JP2013239609A - Airtight member and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airtight member which allows the increase in the adhesiveness of a seal-bonding layer to a high-thermal-conductivity substrate, and in its reliability in airtightly sealing between a glass substrate and the high-thermal-conductivity substrate by use of local heating with electromagnetic waves.SOLUTION: An airtight member 1 comprises: a glass substrate 2; a high-thermal-conductivity substrate 3; and a seal-bonding part 6 for airtightly sealing a gap between the substrates 2 and 3. The seal-bonding part 6 has: a glass layer 7 previously provided on a sealing region of the high-thermal-conductivity substrate 3; and a seal-bonding layer 8 composed of a fusion-fixing layer made of a sealing glass material capable of absorbing electromagnetic waves. The glass layer 7 has an electromagnetic wave-absorbing power, and a thickness in a range of no less than 3 μm and under 20 μm. The seal-bonding layer 8 is formed between the glass substrate 2 and the glass layer 7.

Description

  The present invention relates to an airtight member and a manufacturing method thereof.

  For packages that hermetically seal electronic elements such as crystal resonators, piezoelectric elements, filter elements, sensor elements, imaging elements, organic EL elements, and solar cell elements, for example, a glass substrate is used as a base substrate on which electronic elements are formed or mounted. A package structure using a high thermal conductivity substrate made of a metal material, a ceramic material, or the like excellent in heat dissipation is applied to a cover substrate that is used and hermetically seals an electronic element. In a package that hermetically seals a light-receiving element such as an imaging element or a light-emitting element such as an organic EL element, a package that uses a high thermal conductivity substrate such as a semiconductor substrate as a base substrate and a transparent glass substrate as a cover substrate Structure etc. are also applied.

  As a sealing material that hermetically seals between a glass substrate and a high thermal conductivity substrate made of a metal material, a ceramic material, a semiconductor material, or the like, a sealing resin or a sealing glass is used. Since the sealing resin is inferior in moisture resistance and weather resistance compared to the sealing glass, sealing glass having excellent moisture resistance and the like is applied in applications where it is necessary to improve the hermetic sealing performance of the electronic element. Patent Document 1 describes sealing a base substrate made of a glass substrate or the like and a metal lid using a sealing material made of low-melting glass. Here, the base material and the metal lid are sealed by irradiating the sealing material layer made of low-melting glass with laser light or the like through the glass substrate and locally heating and melting the sealing material layer. It is sealed via a melted and fixed layer (sealing layer) of the adhesive material.

  In Patent Document 2, a gap between a translucent substrate made of glass material, resin material or the like and a support substrate made of glass material, resin material, metal material or the like is defined as a first sealing member made of resin material or glass material. And a photoelectric conversion device sealed with a second sealing member made of a glass material. Moreover, in order to make the film thickness of a 2nd sealing member thin, providing the base part which consists of glass material or a metal material in the surface of a support substrate is described. For example, laser sealing or ultraviolet sealing is applied to the sealing step using the second sealing member. At this time, the second sealing member is selectively heated by increasing the light absorption coefficient of the second sealing member by that of the base.

  When local heating with laser light or the like is applied to the hermetic sealing between the glass substrate and the high thermal conductivity substrate, the high thermal conductivity substrate such as a metal substrate, a ceramic substrate, or a semiconductor substrate has a higher thermal conductivity than the glass substrate. Since the heat generated when the sealing material layer including the low-melting glass is irradiated with laser light etc. escapes to the high thermal conductive substrate side, the sealing material layer can be favorably bonded to the high thermal conductive substrate. Can not. Even if the fusion fixing layer (sealing layer) of the sealing material layer and the high thermal conductive substrate can be bonded, the stress applied to the glass substrate and the sealing layer is increased. The stress applied to the glass substrate and the sealing layer is a factor causing cracks and cracks in the sealing layer and the glass substrate, and reducing the strength and reliability of the sealing portion between the glass substrate and the high thermal conductive substrate. Become.

JP 2003-046012 A JP 2011-029131 A

  The object of the present invention is to apply the local heating by laser light or the like to hermetically seal the gap between the glass substrate and the high thermal conductivity substrate, and to adhere the sealing layer to the high thermal conductivity substrate and its reliability. An object of the present invention is to provide an airtight member having improved properties and a method for manufacturing the same.

  The hermetic member of the present invention includes a glass substrate having a first surface provided with a first sealing region, a second sealing region corresponding to the first sealing region, and the second sealing region. A high thermal conductivity disposed on the glass substrate with a predetermined gap so that the second surface is opposed to the first surface. An electromagnetic wave absorber formed between the first sealing region of the glass substrate and the glass layer so as to hermetically seal a gap between the conductive substrate and the glass substrate and the high thermal conductivity substrate. A sealing layer composed of a melt-fixed layer of a sealing glass material having a function, the glass layer has an electromagnetic wave absorption capability, and the thickness of the glass layer is in a range of 3 μm or more and less than 20 μm. It is a feature.

  The manufacturing method of the airtight member of this invention is equipped with the 1st sealing area | region and the sealing material layer which consists of a baking layer of the glass material for sealing formed in the said 1st sealing area | region and which has electromagnetic wave absorption ability. A step of preparing a glass substrate having a first surface; a second sealing region corresponding to the first sealing region; and a glass layer formed in the second sealing region and having an electromagnetic wave absorbing ability A step of preparing a highly thermally conductive substrate having a second surface comprising: the first surface and the second surface facing each other, and the sealing material layer and the glass layer being in contact with each other , The step of laminating the glass substrate and the high thermal conductivity substrate, and locally heating the sealing material layer and the glass layer by irradiating electromagnetic waves through the glass substrate to melt the sealing material layer. By fixing the glass layer to the glass layer, And a step of forming a sealing layer that hermetically seals a gap between the substrate and the thermally conductive substrate, wherein the glass layer has a thickness in the range of 3 μm to less than 20 μm. .

  According to the hermetic member of the present invention and the manufacturing method thereof, when the gap between the glass substrate and the high thermal conductive substrate is hermetically sealed by applying local heating by electromagnetic waves, the sealing layer is applied to the high thermal conductive substrate. Adhesion and its reliability can be improved. Therefore, it is possible to provide an airtight member hermetically sealed between the glass substrate and the high thermal conductivity substrate with good reproducibility and reliability.

It is sectional drawing which shows the airtight member by embodiment of this invention. It is sectional drawing which expands and shows a part of airtight member shown in FIG. It is sectional drawing which shows the manufacturing process of the airtight member by embodiment of this invention. It is a top view of the glass substrate used at the manufacturing process of the airtight member shown in FIG. It is sectional drawing along the AA line of FIG. It is a top view of the high heat conductive board | substrate used at the manufacturing process of the airtight member shown in FIG. It is sectional drawing along the AA line of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a view showing a configuration of an airtight member according to an embodiment of the present invention, and FIG. 2 is an enlarged view showing a part of the airtight member shown in FIG. FIG. 3 is a diagram showing a manufacturing process of an airtight member according to an embodiment of the present invention, FIGS. 4 and 5 are diagrams showing a configuration of a glass substrate used in the manufacturing process of the hermetic member, and FIGS. 6 and 7 are manufacturing of the hermetic member. It is a figure which shows the structure of the highly heat conductive board | substrate used at a process.

An airtight member 1 shown in FIG. 1 includes a glass substrate 2 and a high thermal conductivity substrate 3. The constituent material of the glass substrate 2 is not particularly limited. For example, soda lime glass, alkali-free glass, silicate glass, borate glass, borosilicate glass, and phosphate glass having various known compositions. Can be applied. These glass substrates 2 have a thermal conductivity of, for example, about 0.5 to 1 W / m · K. Soda lime glass has a thermal expansion coefficient (50 to 250 ° C.) of about 80 to 90 (× 10 ⁻⁷ / ° C.), and non-alkali glass has a thermal expansion coefficient of about 35 to 40 (× 10 ⁻⁷ / ° C.). (50 to 250 ° C.).

  The symbol “˜” indicating a numerical range is used in the sense of including the numerical values described before and after the numerical value as a lower limit value and an upper limit value. Unless otherwise specified, the symbol “˜” in this specification has the same meaning. Unless otherwise specified, the thermal expansion coefficient indicates an average linear expansion coefficient at 50 to 250 ° C., and is simply expressed as “thermal expansion coefficient (50 to 250 ° C.)”.

  Examples of the high thermal conductive substrate 3 include a semiconductor substrate, a metal substrate, and a ceramic substrate. The high thermal conductivity substrate 3 is a substrate having a thermal conductivity higher than that of the glass substrate 2. Various metal substrates can be applied to the high thermal conductive substrate 3 according to the use of the airtight member 1, for example, a single metal such as aluminum, copper, iron, nickel, chromium, zinc, or any one of them. The board | substrate which consists of an alloy which consists of a combination containing a seed | species or more is illustrated. This also applies to ceramic substrates and semiconductor substrates, and is not particularly limited to constituent materials. Examples of the ceramic substrate include a substrate made of an alumina sintered body, a silicon nitride sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a low-temperature co-fired ceramic (LTCC), or the like. Examples of the semiconductor substrate include a silicon substrate and a compound semiconductor substrate made of GaAs, GaN, or the like.

  The airtight member 1 and the manufacturing method thereof according to the embodiment include a glass substrate 2 having a thermal conductivity of 0.5 to 1 W / m · K and a high thermal conductivity of 1.2 to 250 W / m · K. This is suitable when the conductive substrate 3 is used. Furthermore, it is more effective when the high thermal conductivity substrate 3 having a thermal conductivity of 2 W / m · K or more is used. When the thermal conductivity of the high thermal conductivity substrate 3 is 2 W / m · K or more, the heat generated when the sealing material layer is irradiated with electromagnetic waves such as laser light can easily escape to the high thermal conductivity substrate 3 side. Adhesiveness of the sealing material layer to the high thermal conductive substrate 3 tends to decrease. Even in such a case, the adhesiveness of the sealing layer to the high thermal conductive substrate 3 and the reliability thereof can be enhanced by applying the airtight member 1 and the manufacturing method thereof according to the embodiment.

  As shown in FIGS. 4 and 5, a frame-shaped first sealing region 4 is provided in the outer peripheral region of the surface 2 a of the glass substrate 2. The first sealing region 4 is preferably formed over the entire circumference of the outer peripheral region of the glass substrate 2. As shown in FIGS. 6 and 7, a frame-shaped second sealing region 5 corresponding to the first sealing region 4 is provided in the outer peripheral region of the surface 3 a of the high thermal conductive substrate 3. It is preferable that the second sealing region 5 is also formed over the entire circumference of the outer peripheral region of the high thermal conductive substrate 3. The glass substrate 2 and the high thermal conductivity substrate 3 are arranged at a predetermined interval so that the surface 2a having the first sealing region 4 and the surface 3a having the second sealing region 5 face each other. ing. The space | interval between the glass substrate 2 and the highly heat conductive substrate 3 is suitably set according to the use etc. of the airtight member 1, and can provide the space | interval of about 10-200 micrometers, for example.

  A gap between the glass substrate 2 and the high thermal conductivity substrate 3 is sealed by a sealing portion 6. The sealing portion 6 is provided between the sealing region 4 of the glass substrate 2 and the sealing region 5 of the high thermal conductive substrate 3 so as to hermetically seal the gap between the glass substrate 2 and the high thermal conductive substrate 3. Is formed. The sealing portion 6 includes a glass layer 7 provided in advance in the sealing region 5 of the high thermal conductive substrate 3, and a sealing layer 8 formed between the sealing region 4 and the glass layer 7 of the glass substrate 2. It is configured in layers. The sealing layer 8 is composed of a fused and fixed layer of a sealing glass material, which will be described in detail later. The sealing layer 8 is directly bonded (that is, fixed) to the first sealing region 4 with respect to the glass substrate 2, and is a highly thermally conductive substrate. 3 is adhered (that is, fixed) to a glass layer 7 provided in advance in the second sealing region 5.

  As shown in FIGS. 3 to 5, the sealing layer 8 is formed on the sealing material layer 9 made of a fired layer of the sealing glass material formed in the sealing region 4 of the glass substrate 2. It consists of a melted and fixed layer in which the electromagnetic wave is irradiated and heated locally, whereby the sealing material layer 9 is melted and fixed to the sealing region 4 and the glass layer 7 of the glass substrate 2. The sealing layer 8 includes a sealing material layer 9 (see FIGS. 4 and 5) provided on the glass substrate 2, and a glass layer 7 (see FIGS. 6 and 7) formed on the high thermal conductivity substrate 3. After the glass substrate 2 and the high thermal conductivity substrate 3 are laminated so that the two come into contact with each other, the sealing material layer 9 is irradiated with electromagnetic waves such as laser light and infrared rays through the glass substrate 2 and locally heated. Is.

  Glass materials for sealing are, for example, an electromagnetic wave absorbing material (that is, a material that generates heat by absorbing electromagnetic waves such as laser light and infrared rays) and a low expansion filler material in sealing glass (that is, glass frit) made of low melting point glass. A new filler is added. When the sealing glass itself has electromagnetic wave absorbing ability, the addition of the electromagnetic wave absorbing material can be omitted. The glass material for sealing may contain additives other than these as necessary.

  As the sealing glass (glass frit), for example, low-melting glass such as tin-phosphate glass, bismuth glass, vanadium glass, lead glass, zinc borate alkali glass or the like is used. Of these, tin-phosphate glass and bismuth are considered in consideration of the adhesiveness to the glass substrate 2 and the glass layer 7 and their reliability (adhesion reliability and hermetic sealing), and the influence on the environment and the human body. It is preferable to use a sealing glass made of a glass.

Tin-phosphate glass (glass frit) is expressed in mol% in terms of the following oxides: 55-68 mol% SnO, 0.5-5 mol% SnO ₂ , and 20-40 mol% P _2. It is preferable to have a composition of O ₅ (basically, the total amount is 100 mol%). SnO is a component for lowering the melting point of glass. If the SnO content is less than 55 mol%, the viscosity of the glass will be high and the sealing temperature will be too high, and if it exceeds 68 mol%, it will not vitrify.

SnO ₂ is a component for stabilizing the glass. If the content of SnO ₂ is less than 0.5 mol%, SnO ₂ is separated and precipitated in the glass that has been softened and melted during the sealing operation, the fluidity is impaired and the sealing workability is lowered. If the content of SnO ₂ exceeds 5 mol%, SnO ₂ is likely to precipitate during melting of the low-melting glass. P ₂ O ₅ is a component for forming a glass skeleton. If the content of P ₂ O ₅ is less than 20 mol%, the glass does not vitrify, and if the content exceeds 40 mol%, the weather resistance, which is a disadvantage specific to phosphate glass, may be deteriorated.

Here, the ratio (mol%) of SnO and SnO ₂ in the glass frit can be determined as follows. First, after the glass frit (low melting point glass powder) is acid-decomposed, the total amount of Sn atoms contained in the glass frit is measured by ICP emission spectroscopic analysis. Next, since Sn ²⁺ (SnO) is obtained by acidimetric decomposition, Sn ⁴⁺ (SnO ₂ ) is obtained by subtracting the obtained Sn ²⁺ from the total amount of Sn atoms.

The glass formed of the above three components has a low glass transition point and is suitable for a low-temperature sealing material. However, a component that forms a glass skeleton such as SiO ₂ , ZnO, B ₂ O ₃ , Al _{2 O 3, WO 3, MoO} 3, Nb 2 O 5, TiO 2, ZrO 2, Li 2 O, stabilizing _{Na 2 O, K 2 O,} Cs 2 O, MgO, CaO, SrO, the glass BaO, etc. The component to be made may be contained as an optional component. However, if the content of any component is too large, the glass becomes unstable and devitrification may occur, and the glass transition point and softening point may increase. Therefore, the total content of any component is 30 mol%. The following is preferable. The glass composition in this case is adjusted so that the total amount of the basic component and the optional component is basically 100 mol%.

Bismuth-based glass (gas frit) is expressed in terms of mol% in terms of the following oxides: 70 to 90 mass% Bi ₂ O ₃ , 1 to 20 mass% ZnO, and 2 to 12 mass% B ₂ O ₃ ( Basically, the total amount is preferably 100% by mass). Bi ₂ O ₃ is a component that forms a glass network. When the content of Bi ₂ O ₃ is less than 70% by mass, the softening point of the low-melting glass becomes high and sealing at a low temperature becomes difficult. When the content of Bi ₂ O ₃ exceeds 90% by mass, it becomes difficult to vitrify and the thermal expansion coefficient tends to be too high.

ZnO is a component that lowers the thermal expansion coefficient. Vitrification becomes difficult when the content of ZnO is less than 1% by mass. When the content of ZnO exceeds 20% by mass, stability during low-melting glass molding is lowered, and devitrification is likely to occur. B ₂ O ₃ is a component that increases the range in which vitrification is possible by forming a glass skeleton. If the content of B ₂ O ₃ is less than 2% by mass, vitrification becomes difficult, and if it exceeds 12% by mass, the softening point becomes too high, and even if a load is applied during sealing, sealing is performed at a low temperature. It becomes difficult.

The glass formed of the above three components has a low glass transition point and is suitable for a sealing material for low temperature. Al ₂ O ₃ , CeO ₂ , SiO ₂ , Ag ₂ O, MoO ₃ , Nb ₂ O ₃ , Ta ₂ O ₅ , Ga ₂ O ₃ , Sb ₂ O ₃ , Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O, CaO, SrO, BaO, WO ₃ , P ₂ O ₅ , SnO _x (X is 1 or 2) etc. may be contained. However, if the content of any component is too large, the glass becomes unstable and devitrification may occur, and the glass transition point and softening point may increase. Therefore, the total content of any component is 30% by mass. The following is preferable. The glass composition in this case is adjusted so that the total amount of the basic component and the optional component is basically 100% by mass.

The low expansion filler is preferably at least one selected from the group consisting of silica, alumina, zirconia, zirconium silicate, cordierite, zirconium phosphate compound, soda lime glass, and borosilicate glass. Zirconium phosphate compounds include (ZrO) ₂ P ₂ O ₇ , NaZr ₂ (PO ₄ ) ₃ , KZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NbZr (PO ₄ ) ₃ , Zr ₂ (WO ₃ ) (PO ₄ ) ₂ , and complex compounds thereof can be mentioned. The low expansion filler has a lower thermal expansion coefficient than the sealing glass. The content of the low expansion filler is appropriately set so that the thermal expansion coefficient of the sealing glass material approaches that of the glass substrate 2. Although it depends on the thermal expansion coefficient of the sealing glass and the glass substrate 2, the low expansion filler is preferably contained in the range of 0.1 to 50% by volume with respect to the sealing glass material.

As the electromagnetic wave absorber, at least one metal (including an alloy) selected from the group consisting of Fe, Cr, Mn, Co, Ni and Cu, or an oxide containing the metal, such as FeO, Fe ₂ O ₃ , At least one selected from compounds such as CoO, Co ₂ O ₃ , Mn ₂ O ₃ , MnO, and CuO is used. Other pigments may be used. The content of the electromagnetic wave absorbing material is preferably in the range of 0.1 to 40% by volume with respect to the sealing glass material. If the content of the electromagnetic wave absorbing material is less than 0.1% by volume, the sealing material layer 9 may not be sufficiently melted. If the content of the electromagnetic wave absorbing material exceeds 40% by volume, the fluidity at the time of melting of the glass material for sealing may be deteriorated and the adhesiveness with the glass layer 7 may be lowered.

  The glass layer 7 prevents heat generated when the sealing material layer 9 is irradiated with electromagnetic waves from escaping to the high thermal conductivity substrate 3 and is provided on the high thermal conductivity substrate 3 as a thermal barrier layer. . That is, when the gap between the glass substrate 2 and the high thermal conductivity substrate 3 is hermetically sealed by applying local heating by electromagnetic waves such as laser light and infrared rays, the sealing material layer 9 is in contact with the high thermal conductivity substrate 3. Then, the heat generated in the sealing material layer 9 during the irradiation of electromagnetic waves is directly transferred to the high thermal conductivity substrate 3. For this reason, the sealing material layer 9 cannot be heated sufficiently, and it becomes difficult to bond the sealing material layer 9 to the high thermal conductive substrate 3 satisfactorily.

  Therefore, in the hermetic member 1 of this embodiment, the glass layer 7 having electromagnetic wave absorbing ability is formed in advance in the sealing region 5 of the high thermal conductive substrate 3. The end of the sealing material layer 9 on the side of the high thermal conductive substrate 3 is brought into contact with the glass layer 7 formed in advance in the second sealing region 5, thereby generating the sealing material layer 9 during irradiation with electromagnetic waves. Heat can be shielded by the glass layer 7 having the same thermal conductivity as that of the sealing material layer 9 without directly transferring heat to the high thermal conductive substrate 3. Therefore, the sealing layer 8 made of the melt-fixed layer of the sealing material layer 9 can be satisfactorily bonded to the high thermal conductive substrate 3 through the glass layer 7. In order for the glass layer 7 to function as a heat shield layer, it is preferable to increase the thickness of the glass layer 7.

  In general, as the size of the sealing portion (the portion 6 in which the sealing layer 8 and the glass layer 7 are combined in this embodiment) is large, the location where the crack exists and the material composition of the sealing portion configuration become non-uniform. There is a high probability that there is a portion where the thickness or width of the sealing portion is uneven, or the like. The presence of cracks causes a decrease in the material strength of the sealing portion, and is easily broken when an external stress is applied. On the other hand, external stress is applied to locations where the material composition of the sealed portion configuration is uneven and where the thickness and width of the sealed portion are uneven because stress tends to concentrate. It will be easy to destroy. If the thickness of the glass layer 7 is too thick, the glass layer 7 becomes a factor that decreases the strength and reliability of the sealing portion 6. On the other hand, by reducing the thickness of the glass layer 7, cracks and stress generated in the glass layer 7 can be reduced, but the function as a heat shielding layer of the glass layer 7 is lowered.

  Therefore, in this embodiment, the thickness of the glass layer 7 is in the range of 3 μm or more and less than 20 μm, and the glass layer 7 is provided with electromagnetic wave absorbing ability. By setting the thickness of the glass layer 7 to less than 20 μm, cracks and stress generated in the glass layer 7 can be reduced, and the strength and reliability of the sealing portion 6 can be improved. Further, since the glass layer 7 has the ability to absorb electromagnetic waves, the electromagnetic wave transmitted through the sealing material layer 9 when the sealing material layer 9 is irradiated with electromagnetic waves or the electromagnetic waves that have passed through other than the formation region of the sealing material layer 9 are irradiated. As a result, the glass layer 7 itself generates heat. Therefore, even if the glass layer 7 has a thickness of less than 20 μm, the sealing material layer 9 can be heated and melted well. Thus, the glass layer 7 functions as a heat shield layer and a heat generating layer for the high thermal conductive substrate 3.

  However, even if the glass layer 7 has electromagnetic wave absorbing ability, if the thickness of the glass layer 7 is too thin, the functions as a heat shielding layer and a heat generation layer are lowered, and the sealing material layer 9 is heated and melted well. I can't. For this reason, the thickness of the glass layer 7 shall be 3 micrometers or more. If the thickness of the glass layer 7 having electromagnetic wave absorbing ability is 3 μm or more, the glass layer 7 can function well as a heat shield layer and a heat generating layer. From the viewpoint of improving the strength and reliability of the sealing portion 6, the thickness of the glass layer 7 is more preferably 17 μm or less. From the viewpoint of functioning as a heat shield layer and a heat generating layer of the glass layer 7, the thickness of the glass layer 7 is more preferably 5 μm or more.

  In obtaining the effect of suppressing the heat transfer to the high thermal conductive substrate 3 by the glass layer 7 described above, the width of the glass layer 7 (that is, the width corresponding to the line width of the frame-shaped sealing region 5) W2 is: The line width W11 of the sealing layer 8 (and the line width W12 of the sealing material layer 9 described later) is preferably larger. Moreover, it is preferable that the both ends of the width direction of the sealing layer 8 (and the sealing material layer 9) are located inside the both ends of the glass layer 7 in the width direction. As a result, the effect of suppressing heat transfer to the high thermal conductive substrate 3 can be enhanced, and the irradiation amount of the electromagnetic wave on the glass layer 7 can be increased at the time of electromagnetic wave irradiation. That is, not only the electromagnetic wave that has passed through the glass substrate 2 and the formation region of the sealing material layer 9 but also the electromagnetic wave that has passed through only the glass substrate 2 can be easily irradiated to the glass layer 7, and the glass layer 7 can generate heat better. be able to.

  The line width W2 of the glass layer 7 is more preferably 1.1 times or more (1.1W11 ≦ W2) of the line width W11 of the sealing layer 8. The line width W2 of the glass layer 7 is more preferably 1.1 times or more (1.1W12 ≦ W2) of the line width W12 of the sealing material layer 9 described later. By these, the heat-shielding effect to the high heat conductive substrate 3 at the time of irradiation of electromagnetic waves and the heat generation effect of the glass layer 7 can be further enhanced. The upper limit value of the line width W2 of the glass layer 7 is not particularly limited, and may be formed on the entire surface 3a of the high thermal conductivity substrate 3 in some cases. However, even if the line width W2 of the glass layer 7 is too wide, not only a further effect cannot be expected, but also a factor for increasing the manufacturing cost. In such a case, the line width W2 of the glass layer 7 is preferably 5 times or less (W2 ≦ 5W11) of the line width W11 of the sealing layer 8, and the line width W12 of the sealing material layer 9 to be described later is set. 5 times or less (W2 ≦ 5W12) is preferable.

The glass layer 7 having electromagnetic wave absorbing ability is, for example, a low-melting glass frit such as the above-described tin-phosphate glass, bismuth glass, vanadium glass, lead glass, zinc borate alkali glass, or SiO ₂ —B. ₂ O ₃ —REO (RE: alkaline earth metal), SiO ₂ —B ₂ O ₃ —PbO, B ₂ O ₃ —ZnO—PbO, SiO ₂ —ZnO—REO, SiO ₂ —REO, SiO ₂ —PbO, SiO ₂ —B ₂ O ₃ —R ₂ O (R: alkali metal), SiO ₂ —B ₂ O ₃ —Bi ₂ O ₃ , B ₂ O ₃ —ZnO—Bi ₂ O ₃ A glass material obtained by adding the above-described electromagnetic wave absorbing material to a glass frit such as a SiO ₂ —ZnO—R ₂ O system or a B ₂ O ₃ —Bi ₂ O ₃ system is used as a sealing region 5 of the high thermal conductive substrate 3. Can be formed by baking.

  The content of the electromagnetic wave absorbing material is preferably in the range of 0.1 to 40% by volume with respect to the glass material that is the forming material of the glass layer 7. If the content of the electromagnetic wave absorbing material is less than 0.1% by volume, the glass layer 9 may not be able to sufficiently generate heat during irradiation with electromagnetic waves. When the content of the electromagnetic wave absorbing material exceeds 40% by volume, the temperature distribution in the thickness direction of the glass layer 7 becomes large when applying the local heating by the electromagnetic wave to perform hermetic sealing, so that the generated stress increases, cracks and There is a risk of poor sealing such as cracks. When the glass frit itself, which is a material for forming the glass layer 7, has an electromagnetic wave absorbing ability, the addition of the electromagnetic wave absorbing material to the glass frit can be omitted. Examples of the glass frit having electromagnetic wave absorbing ability include those made of vanadium glass, tin-phosphate glass, bismuth glass and the like containing a transition metal oxide as a glass component. The glass layer 7 may contain additives other than the electromagnetic wave absorbing material as necessary.

  As described above, when the gap (space) between the glass substrate 2 and the high thermal conductive substrate 3 is hermetically sealed by applying local heating by electromagnetic waves, the electromagnetic wave is previously applied to the sealing region 5 of the high thermal conductive substrate 3. By forming the glass layer 7 having an absorption capacity and a thickness of less than 20 μm, the gap between the glass substrate 2 and the high thermal conductive substrate 3 is constituted by the glass layer 7 and the sealing layer 8. The sealed portion 6 thus made can be hermetically sealed with good reproducibility. Furthermore, the crack of the glass layer 7 which arises at the time of formation of the glass layer 7 or the sealing layer 8, and an increase in stress, and the crack or crack of the glass substrate 2 or the sealing layer 8 which occurs at the time of forming the sealing layer 8 are suppressed. Can do. Accordingly, it is possible to increase the productivity of the hermetic member 1 in which the gap between the glass substrate 2 and the high thermal conductive substrate 3 is hermetically sealed, and to improve the hermetic sealability and reliability of the hermetic member 1. Become.

  Further, when the thermal expansion coefficient of the glass layer 7 is larger than that of the high thermal conductive substrate 3, a tensile residual stress is generated in the glass layer 7 when the glass layer 7 is formed. The tensile stress generated in the glass layer 7 causes a crack in the glass layer 7 or causes a decrease in the reliability of the glass layer 7 and the sealing portion even if no crack is generated. In contrast, in the embodiment, since the thickness of the glass layer 7 is as thin as less than 20 μm, cracks and stress generated in the glass layer 7 can be reduced. As a result, the bonding strength and reliability of the glass layer 7 and the sealing layer 8 and the strength and reliability of the sealing portion 6 can be increased. The airtight member 1 of the embodiment is more effective when the thermal expansion coefficient of the glass layer 7 is larger than that of the high thermal conductive substrate 3.

  In the airtight member 1 shown in FIG. 1, a space hermetically sealed by the glass substrate 2, the high thermal conductivity substrate 3 and the sealing portion 6, that is, the airtight space 10 includes, for example, a crystal resonator, a piezoelectric element, a filter element, An electronic element such as a sensor element, an imaging element, an organic EL element, a solar cell element, or a reflective film constituting a reflecting mirror is disposed. When the electronic element is arranged in the hermetic space 10, the hermetic member 1 functions as an airtight package of the electronic element, and constitutes an electronic device as a whole. Further, when a reflective film such as a silver film is formed on the surface 2a of the glass substrate 2 and disposed in the airtight space 10, the airtight member 1 functions as an airtight package of the reflective film. It constitutes a reflecting mirror. The airtight member 1 is not limited to the airtight package of various members, and may be a multilayer component having the airtight space 10.

  When the hermetic member 1 is used as an airtight package for an electronic element, the electronic element is provided on at least one of the glass substrate 2 and the high thermal conductivity substrate 3 according to its structure and characteristics. For example, the organic EL element is formed on the high thermal conductivity substrate 3 so that the light emitting surface is on the glass substrate 2 side. The solar cell element is formed on the glass substrate 2 or the high thermal conductivity substrate 3 so that the light receiving surface is on the glass substrate 2 side. Depending on the structure of the solar cell element, an element film or the like is formed on the glass substrate 2 and the high thermal conductivity substrate 3, respectively. The structure of the electronic element disposed in the airtight member 1 is not particularly limited, and various known structures are applied.

  Next, the manufacturing process of the airtight member 1 of the embodiment will be described with reference to FIG. First, a sealing material paste is prepared by mixing a sealing glass material, which is a forming material of the sealing material layer 9, with a vehicle. The glass material for sealing is as described above.

  The vehicle is obtained by dissolving a resin as a binder component in a solvent. Examples of the resin for the vehicle include cellulose resins such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, propyl cellulose, nitrocellulose, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, An organic resin such as an acrylic resin obtained by polymerizing one or more acrylic monomers such as 2-hydroxyethyl acrylate is used. Solvents such as terpineol, butyl carbitol acetate, and ethyl carbitol acetate are used for cellulose resins, and solvents such as methyl ethyl ketone, terpineol, butyl carbitol acetate, and ethyl carbitol acetate are used for acrylic resins. It is done.

  The viscosity of the sealing material paste may be adjusted to the viscosity corresponding to the apparatus applied to the glass substrate 2 and can be adjusted by the ratio of the resin (binder component) and the solvent and the ratio of the sealing glass material component and the vehicle. . A known additive may be added to the sealing material paste as a glass paste such as an antifoaming agent or a dispersing agent. A known method using a rotary mixer equipped with a stirring blade, a roll mill, a ball mill or the like can be applied to the preparation of the sealing material paste.

  As shown in FIG. 3A, the sealing material paste is applied to the sealing region 4 of the glass substrate 2 and dried to form an application layer of the sealing material paste. The sealing material paste is applied to the sealing region 4 by applying a printing method such as screen printing or gravure printing, or is applied along the sealing region 4 using a dispenser or the like. The coating layer of the sealing material paste is preferably dried at a temperature of 120 ° C. or more for 10 minutes or more, for example. A drying process is implemented in order to remove the solvent in an application layer. If the solvent remains in the coating layer, the binder component may not be sufficiently removed in the firing step.

  Next, the sealing material layer 9 is formed by baking the coating layer of the sealing material paste. In the firing step, the coating layer is heated to a temperature not higher than the glass transition point of the sealing glass (glass frit), the binder component in the coating layer is removed, and then the temperature not lower than the softening point of the sealing glass (glass frit). The glass material for sealing is melted and baked on the glass substrate 3. In this manner, the sealing material layer 9 made of the fired layer of the glass material for sealing is formed in the sealing region 4 of the glass substrate 2.

  Next, as shown in FIG. 3B, a glass layer 7 is formed in the sealing region 5 of the high thermal conductive substrate 3. The glass material as a forming material of the glass layer 7 is as described above. The glass material is mixed with the vehicle in the same manner as the sealing material paste manufacturing step to prepare a glass material paste. Such a glass material paste is applied to the sealing region 5 of the high thermal conductive substrate 3 and dried to form a coating layer of the glass material paste. The glass material paste is applied in the same manner as the sealing material paste application step. Moreover, it is preferable to implement a drying process after application | coating. Next, the coating layer of the glass material paste is heated to a temperature below the glass transition point of the glass frit to remove the binder component in the coating layer, and then heated to a temperature above the softening point of the glass frit to melt the glass frit. Bake on the high thermal conductivity substrate 3. In this way, the glass layer 7 is formed in the sealing region 5 of the high thermal conductive substrate 3.

  When the high thermal conductive substrate 3 is a ceramic substrate having heat resistance such as an alumina substrate, the firing temperature when baking the coating layer of the glass material paste can be set high. For example, when an alumina substrate is used, it can be fired at a temperature around 1000 ° C. For this reason, a glass frit having a high melting point can be used. On the other hand, when the high thermal conductive substrate 3 is a metal substrate, it is preferable to fire at a relatively low temperature in order to suppress warping during firing. For this reason, it is preferable that the softening point of the glass frit is low. The softening point of the glass frit is preferably 600 ° C. or lower, and more preferably 400 ° C. or lower.

  As described above, the glass layer 7 has a thickness in the range of 3 μm or more and less than 20 μm, and has electromagnetic wave absorbing ability. The line width W2 of the glass layer 7 is preferably wider than the line width W12 of the sealing material layer 9 (W12 <W2), and more than 1.1 times the line width W12 of the sealing material layer 9 (1. It is more preferable that 1W12 ≦ W2). By these, when the sealing material layer 9 is irradiated with electromagnetic waves, it is possible to effectively suppress the heat generated in the sealing material layer 9 from being transmitted to the high thermal conductive substrate 3, and the glass layer 7 is excellent. Can be heated.

  Next, as shown in FIG.3 (c), the glass substrate 2 and the high thermal conductivity board | substrate 3 are laminated | stacked through the sealing material layer 9 so that those surfaces 2a and 3a may oppose. The sealing material layer 9 is disposed in contact with the glass layer 7. Next, as shown in FIG. 3 (d), the sealing material layer 9 is irradiated with an electromagnetic wave 11 such as laser light or infrared rays through the glass substrate 2 from above the glass substrate 2. When laser light is used as the electromagnetic wave 11, the laser light is irradiated while scanning along the frame-shaped sealing material layer 9. The laser light is not particularly limited, and laser light from a semiconductor laser, carbon dioxide laser, excimer laser, YAG laser, HeNe laser, or the like is used. When infrared rays are used as the electromagnetic wave 11, it is preferable to selectively irradiate the sealing material layer 9 with infrared rays by, for example, masking portions other than the formation site of the sealing material layer 9 with an infrared reflection film or the like.

  When a laser beam is used as the electromagnetic wave 11, the sealing material layer 9 is melted in order from the portion irradiated with the laser beam scanned along it, and is rapidly solidified at the end of the laser beam irradiation to be fixed to the glass layer 7. . When infrared rays are used as the electromagnetic waves 11, the sealing material layer 9 is locally heated and melted based on the irradiation of infrared rays, and is rapidly solidified upon completion of the irradiation of infrared rays and is fixed to the high thermal conductive substrate 3. At this time, the glass layer 7 is also heated by irradiating the glass layer 7 with laser light or infrared light that has passed through the sealing material layer 9 and further with laser light or infrared light that has passed outside the region where the sealing material layer 9 is formed. The Accordingly, the heating of the sealing material layer 9 can be promoted and melted satisfactorily. In this way, as shown in FIG. 3E, the sealing layer 8 that hermetically seals the gap between the glass substrate 2 and the high thermal conductivity substrate 3 is formed over the entire circumference of the sealing region. .

  According to the hermetic member 1 of this embodiment and its manufacturing process, the gap (that is, the hermetic space 10) between the glass substrate 2 and the high thermal conductive substrate 3 is constituted by the glass layer 7 and the sealing layer 8. The sealing part 6 can be hermetically sealed well. Furthermore, the crack of the glass layer 7 which arises at the time of formation of the glass layer 7 or the sealing layer 8, and an increase in stress, and the crack or crack of the glass substrate 2 or the sealing layer 8 which occurs at the time of forming the sealing layer 8 are suppressed. Can do. As a result, the productivity of an airtight member in which the gap between the glass substrate 2 and the high thermal conductive substrate 3 is hermetically sealed can be increased, and the hermetic sealability and its reliability can be improved.

  Next, specific examples of the present invention and evaluation results thereof will be described. In addition, the following description does not limit this invention, The modification | change in the form along the meaning of this invention is possible.

Example 1
First, in terms of oxide, it has a composition of Bi ₂ O ₃ 83% by mass, B ₂ O ₃ 5% by mass, ZnO 11% by mass, Al ₂ O ₃ 1% by mass and an average particle size (D50) of 1. Bismuth glass frit of 0 μm (softening point: 410 ° C.), cordierite powder having an average particle size (D50) of 4.3 μm as a low expansion filler, Fe ₂ O ₃ —Al ₂ O ₃ —MnO—CuO composition And an average particle diameter (D50) of 1.2 μm was prepared. The average particle size was measured using a laser diffraction / scattering particle size measuring device (manufactured by Nikkiso Co., Ltd .: Microtrac HRA).

  A glass material for sealing was produced by mixing 66.8% by volume of the bismuth-based glass frit described above, 32.2% by volume of cordierite powder, and 1.0% by volume of the laser absorber. Next, 83% by mass of this glass material for sealing was mixed with 17% by mass of a vehicle to prepare a sealing material paste (hereinafter sometimes referred to as electromagnetic wave absorbing glass material paste 1). The vehicle is obtained by dissolving ethyl cellulose (5% by mass) as a binder component in a solvent (95% by mass) composed of diethylene glycol mono-2-ethylhexyl ether.

Next, a glass substrate (dimensions: outer shape 50 × 50 mm, thickness 0.7 mm) made of alkali-free glass (thermal expansion coefficient (50 to 250 ° C.): 38 × 10 ⁻⁷ / ° C.) is prepared. The sealing material paste was applied to the sealing area of the film by a screen printing method. Next, the glass substrate was placed in a firing furnace and dried under conditions of 120 ° C. × 10 minutes. Thereafter, the sealing material paste coating layer was baked under conditions of 480 ° C. × 10 minutes to form a sealing material layer having a line width of 0.55 mm and a film thickness of 15 μm. The thermal expansion coefficient (50 to 250 ° C.) of the sealing material layer is 66 × 10 ⁻⁷ / ° C.

Using the electromagnetic wave absorbing glass material paste 1 described above, a glass layer was formed in a sealing region of a silicon substrate (thermal expansion coefficient (50 to 250 ° C.): 31 × 10 ⁻⁷ / ° C.) as a high thermal conductivity substrate. . The glass layer was formed as follows. First, the glass material paste 1 for electromagnetic wave absorption was printed on the sealing area | region of a silicon substrate using the screen plate of the calendering 325 mesh. Next, the silicon substrate was placed in a firing furnace and dried under conditions of 120 ° C. × 10 minutes. After that, the glass material paste 1 coating layer was baked under conditions of 480 ° C. × 10 minutes to form a glass layer having a line width of 1.5 mm and a film thickness of 10 μm. The thermal expansion coefficient (50 to 250 ° C.) of the glass layer is 66 × 10 ⁻⁷ / ° C.

The glass substrate having the sealing material layer described above and the silicon substrate having the glass layer were laminated so that the sealing material layer and the glass layer were in contact with each other. Next, a laser having a wavelength of 808 nm, a spot diameter of 1.75 mm, and an output density of 17.7 W / mm ² is passed through the glass substrate from above the glass substrate with a pressure of 0.05 MPa applied from above the glass substrate. A sealing layer for sealing the glass substrate and the silicon substrate was formed by irradiating light (semiconductor laser) at a scanning speed of 4 mm / second to melt and rapidly solidify the sealing material. The intensity distribution of the laser beam was not shaped uniformly, and a laser beam having a protruding intensity distribution was used. As the spot diameter at this time, the radius of the contour line at which the laser intensity becomes 1 / e ² (e: natural number) was used.

  When the appearance of the glass substrate and the sealing layer was observed after laser sealing, the sealing layer was well adhered to the glass layer, and no occurrence of peeling or the like was observed. Moreover, generation | occurrence | production of the crack, a crack, etc. was not recognized by the glass layer or the sealing layer. When the airtightness of the airtight member in which the gap between the glass substrate and the silicon substrate was sealed with the sealing portion was evaluated by a helium leak test, it was confirmed that good airtightness was obtained.

(Comparative Example 1)
First, a glass material paste having no electromagnetic wave absorbing ability was prepared as follows. A glass material (thermal expansion coefficient (50 to 250 ° C.): 66 × 10 ⁻⁷ / ° C.) was prepared by mixing 67.5 vol% of the bismuth glass frit described above and 32.5 vol% of cordierite powder. A glass material paste was prepared by mixing 83% by mass of the glass material with 17% by mass of the vehicle. The glass substrate and the silicon substrate were sealed in the same manner as in Example 1 except that the glass layer was formed using the glass material paste having no electromagnetic wave absorbing ability. When the appearance of the glass substrate and the sealing layer was observed after laser sealing, peeling was observed at the interface between the sealing layer and the glass layer, and it was not possible to hermetically seal.

  DESCRIPTION OF SYMBOLS 1 ... Airtight member, 2 ... Glass substrate, 2a ... Surface, 3 ... High heat conductive substrate, 3a ... Surface, 4 ... 1st sealing area | region, 5 ... 2nd sealing area | region, 6 ... Sealing part, 7 DESCRIPTION OF SYMBOLS ... Glass layer, 8 ... Sealing layer, 9 ... Sealing material layer, 10 ... Airtight space, 11 ... Electromagnetic wave.

Claims (13)

A glass substrate having a first surface with a first sealing region;
A second surface comprising a second sealing region corresponding to the first sealing region; and a glass layer formed in the second sealing region, wherein the second surface is the first surface A highly thermally conductive substrate disposed on the glass substrate with a predetermined gap so as to face the surface of 1;
A seal formed between the first sealing region of the glass substrate and the glass layer so as to hermetically seal a gap between the glass substrate and the high thermal conductivity substrate, and having an electromagnetic wave absorption capability. Comprising a sealing layer composed of a melt-fixed layer of a wearing glass material,
The airtight member, wherein the glass layer has an electromagnetic wave absorbing ability, and the thickness of the glass layer is in a range of 3 μm or more and less than 20 μm.   The hermetic member according to claim 1, wherein the glass layer has a width wider than that of the sealing layer.   The airtight member according to claim 1 or 2, wherein both end portions in the width direction of the sealing layer are located inside both end portions in the width direction of the glass layer.   The airtight member according to any one of claims 1 to 3, wherein the glass layer has a thermal expansion coefficient larger than that of the high thermal conductivity substrate.   The airtight member according to any one of claims 1 to 4, wherein the high thermal conductivity substrate is a semiconductor substrate, a metal substrate, or a ceramic substrate.   The sealing layer includes a sealing glass made of a low melting point glass, an electromagnetic wave absorbing material in a range of 0.1 volume% to 40 volume%, and a low expansion filling in a range of 0.1 volume% to 50 volume%. The airtight member according to any one of claims 1 to 5, wherein the hermetic member comprises a melt-fixed layer of the sealing glass material containing a material. A glass substrate having a first surface provided with a first sealing region and a sealing material layer formed in the first sealing region and made of a fired layer of a sealing glass material having electromagnetic wave absorbing ability is prepared. And a process of
A highly thermally conductive substrate having a second surface comprising: a second sealing region corresponding to the first sealing region; and a glass layer formed in the second sealing region and having an electromagnetic wave absorption capability. A process to prepare;
Laminating the glass substrate and the high thermal conductivity substrate while facing the first surface and the second surface, and contacting the sealing material layer and the glass layer;
The sealing material layer and the glass layer are irradiated with electromagnetic waves through the glass substrate and locally heated, and the sealing material layer is melted and fixed to the glass layer. Forming a sealing layer that hermetically seals a gap between the conductive substrate and the substrate,
The method for producing an airtight member, wherein the glass layer has a thickness of 3 μm or more and less than 20 μm.   The method for manufacturing an airtight member according to claim 7, wherein the glass layer has a width wider than that of the sealing material layer.   The sealing material layer is brought into contact with the glass layer so that both end portions in the width direction of the sealing material layer are located inside both end portions in the width direction of the glass layer. The manufacturing method of the airtight member of 8.   The method for manufacturing an airtight member according to any one of claims 7 to 9, wherein the glass layer has a thermal expansion coefficient larger than that of the high thermal conductivity substrate.   The method for manufacturing an airtight member according to any one of claims 7 to 10, wherein the high thermal conductivity substrate is a semiconductor substrate, a metal substrate, or a ceramic substrate.   The glass material for sealing includes a sealing glass made of a low melting point glass, an electromagnetic wave absorbing material in a range of 0.1 to 40% by volume, and a low expansion in a range of 0.1 to 50% by volume. The method for producing an airtight member according to any one of claims 7 to 11, further comprising a filler.   The method for manufacturing an airtight member according to any one of claims 7 to 12, wherein a laser beam is irradiated as the electromagnetic wave while scanning along the sealing material layer.

Images