JP6650885B2 - Low temperature sealing material - Google Patents

Description

  The present invention relates to a novel low-temperature sealing material. More specifically, the present invention relates to a sealing material that can be sealed at a relatively low temperature in electronic devices such as an IC package and a crystal resonator package.

  Sealing materials used for sealing electronic devices such as IC packages and crystal resonator packages are, in particular, 1) that they can be sealed at as low a temperature as possible, and 2) the thermal expansion coefficient of the package material (the material to be sealed). It is required to have an approximate coefficient of thermal expansion and 3) to have sufficient fluidity during firing.

As a sealing material that can be sealed at a relatively low temperature, glass such as PbO—B ₂ O ₃ or PbO—B ₂ O ₃ —Bi ₂ O _{3 is} generally used. A sealing material to which a low-expansion ceramic is added in order to meet the requirements has been proposed.

Patent Document 1, made of low-melting glass powder and lead titanate solid solution powder, the lead titanate solid solution powder, _PbO by weight percentages: 60~73%, TiO 2: 7~23 %, Fe 2 O 3, ZnO, MgO, MnO, CoO, 1 or more selected from the group of _{NiO: 0.5~10%, Nb 2 O} 5, Ta 2 O 5, 1 or more selected from the group consisting of _Sb 2 _{O 5: 2~} A low-melting and low-expansion sealing material characterized by having a composition of 18%, at least one selected from the group consisting of CaO, SrO and BaO: 0 to 7%.

Patent Document 2, in weight _{percent, PbO: 70.3~92.0%, B 2} O 3: 1.0~10.0%, Bi 2 O 3: 5.2~20.0%, F _{2: 0.01~8.0%, ZnO: 0~15.0} %, V 2 O 5: 0~5.0%, SiO 2: 0~2.0%, Al 2 O 3: 0~2 _{.0%, SnO 2: 0~2.0%} , BaO: have from 0 to 4.0% of the composition, _and, characterized in that B ₂ O 3 / PbO ratio is 0.11 or less of the glass powder Has been proposed.

  Patent Document 3 discloses a semiconductor element housing package in which an insulating base and a lid are joined via a sealing material, and a semiconductor element is hermetically housed in a container including the insulating base and the lid. The sealing material is 30.0 to 50.0% by weight of lead oxide, 10.0 to 20.0% by weight of lead fluoride, 3.0 to 13.0% by weight of bismuth oxide, and 1.0 to 5.0% of boron oxide. A semiconductor element housing comprising glass in which 25.0 to 45.0% by weight of a lead titanate-based compound as a filler is added to a glass component containing 1.0% to 5.0% by weight of zinc oxide and 1.0% to 5.0% by weight of zinc oxide. A package is disclosed.

Patent Document 4 discloses a low melting point sealing composition comprising a mixture of a glass powder containing PbF ₂ and a refractory filler.

In Patent Document 5, in _{weight%, PbO: 70~80%, B} 2 O 3: 5~12%, ZnO: 0~5%, SiO 2: 0~1%, Al 2 O 3: 0~3% , SnO ₂ : 0 to 1%, Bi ₂ O ₃ : 3 to 12%, V ₂ O ₅ : 0.1 to 1%, CuO: 0.1 to 5%, F: 0.1 to 3% A sealing composition characterized by containing 25 to 40% by volume of a refractory filler powder in a glass powder having the following formula:

Patent Document 6 discloses a low-melting-point sealing glass composition of a PbO—B ₂ O ₃ —Bi ₂ O ₃ —SiO ₂ -based glass powder and a lead titanate powder and / or a β-eucryptite powder. I have.

Patent Document 7 discloses that PbO 50 to 75%, PbF ₂ 1 to 20%, B ₂ O ₃ 6 to 12%, TeO ₂ 1 to 10%, ZnO 1 to 5%, and SiO ₂ 0.5 by mass percentage. _{~2%, Al 2 O 3 0.5~2} %, Bi 2 O 3 and 50 to 90 vol% glass powder having a composition consisting of 0-10%, to consist of 10 to 50 vol% low expansion ceramic filler powder A low temperature sealing composition is disclosed.

Patent Document 8, in _{weight%, PbO 71.0~90.0%, B 2} O 3 3.0~12.0%, Bi 2 O 3 1.0~20.0%, ZnO 0.1 １10.0%, Sb ₂ O ₃ 0.3 to 5.0%, F ₂ 0.1 to 10.0%, FeO 0.1 to 3.0%, MnO ₂ 0.1 to 5.0% , _SiO 2 _0~3.0%, low-temperature sealing composition which is a _Al 2 O 3 0~3.0% and low melting glass consisting of CuO 0 to 3.0% of the composition disclosed Have been.

JP-A-5-17179 JP-A-5-97470 JP-A-8-306814 JP-A-4-357132 JP-A-5-105480 JP-A-53-72029 JP-A-8-253345 JP-A-11-116275

  However, these conventional techniques have various problems as described below, and there is still room for improvement.

In the low-melting-point, low-expansion sealing material of Patent Document 1, since the glass composition does not contain fluorine, the glass has a high softening point and cannot be sealed at a low temperature. Further, although a composition containing fluorine is disclosed, crystallization may occur due to a large PbO / Bi ₂ O ₃ ratio.
In the low melting point sealing composition of Patent Document 2, it is necessary to contain a poison such as V ₂ O _{5 in} order to lower the glass softening point.
The sealing material of Patent Document 3, PbO + PbF ₂ content higher softening temperature due to the low, also glass since small amount of B ₂ O ₃ is a problem that tends to crystallize.
The low-melting-point sealing composition disclosed in Patent Document 4 has a problem that crystallization of PbO or the like changes due to the inclusion of Fe ₂ O ₃ , so that crystallization is easy.
The sealing composition of Patent Literature 5 has a problem similar to Patent Literature 2 in that the glass composition contains toxic V ₂ O ₅ .
The low melting point sealing glass composition of Patent Document 6 has a problem that the softening point does not decrease because of a low fluorine content.
The low-temperature sealing composition of Patent Document 7 has a problem of containing TeO ₂ which is a harmful substance.
The low-temperature sealing composition of Patent Document 8 also has a problem that it contains a deleterious substance, Sb ₂ O ₃ .

As described above, these conventional techniques rely on toxic compounds (elements) such as V ₂ O ₅ , TeO ₂ and Sb ₂ O ₃ to lower the softening point. In addition, due to the fact that the fluorine content or the PbO / Bi ₂ O ₃ ratio is not appropriate, crystals are precipitated from glass by repeated firing in the process of sealing the IC package or the quartz oscillator, or the glass powder and the filler powder are mixed. May cause a reaction. If crystals precipitate during the flow process of the glass, the flowability will be reduced, or sufficient sealing cannot be performed. Further, when the glass powder and the filler powder react, the glass composition apparently changes, crystallization occurs, and sufficient sealing cannot be achieved.

  In particular, when glass is used as a paste, the above-described problem of crystallization is likely to occur. When sealing an electronic device such as a quartz oscillator, a paste obtained by mixing a solvent or the like with lead-based glass is usually used as a sealing material. However, fluorine-containing lead-based glass and the like have low chemical durability, and crystals tend to precipitate when fired in the presence of a solvent. When crystals are precipitated, the fluidity deteriorates, and it becomes impossible to spread the sealing material over the adhesive surface between the container (housing) accommodating the quartz oscillator and the lid, so that the desired adhesiveness cannot be obtained. In addition, the sealing itself may be insufficient.

Therefore, a main object of the present invention is to provide a material that can exhibit more excellent properties as a sealing material without relying on V ₂ O ₅ , TeO ₂ , Sb ₂ O ₃ , Fe ₂ O _{3, and the} like. is there. Another object of the present invention is to provide a sealing material capable of exhibiting good fluidity because crystals are unlikely to precipitate during firing even in the presence of a solvent.

  The present inventor has conducted intensive studies in view of the problems of the prior art, and as a result, has found that the above object can be achieved particularly by employing a glass composition having a specific composition, thereby completing the present invention.

That is, the present invention relates to the following low-temperature sealing material.
1. A sealing material containing a lead glass powder and a lead titanate-based filler powder,
(1) The lead glass is
1) PbO: 69.0 to 80.0% by weight,
₂₎ Bi 2 O 3: 3.1~12.5 wt%,
₃₎ B ₂ O 3: 3.5~11.5 wt%,
4) ZnO: 1.7-8.2% by weight,
₅₎ SiO 2: 0~3.5% by weight,
6) CuO: 0-4.0% by weight and 7) F: 1.3-5.0% by weight
Contains as a glass component,
(2) the weight ratio of [PbO / _Bi 2 _{O 3]} in the lead glass is from 5.6 to 25.5,
A low-temperature sealing material, characterized in that:
2. (1) the lead glass powder is 1) PbO: 71.0-80.0 _{wt%, 2) Bi 2 O 3} : 3.1~9.5 _{wt%, 3) B 2 O 3} : 3.5~ 11.5 wt%, 4) ZnO: 1.7~8.2 _wt%, 5) SiO 2: _0~3.5 wt%, 6) CuO: 0~4.0 wt% and 7) F: 2 0.0-5.0% by weight as a glass component,
(2) the weight ratio of the [PbO / _Bi 2 _{O 3]} is 7.7 to 18.5,
Item 2. The low-temperature sealing material according to Item 1.
3. (1) the lead glass powder is 1) PbO: from 71.0 to 78.0 _{wt%, 2) Bi 2 O 3} : 5.0~8.5 _{wt%, 3) B 2 O 3} : 5.5~ 10.0 wt%, 4) ZnO: 1.7~6.5 _wt%, 5) SiO 2: _0.5~3.0 wt%, 6) CuO: 1.0~2.0 wt% and 7 ) F: 2.4 to 4.1% by weight as a glass component,
(2) the weight ratio of the [PbO / _Bi 2 _{O 3]} is 8.5 to 13.0,
Item 2. The low-temperature sealing material according to Item 1.
4. The glass powder further contains 0.01 to 1 wt% of at least one of the TiO ₂ and ZrO ₂ in total as the glass component, the low-temperature sealing material according to any one of claim 1 to 3.
5. The total of 100 parts by weight of the lead glass powder and the lead titanate-based filler powder, including 90 to 60 parts by weight of the lead glass powder and 10 to 40 parts by weight of the lead titanate-based filler powder, Low temperature sealing material.
6. The oxide composition of the lead titanate-based filler is as follows: PbO: 60.0 to 70.0% by weight, TiO ₂ : 15.0 to 25.0% by weight, CaO: 0 to 5.0% by weight, in terms of oxide. Fe ₂ O _3: 0~5 wt% and _Nb 2 _O 3: _0~10.0 containing wt%, the low-melting sealing material according to any one of claim 1 to 5.
7. Item 7. The low-temperature sealing material according to any one of Items 1 to 6, further comprising at least one of a solvent and an organic binder, and having a paste-like form.
8. Item 8. The low-temperature sealing material according to Item 7, wherein no crystals are precipitated when fired at 370 ° C. in the atmosphere.
9. Item 9. A package for housing a semiconductor element, comprising the low-temperature sealing material according to any one of Items 1 to 8.

In the low-temperature sealing material of the present invention, since a composition composed of a specific glass component is particularly employed, more excellent properties can be exhibited as the sealing material. More specifically, the following effects can be obtained.
(1) Crystallization of glass can be effectively suppressed. As a result, the fluidity and the like of the glass at the time of softening can be more favorably maintained, so that various problems (sealing failure, insufficient sealing, and the like) caused by crystallization of the glass can be more reliably avoided.
(2) The reaction between the glass and the filler that may occur during firing can be effectively suppressed. Thereby, it is possible to suppress or prevent deterioration (deterioration) of the glass such as a change in the glass composition and crystallization of the glass. As a result, for example, the glass is hardly crystallized even when subjected to repeated firing in a manufacturing process of a quartz oscillator or the like, and a sufficient sealing effect can be obtained. In particular, as in the case where the sealing material is used in the form of a paste, even in the presence of a solvent, crystals are unlikely to precipitate during firing, and good fluidity can be ensured, resulting in highly reliable sealing. Can be realized.
(3) Further, since the reaction between the glass and the filler can be effectively suppressed, the degree of freedom of the range of use of the filler can be ensured, so that the coefficient of thermal expansion can be controlled relatively freely. More specifically, it is possible to freely control the coefficient of thermal expansion in the temperature range of 50 to 150 ° C., for example, in the range of 50 to 150 × 10 ⁻⁷ / ° C. As a result, it is relatively easy to match (approximate) the thermal expansion coefficient of the material to be sealed.
(4) The sealing material of the present invention has a relatively low use temperature, and can be sealed at a relatively low temperature of, for example, 380 ° C. or less, which is a general sealing temperature of a quartz oscillator or the like.

  As described above, the sealing material of the present invention can realize sealing excellent in mechanical strength, durability, and the like, and is therefore useful for sealing electronic devices such as IC packages and crystal resonator packages. It can be suitably used as a sealing material.

1. Low-temperature sealing material The low-temperature sealing material of the present invention (material of the present invention) is a sealing material containing a lead glass powder and a lead titanate-based filler powder,
(1) The lead glass is
1) PbO: 69.0 to 80.0% by weight,
₂₎ Bi 2 O 3: 3.1~12.5 wt%,
₃₎ B ₂ O 3: 3.5~11.5 wt%,
4) ZnO: 1.7-8.2% by weight,
₅₎ SiO 2: 0~3.5% by weight,
6) CuO: 0-4.0% by weight and 7) F: 1.3-5.0% by weight
Contains as a glass component,
(2) the weight ratio of [PbO / _Bi 2 _{O 3]} in the lead glass is from 5.6 to 25.5,
It is characterized by the following.

A. Lead glass powder (A-1) Glass composition As described above, the glass component in the material of the present invention is such that each component such as Pb, Bi, B, Zn, Si, Cu, and F has a predetermined content in terms of oxide. Have Hereinafter, each component and its content will be described.

PbO
PbO is an oxide forming glass, and is preferably contained in the range of 69.0 to 80.0% by weight. If the PbO content is less than 69.0% by weight, the glass may not be obtained, and even if it is obtained, the softening point of the glass may increase, and sealing at a desired temperature may not be possible. If the PbO content is more than 80.0% by weight, crystallization may occur at the time of sealing, and the fluidity during softening may deteriorate.
In the present invention, PbO is more preferably contained in an amount of 71.0 to 80.0% by weight, particularly preferably 71.0 to 78.0% by weight, in consideration of the moldability of the glass, the sealing temperature and the like. More preferred.

Bi ₂ O ₃
Bi ₂ O ₃ is a component for stabilizing the glassy state, and is preferably contained in the range of 3.1 to 12.5% by weight. If the Bi ₂ O ₃ content is less than 3.1% by weight, crystals may be precipitated. When the Bi ₂ O ₃ content exceeds 12.5% by weight, glass may not be obtained, and even if glass is obtained, the fluidity of glass may be deteriorated.
In the present invention, Bi ₂ O ₃ is more preferably contained in an amount of 3.1 to 9.5% by weight, particularly preferably 5.0 to 8.5% by weight, particularly in consideration of the moldability and fluidity of glass. More preferably,

B ₂ O ₃
B ₂ O ₃ is a component that forms glass, and is contained in the range of 3.5 to 11.5% by weight. If the B ₂ O ₃ content is less than 3.5% by weight, glass may not be obtained. If the B ₂ O ₃ content exceeds 11.5% by weight, the glass may not be obtained, and even if the glass is obtained, the glass has a high softening temperature, which may deteriorate the fluidity of the glass. is there.
In the present invention, B ₂ O ₃ is more preferably contained in an amount of 3.5 to 11.5% by weight, particularly preferably 5.5 to 10.0% by weight, in consideration of the moldability and fluidity of glass. More preferably,

ZnO
ZnO is a component that enhances the moldability of glass, and is preferably contained in the range of 1.7 to 8.2% by weight. If the ZnO content is less than 1.7% by weight, the glass may crystallize and may not flow. If the ZnO content is more than 8.2% by weight, glass may not be obtained.
In the present invention, the content of ZnO is preferably 1.7 to 8.2% by weight, and more preferably 1.7 to 6.5% by weight, particularly in consideration of the moldability and fluidity of glass. Is more preferable.

SiO ₂
SiO ₂ is a component forming glass, and is preferably contained at 0 to 3.5% by weight. When the SiO ₂ content is more than 3.5% by weight, the softening temperature of the glass increases, and the fluidity of the glass may deteriorate.
In the present invention, SiO ₂ is more preferably contained in an amount of 0.5 to 3.0% by weight, particularly 1.5 to 3.0% by weight, in consideration of the moldability and fluidity of the glass. Is most preferred. In particular, by containing 1.5 to 3.0% by weight of SiO ₂ , precipitation of crystals that can occur in the presence of a solvent when the material of the present invention is used in a form containing at least a solvent is more effectively suppressed. Or prevent it. That is, by effectively suppressing or preventing crystallization during firing of the material of the present invention, good fluidity can be ensured, and as a result, highly reliable sealing can be realized more reliably. Becomes

CuO
CuO is a component for preventing crystallization of glass, and is preferably contained at 0 to 4% by weight. When the CuO content is more than 4% by weight, the glass may be crystallized, and the fluidity during softening may be reduced.
In the present invention, the content of CuO is more preferably 1 to 2% by weight, particularly in consideration of the fluidity of glass.

F (fluorine)
The fluorine component is a component that lowers the softening temperature of the glass and improves the fluidity of the glass, and is preferably contained in the range of 1.3 to 5.0% by weight. When the fluorine content is less than 1.3% by weight, the softening temperature of the glass is increased, and the fluidity may be deteriorated. When the fluorine content is more than 5.0% by weight, it is likely to react with the filler, and there is a possibility that glass cannot be obtained.
In the present invention, the fluorine content is more preferably 2.0 to 5.0% by weight, particularly 2.4 to 4.1% by weight, in consideration of the fluidity of the glass, the reactivity with the filler, and the like. Is more preferable.

TiO ₂ and ZrO ₂
In addition to the above components, for example, at least one of TiO ₂ and ZrO ₂ is used in a total amount of 0.01 to 1% by weight for the purpose of improving stability during glass production, suppressing crystallization, adjusting the thermal expansion coefficient, and the like. It can be contained.

Other components As other components, for example, alkaline earth oxides such as CaO, SrO, and BaO may be used for the purpose of improving stability during glass production, suppressing crystallization, adjusting the thermal expansion coefficient, and the like. Can be added.
Further, the material of the present invention may contain at least one of CoO and an alkali metal oxide as needed, as long as the effects of the present invention are not impaired. By blending these components, the fluidity of the material of the present invention at the time of firing (at the time of use) can be increased without depending on the increase in the amount of PbO. The contents of these are not limited, but generally may be in the range of 0.3 to 2.0% by weight in total.
On the other hand, in the lead glass (and the sealing material) according to the present invention, V, Te, Sb, and Fe, which can be highly harmful components or components that deteriorate, are preferably 0.1% by weight or less in total. More preferably, it is more preferably 0% by weight in total. That is, unlike the conventional sealing material, the material of the present invention can exhibit desired characteristics without depending on these components.

The weight ratio of [PbO / _Bi 2 _{O 3]} in the lead glass according to the weight ratio present invention [PbO / _Bi 2 _{O 3]} is usually set to 5.6 to 25.5, and from 7.7 to 18.5 More preferably, it is particularly preferably 8.5 to 13.0. If the weight ratio is less than 5.6, the softening point of the glass may be too high. On the other hand, if the weight ratio exceeds 25.5, the reactivity with the filler may increase.

(A-2) Production of Lead Glass Powder The lead glass powder of the present invention can be produced by a method similar to a known method for producing a glass composition. As a material, a compound serving as a supply source of each component of the glass in the present invention may be used as a starting material. For example PbO, etc. as Pb supply source, etc. _Bi 2 _{O 3} as a Bi supply source, _H 3 _BO 3 as a B supply _source, B 2 _{O 3,} etc., ZnO or the like as a Zn supply source, _SiO 2, Cu supply source as Si supplying raw For example, PbF ₂ or the like as a fluorine supply source, TiO ₂ or the like as a Ti supply source, ZrO ₂ or the like as a Zr supply source. As described above, various starting materials commonly used in the production of glass, such as oxides, hydroxides, carbonates, and nitrates, can be used.

  The raw materials are prepared and mixed at a predetermined ratio, and the mixture is put into a platinum crucible and melted at a temperature of 750 to 950 ° C. for a predetermined time (about 1 to 2 hours). The flakes are obtained, and the flakes are poured out onto a preheated carbon plate to form a block. Thereafter, the block is placed in an electric furnace set at a temperature about 50 ° C. higher than the expected glass transition point, and is gradually cooled. Further, glass flakes are put in a pot mill and pulverized into glass powder. This glass powder can be subjected to a treatment such as classification or sieving as required.

(A-3) Physical Properties of Lead Glass Powder The properties of the lead glass powder of the present invention are usually used as a powder. Although the average particle size (D ₅₀ ) is not limited, it can usually be appropriately adjusted within the range of 30 μm or less according to the use form, application and the like. For example, when the material of the present invention is prepared as a paste, the particle size may be appropriately adjusted to the particle size described later.

  The lead glass powder of the present invention has a characteristic of not having a crystallization temperature. Thereby, there is obtained an effect that the fluidity is good at the time of sealing and that insufficient sealing does not occur.

  Further, the glass transition point of the lead glass powder is not limited, but usually may be in the range of about 200 to 280 ° C, and more preferably 220 to 260 ° C. Thereby, the sealing can be performed at a relatively low temperature, and the coefficient of thermal expansion can be controlled to be close to that of the material to be sealed by mixing the filler powder.

B. Lead titanate-based filler powder The lead titanate-based filler powder used in the present invention is at least a solid solution in which lead titanate (PbTiO ₃ ) and a part of which are replaced by other atoms (for example, Ca, Fe, Nb, etc.). One can be used. These can also use a well-known thing.

As the composition in lead titanate, or solid solutions, PbO on an oxide basis: 60.0 to 70.0 _wt%, TiO 2: 15.0 to 25.0 wt%, CaO: 0 to 5.0 wt%, Fe ₂ O _3: 0~5 wt% and _Nb 2 _O 3: _0~10.0 it is desirable to employ a composition containing by weight%. Within the above composition range, the coefficient of thermal expansion can be reduced, and even if the content of the lead titanate-based filler powder is small, there is an effect, so that good fluidity can be more effectively obtained.

The average particle diameter (D ₅₀ ) of the lead titanate-based filler powder is not particularly limited, but is usually preferably from 7 to 30 μm, and more preferably from 7 to 15 μm. When the average particle size is less than 7 μm, the lead titanate-based filler powder easily reacts with glass. On the other hand, when the average particle size exceeds 30 μm, the workability when the paste is formed may be deteriorated, or sedimentation may be easily caused.

  The content of the lead titanate-based filler powder is, in particular, from the viewpoint of lowering the thermal expansion coefficient of the sealing material by the lead glass powder, in a total of 100 parts by weight of the lead glass powder and the lead titanate-based filler powder, It is preferable to use 90 to 60 parts by weight of a lead glass powder and 10 to 40 parts by weight of a lead titanate-based filler powder. If the content of the lead titanate-based filler powder is less than 10 parts by weight, the effect may not be sufficiently obtained. On the other hand, when the content of the lead titanate-based filler powder exceeds 40 parts by weight, the amount of glass is reduced, so that the fluidity is deteriorated and there is a possibility that poor adhesion may occur. Considering the fluidity at the time of firing, the content of the lead titanate-based filler powder is more preferably 25 to 35 parts by weight (75 to 65 parts by weight of lead glass powder). The proportion occupied by the total of the lead glass powder and the lead titanate-based filler in the present invention is not limited, and is, for example, 60 to 100% by weight, particularly 80 to 100% by weight, and more preferably 95 to 100% by weight in the material of the present invention. It can be.

  In the present invention, a ceramic filler can be added in addition to the lead titanate-based filler powder for the purpose of, for example, finely adjusting the thermal expansion coefficient and improving the strength of the sealing material. As the ceramic filler (powder), for example, at least one of β-eucryptite, cordierite, zircon, and the like can be used. The amount of the ceramic filler added may be within a range of 50 parts by weight or less based on 100 parts by weight of the total amount of the lead titanate-based filler powder and the lead glass composition.

2. Production of low-temperature sealing material The material of the present invention can be obtained by mixing the above-mentioned lead glass powder and lead titanate-based filler powder. The mixing method may be either a dry method or a wet method, but it is particularly preferable to perform the dry mixing. The mixing can be performed by using a known or commercially available mixing device or the like.

3. Use of Low-Temperature Sealing Material The material of the present invention can be used in the same manner and in the same manner as known sealing materials. In this case, the material of the present invention can be used as it is in a powder form, but can be suitably used, for example, in the form of a paste.

  When used in a liquid form, it may be prepared by mixing a sealing material with at least one of a solvent and an organic binder. For example, a liquid (paste) composition that can be prepared by mixing a sealing material (powder), a solvent, and an organic binder of the present invention can be prepared by firing (at least in the atmosphere) (Calcination at 370 ° C.). That is, in the case of a conventional paste containing a solvent, the cause is not clear, but since crystals are easily precipitated during firing, the fluidity is also reduced. On the other hand, the liquid composition according to the present invention is less likely to be crystallized even if it contains a solvent, and a desired fluidity can be ensured. As a result, highly reliable sealing can be realized. .

The average particle size of the powder of the sealing material in this case _{(D 50) determined} not particularly limited, usually a 2 to 30 m, it is preferable that the particular 5 to 15 [mu] m. When the average particle size is less than 2 μm, a large amount of organic binder is required when preparing the paste, the degree of volume shrinkage before and after firing becomes large, and it takes a long time to burn off the binder. May be reduced. If the average particle size exceeds 30 μm, there is a possibility that trouble may occur during sealing. The maximum particle size of the powder is not limited, but is usually 200 μm or less, preferably 100 μm or less, and more preferably 80 μm or less.

  The organic binder is not particularly limited. It can be appropriately selected from known or commercially available binders according to the specific use (sealing material) of the sealing material. For example, a cellulose resin such as ethyl cellulose, a copolymer (acrylic resin) of methyl methacrylate, which is a main component, with various acrylates, methacrylate, acrylamide, styrene, acrylonitrile, etc. with acrylic acid, methacrylic acid and the like, and various other resins. Those to which a saturated group is added are exemplified.

  The organic solvent may be appropriately selected according to the type of the binder and the like. Examples of the organic solvent include alcohols such as ethanol, methanol, and IPA, and terpineol (α-terpineol or β-terpineol containing α-terpineol as a main component). , Γ-terpineol), butyl carbitol, butyl carbitol acetate, ethylene glycol alkyl ether, diethylene glycol alkyl ether, ethylene glycol alkyl ether acetate, diethylene glycol alkyl ether acetate, diethylene glycol dialkyl ether acetate, triethylene glycol alkyl ether acetate, Triethylene glycol alkyl ether, propylene glycol alkyl ether, propylene glycol Phenyl ether, dipropylene glycol alkyl ether, tripropylene glycol alkyl ether, propylene glycol alkyl ether acetates, dipropylene glycol alkyl ether acetate, tripropylene glycol alkyl ether acetate, .gamma.-butyrolactone and the like. These solvents may be used alone or in combination of two or more.

  In addition, in the preparation of the liquid composition (particularly, a paste-like composition), if necessary, known additives such as a plasticizer, a thickener, a sensitizer, a surfactant, and a dispersant may be used. Can be appropriately blended.

  Hereinafter, examples and comparative examples are shown, and the features of the present invention will be described more specifically. However, the scope of the present invention is not limited to the examples.

Examples 1-42 and Comparative Examples 1-2
The mixing ratio of the lead glass powder and the lead titanate-based filler powder produced as described in (1) and (2) below is shown in Tables 1 to 7 (total 100 weight of the lead glass powder and the lead titanate-based filler powder) %) To obtain powdery sealing materials.

(1) Production of Lead Glass Powder After blending and mixing the respective raw materials so as to have the glass compositions shown in Tables 1 to 7, the resulting mixture was placed in a platinum crucible and heated at a temperature of 800 to 950 ° C. for 1 hour. After melting, the glass flakes were quenched by a twin roll method to obtain glass flakes, and were poured out onto a previously heated carbon plate to prepare blocks. Thereafter, the block was gradually cooled in an electric furnace set at a temperature about 50 ° C. higher than the expected glass transition point. The glass flakes were put into a pot mill and pulverized to obtain glass powder.
The glass raw materials include Pb component supply source: PbO, Bi component supply source: Bi ₂ O ₃ , B component supply source: H ₃ BO ₃ , Zn component supply source: ZnO, Si component supply source: SiO ₂ , Cu Component supply source: CuO, fluorine component supply source: PbF ₂ , Ti component supply source: TiO ₂ , Zr component supply source: ZrO ₂ , respectively.

(2) Production of Lead Titanate-Based Filler Powder Each raw material was prepared and mixed to have the composition shown in Table 8, and the obtained mixture was fired at 1100 to 1300 ° C. And crushed. By performing this step several times, a lead titanate-based filler powder (fillers 1 to 6) was obtained.

Test example 1
The physical properties of the lead glass powder and the lead titanate-based filler powder and the physical properties (performance) of the sealing material obtained in each of Examples and Comparative Examples were measured according to the following measurement methods.

(1) Crystallization temperature About 60 to 80 mg of the above lead glass powder was filled in a platinum cell, and the temperature was raised from room temperature at a rate of 20 ° C./min using a DTA measuring device (Thermo Plus TG8120 manufactured by Rigaku Corp.). (° C.) was detected.

(2) Glass transition point (Tg1) and coefficient of thermal expansion (α1) of lead glass
The glass block was cut into a size of about 5 mm × 5 mm × 15 mm, and polished to obtain a sample for measurement. From the thermal expansion curve obtained when the temperature was raised from room temperature at 10 ° C./min using a TMA measuring device, the thermal expansion coefficient based on the glass transition point (Tg1) (° C.) and the two points of 50 ° C. and 150 ° C. ( α1) (× 10 ⁻⁷ / ° C.).

(3) Flow diameter of lead glass (flow diameter 1)
The lead glass powder was placed in a mold having an inner diameter of 20 mm, pressed, molded, and fired at 360 ° C. The diameter of the obtained sintered body was measured and defined as a flow diameter (mm). The larger the flow diameter, the better the fluidity.

(4) Average particle size of lead titanate-based filler powder The value of D ₅₀ (μm) in the volume distribution mode was determined using a laser scattering type particle size distribution meter.

(5) Flow diameter of sealing material (flow diameter 2)
The obtained sealing material (mixed powder of lead glass powder and lead titanate-based filler powder) was placed in a mold having an inner diameter of 20 mm, pressed, molded, and fired at 360 ° C. The diameter of the obtained sintered body was measured and defined as a flow diameter (mm). The larger the flow diameter, the better the fluidity.

(6) Glass transition point (Tg2) and coefficient of thermal expansion (α2) of the sealing material
The sintered body obtained in the above (4) was cut out into a size of about 5 mm × 5 mm × 15 mm to prepare a test body. From the thermal expansion curve obtained when the specimen was heated from room temperature at a rate of 10 ° C./min using a TMA measuring apparatus, it was determined that the specimen had a glass transition point (Tg2) (° C.) and two points of 50 ° C. and 150 ° C. Thermal expansion coefficient (α2) (× 10 ⁻⁷ / ° C.) based on the above.

As is clear from the results of Tables 1 to 7, in the sealing material of each example, the difference between the glass transition point and the lead glass alone was as low as 10 ° C. or less (particularly 5 ° C. or less). You can see that there is. This is thought to be due to the fact that no or little reaction between the lead glass and the lead titanate-based filler powder occurred.
On the other hand, in Comparative Example 1, the difference between the glass transition point and the glass alone was as high as 24 ° C. This is presumably because the glass and the filler reacted and the filler was incorporated into the glass, so that the glass transition point increased. In Comparative Example 2, the crystallization temperature was detected because the [PbO / Bi ₂ O ₃ ] ratio was not appropriate.

Examples 43 to 61
Except that no filler was used, a powdery sealing material (glass powder) was prepared by uniformly mixing the components in the same proportions as shown in Tables 9 to 11 except that no filler was used. .

Test example 2
The physical properties of the sealing materials obtained in Examples 43 to 61 were measured in the same manner as in Test Example 1. The reactivity of the sealing material with the solvent was also measured. The measuring method is as shown below. Tables 9 to 11 show these measurement results.

(7) Reactivity with Solvent 2-3 g of each glass powder was placed in a plastic container, and about 1 g of a solvent (acetone or water) was added and mixed. After the obtained mixture was applied on an alumina substrate with a brush and dried, the alumina substrate was baked at 370 ° C. for 15 minutes in the atmosphere. The presence or absence of crystals was confirmed by performing X-ray diffraction analysis on the obtained fired body (coating film).

As is clear from the results of Tables 9 to 11, in particular, in the sealing material of the present invention containing 1.5 to 3% by weight (furthermore, 1.5 to 1.8% by weight) of SiO ₂ , It can be seen that crystallization is effectively suppressed during firing even in the presence.

The sealing material of the present invention can more reliably seal even at a relatively low temperature of 380 ° C. or less. In addition, the filler and the glass do not react even after repeated firing, and no crystal is precipitated, and the fluidity during softening of the glass is excellent, so that the sealing effect has excellent mechanical strength and durability. Can be obtained. Therefore, it can be used as a sealing material suitable for sealing electronic components such as an IC package and a crystal resonator package.

Claims (9)

A sealing material containing a lead glass powder and a lead titanate-based filler powder,
(1) The lead glass is
1) PbO: 69.0 to 80.0% by weight,
_{2) Bi 2 O 3: 7.3} ~12.5 wt%,
₃₎ B ₂ O 3: 3.5~11.5 wt%,
4) ZnO: 1.7-8.2% by weight,
₅₎ SiO 2: 0~3.5% by weight,
6) CuO: 0 to 4.0% by weight;
7) F: 1.3-5.0% by weight and
8) V, Te, Sb and Fe contain 0.1% by weight or less in total as a glass component;
(2) the weight ratio of [PbO / _Bi 2 _{O 3]} in the lead glass is from 5.6 to 25.5,
A low-temperature sealing material, characterized in that: 1) PbO: 69.0 to 80.0% by weight, 2) Bi ₂ O ₃ : 7.6 to 12.5% by weight, 3) B ₂ O ₃ : 3.5 to 11.5% by weight, 4) ZnO: 1.7 to 8.2% by weight, 5) SiO ₂ : 1.5 to 3.0% by weight, 6) CuO: 0 to 4.0% by weight, 7) F: 1.3 to 5.0% by weight and 8) V, Te, Sb and Fe are 0 in total. 0.1% by weight or less as a glass component,
(2) [PbO / Bi in the lead glass ₂ O ₃ Is 5.6 to 25.5,
The low-temperature sealing material according to claim 1. The low-temperature sealing material according to claim 1, wherein the lead glass has a glass transition point of 200 to 260 ° C. 4. The lead glass powder further contains 0.01 to 1 wt% of at least one of the TiO ₂ and ZrO ₂ in total as the glass component, the low-temperature sealing material according to any one of claims 1 to 3. The lead glass powder and the lead titanate-based filler powder in a total of 100 parts by weight, the lead glass powder 90 to 60 parts by weight and the lead titanate-based filler powder contains 10 to 40 parts by weight, according to any one of claims 1 to 4 Low temperature sealing material. Oxide composition in the lead titanate-based filler, PbO on an oxide basis: 60.0 to 70.0 _wt%, TiO 2: 15.0-25.0 wt%, CaO: 0 to 5.0 wt%, Fe ₂ O _3: 0~5 wt% and _Nb 2 _O 3: _0~10.0 containing wt%, low melting point sealing material according to any one of claims 1 to 5. The low-temperature sealing material according to claim 1, further comprising at least one of a solvent and an organic binder, and having a paste-like form. The low-temperature sealing material according to claim 7, wherein no crystal is precipitated when fired at 370 ° C in the atmosphere. A package for housing a semiconductor element, comprising the low-temperature sealing material according to claim 1.