JPS60137848A - Glass composition for sintered silicon carbide - Google Patents

Abstract

PURPOSE:To provide the titled composition composed of PbO, ZnO, B2O3, silica, alumina and P2O5 at specific ratios, and having high adhesivity to a sintered material composed mainly of SiC and having excellent hermetic sealing property. CONSTITUTION:A glass composition having a softening point of 500-570 deg.C and a thermal expansion coefficient of 40-60X10<-7>/ deg.C is prepared by mixing 10- 50(wt)% PbO, 20-50% ZnO, <=40% B2O3, <=30% silica, and if necessary, <=10% alumina and/or <=5% P2O5, heating and melting the mixture, and quenching and pulverizing the molten composition. The glass composition is mixed with an organic binder (e.g. a terpineol solution of nitrocellulose) in the form of paste, applied to a thick-film resistor formed on the surface of a sintered substrate composed mainly of SiC, and baked to obtain a coating film of the glass composition.

Description

[Detailed Description of the Invention] [Detailed Description of the Invention] The present invention relates to a novel glass composition for a silicon carbide sintered body, and particularly to a thick film resistor formed on the surface of a substrate made of a silicon carbide sintered body. The present invention relates to electrical devices such as a hybrid integrated circuit device having a coating on its body surface and a ceramic package semiconductor device having an 11-piece semiconductor device sealed with ceramics.

[Background of the invention]

A single film hybrid Toshiba circuit is generally constructed by bonding semiconductor elements and other electronic components to elements such as conductors and resistors formed on a ceramic substrate by screen printing and firing techniques. Conventionally, alumina has been mainly used for the ceramic substrate. In response, electrically insulating silicon carbide ceramics, which have thermal conductivity approximately 10 times greater than alumina and are expected to be superior as substrates for capacitive circuits, have been developed and are being studied as substrates.

Generally, lead borosilicate glass known from Japanese Patent Application Laid-open No. 49-61216 is used as a glass applied to oxide ceramics, and it is thought that the glass melts and reacts with ceramics to bond them. There is. However, this glass bath melt has a small coefficient of thermal expansion (40X
10-7/C) An object such as a silicon carbide sintered body that has 41 and has little reaction between oxides may cause cracks to occur due to differences in thermal expansion, or reduce oxides contained in glass (e.g. PbO* BizOs, cao)
A reaction gas (CO or C
The inventors have discovered that the generation of 0z) causes a number of bubbles, resulting in poor bonding.

[Purpose of the invention]

An object of the present invention is to provide a glass composition that has good adhesion to a substrate made of a sintered body containing silicon carbide as a main component and has excellent airtightness. In particular, the object of the present invention is to
Thermal conductivity of 5m/Crr1・Wholesale-C or higher and 4 at room temperature
It has a coefficient of thermal expansion of less than
An object of the present invention is to provide an electrical device made of an 8iC ceramic sintered body having an electrical insulation property of Ω·on or more, which has good adhesion to a substrate and has excellent airtightness.

[Summary of the invention]

The present invention relates to a glass composition formed on the surface of a substrate made of a sintered body mainly composed of silicon carbide, the glass composition having a composition before melting of 10 lead oxide (PbO) by weight.
~35%, zinc oxide (Z'n0) 20~50%, and one or more of boron oxide (30% or less) and silica (30% or less).

In other words, a glass with a thermal expansion coefficient close to that of the silicon carbide sintered body that does not foam, crack, and has good adhesion to the sintered body whose main component is silicon carbide is required. , and gases (e.g. CO) generated by decomposition of the silicon carbide sintered body during firing.

In order to suppress the generation of CO2) as much as possible, we focused on the following three points: the glass must have a low melting point, and the glass itself must not generate gas. Conventionally,
PbO is an oxide that is effective in lowering the melting point of glass, and is used as the main component of low-melting glass. However, PbO glass lowers the melting point but has a thermal expansion coefficient of only 100%, and also has the problem of generating reaction scum with the silicon carbide sintered body when melted. Therefore, the above problem was solved by adding zinc oxide, which has a small coefficient of thermal expansion and has the function of suppressing reactive gases, and by finding a range of its composition.

The blending ratio of the glass composition is Pb010-501q:5
6, Z n 020-50% by weight and B 20 s≦3
0% by weight and 5ift≦30〉1t'l: If the content of PbO is greater than 50%, %ml or cracks will occur at the interface of the silicon carbide sintered body. If ZIIO is less than 20 inches, the coefficient of thermal expansion will increase, causing cracks in the glass and impairing the adhesion. PbO is particularly preferably 10 to 35 inches. Further, the above-mentioned glass components KAl,xOx and P2O5 may be added, and these additions are advantageous in terms of bondability to silicon carbide/sintered body traps, and the amount of addition is greater than A40.
3≦10 and P205≦5 are good. Furthermore, the incorporation of active oxides and compounds deteriorates the adhesion to silicon carbide. Especially Cab.

T i O, Cu'Q, Cu P, BP, Fe2
O3 is bad.

In particular, PbO25~35q, Zn025~45
%, 8 r 0215-25% and 820210-20
% is preferred.

In addition, in the present invention, as the organic binder, polymers that easily decompose and completely volatilize under firing conditions, such as cellulose derivatives such as ethylcellulose and nitrocellulose, and polymers of methacrylic acid ester and acrylic acid ester, are used. used. Furthermore, in the present invention, an organic solvent is used that can dissolve the binder and wet the glass powder well, and examples thereof include glycol ethers, esters, ketones, and terpineol. The blending amount of the organic binder and solvent is selected depending on the workability required in the process of printing or forming the paste and the subsequent firing. The amount of 100 parts by weight of terpineol may be used.The blending method is not limited at all, and the organic binding solution can be added to the glass powder and kneaded to form a uniform dispersion using a conventional device.

The glass composition of the present invention has a coefficient of thermal expansion of 40 to 60X1
0-'/C, which is close to 40X10-'/C of a sintered body containing silicon carbide as a main component, and therefore the glass does not crack after firing.

Further, this glass composition is applied to a silicon carbide sintered body and fired by known techniques. Since the softening temperature of this glass composition is 500 to 570C, the firing temperature is preferably 570 to 620C, at which it melts and softens, and is preferably carried out in compressed air. It can be applied by a brushing screen printing method or the like.

The sintered body containing silicon carbide as a main component according to the present invention particularly contains 0.1 to 3.5% by weight of Be or +38 compound.
Contains a theoretical density of 90 cm or higher, particularly 95 cm or higher, and has a density of 0.25 cal/cm-3eC1 at room temperature.
・C or higher, especially 0.4 cal/crn ・Be
Thermal conductivity of Ce C or higher, 107Ω'm or higher, especially 1
It is preferable to have an electrical resistivity of 0I0Ω”on or more.

In the present invention, a resistor with a thickness of 11q is formed on the surface of a substrate made of a sintered body mainly composed of silicon carbide, and the surface of the low antibody is covered with a glass film. The composition before dissolution is by weight, Pb010~5 (1%,
Zn020~50%, 820840% or less and 5iC
A hybrid integrated circuit device characterized by containing at least one type of h30% or less. Conventional P b 0-11203-8 i 02 glass is used for the thick film resistor according to the present invention.

Honkenmei rJ, V4L mounted on a substrate whose main component is silicon carbide
In the case where the semi-enclosed body is sealed with a sealing body made of a ceramic sintered body, the composition of the base body and the sealing body before melting is Pb010~'50% by weight, Z
A ceramic package semiconductor device characterized in that the ceramic package semiconductor device is bonded by glass containing n 020 to 50% and 1.1) 11 or more of B20840q or less and 5i0230 or less.

Alumina, silicon carbide, mullite/sintered body, etc. are used for the sealing body. Silicon carbide having the same composition as described above can be used. This semiconductor device is provided with a lead frame, and this lead frame is generally made of Farnico and is bonded with a similar glass.

Historically, the base body is provided with metal radiation fins, and is made of At.

[Embodiments of the invention]

(Example 1) Raw material lead powder having a glass composition shown in Table 1 was weighed and mixed using a V-type mixer. The mixed lead powder was placed in an aluminum crucible, heated to 1200 tZ' in an electric heating furnace, and melted.
The melt was poured into water and rapidly cooled to produce a four-shaped glass.The glass was thoroughly ground in a ball mill made entirely of agate to form a powder.

To the glass powder, a solution of terpineol with a concentration of 6 and ethyl cellulose as an organic binder was added to 100 parts by weight of the glass powder, and 18II1. Add and knead at the proportion of the line part,
A slurry paste was prepared.

Next, on a substrate made of a silicon carbide sintered body containing beryllia (He O), which had been previously degreased and washed, a glass paste (1) was screen printed, and then fired in a large-scale oven. The firing temperature is 450C.

500C, 570C, 600G, 620 (1", 650
G, 700C, and 750C for 15 minutes.

The sample prepared and immersed in this manner was tested as follows to determine the adhesion status between the glass and the substrate.

The appearance of the glass was observed using a magnifying microscope, and the appearance of bubbles and the photogenic state of cracks were all investigated.The glass part was scratched with tweezers to evaluate the strength of the four-trap bond.

The SiC sintered body according to the present invention has a theoretical density of 7.1 f, which is about 100 yen, and has a density of 3.7X10-'/C,0,(
3”' /CTn ” Thermal conductivity of fil II C,
It had an electric abrasive resistance of 1013 Ω"an.

The evaluation results are shown on the second coat. [Bubble] in the table indicates the generation of bubbles, and those with bubbles are indicated by an X mark, and those without bubbles are indicated by an O mark. [Discount] indicates the occurrence of cracks, and those with cracks are indicated by an X mark, and those without cracks are indicated by an ○ mark. [Pull] is from the situation where it was scratched with a bottle set? Those with extremely poor A adhesion are marked with an x mark, those with rather good adhesion are marked with a Δ mark, and those with good adhesion properties are marked with an ○ mark. As shown in the table, the glass compositions A11 to A13 of the present invention did not have a single bubble and had excellent adhesion.

(Example 2) FIG. 1 is a sectional view of a hybrid integrated circuit device after forming a thick film resistor on a substrate made of a SiC sintered body used in Example 1.

Using the glass composition of /K 11 used in implementation t+r+i, Ag
-After printing a PD-based conductor paste and firing it in the atmosphere at 700C to form a conductor 9, glass of the same composition is used to connect it to the conductor, and the sheet resistance 5 is set to Ω/5.
Print the tuo□ type resistance paste and expose it to the atmosphere at 6
The thick film resistor 5 was formed by firing at 20 t:'. A glass paste having the composition and properties shown in Table 1 was printed thereon and fired in the atmosphere at a temperature of 590C to form a glass coating. The glass was formed in a semi-molten state and was free of pores.

Results of calculating the rate of change in resistance due to low antibody glass coating +
The resistance change is small at 0.01 to +0.02%. Further, FIG. 2 shows the change in resistance value over time when the thick film circuit formed body was left at 150 C for 1000 hours. The rate of change in resistance value is extremely small.

(Embodiment 3) FIG. 3 is a sectional view of a ceramic span cage semiconductor device which is an example of the electrical device of the present invention.

In the device of the present invention, an 8i element 4 is bonded with gold to a substrate 1 made of the silicon carbide sintered body used in Example 1, and a bonding wire 6 (Au, Ag , Pd, A/, wire, etc.), and is sealed with the All-all sealing glass 11 shown in Example 1 using a ceramic cap 12. Furthermore, At fins 16 are bonded to the SiC sintered body 1 with silicone rubber 7. It was confirmed that the device of the present invention has extremely high heat dissipation properties, and that it is possible to increase the density of Si elements.

〔Effect of the invention〕

According to the present invention, a substrate made of a sintered body mainly composed of silicon carbide can be coated and bonded with high adhesive strength without generation of bubbles or cracks, and a hybrid integrated circuit device and a ceramic span cage semiconductor device can be coated and bonded. A pickled effect is exhibited.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hybrid integrated circuit device which is an example of the electrical device of the present invention, FIG. 2 is a diagram showing the relationship between resistance change rate and standing time, and FIG. 1 is a cross-sectional view of a ceramic packaged semiconductor device, which is an example of a typical device. DESCRIPTION OF SYMBOLS 1... SiC sintered body base, 2.16... Heat radiation fin, 3... Solder, 4, 7... Si element, 5... Thick film resistor, 6... Bonding wire , 8... Heat sink, 9... Thick film conductor, 10... Glass coating, 11
...Sealing glass, 12...Cap, 13...Lead frame, 14...AUl 15...Silicone rubber. Agent Patent Attorney Akio Takahashi Figure 1 (Kuu Cb)

Claims (1)

[Scope of Claims] 1. A glass composition formed on the surface of a substrate made of a sintered body mainly composed of silicon carbide, whose composition before popularization is 10 to 50% by weight of lead oxide, 10% to 50% of lead oxide, Lead waste 20-50%
A glass composition for a silicon carbide sintered body, characterized in that it contains at least 40% of boron oxide and 30% or less of silica. 2. The glass composition for a silicon carbide sintered body according to claim 1, wherein the glass composition is a paste containing an organic binder. 3. The silicon carbide sintered body contains Be or a Be compound.
The glass composition for a silicon carbide sintered body according to claim 1 or 2, which is an electrically insulating sintered body containing 0.1 to 3.5% by weight of e. 4. A group consisting of a sintered body whose main component is silicon carbide. A glass composition formed on the body surface whose composition before melting is 10 to 50 inches of lead oxide and 20 to 20 inches of zinc oxide.
50%, less than 40% boron oxide, 30% silica, one or more of the following, less than 10% alumina, and 5% phosphorus pentoxide.
A glass composition for a silicon carbide sintered body, characterized by containing one or more of the following: 5. In the case where a thick film resistor is formed on the surface of a substrate made of a sintered body mainly composed of silicon carbide, and the surface of the resistor is covered with a glass film, the glass film is The composition is 10-50% lead oxide, 2% zinc oxide.
0-50%, boron oxide 40% or less and silica 30%
An electrical device comprising one or more of the following: 6. In a device in which a semiconductor element placed on a base made of a sintered body mainly composed of silicon carbide is sealed with a sealing body made of a ceramic sintered body, the base body and the sealing body are Composition before melting is 10-50% lead oxide by weight,
1. A toxic gas device, characterized in that it is joined by glass containing 20 to 50% zinc oxide and one or more of 40% or less boron oxide and 30% or less silica.