the lid is joined is reduced to suppress the generation of cracks. To do.

  If the package becomes thin, cracks due to water corrosion under residual stress will cause the package to break down in a short time or internal electronic components will likely break down. This is particularly effective for ultra-small and ultra-thin packages.

  That is, the ceramic package of the present invention includes an insulating substrate comprising a substrate bottom portion for surface-mounting an electric element, a substrate bank portion integrally provided on the outer periphery of the substrate bottom portion, and an inside and / or surface of the insulating substrate. And a metal bonding layer provided for bonding a lid to at least a part of the substrate bank portion, and the substrate bottom is warped so as to protrude toward the lid. Therefore, even if the residual stress is generated, the stress is relieved because the warpage is restored, the residual stress of the package is reduced, the generation and extension of cracks are inhibited, and the product life can be extended.

  Since the minimum height of the substrate bank portion is 0.5 mm or less, the width of the bank portion is 0.1 to 0.3 mm, and the thickness of the substrate bottom portion is 0.1 to 0.3 mm, a relatively small residual stress However, cracks occurred, resulting in defective products and reduced product reliability. However, the present invention is particularly effective in such ultra-small and ultra-thin packages. It becomes easy to suppress.

  In particular, if the warp amount X at the bottom of the substrate is set to 0 <X ≦ 15 μm in advance, the residual stress generated when the lid is joined is effectively reduced, and the handling until the lid is joined is also possible. It becomes easy to suppress the occurrence of defects.

  In addition, since the warpage amount Y of the substrate bottom after joining the lid to the metal joining layer is 0 <Y ≦ 10 μm, the residual stress at the time of joining can be effectively reduced, and the warpage amount is small. Even during use, the extension of cracks is effectively suppressed, and it is possible to achieve a further increase in life.

  Furthermore, since the maximum residual stress at the bottom of the substrate after joining the lid is 250 MPa or less, the generation of cracks can be effectively prevented.

  The ceramic package of this invention is demonstrated using figures.

  As shown in FIG. 1A, for example, the ceramic package of the present invention includes an insulating substrate 1 composed of a substrate bottom portion 1a and a substrate bank portion 1b, a wiring conductor 2 provided on the substrate bottom portion 1a, and a substrate bank portion. The insulating substrate 1 includes a substrate bank portion 1b integrally provided on the outer periphery of the substrate bottom portion 1a.

  The wiring conductor 2 is composed of a surface wiring conductor 2a provided on the surface of the substrate bottom 1a and an internal wiring conductor 2b formed inside the substrate bottom 1a, and is provided on the back surface for electrical connection with the outside. It is connected to the terminal electrode 2c, and the warped shape of the substrate bottom 1a is convex toward the lid. This makes it possible to reduce the residual stress by deforming the tensile stress on the substrate bottom 1a due to the difference in thermal expansion between the lid and the insulating portion into a concave shape when the lid is joined.

  According to the present invention, even when a ceramic package that is ultra-small, ultra-thin and easily broken is formed by deforming the substrate bottom 1a in advance so as to be convex toward the lid body, Further, it is possible to relieve the tensile stress generated at the substrate bottom 1a and prevent the ceramic package from being broken due to the generation of cracks or the extension of cracks.

  Also, in FIG. 1B, one terminal electrode 2c is provided at each of the four corners of the insulating substrate 1. This simplifies the structure, facilitates connection from the outside to the terminal electrode 2c, and has symmetry, so that it is effective for dispersing residual stress, and it is easy to prevent stress concentration.

  According to the present invention, the warp amount X of the substrate bottom 1a of the ceramic package is preferably 0 <X ≦ 15 μm, particularly 0 <X ≦ 13 μm, and 0 <X ≦ 11 μm. When the warp amount X is set within this range, it is easy to prevent breakage during the handling up to the joining of the lid, or to prevent cracking and destruction during handling and use after joining the lid, and the electronic element and the surface. It becomes easy to ensure the bonding reliability of the wiring conductor 2a.

  Moreover, although the lower limit value of X is larger than 0, considering the stress at the time of joining the lid, it is particularly preferably 0.5 or more, and more preferably 1 or more in order to make it easier to protrude toward the lid after joining.

  The insulating substrate 1 contains alumina as a main component, and preferably contains 4% by mass or more, particularly 6% by mass or more, and more preferably 8% by mass or more of a sintering aid. By sufficiently adding such a sintering aid, low temperature firing is possible, and as a result, simultaneous firing with the wiring conductor 2 and the metal bonding layer 3a is possible.

  The main component alumina preferably contains alumina in an amount of 90% by mass or more, particularly 90 to 96% by mass, and more preferably 93 to 96% by mass. Thereby, it becomes easy to set the three-point bending strength of the insulating substrate 1 to 500 MPa or more, the thermal conductivity to 15 W / mK or more, and the Young's modulus to 320 GPa or less.

As the second component, 2 to 8 mass% of Mn in _Mn 2 _{O 3} in terms of, in particular 3 to 8% by weight, and more preferably in a proportion of 3-6 wt%. This is because the Mn component acts as a sintering aid, and by selecting the above ratio, the sinterability is enhanced, and it becomes easy to achieve densification at a firing temperature of 1250 to 1400 ° C., MnAl ₂ O ₄ is easily precipitated appropriately. Such an appropriate amount of MnAl ₂ O ₄ crystal precipitation has the effect of increasing the bending strength of the sintered body.

Further, 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%. Since SiO ₂ is involved in the generation of a liquid phase during sintering, by selecting the above ratio, it is easy to achieve densification, and there is little residual amorphous phase, and appropriate MnAl ₂ O ₄ crystals High strength is easily maintained by precipitation.

  Further, if desired, as a fourth component, at least one of Mg, Ca, Sr, and Ba is used to enhance the co-sinterability with the wiring conductor, so that the composition up to the third component is 100% by mass. Further, it may be contained at a ratio of 3% by mass or less in terms of oxide. Furthermore, if desired, as a fifth component, a component such as W or Mo is used as a component for blackening the sintered body at a ratio of 2% by mass or less with respect to 100% by mass of the composition up to the third component. May be included.

  The warpage shape of the substrate bottom 1a is warped so that the surface on the lid side, that is, the side where the substrate bank portion 1b is provided is convex, and conversely, the bottom surface provided with the connection terminal 2a is concave, but the amount of warpage As a method for setting 0 <X ≦ 15 μm, it is possible to employ a method of pressing a convex molding jig against the substrate bottom 1a of the molded body before firing, thereby adjusting the warp amount X. be able to.

  At that time, it is necessary to appropriately adjust the height of the forming jig and the pressing pressure. By using such a shape and warping amount, the residual stress can be reduced, and the insulating substrate 1 can be more effectively prevented from being destroyed after sealing.

  The wiring conductor 2 and the metal bonding layer 3a can be connected to various metal terminals or sealed with a lid, and have W and / or Mo as main components in order to maintain a strong adhesive force with the insulating substrate 1. It is preferable to contain 10% by mass or less, particularly 8% by mass or less of alumina.

  An example of a state in which an electronic element is mounted on the ceramic package of the present invention is shown in FIG. According to FIG. 2, an electronic element 104 such as an electric component 104a or a semiconductor element 104b is placed in a cavity 108, which is an internal space of the insulating substrate 101, and a metal bonding layer 103a and a plating layer 103b provided thereon are provided. The lid 109 is hermetically sealed, and the electrical component 104a and the semiconductor element 104b connected to the wiring conductor 102 provided on the substrate bottom 101a of the insulating substrate 101 can be placed. The number of electronic elements 104 to be mounted is not particularly limited and may be one or more.

  As the electrical component 104a, at least one of a crystal oscillator, a dielectric, a resistor, a filter, and a capacitor can be used, and it can be electrically connected to the surface wiring conductor 102a using a conductive adhesive 105a. Is possible. Similarly, the semiconductor element 104b is connected to the surface wiring conductor 102a using the conductive adhesive 105b.

  According to the present invention, even after the ceramic package is bonded to the lid body 109 via the metal bonding layer 103a provided at the end of the substrate bank 101b, the substrate bottom 101a is on the cavity 108 side or the lid body 109 side. It is preferable to warp so as to be convex. As described above, even if the cover body 109 is joined, if it is convex toward the cover body 109 side, the generation and extension of cracks can be suppressed, and the joined package of the cover body 109 can be mounted on a printed wiring board or the like. It becomes easy to effectively prevent package cracking due to pressing.

  The warp amount Y of the substrate bottom 101a is preferably 0 <Y ≦ 10 μm, 0 <Y ≦ 8 μm, and 0 <Y ≦ 6 μm. For this purpose, it is necessary to appropriately adjust the warpage amount X of the substrate substrate 101a before the lid 109 is bonded, the lid 109 material, the brazing material 106, the bonding conditions, and the like. As a result, it becomes easy to prevent cracking due to handling during packaging and mounting of the package to which the lid 109 is joined.

  The lower limit value of Y is larger than 0, but in order to further suppress the generation of cracks, it is particularly preferably 0.2 or more, and more preferably 0.5 or more.

  The thermal expansion coefficient of the lid 109 is preferably close to the thermal expansion coefficient of the insulating substrate 101, and the warpage amounts X and Y can be controlled by adjusting the thermal expansion coefficient. For example, when the insulating substrate 101 is made of an alumina sintered body, an Fe—Ni—Co alloy can be preferably used. By using such an alloy, the thermal stress generated at the time of sealing can be reduced, and the insulating substrate 101 can be more effectively prevented from being destroyed at the time of sealing.

  Conventionally, residual stress is generated in the substrate bottom 101a of the insulating substrate 101 of the ceramic package obtained by bonding the lid 109 due to thermal contraction during bonding, and the substrate bottom 101a generally protrudes on the opposite side of the cavity 108. It transforms to become. Accordingly, when the residual stress increases, a large tensile stress is applied to the substrate bottom 101a, cracks are generated, and the substrate is easily extended.

  On the other hand, in the present invention, even if the lid body 109 is joined, it protrudes toward the cavity 108 side, so that even if residual stress is applied, cracks are generated in the insulating substrate 101 and the extension is suppressed. However, in order to more effectively prevent water corrosion and cracking of the ceramic package, the maximum residual stress (maximum residual stress) is preferably 250 MPa or less, particularly 225 MPa or less, and more preferably 200 MPa or less. For this purpose, it is necessary to appropriately adjust the lid material, the brazing material, the joining conditions, and the like.

  Further, according to the present invention, the width d of the substrate bank portions 1b and 101b is 0.1 to 0.3 mm, the thickness D of the substrate bottom portions 1a and 101a is 0.1 to 0.3 mm, and the height of the package. T is preferably set to 0.3 to 0.5 mm. By setting the dimensions as described above, the strength of the alumina sintered body as the insulating substrates 1 and 101 can be taken into consideration, and the damage to the thermal stress at the time of sealing the lid body 109 can be more effectively prevented. The volume of the ceramic package can be further reduced.

  In particular, by setting the height T of the insulating substrates 1 and 101 to 0.5 mm or less, it can be applied to an IC card or the like as an ultra-small and ultra-thin ceramic package on which the electronic element 104 is mounted. In addition, it is preferable that the cover body 109 is thinner in terms of being able to improve the reduction in height.

  Next, a method for manufacturing the ceramic package of the present invention will be specifically described in the case where a connecting substrate in which a plurality of insulating substrates are connected is manufactured and one of them is used separately.

  First, an alumina powder having an average particle diameter of 0.5 to 2.0 μm, particularly 1.0 to 1.5 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 powder cost can be easily prevented from increasing. Moreover, by setting it as 2.0 micrometers or less, densification by baking at 1400 degrees C or less can be accelerated | stimulated, and sintering can be made easy.

Further, Mn ₂ O ₃ powder having a purity of 99% or more and an average particle diameter of 0.5 to 5 μm as the second component, and SiO ₂ powder having a purity of 99% or more and an average particle diameter of 0.5 to 3 μm as the third component. prepare. In addition to the above oxide powder, Mn and Si may be added as carbonate, nitrate, acetate, etc. that can form an oxide by firing.

These components are ₂ to 8% by mass of Mn ₂ O ₃ powder, particularly 3 to 8% by mass, more preferably 3 to 6% by mass, and 1 to 6% by mass of SiO ₂ powder, especially 2% with respect to the alumina powder. It is preferable to add at a ratio of ˜5 mass%, further 3 to 5 mass% in order to enhance the sinterability and promote densification.

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

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

  After appropriately adding an organic binder to the above mixed powder, a green sheet for forming the insulating substrate 1 is produced by using a known molding method such as a press method, a doctor blade method, a rolling method, an injection method or the like. . For example, an organic binder or 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.

  Since each insulating substrate has a small shape, it is preferable to form a plurality of insulating substrates on one connecting substrate and use them separately to increase productivity. Corresponding to this, a wiring conductor paste is formed on each green sheet by a method such as screen printing or gravure printing on the green sheet, in the form of a wiring pattern for forming the wiring conductor 2, or the metal bonding layer 3a. Is printed in a ring shape to form

  If desired, via holes having a diameter of 50 to 250 μm are formed in advance on the green sheet with a micro drill, laser, or the like, and the above-described wiring conductor paste is filled into the via holes.

  The wiring conductor paste preferably uses W and / or Mo as a wiring conductor component and is added with alumina powder 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 wiring conductor 2 while keeping the conduction resistance of the wiring conductor 2 low, and can easily prevent the occurrence of defects such as lack of plating. 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 0.05 to 2% by volume of an oxide such as Ni may be added. It is also possible to add in proportions.

  Thereafter, the green sheet on which the wiring conductor paste is printed is aligned and laminated and pressed, and then the laminate is placed on a convex carbon jig and pressed. Thereafter, a plurality of notch grooves for separating the insulating substrate are formed. As a method for forming the notch groove, methods such as a cutter blade, a mold, and laser processing can be used, and among these methods, the mold and laser processing are particularly preferable because they can be mass-produced at low cost.

  The laminated body in which the notched grooves are formed is heated from at least 1000 ° C. to the firing maximum temperature at a heating rate of 150 ° C./h or more, fired in a non-oxidizing atmosphere of 1250 to 1400 ° C., and up to 1000 ° C. It is important to calcinate at a cooling rate of 250 ° C./h or less.

  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, the bending strength may 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.

  In addition, the firing temperature sufficiently promotes densification, easily achieves a bending strength of 500 MPa or more, and decreases the adhesive strength with alumina due to the progress of sintering of W and / or Mo itself, and the grains of alumina. Baking is preferably performed at 1250 to 1400 ° C. in terms of suppressing growth and improving 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. It becomes possible to easily crystallize MnAl ₂ O ₄ and improve the bending strength. The cooling rate is particularly preferably 200 ° C./h or less from the viewpoint of increasing the strength.

  The firing atmosphere is preferably a non-oxidizing atmosphere so that the metal is not oxidized. Specifically, it is desirable 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 wiring conductor 2 may be formed with a plating layer made of at least one of Ni, Co, Cr, Au and Cu for surface protection and solder bonding.

  By the above manufacturing method, the insulating substrate 1 that can be fired simultaneously with the metal bonding layer 3a, has a bottom of the substrate convex toward the lid, and can be suitably used as a small ceramic package having a strength of 500 MPa or more. Can be manufactured.

  Further, the electronic element 4 and / or the semiconductor element 6 are mounted inside the obtained insulating substrate 1, electrically connected to the wiring conductor 2, and the plated layer 8 is provided on the surface of the ring-shaped metal bonding layer 3a. The lid 10 is joined by seam welding or the like with the eutectic Ag-Cu brazing material 9 or the like. Even in this case, it is possible to obtain a semi-wiring conductor device in which the electronic element 4 is hermetically sealed with the bottom of the substrate projecting toward the lid.

  The plating layer 8 is preferably made of at least one of Ni, Co, Cr, Au, and Cu in order to prevent diffusion of the brazing material and obtain good adhesion.

Mn ₂ O ₃ powder having a purity of 99% or more and an average particle size of 0.7 μm is 3.5% by mass, SiO ₂ powder having a purity of 99% or more and an average particle size of 1.0 μm is 3.5% by mass, and purity is 99.9. % Of Mo powder with an average particle diameter of 1.2 μm is 0.5 mass%, purity is 99% or more, Co ₃ O ₄ powder with an average particle diameter of 1.0 μm is 0.05 mass%, and purity is 99% or more, average The alumina powder having a particle diameter of 1.5 μm was prepared so as to be the remainder.

  After mixing these raw material powders, an acrylic binder as a molding organic resin (binder) and toluene are mixed as a solvent to prepare a slurry, and then a green sheet having a thickness of 150 μm is prepared by a doctor blade method. did.

  After laminating the obtained green sheets to a predetermined thickness and degreasing in a nitrogen-hydrogen mixed atmosphere with a dew point of + 25 ° C., the temperature was subsequently raised from 1000 ° C. to the maximum firing temperature at the rate of temperature rise shown in Table 2. After firing for 1 hour in a nitrogen-hydrogen mixed atmosphere at a dew point of + 25 ° C. at the highest firing temperature, the temperature was lowered to 1000 ° C. at the rate shown in Table 2.

  The strength of the obtained sintered body was measured at room temperature based on JIS R1601 by preparing a beam-like sample having a thickness of 3 mm, a width of 4 mm, and a length of 40 mm. The Young's modulus was measured at room temperature based on JIS R1602, and the thermal conductivity was measured at room temperature by the laser flash method.

  As a result, the strength was 550 MPa, the Young's modulus was 315 GPa, and the thermal conductivity was 18 W / mK.

  On the other hand, Cu, Au, and Ag (low resistance metal) are added to W powder having an average particle diameter of 1.2 μm, Mo powder having an average particle diameter of 1.2 μm, and alumina powder having an average particle diameter of 1.5 μm. After preparing to the composition shown in 1, an acrylic binder and acetone were mixed as a solvent to prepare a wiring conductor paste.

  Then, the green sheet produced in the same manner as described above is punched to form a via hole having a diameter of 100 μm, and the wiring conductor paste is filled in the via hole by a screen printing method. Printing was applied in a pattern (wiring conductor) and a ring (metal bonding layer). In addition, the green sheet in which the ring-shaped metallization was formed was removed by punching a site for storing the electronic element.

  The green sheets thus produced were aligned and laminated and pressed to produce a laminate. After that, pressurization is performed on a convex carbon jig having a height of 5 μm with the pressure shown in Table 1, and a 4 mm wide notch groove is formed in the laminate, and the compact is mixed with nitrogen and hydrogen at a dew point of + 25 ° C. After degreasing in an atmosphere, degreasing in a nitrogen-hydrogen mixed atmosphere with a dew point of + 25 ° C, and subsequently raising the temperature from 1000 ° C to the maximum firing temperature at a temperature increase rate of 200 ° C / h, the maximum firing temperature After baking for 1 hour at 1400 ° C. in a nitrogen-hydrogen mixed atmosphere with a dew point of 25 ° C., the temperature was lowered to 1000 ° C. at a rate of 100 ° C./h.

  The amount of warping of the substrate bottom of the obtained sintered body was measured with a micrometer.

  Next, electrolytic Ni plating was applied to the surface of the wiring conductor and the metal bonding layer formed in a ring shape, and 0.2 μm Au plating was further applied to the surface. For the wiring conductor and the ring-shaped metal bonding layer thus formed with the plating layer 8, electronic elements are bonded to the wiring conductor using spherical Au bumps, and the eutectic Ag− is used for the ring-shaped metal bonding layer. Using a Cu brazing material, a lid body made of Fe—Co—Ni alloy having a thickness of 0.1 mm was joined by seam welding and hermetically sealed.

  The obtained samples were checked for wiring continuity between the terminals on the back side, and evaluated as ◯ for those that were conductive and × as those that were not conductive.

  Furthermore, with respect to the conducting sample, at a humidity of 100%, after conducting a heat cycle test up to 100 cycles with 5 minutes holding at -65 ° C. and 5 minutes holding at 150 ° C. as a cycle, hermetic sealing performance The sealing test which evaluates a sealing state by He leak method was implemented.

In the He leak method, the gas is taken out after being held in a 0.41 MPa He pressurized atmosphere for 2 hours, the amount of He gas detected in a vacuum atmosphere is measured, and 1 × 10 ⁻¹⁰ MPa · cm ³ / sec or less. ^Was evaluated as x when a value exceeding ○ × 5 ^{−10 −9} MPa · cm ³ / sec was evaluated.

本発明の試料Ｎｏ．３〜１４は、基板底部が蓋体側に凸である形状を呈しており、蓋体の接合する前の基板底部の反り量Ｘが０＜Ｘ≦１５μｍ、蓋体を接合した後の基板底部の反り量Ｙが０＜Ｙ≦１０μｍ、蓋体を接合後の残留応力が２５０ＭＰａ以下で、導通テスト及び封止テストでも異常は観察されなかった。 Thereafter, the residual stress at the bottom of the substrate was measured by X-ray diffraction. The residual stress was calculated by the parallel tilt method from a diffraction peak (2θ) of 152 ° measured by X-ray diffraction. The results are shown in Table 1.

Sample No. of the present invention. Nos. 3 to 14 have a shape in which the bottom of the substrate is convex toward the lid, the warp amount X of the substrate bottom before the lid is joined is 0 <X ≦ 15 μm, and the bottom of the substrate after the lid is joined The warpage amount Y was 0 <Y ≦ 10 μm, the residual stress after joining the lid was 250 MPa or less, and no abnormality was observed in the continuity test and the sealing test.

  On the other hand, the sample No. 5 outside the scope of the present invention having a shape in which the bottom of the substrate is concave on the lid side. Nos. 1 and 2 concluded that the residual stress exceeded 250 MPa, a large leak occurred in the sealing test, and this was caused by cracks.

The structure of the ceramic package of this invention is shown, (a) is a schematic sectional drawing, (b) is a schematic back terminal layout. It is a schematic sectional drawing which shows the state which joined the lid to the ceramic package of this invention, and mounted the electrical element inside. It is a schematic sectional drawing which shows the structure of the conventional ceramic package.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Insulating substrate 1a, 101a ... Substrate bottom part 1b, 101b ... Substrate bank part 2, 102 ... Wiring conductor 2a, 102a ... Surface wiring conductor 2b, 102b ... Internal wiring Conductor 2c, 102c ... Terminal electrode 3a, 103a ... Metal bonding layer 3b, 103b ... Plating layer 104 ... Electronic element 104a ... Electrical component 104b ... Semiconductor element 105a, 105b ... Conductive adhesive 106 ... brazing material 108 ... cavity 109 ... lid T ... insulating substrate height D ... substrate bottom thickness d ... substrate ridge width

Claims (5)

An insulating substrate comprising a substrate bottom portion for surface-mounting an electric element and a substrate bank portion integrally provided on the outer periphery of the substrate bottom; a conductor layer provided in and / or on the surface of the insulating substrate; A ceramic package comprising a metal bonding layer provided for bonding a lid to at least a part of a substrate bank portion, wherein the substrate bottom is warped so as to protrude toward the lid . The minimum height of the substrate bank portion is 0.5 mm or less, the width of the bank portion is 0.1 to 0.3 mm, and the thickness of the substrate bottom portion is 0.1 to 0.3 mm. The ceramic package according to 1. 3. The ceramic package according to claim 1, wherein a warp amount X of the bottom of the substrate satisfies 0 <X ≦ 15 μm. The ceramic package according to any one of claims 1 to 3, wherein a warp amount Y of the bottom of the substrate after bonding the lid to the metal bonding layer is 0 <Y ≦ 10 μm. The ceramic package according to any one of claims 1 to 4, wherein the maximum residual stress at the bottom of the substrate after joining the lid is 250 MPa or less.

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