JP2011184216A - Glass for sealing semiconductor, mantle tube for sealing semiconductor and semiconductor electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide glass for sealing a semiconductor, the glass having high heat resistance and low temperature sealing property even when the glass does not contain a harmful component such as PbO. <P>SOLUTION: The sealing glass has a strain point of 650°C or higher and shows a temperature of lower than 1,200°C at a viscosity of 10<SP>4</SP>dPa s. Specifically, the glass has a glass composition of, by mass%, 30 to 50% of SiO<SB>2</SB>, 0 to 10% of Al<SB>2</SB>O<SB>3</SB>, 0 to 20% of CaO+SO (sum amount of CaO and SrO), 15 to 35% of BaO, 0 to 25% of ZrO<SB>2</SB>+TiO<SB>2</SB>(sum amount of ZrO<SB>2</SB>and TiO<SB>2</SB>), and 0 to 20% of La<SB>2</SB>O<SB>3</SB>+Nb<SB>2</SB>O<SB>5</SB>(sum amount of La<SB>2</SB>O<SB>3</SB>and Nb<SB>2</SB>O<SB>5</SB>). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a semiconductor sealing glass, a semiconductor sealing outer tube, and a semiconductor electronic component, and in particular, a semiconductor sealing glass for sealing a semiconductor element used at a high temperature, for example, a thermistor chip, and a semiconductor sealing. The present invention relates to an outer tube and a semiconductor electronic component.

  The thermistor is a kind of semiconductor electronic component, and is a semiconductor electronic component that can measure the temperature by using a characteristic (negative or positive temperature coefficient) that changes the electrical resistance value of the semiconductor element due to a temperature rise.

  As shown in FIG. 1, a semiconductor electronic component (thermistor) 10 called a bead-type thermistor or a glass thermistor includes a semiconductor element (thermistor chip) 1, a metal wire (lead wire) 2, and a semiconductor sealing glass (thermistor sealed). The thermistor chip 1 and a part of the lead wire 2 are covered and sealed by the thermistor sealing glass 3. For this reason, it can be used even in a high-temperature oxidizing atmosphere. As the thermistor chip 1, an oxide-based material or a non-oxide-based material such as nitride, carbide, boride, or silicide is known. At present, oxide-based materials are widely used from the viewpoint of characteristics and price. Further, as the lead wire 2, a jumet wire (Ni—Fe alloy coated with Cu), a platinum wire, or the like is widely used.

Conventionally, as the thermistor sealing glass, PbO—SiO ₂ —B ₂ O ₃ —K ₂ O-based high lead-containing glass (for example, see Patent Document 1), alkali borosilicate glass (for example, Patent Documents 2, 3) Have been proposed).

  The thermistor sealing glass mainly requires the following characteristics. (1) To have a high volume resistance value in a combustion atmosphere at a normal maximum temperature (for example, 700 ° C. or higher), that is, to have high heat resistance so as not to affect the electric resistance characteristics of the thermistor chip, (2) Lead Capable of being sealed at a temperature lower than the heat resistance temperature of the wire or thermistor chip, that is, having a low temperature sealing property. The “ordinary maximum temperature” is the maximum temperature at which characteristics such as electric resistance characteristics hardly deteriorate even if the apparatus is used for a long time.

JP-A-8-67534 JP 2002-37641 A International Publication No. 2006/035882 Pamphlet

  In recent years, environmental pollution due to harmful components such as lead, cadmium and arsenic has been regarded as a problem, and it is required to remove these harmful components from industrial products. Therefore, although the thermistor sealing glass described in Patent Document 1 has a low-temperature sealing property, it contains a large amount of harmful component PbO, which may cause a problem of environmental pollution.

In addition, from the standpoint of environmental measures to reduce carbon dioxide and prevent acid rain, it is required to keep the heat source and the combustion system of the power generator in an optimal operating state in order to minimize the generation of CO ₂ and NO _X. ing. For this purpose, it is necessary to directly monitor and automatically manage the temperature of the combustion atmosphere. However, since the glass for thermistor sealing described in Patent Documents 1 and 2 has low heat resistance, it tends to soften and deform in a combustion atmosphere of 700 ° C. or higher, and in some cases 500 to 600 ° C. With the change, thermistor characteristics may be adversely affected.

  Furthermore, the thermistor sealing glass described in Patent Document 3 has high heat resistance, but has a high sealing temperature and does not have low-temperature sealing properties.

  As can be seen from the above description, the required characteristics (1) and (2) are difficult to achieve at the same time, and the conventional thermistor sealing glass does not satisfy the required characteristics (1) or (2).

  In view of the above circumstances, an object of the present invention is to create a glass for semiconductor encapsulation having high heat resistance and having low-temperature sealing properties even without containing harmful components such as PbO.

As a result of intensive studies, the present inventors have found that the above required characteristics (1) and (2) are satisfied by strictly regulating the viscosity characteristics (strain point, temperature at 10 ⁴ dPa · s) of the glass, The present invention is proposed. That is, the glass for semiconductor encapsulation of the present invention has a strain point of 650 ° C. or higher and a temperature at 10 ⁴ dPa · s of less than 1200 ° C.

  The glass for semiconductor encapsulation of the present invention has a strain point of 650 ° C. or higher, preferably 670 ° C. or higher, preferably 680 ° C. or higher, more preferably 690 ° C. or higher, and further preferably 700 ° C. or higher. The strain point is a characteristic that serves as an index of heat resistance. The higher the strain point, the better the heat resistance. If the strain point is regulated to 650 ° C. or higher, the required characteristic (1) can be satisfied, and the normal maximum temperature of a semiconductor electronic component such as a thermistor tends to be 700 ° C. or higher. The heat resistance of the semiconductor electronic component such as the thermistor depends on the heat resistance of the semiconductor sealing glass.

The glass for semiconductor encapsulation of the present invention has a temperature at 10 ⁴ dPa · s of less than 1200 ° C., preferably 1130 ° C. or less, more preferably 1090 ° C. or less, and further preferably 1060 ° C. or less. The temperature at 10 ⁴ dPa · s corresponds to the sealing temperature, and the lower the temperature, the better the low-temperature sealing property. If the temperature at 10 ⁴ dPa · s is regulated to less than 1200 ° C., the lead wire (for example, platinum wire, Ni-plated dumet wire, Fe—Ni alloy wire, etc.) can be sealed at a low temperature below the heat resistance temperature. Furthermore, the lifetime of the sealing device can be extended.

Second, the glass for semiconductor encapsulation of the present invention is characterized in that the temperature at 10 ¹⁰ dPa · s is 700 ° C. or higher (preferably 750 ° C. or higher, particularly 800 ° C. or higher). The temperature at 10 ¹⁰ dPa · s generally corresponds to the temperature at which glass is deformed for the first time when external force is applied, and the glass corners are slightly softened and deformed by holding for a long time, but lead wires and thermistors This temperature does not react with the chip. If the temperature at 10 ¹⁰ dPa · s is regulated to 700 ° C. or higher, the maximum normal temperature of semiconductor electronic components such as thermistors tends to be 700 ° C. or higher.

  Third, the glass for semiconductor encapsulation of the present invention has a softening point of 800 ° C. or higher (preferably 840 ° C. or higher, particularly 870 ° C. or higher). The softening point is generally a temperature at which the glass is slightly softened and deformed.If the glass is held for a short time, the corners of the glass remain slightly softened and deformed. This is a temperature that may adversely affect the thermistor characteristics in accordance with the change of. Therefore, the softening point corresponds to the maximum use temperature of a semiconductor electronic component such as a thermistor, that is, the maximum temperature that can be used for a short time. If the softening point is regulated to 800 ° C or higher, the maximum use temperature tends to be 850 ° C or higher.

The strain point, softening point, temperature at 10 ^2.5 dPa · s, temperature at 10 ⁴ dPa · s, and temperature at 10 ¹⁰ dPa · s can be determined as follows. Strain point by fiber method to first conform to ASTM C338, the softening point is measured, further calculates the ^temperature, the temperature at 10 4 dPa · s at ¹⁰ 2.5 dPa · s of platinum ball pulling method. Next, these temperatures and viscosity values are applied to the Fullcher equation to calculate the temperature at 10 ¹⁰ dPa · s.

Fourth, the glass for semiconductor encapsulation of the present invention has a glass composition, in _{mass%, SiO 2 30~50%, Al} 2 O 3 0~10%, CaO + SrO (CaO, the total amount of SrO) 0 to 20 %, BaO 15-35%, ZrO ₂ + TiO ₂ (total amount of ZrO ₂ , TiO ₂ ) 0-25%, La ₂ O ₃ + Nb ₂ O ₅ (total amount of La ₂ O ₃ , Nb ₂ O ₅ ) 0 It is characterized by containing ~ 20%.

  Fifth, the glass for semiconductor encapsulation of the present invention is characterized by containing substantially no PbO. Here, “substantially does not contain PbO” refers to a case where the content of PbO in the glass composition is 1000 ppm or less.

Sixth, the glass for semiconductor encapsulation of the present invention has a thermal expansion coefficient in a temperature range of 30 to 380 ° C. of 60 to 100 × 10 ⁻⁷ / ° C. Here, “thermal expansion coefficient in the temperature range of 30 to 380 ° C.” refers to an average value measured with a self-described differential thermal dilatometer using a cylindrical measurement sample having a diameter of about 3 mm and a length of about 50 mm.

Seventh, the glass for semiconductor encapsulation of the present invention is characterized by having a liquidus viscosity of 10 ^3.5 dPa · s or more. The liquid phase viscosity can be measured as follows. The glass powder pulverized to a particle size of 300 to 500 μm was placed in a boat-shaped platinum container and held in a temperature gradient furnace for 24 hours. Next, after removing the platinum container from the temperature gradient furnace, the surface of the glass is observed with a microscope to calculate the temperature at which the initial phase of the crystal is precipitated, and this is used as the liquidus temperature. Finally, the viscosity of the glass at the liquidus temperature, that is, the liquidus viscosity is calculated by the platinum ball pulling method.

Eighth, the glass for semiconductor encapsulation of the present invention has a volume resistance value (Ωcm) at 500 ° C. of 5 or more in Log ₁₀ ρ. Here, “volume resistance value log ₁₀ ρ at 500 ° C.” refers to a value measured by a method based on ASTM C-657.

  Ninthly, the outer tube for semiconductor sealing of the present invention is made of the above-mentioned glass for semiconductor sealing.

  Tenth, a semiconductor electronic component of the present invention is a semiconductor electronic component comprising a semiconductor element, a metal wire, and a semiconductor sealing outer tube that covers and seals a part of the metal wire. Is composed of the above-described outer tube for semiconductor sealing.

  Eleventhly, the semiconductor electronic component of the present invention is a semiconductor electronic component comprising a semiconductor element, a metal wire, and a semiconductor sealing envelope that covers and seals a part of the metal wire. The tube is made of the above-described outer tube for semiconductor sealing, and the semiconductor element is a high temperature type thermistor chip capable of measuring a temperature of 700 ° C. or higher.

It is explanatory drawing which shows the structure of a semiconductor electronic component (thermistor).

The glass for semiconductor encapsulation of the present invention has a glass composition of 30% by mass, SiO ₂ 30-50%, Al ₂ O ₃ 0-10%, CaO + SrO 0-25%, BaO 15-35%, ZrO ₂ + TiO _{2. 0%} to _25%, preferably contains _{2 O 3 + Nb 2 O 5} 0~20% La. The reason for limiting the content of each component as described above is as follows.

SiO ₂ is a glass network former, a component that increases the strain point, and a component that increases chemical durability, particularly acid resistance, and its content is 30 to 50%, preferably 31 to 45%. More preferably, it is 35 to 40%. When the content of SiO ₂ is less than 30%, chemical durability tends to be lowered. On the other hand, when the content of SiO ₂ is more than 50%, the high temperature viscosity becomes too high, and it becomes difficult to match the thermal expansion coefficient of the lead wire or the semiconductor element. If the content of SiO ₂ is more than 50%, the liquidus viscosity tends to decrease. If the content of SiO ₂ is 35% or more, the strain point tends to be 650 ° C. or more.

Al ₂ O ₃ is a component that increases the strain point and is a component that increases chemical durability, particularly acid resistance, and its content is 0 to 10%, preferably 0.5 to 5%. When the content of Al ₂ O ₃ is more than 10% tends viscosity at high temperature increases, the meltability tends to decrease. Incidentally, if the content of Al ₂ O ₃ to 5% or less, making the outer tube, it becomes easy to prevent a situation in which the glass is devitrified.

  The content of CaO + SrO is 0 to 25%, preferably 1 to 20%, more preferably 5 to 15%. If the content of CaO + SrO is more than 25%, the liquidus temperature tends to decrease (or the liquidus viscosity tends to increase), making it difficult to produce a semiconductor sealing outer tube. In addition, if the content of CaO + SrO is set to 17% or less, it becomes easy to prevent a situation where the chemical durability is lowered.

CaO is a component that lowers the high-temperature viscosity (particularly the temperature at 10 ⁴ dPa · s) to improve the meltability, moldability, and low-temperature sealing properties, and increase the strain point, and its content is 0 to 10%. , Preferably 0 to 8%. If the content of CaO is more than 10%, the liquidus temperature tends to decrease (or the liquidus viscosity tends to increase), making it difficult to produce a semiconductor sealing outer tube. In addition, if the content of CaO is 8% or less, it is easy to prevent a situation where the chemical durability is lowered.

SrO is a component that lowers the high-temperature viscosity (particularly the temperature at 10 ⁴ dPa · s) to increase the meltability, moldability, and low-temperature sealing properties, and increase the strain point, and its content is 0 to 10%. , Preferably 0 to 8%. If the SrO content is more than 10%, the liquidus temperature tends to decrease (or the liquidus viscosity tends to increase), making it difficult to produce a semiconductor sealing outer tube. If the SrO content is 8% or less, it is easy to prevent a situation where the chemical durability is lowered.

BaO significantly lowers the high temperature viscosity (especially the temperature at 10 ⁴ dPa · s), improves the meltability, moldability, and low temperature sealing properties, and lowers the devitrification resistance compared to CaO and SrO. Although it is a difficult component, it is also a component that lowers the strain point, and its content is 15 to 35%, preferably 20 to 32%, more preferably 25 to 30%. When the content of BaO is less than 15%, the temperature at 10 ⁴ dPa · s is likely to rise, so that the low-temperature sealing property is lowered, and the dimensional accuracy of the outer tube for semiconductor sealing is likely to be lowered. On the other hand, when the content of BaO is more than 35%, the glass tends to be devitrified, so that the moldability is lowered and the dimensional accuracy of the outer tube for semiconductor encapsulation is easily lowered. In addition, if the content of BaO is 30% or less, it becomes easy to prevent a decrease in strain point.

The content of ZrO ₂ + TiO ₂ is 0 to 25%, preferably 0.5 to 20%, more preferably 5 to 15%. If the content of ZrO ₂ + TiO ₂ is more than 25%, the glass tends to be devitrified, so that the liquidus temperature tends to be lowered. If the content of ZrO ₂ + TiO ₂ is 5% or more, the strain point tends to be 650 ° C. or more.

ZrO ₂ is a component that enhances heat resistance and chemical durability, and its content is 0 to 10%, preferably 0.1 to 8%, more preferably 1 to 5%. If the content of ZrO ₂ is more than 10%, the glass tends to be devitrified, so that the liquidus temperature tends to decrease. Incidentally, when the content of ZrO ₂ is more than 1%, the strain point tends to be higher 650 ° C..

TiO ₂ is a component that enhances chemical durability, and its content is 0 to 15%, preferably 3 to 12%, more preferably 5 to 12%. If the content of TiO ₂ is more than 15%, the glass tends to devitrify, and the liquidus temperature tends to decrease.

The content of La ₂ O ₃ + Nb ₂ O ₅ is 0 to 20%, preferably 1 to 18%, more preferably 5 to 15%. When the content of La ₂ O ₃ + Nb ₂ O ₅ is more than 20%, the high-temperature viscosity is likely to increase, so that the meltability, moldability, and low-temperature sealing property are likely to decrease.

La ₂ O ₃ is a component that enhances heat resistance, meltability, moldability, and low-temperature sealing properties, and its content is 0 to 15%, preferably 0.1 to 12%, more preferably 3 to 10%. It is. If the content of La ₂ O ₃ is more than 15%, the strain point tends to be less than 650 ° C. If the content of La ₂ O ₃ is 3% or more, the liquidus temperature tends to decrease (or the liquidus viscosity tends to increase), and it becomes easy to produce a semiconductor sealing outer tube.

Nb ₂ O ₅ is a component that significantly lowers the high-temperature viscosity (particularly the temperature at 10 ⁴ dPa · s) and improves the meltability, moldability, and low-temperature sealability, and its content is 0 to 15%. Preferably it is 0.1 to 12%, More preferably, it is 3 to 10%. When the content of Nb ₂ O ₅ is more than 15%, the high-temperature viscosity is likely to increase, so that the meltability, moldability, and low-temperature sealing properties are likely to be lowered.

  In addition to the above components, the following components can be added.

  MgO is a component that increases the strain point and lowers the high-temperature viscosity, and its content is preferably 0 to 10%, particularly preferably 0 to 8%. If the content of MgO is more than 10%, the liquidus temperature tends to decrease (or the liquidus viscosity tends to increase), making it difficult to produce a semiconductor sealing outer tube. In addition, if the content of MgO is 8% or less, chemical durability is easily improved.

ZnO is a component that lowers the high-temperature viscosity (particularly the temperature at 10 ⁴ dPa · s), and its content is preferably 0 to 20%, 0 to 15%, particularly preferably 0 to 10%. When there is more content of ZnO than 20%, it will become easy to devitrify glass. If the ZnO content is 15% or less, the strain point tends to be 650 ° C. or more, and if the ZnO content is 5% or less, the temperature at 10 ¹⁰ dPa · s tends to be 700 ° C. or more. .

Li ₂ O is a component that increases the coefficient of thermal expansion and is a component that decreases high-temperature viscosity, but it is a component that significantly decreases chemical durability and electrical insulation, and its content is 0 to 5%. In particular, it is preferable that it is not substantially contained, that is, less than 0.1%.

Na ₂ O is a component that increases the coefficient of thermal expansion and a component that decreases the high-temperature viscosity, and its content is preferably 0 to 8%, particularly preferably 0 to 4%. When the content of Na ₂ O is more than 8%, the strain point tends to be 650 ° C. or higher. Note that if is less than 4% content of Na ₂ O, the volume resistivity at 500 ℃ (Ω · cm) tends to be 5 or more in _{Log 10} [rho.

K ₂ O is a component that increases the coefficient of thermal expansion, and is inferior to Na ₂ O, but is a component that decreases high-temperature viscosity. Further, compared with Na ₂ O, the decrease in volume resistance is small. It is a component, and its content is preferably 0 to 18%, particularly preferably 0 to 14%. If the content of K ₂ O is more than 18%, the strain point tends to be less than 650 ° C. Incidentally, the content of K 2 _O be below 14%, it is possible to avoid a significant reduction in chemical durability.

B ₂ O ₃ is a component that lowers the high temperature viscosity and is a component that increases the volume resistance value at 500 ° C., and its content is preferably 0 to 20%, 0 to 10%, particularly preferably 0 to 5%. If the content of B ₂ O ₃ is more than 20%, the strain point tends to be less than 650 ° C., and the glass tends to devitrify. Incidentally, if the content of B ₂ O ₃ 5% or less, in a high-temperature acid atmosphere such as exhaust gas environment, easily prevent the glass is deformed or eroded.

WO ₃ and Ta ₂ O ₅ are components that increase the strain point and lower the high-temperature viscosity, and their content is preferably 0 to 5%. If the contents of WO ₃ and Ta ₂ O ₅ are each greater than 5%, the batch cost tends to increase.

P ₂ O ₅ is a component that suppresses devitrification, and its content is preferably 0 to 3%, particularly preferably 0.01 to 1%. If the content of P ₂ O ₅ is more than 3%, the glass is phase-separated at the time of sealing, and is likely to become opaque. As a result, it becomes difficult to find defects when inspecting semiconductor electronic components. The acid resistance tends to decrease.

In addition to the above, SnO ₂ , SO ₃ , Sb ₂ O ₃ , F, Cl, etc. may be added in an amount of 3% or less for the purpose of adjusting high temperature viscosity, improving chemical durability, improving clarity, etc. it can. Note that As ₂ O ₃ also has a good clarification effect, but from the environmental viewpoint, it is preferably not contained, that is, less than 0.1%. As described above, it is preferable that PbO is not substantially contained from the environmental viewpoint.

In the case of the thermistor, when the amount of Fe ^{2+ in} the glass increases, the glass easily absorbs infrared rays, and it becomes difficult to accurately measure the temperature. For this reason, the content of Fe ₂ O ₃ is preferably 2% or less, and the mass ratio Fe ²⁺ / total Fe is preferably 0.4 or less. If the glass is melted in an oxidizing atmosphere, the mass ratio Fe ²⁺ / total Fe tends to be 0.4 or less.

In the glass for semiconductor encapsulation of the present invention, the thermal expansion coefficient in the temperature range of 30 to 380 ° C. is preferably 60 to 100 × 10 ⁻⁷ / ° C., particularly preferably 70 to 90 × 10 ⁻⁷ / ° C. This makes it easy to match the thermal expansion coefficient between the semiconductor element such as the thermistor chip and the lead wire, and therefore, when sealing the semiconductor element and the lead wire, undue stress hardly remains, and as a result Cracks are less likely to occur, and the outer tube for semiconductor sealing is less likely to be damaged.

In the glass for semiconductor encapsulation of the present invention, the liquid phase viscosity is preferably 10 ^3.5 dPa · s or more, particularly preferably 10 ^4.0 dPa · s or more. In this way, when the outer tube for semiconductor encapsulation is produced using the Danner method, the velo method, the downdraw method, the updraw method, or the like, the crystals are less likely to precipitate (i.e., less devitrified) during molding. If crystals are precipitated during molding, the viscosity of the glass in the vicinity thereof increases, and the dimensional accuracy of the outer tube for semiconductor encapsulation tends to be lowered.

In the glass for semiconductor encapsulation of the present invention, the volume resistance value (Ωcm) at 500 ° C. is preferably 5 or more in Log ₁₀ ρ. This makes it difficult to adversely affect the electrical resistance characteristics of semiconductor elements such as thermistor chips. In other words, if the volume resistance value (Ωcm) at 500 ° C. is less than 5 at Log ₁₀ ρ, a slight amount of electricity flows between the lead wires at a location where there is no semiconductor element such as a thermistor chip, as if parallel to the semiconductor element. As a result, a circuit having a resistor is produced, which may change the characteristics of the semiconductor electronic component.

In the glass for semiconductor encapsulation of the present invention, the temperature at 10 ^2.5 dPa · s is preferably 1400 ° C. or lower. In this way, the melting temperature is likely to be lowered, so that the combustion energy at the time of melting is reduced, the life of the melting furnace is increased, and the melting efficiency is also improved.

  Next, a method for manufacturing a semiconductor sealing glass and a semiconductor sealing outer tube will be described.

  First, various glass raw materials are prepared and mixed. The glass raw material usually contains minerals and impurities composed of a plurality of components. In such a case, the glass raw material may be formulated so as to have a desired glass composition in consideration of the component analysis value of the glass raw material. Subsequently, various glass raw materials are mixed with a mixer such as a V mixer, a rocking mixer, and a mixer equipped with stirring blades to obtain input raw materials.

Next, the input raw material is charged into a melting furnace to obtain molten glass. The melting furnace has a melting tank for obtaining molten glass, a clarification tank for removing bubbles in the molten glass, and a passage for lowering the clarified molten glass to a viscosity suitable for molding and guiding it to a molding apparatus. (Feeder) etc. The melting furnace is heated by a burner or electrical energization. The input material is usually melted in a melting tank at 1300 to 1600 ° C. and further enters a clarification tank at 1400 to 1600 ° C. In the process of moving the molten glass from the clarified rice cake through the feeder to the molding apparatus, the temperature is lowered and the viscosity becomes 10 ^3.5 to 10 ⁶ dPa · s suitable for molding.

  Next, the molten glass is formed into a tubular shape with a forming apparatus. As a forming method, a Danner method, a tongue method, a downdraw method, an updraw method, or the like can be applied.

  If the obtained glass tube is cut into a predetermined size, a semiconductor sealing outer tube can be produced. When cutting a glass tube, it is possible to cut the glass tube individually with a diamond wheel cutter. However, a method in which a large number of glass tubes are bound and then cut with a diamond wheel cutter is suitable for mass production.

  Next, a semiconductor element sealing method using a semiconductor sealing mantle will be described.

  First, a metal wire such as a jumet wire or a platinum wire is fixed so that the semiconductor element is sandwiched from both sides in the outer tube for semiconductor sealing. Next, the semiconductor element is sealed by heating to a temperature of 1400 ° C. or lower to soften and deform the semiconductor sealing outer tube. In this way, a semiconductor electronic component such as a thermistor can be manufactured.

  The semiconductor sealing glass of the present invention is used as a semiconductor sealing outer tube, for example, by pulverizing it into a powder and then pasting it, winding it around a semiconductor element, and firing it. Can also be sealed.

  Hereinafter, the present invention will be described in detail with reference to examples.

  Tables 1 and 2 show examples (sample Nos. 1 to 10) and comparative examples (sample No. 11) of the present invention.

  First, considering the yield and the amount of impurities so that the glass composition in the table is obtained, silica oxide, aluminum oxide, magnesium oxide, calcium carbonate, strontium nitrate, barium carbonate, sodium carbonate, potassium carbonate, potassium nitrate, zirconate silicate Niobium oxide, tungsten oxide, tantalum oxide, phosphate, sodium sulfate and the like were prepared and mixed thoroughly with a V-type mixer.

  Next, the prepared raw material was put into a melting furnace, melted at 1500 to 1600 ° C., and then formed into a tubular shape by a downdraw method. Next, the obtained glass tube was cut into an appropriate length (for example, 1 m). The inner diameter and thickness of the glass tube were controlled by the flow rate, air pressure, and pulling speed of the molten glass.

  Subsequently, using a bundling device, 1000 glass tubes are fixed integrally, and after immersing them in a resin bath so that resin such as pine yarn enters between each glass tube, it is taken out from the resin bath. The rod-shaped body was obtained by cooling. This rod-shaped body was cut into a length of 1 to 4 mm with a diamond cutter to obtain a pellet in which 1000 glass tubes were integrated. Then, the resin was removed, the glass tubes were unbound, washed and dried to obtain a semiconductor sealing outer tube having a predetermined length. In the case of a bead-type thermistor sealing outer tube, the semiconductor sealing outer tube thus obtained has an inner diameter of 0.6 to 2.1 mm and a wall thickness of 0.2 to 0.8 mm.

Moreover, after preparing a glass raw material so that it may become a glass composition shown in the table | surface and melting it at 1500-1600 degreeC using a platinum crucible for 6 hours, a molten glass is shape | molded and processed into a predetermined shape, and each evaluation It was used for. For each sample, density, thermal expansion coefficient α, strain point Ps, temperature at 10 ¹⁰ dPa · s, softening point Ts, temperature at 10 ⁴ dPa · s, temperature at 10 ^2.5 dPa · s, liquidus temperature TL, The liquidus viscosity log ₁₀ η _TL and the volume resistance value log ₁₀ ρ at 500 ° C. were measured. The results are shown in Tables 1 and 2.

  The density is a value measured by a well-known Archimedes method.

  The thermal expansion coefficient α is an average value of linear thermal expansion coefficients measured by a self-described differential thermal dilatometer in a temperature range of 30 to 380 ° C. as a cylindrical measurement sample having a diameter of about 3 mm and a length of about 50 mm.

The temperature at the strain point Ps, 10 ¹⁰ dPa · s, the softening point Ts, the temperature at 10 ⁴ dPa · s, and the temperature at 10 ^2.5 dPa · s were determined as follows. First, the strain point Ps and the softening point Ts were measured by a fiber method conforming to ASTM C338, and further, a temperature at 10 ⁴ dPa · s was calculated by a platinum ball pulling method, and a temperature at 10 ^2.5 dPa · s was calculated. Next, these temperature and viscosity values were applied to the Fullcher equation to calculate the temperature at 10 ¹⁰ dPa · s.

  The liquidus temperature TL was measured as follows. The glass powder pulverized to a particle size of 300 to 500 μm was placed in a boat-shaped platinum container and held in a temperature gradient furnace for 24 hours. Next, after removing the platinum container from the temperature gradient furnace, the surface of the glass was observed with a microscope, and the temperature at which the initial phase of the crystal was precipitated was calculated, and this was taken as the liquidus temperature.

The liquidus viscosity log ₁₀ η _TL is a value calculated from the above Fullcher equation and the liquidus temperature.

The volume resistance value log ₁₀ ρ at 500 ° C. is a value measured by a method based on ASTM C-657.

As apparent from Tables 1 and 2, Sample No. Nos. 1 to 10 have a strain point of 650 ° C. or higher, and the temperature at 10 ⁴ dPa · s is less than 1200 ° C., and thus are considered suitable as glass for semiconductor encapsulation. On the other hand, sample No. No. 11 was inferior in low-temperature sealing properties because the temperature at 10 ⁴ dPa · s was 1310 ° C. Sample No. 1-10, includes 10～250Ppm (mass) of _Fe 2 _{O 3} as an impurity, the value of the mass ratio ^{Fe 2+} / total Fe was 0.4 or less.

  As is clear from the above description, the glass for semiconductor encapsulation of the present invention has high heat resistance and low temperature sealing properties even if it does not contain harmful components such as PbO. It can be used suitably for a type thermistor, and can also be suitably used for a thermistor for temperature measurement such as an engine of an automobile or a boiler. Furthermore, the glass for semiconductor encapsulation of the present invention can be suitably used for semiconductor electronic components such as silicon diodes and light emitting diodes.

1 Semiconductor element (Thermistor chip)
2 Metal wire (lead wire)
3 Semiconductor sealing glass (Thermistor sealing glass)
10 Semiconductor Electronic Components (Thermistor)

Claims (11)

A glass for semiconductor encapsulation, having a strain point of 650 ° C. or higher and a temperature at 10 ⁴ dPa · s of less than 1200 ° C. 2. The glass for semiconductor encapsulation according to claim 1, wherein the temperature at 10 ¹⁰ dPa · s is 700 ° C. or higher.   The glass for semiconductor encapsulation according to claim 1, wherein the softening point is 800 ° C. or higher. As a glass composition, in _{mass%, SiO 2 30~50%, Al} 2 O 3 0~10%, CaO + SrO 0~25%, BaO 15~35%, ZrO 2 + TiO 2 0~25%, La 2 O 3 + Nb semiconductor sealing glass according to any one of claims 1 to 3, characterized in that it contains ₂ O _{5 0~20%.}   The glass for semiconductor encapsulation according to any one of claims 1 to 4, which does not substantially contain PbO. 6. The glass for semiconductor encapsulation according to claim 1, wherein a coefficient of thermal expansion in a temperature range of 30 to 380 ° C. is 60 to 100 × 10 ⁻⁷ / ° C. 6. Liquid phase viscosity is 10 < ^3.5 > dPa * s or more, Glass for semiconductor sealing in any one of Claims 1-6 characterized by the above-mentioned. 8. The glass for semiconductor encapsulation according to claim 1, wherein a volume resistance value (Ωcm) at 500 ° C. is 5 or more in Log ₁₀ ρ.   An outer tube for semiconductor sealing, which is made of the glass for semiconductor sealing according to claim 1. In a semiconductor electronic component comprising a semiconductor element, a metal wire, and a semiconductor sealing outer tube that covers and seals a part of the metal wire,
A semiconductor electronic component, wherein the semiconductor sealing outer tube comprises the semiconductor sealing outer tube according to claim 9. The semiconductor electronic component according to claim 10, wherein the semiconductor element is a high temperature type thermistor chip capable of measuring a temperature of 700 ° C. or higher.