JPH11349347A - Crystalline low melting point glass composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass composition without containing lead at all, capable of using for sealing, coating, conductor, formation of partition wall, etc. SOLUTION: This glass composition is obtained by adding 1-10,000 wt.ppm crystal powder of compound oxide containing phosphorus, tin and/or zinc to low-melting point glass powder comprising 0.1-45 mol.% SnO, 5-74.9 mol.% ZnO, 25-50 mol.% P2 O5 , 0-20 mol.% Al2 O3 , 0-20 mol.% B2 O3 , 0-40 mol.% Li2 O+ Na2 O+K2 O and 0-40 mol.% MgO+CaO+SrO+BaO.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystalline low-melting glass composition containing no lead component, and further uses the same to seal a cathode ray tube panel to a funnel, a plasma display panel (PDP) or a fluorescent display. Tube (VF
The present invention relates to a sealing composition, a composition for coating a substrate, a composition for forming a partition wall of PDP and VFD, etc. used for the sealing in D).

[0002]

Conventionally, the sealing of the cathode ray tube panel and the funnel, using a type of _{PbO-B 2 O 3 -ZnO-} SiO 2 based crystalline low melting glass disclosed in JP-B 36-17821, 30-4 at a temperature of 440-450 ° C
It was held for about 0 minutes and sealed. The panel and the funnel thus sealed are exhausted while being heated to 300 to 380 ° C. in order to obtain a high vacuum of 10 ⁻⁶ Torr or more.

[0003] Conventionally, low-melting glass has been used for sealing glass substrates in PDPs and VFDs.
Sealed at ℃. The panel sealed in this way is VF
In the case of D, the gas is exhausted while being heated to 250 to 380 ° C. in order to obtain a vacuum, and is sealed. In the case of PDP, exhaust is also performed while being heated to 250 to 380 ° C.
100 discharge gas such as neon, Ne-Xe, He-Xe
It is sealed so as to be ~ 500 Torr.

[0004]

A glass containing a lead component has been used as a conventional powdered glass for sealing. Recently, however, a glass containing no lead component has been demanded.

[0005] Further, in the conventional powdered glass for sealing, the coefficient of thermal expansion with the bulb or the glass substrate does not match, the panel is broken, the glass flows due to heating at the time of exhausting,
It was foaming or the seal was cracked.

[0006] Lead-free sealing glasses include R
A glass mainly composed of ₂ O (R: alkali metal), ZnO, and P ₂ O ₅ has been proposed (US Pat. No. 5,124,224).
No. 84), this glass has a problem that if it is sealed at a temperature lower than 450 ° C. for a short time, the fluidity is insufficient and it is difficult to sufficiently seal the glass. There is a problem.

[0007] A crystalline low-melting glass containing SnO, ZnO, and P ₂ O ₅ as main components has been proposed (US Pat. No. 5,246,890), but has insufficient fluidity.

Further, SnO, ZnO, P ₂ O ₅
US Pat. No. 5,281,560 also discloses a low-melting glass mainly composed of
This glass is an amorphous glass, and may be broken or deformed when the temperature is raised in an exhaust process.

[0009]

SUMMARY OF THE INVENTION The present invention provides a tin oxide substantially converted to SnO in the form of mol: 0.1 to 45.
%, ZnO: 5~74.9%, P 2 O 5: 25~50
%, Al ₂ O ₃ : 0 to 20%, B ₂ O ₃ : 0 to 20%,
_{Li 2 O + Na 2 O +} K 2 O: 0~40%, MgO + C
aO + SrO + BaO: 0-40%, a low-melting-point glass powder, a composite oxide crystal powder containing phosphorus, tin and / or zinc is added to the low-melting-point glass powder by 1 to 1%.
Provided is a crystalline low-melting glass composition to which 10,000 ppm by weight is added. The present glass composition comprises a cathode ray tube, P
Sealing of DP and VFD, for coating of substrate, PDP, VFD
It is suitable for use as a composition for forming barrier ribs or the like or a functional paste such as a conductive paste or a resistance paste.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The crystallinity of glass as referred to in the present specification,
Non-crystallinity is distinguished by whether or not there is an exothermic peak due to crystallization when differential thermal analysis (DTA) is performed. That is, the temperature is raised at a rate of 10 ° C./min, and the firing temperature (430 to 600
(C) for 2 hours, and those that generate an exothermic peak are made crystalline, and those that do not are made non-crystalline. Also,
That the glass has a low melting point means that the softening point is 600 ° C. or lower. Furthermore, the low expansion ceramic filler has an average thermal expansion coefficient of 7 at 50 to 300 ° C.
A ceramic filler of 0 × 10 ⁻⁷ / ° C. or less.

The composition range of the crystalline low melting glass composition of the present invention will be described. If the tin oxide content in terms of SnO is less than 0.1 mol% (hereinafter simply referred to as “%”), the softening point becomes too high, the fluidity is poor, and the strength and airtightness of the sealing portion may be impaired. is there. From this viewpoint, a more preferable content is 1% or more. If it exceeds 45%, vitrification becomes difficult. The more preferable content in this respect is 4
3% or less.

If ZnO is less than 5%, the coefficient of thermal expansion becomes large, and the matching between the panel and the funnel or glass substrate may be deteriorated. If the content exceeds 74.9 mol%, devitrification tends to occur. From this viewpoint, a more preferable content is 70% or less.

When the content of P ₂ O ₅ is less than 25%, vitrification becomes difficult. A more preferred content is 30% or more. If it exceeds 50%, the water resistance of the sealed article will be reduced. A more preferred content is 40% or less.

Although Al ₂ O ₃ is not an essential component, the inclusion of Al ₂ O ₃ can lower the thermal expansion coefficient of the sealed article. If the content is more than 20%, the softening point of the glass becomes too high, the fluidity becomes poor, the strength and the airtightness of the sealed portion are impaired, and the crystallization is further suppressed. More preferred content is 10%
It is as follows.

Although B ₂ O ₃ is not an essential component, its inclusion can lower the coefficient of thermal expansion of the sealed article. If the content is more than 20%, the softening point of the glass becomes too high, the fluidity becomes poor, and the strength and airtightness of the sealed portion are impaired. A more preferred content is 10% or less.

Although Li ₂ O, Na ₂ O and K ₂ O are not essential components, the inclusion of at least one of them improves the adhesion between the object to be sealed and the sealing composition. sell. If the total amount exceeds 40%, the crystallinity increases and the fluidity is impaired. A more preferred content is 30% or less in total.

Although MgO, CaO, SrO and BaO are not essential components, the inclusion of at least one of them can improve the adhesion between the object to be sealed and the sealing composition. If the total amount exceeds 40%, the softening point of the glass becomes too high, and the fluidity is impaired. A more preferred content is 30% or less.

In the present invention, the low-melting glass powder having the above-mentioned composition is mixed with a composite oxide crystal powder containing phosphorus, tin and / or zinc by 1 to 10 times the low-melting glass powder.
000 ppm by weight. This crystal powder becomes a nucleus (seed crystal) at the time of crystallization of the low melting point glass powder, and functions to promote crystallization. That is, during crystallization, SnO and P
₂ O ₅ , SnO and P ₂ O ₅ and ZnO, or ZnO and P ₂
To promote the precipitation of consisting of O ₅ crystal.

If the amount of the crystal powder is less than 1 ppm,
The effect of accelerating the precipitation of crystals cannot be obtained, and if it exceeds 10,000 ppm, the precipitation of crystals is excessively promoted, and the fluidity may be impaired.

The crystal powder may contain another oxide component. For example, Li ₂ O, Na ₂ O, K ₂
Those containing O, MgO, CaO, SrO or BaO can be used. In this case, the total amount of the composite oxide of phosphorus, tin, and / or zinc in the composite oxide containing phosphorus, tin, and / or zinc is the total amount of SnO, P ₂ O ₅ , and ZnO, respectively. If it is 80% or more in terms of mole, a sufficient crystal precipitation promoting effect can be obtained. Also, the particle size of the crystal powder is
In order to speed up crystal precipitation, the thickness is preferably 100 μm or less.

As a method for preparing the above crystal powder, SnO /
P ₂ O ₅ / ZnO is, for example, 0.1 to 45/2 in a molar ratio.
It can be produced by sintering a raw material containing 5-50 / 5-74.9 or crystallizing a glass having a corresponding composition.

When the crystalline low melting point glass composition of the present invention is used for sealing a cathode ray tube, the crystalline low melting point glass composition powder is 60 to 100% by weight, and the low expansion ceramic filler powder is not essential. The composition is preferably 0 to 40% by weight, and preferably has an average coefficient of thermal expansion at 50 to 300 ° C. after firing of 80 × 10 ^{−7 to} 110 × 10 ⁻⁷ / ° C. By mixing with the low expansion ceramic filler powder, the coefficient of thermal expansion can be reduced, and the panel and funnel can be matched with the average coefficient of thermal expansion.

When the content of the crystalline low-melting glass composition powder is less than 60% by weight, the glass content is small, the fluidity is deteriorated, and the airtightness of the sealing portion is impaired.

In this case, the average coefficient of thermal expansion of the sealed body after firing with the sealing composition of the present invention at 50 to 300 ° C. is in the range of 80 × 10 ^{-7 to} 110 × 10 ^-7 / ° C. . If the average coefficient of thermal expansion is out of this range, a tensile stress acts on the panel glass, the funnel glass or the sealing portion, and the pressure resistance of the bulb decreases.

Examples of the low expansion ceramic filler include zircon, cordierite, alumina, mullite, silica, β-eucryptite, β-spodumene and β-
One or more selected from quartz solid solutions are preferred. Among these ceramic fillers, cordierite and zircon are particularly preferable because of their excellent sealing strength.

The sealing composition can be sealed at a temperature of 400 to 600 ° C. for 5 to 60 minutes to seal a panel of a color CRT with a funnel,
Heating at the time of evacuation at 380 ° C. does not cause fluidization, foaming, or loss of mechanical strength.

When the crystalline low melting point glass composition of the present invention is used for sealing PDP or VFD, the crystalline low melting point glass composition powder should be 50 to 100% by weight, and the low expansion ceramic filler powder is essential. Not 50
% By weight, and after firing, 50 to 250 ° C.
Preferably has an average thermal expansion coefficient of 60 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C. Mixing with the low expansion ceramic filler has the effect of reducing the coefficient of thermal expansion and matching glass substrates as in the case of the sealing composition for cathode ray tubes.

When the content of the crystalline low-melting glass composition powder is less than 50% by weight, the glass content is small, the fluidity is deteriorated, and the airtightness of the sealed portion is impaired.

In this case, the average thermal expansion coefficient of the sealing composition at 50 to 250 ° C. after firing is 60 to 90 ×.
It is preferably 10 ^-7 / ° C. If the coefficient of thermal expansion is out of this range, a tensile stress acts on the substrate glass or the sealing portion, and the pressure resistance decreases.

The low expansion ceramic filler is selected from zircon, cordierite, alumina, mullite, silica, β-eucryptite, β-spodumene and β-quartz solid solution as in the case of the sealing composition for cathode ray tubes. One or more types are preferable, and among these ceramic fillers, cordierite and zircon are particularly preferable because of their excellent sealing strength.

The sealing composition is heated at 430 to 600 ° C. for about 5 to 60 minutes to form a glass substrate for PDP or a glass substrate.
A glass substrate for FD can be sealed, and 280 to 380 after bonding.
There is no flow, no foaming, and no loss in mechanical strength due to heating at the time of exhaustion at ° C. A pigment may be added to the composition for coloring.

When the crystalline low melting glass composition of the present invention is used for coating a substrate, the powder of the crystalline low melting glass composition is 50 to 100% by weight, and the low expansion ceramic filler powder is 0 to 100% by weight. Preferably, the composition is 50% by weight. Such coating compositions are 400-700.
The substrate can be coated by heating at a temperature of about 5 minutes to 1 hour. Here, a heat-resistant material such as glass or ceramics can be used as the material of the base. As the low expansion ceramic filler, those described above can be used.

When the crystalline low-melting glass composition of the present invention is used for forming barrier ribs for PDP and VFD, the powder of the crystalline low-melting glass composition is 50 to 100% by weight,
It is preferable to use a composition containing 0 to 50% by weight of the low expansion ceramic filler powder. Depending on the case, a white pigment (for example, TiO ₂ ), a black pigment (for example, Fe—Mn type,
Fe-Co-Cr-based and Fe-Mn-Al-based pigments) can be added. As the low expansion ceramic filler, those described above can be used.

The powder of the crystalline low-melting glass composition of the present invention or the composition powder for various uses using the same may be a resin component such as ethyl cellulose, nitrocellulose, acrylic resin, poly α-methylstyrene resin, butyral resin, or the like. α-
Suitable solvents such as terpineol, isoamyl acetate, 2,2,4-trimethyl-1,3 pentanediol monoisobutyrate, phenoxyethanol, ethyl cellosolve, dibutyl cellosolve, butyl carbitol, butyl carbitol acetate, ethylene glycol monophenyl ether Can be kneaded with a vehicle containing and used as a paste.

Further, the crystalline low melting point glass composition of the present invention can be used as a binder such as a conductive paste, a resistance paste, and a dielectric paste. For example, when used as a binder for a conductive paste, 1 to 50% by weight of a crystalline low melting point glass powder and 50 to 50% of a conductive powder are used.
The conductive composition is 90% by weight and, if necessary, 0 to 10% by weight of the low expansion ceramic filler powder. When used as a conductive paste, an organic vehicle is preferably added to the paste to form a paste.
Here, as the conductive powder, Ag, Pd, Al, Ni,
A conductive powder such as Cu, Au, or a mixture thereof. Such a conductive paste is at 400 to 900 ° C., 5
The conductor can be formed by heating and baking for about one minute to one hour.

[0036]

EXAMPLE A raw material slurry obtained by dropping 85% orthophosphoric acid into a solid raw material excluding the P ₂ O ₅ component among the low melting glass components was thoroughly mixed, and then dried at 120 ° C. to obtain a powder batch. It was created. This raw material was placed in a quartz crucible, covered and melted at 1000 to 1100 ° C., and then flaked into glass by granulation or through a roller. Next, the mixture was pulverized for a predetermined time by a ball mill, and Example 9 in Tables 1 and 2 was used.
The low-melting glass powders shown in the glass composition columns of Nos. To 12 were produced.

On the other hand, a glass having the composition shown in Table 3 was similarly melted and vitrified, and kept at 600 ° C. for 1 hour to prepare a crystallized glass, which was pulverized by a ball mill for a predetermined time to obtain SnO, ZnO, A composite oxide crystalline powder was prepared as a seed crystal having a composition containing a P ₂ O ₅ component. The glass described in the glass composition of Table 1 as a seed crystal may be fired, crystallized, pulverized, and powdered for use. In that case, the glass is fired at a temperature 100 ° C. higher than the firing temperature shown in Table 1 to produce a crystallized glass, which is ground and powdered.

The low melting point glass powder, the seed crystal powder, and the low expansion ceramic filler powder are mixed at the weight ratio shown in the constitution column of Table 1 (the seed crystal is added to the low melting point glass powder), and a sealing composition is prepared. Was prepared. Seed crystal No.
In the case of using 6, a glass composition obtained by firing the glass composition in the corresponding column in the above manner and crystallizing is used.

Table 1 shows the results of measuring the flow button diameter, the residual adhesive strain, and the coefficient of thermal expansion of this sealing composition. Examples 1 to 3 and 10 of Table 1 and Table 2 are examples when the sealing composition of the present invention is used for a cathode ray tube.
Examples 4 to 9, 11, and 12 in Table 2 are examples when used for sealing PDP or VFD. In Tables 1 and 2, Examples 1 to 9 are Examples and Examples 10 to 12 are Comparative Examples. The measuring methods of the characteristics shown in the table are as follows.

Flow button diameter: This indicates the fluidity of the composition at the time of sealing. For a cathode ray tube, the procedure was as follows.
5.5 g of a sample powder of the sealing composition was press-molded into a columnar shape having a diameter of 12.7 mm, and then maintained at the firing temperature (unit: ° C.) described in Tables 1 and 2 for 10 minutes. It is the diameter (unit: mm) through which the material has flowed. The diameter of the flow button is desirably 26.5 mm or more.

In PDP and VFD, the procedure was as follows. 3.5 g of a sample powder of the sealing composition
It is the diameter (unit: mm) at which the sealing composition flowed when pressed at a firing temperature (unit: ° C.) described in Tables 1 and 2 for 15 minutes after being pressed into a 2.7 mm cylindrical shape. . This flow button diameter is desirably 20 mm or more.

Adhesive residual strain: A paste was prepared by mixing the sealing composition and a vehicle (a solution of 1.2% nitrocellulose in isoamyl acetate) at a weight ratio of 6.5: 1. This paste is coated on a funnel glass piece for cathode ray tubes and a substrate glass piece for PDP and VFD, and fired under the same conditions as for the flow button diameter, respectively.
The residual strain (unit: nm / cm) generated between the glass piece and the sealing composition was measured using a polarimeter. "+" Indicates that the sealing composition is subjected to compressive strain.
"-" Indicates the case where the sealing composition is subjected to tensile strain. This residual strain is -100 to +500 nm /
The range of cm is desirable.

Coefficient of thermal expansion: After baking the sealing composition under the same conditions as in the case of the flow button diameter, it is polished to a predetermined size, and the amount of elongation is measured by a thermal expansion measuring device at a temperature rising rate of 10 ° C./min. It was measured. Average coefficient of thermal expansion up to 50 to 300 ° C for cathode ray tubes, 50 to 300 ° C for PDP and VFD
The average coefficient of thermal expansion up to 250 ° C. (unit: 10 ⁻⁷ / ° C.) was calculated. Considering the matching of the coefficient of thermal expansion with the CRT glass, the average coefficient of thermal expansion is 80 to 110 × 10
^-7 / ° C. is desirable, and in consideration of matching of the coefficient of thermal expansion with the substrate glass, the average coefficient of thermal expansion is 60 to 90.
A range of × 10 ^-7 / ° C is desirable.

The compositions for sealing CRTs shown in Tables 1 and 2 were pasted, interposed between the funnel and the panel of a 25-inch CRT, and kept at 400 to 600 ° C. for 30 minutes to bond the funnel and the panel. The valve was manufactured by sealing. Further, the sealing compositions for PDPs and VFDs in Tables 1 and 2 are pasted and applied in a frame shape to the edge of a PDP glass substrate on which discharge electrodes, ribs and the like are formed in advance, and another PDP glass is formed. After a cell for PDP was formed facing the substrate, the glass substrates were sealed at 430 to 600 ° C. for 30 minutes to produce a PDP. In addition, a paste of a glass ceramic composition is applied in a frame shape to the end of the substrate on which the light emitting portion is formed by the electrode and the phosphor, and another grid is interposed by placing a grid between the ends of the substrate. After forming a VFD cell facing the glass substrate, 430-6
Hold at 00 ° C for 30 minutes to seal the glass substrates together,
VFD was manufactured. Tables 1 and 2 show the results of measuring the water pressure resistance, the heat resistance, and the limit exhaust gas heating rate for these valves and panels. Each measuring method is as follows.

Water pressure strength: The pressure difference when breaking by applying a pressure difference between water inside and outside the valve or panel was measured (unit: kg / cm ² , average value of 5 pieces). In order to guarantee the strength of the valve or panel, this strength is usually 3
It is preferably at least kg / cm ² .

Heat resistant strength: The temperature difference when breaking by applying a temperature difference between water and hot water inside and outside the valve or panel was measured (unit: ° C., average value of 5 pieces). Valve, PDP, VF
In consideration of the thermal stress generated in the heat treatment step when manufacturing the panel D, it is usually preferable that the strength be 40 ° C. or higher.

Critical Exhaust Heating Rate: When elevating the temperature to 350 ° C. while evacuating the valve or panel, the critical heating rate at which no cracking occurs was measured (unit: ° C./min). In order to prevent cracking of the panel in the evacuation step, the temperature is preferably 10 ° C./min or more.

[0048]

[Table 1]

The low-melting glass of the present invention is used for coating a substrate (described as coating in the table), as a binder for a conductive paste (described as conductor in the table), and for forming partition walls (described as partition walls in the table). Table 2 shows an example in the case of using the above. In each case, the sinterability and average coefficient of thermal expansion when fired at the firing temperatures in the table are described. Examples 13 to 15 are working examples, and example 16 is a comparative example. The evaluation of sinterability was performed by observing the cross section of the sintered body after firing at a magnification of 1000 with an electron microscope, and those having a void ratio (void ratio) of less than 20% were regarded as having good sinterability.
Those with 20% or more were determined to have poor sinterability.

When used for coating a substrate, the low melting point glass powder, the ceramic filler powder and the crystal powder were mixed at the ratios shown in Table 2 to dissolve α-cellulose in which ethyl cellulose was dissolved.
It was kneaded with a vehicle consisting of terpineol and made into a paste. The paste was screen printed and fired at the firing temperatures shown in the table. Average coefficient of thermal expansion after sintering (50 to 250
° C) is shown in Table 2.

When used as a conductive paste, a conductive powder, a low-melting glass powder and a crystal powder are mixed at the ratios shown in Table 2, and kneaded with a vehicle made of α-terpineol in which ethyl cellulose is dissolved to form a paste. did.
The paste was screen-printed in a predetermined pattern, dried, and fired at the firing temperature shown in the table to form a conductor pattern. Table 2 shows the average coefficient of thermal expansion (50 to 250 ° C.) after sintering.
Shown in

When used for the partition walls of PDP and VFD, low melting glass powder, ceramic filler powder and crystal powder are mixed at the ratio shown in Table 2 and kneaded with a vehicle made of α-terpineol in which ethyl cellulose is dissolved. , Into a paste. The paste may be screen-printed and dried, followed by patterning by sandblasting. Alternatively, a photosensitive resin may be mixed into the paste, screen-printed, dried, exposed, and etched to form a pattern. After the pattern formation, baking was performed at the baking temperature shown in the table to form predetermined partition walls (ribs). Table 2 shows the average coefficient of thermal expansion (50 to 250 ° C.) after sintering.

From the table, it can be seen that the composition according to the present invention has more properties than conventional products.

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

According to the present invention, no lead is contained, a cathode ray tube, PDP, VFD sealing, substrate coating, PD
A crystalline low-melting glass composition suitable for use as a composition for forming a partition such as P or VFD or a functional paste such as a conductive paste or a resistive paste is obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuneo Manabe Asahi Glass Co., Ltd., 1150 Hazawacho, Kanagawa-ku, Yokohama, Kanagawa

Claims (6)

[Claims] 1. Tin oxide 0.1 to 45% in terms of SnO, ZnO 5 to 74.9 substantially in molar terms.
_{%, P 2 O 5 25~50%} , Al 2 O 3 0~20%, B 2 O 3 0~20%, Li 2 O + Na 2 O + K 2 O 0~40%, MgO + CaO + SrO + BaO 0~40%, low consisting A crystalline low-melting glass composition comprising a melting point glass powder and a complex oxide crystal powder containing phosphorus, tin and / or zinc added to the low-melting glass powder in an amount of 1 to 10,000 ppm by weight. 2. A composition comprising 60 to 100% by weight of the crystalline low-melting glass composition powder according to claim 1 and 0 to 40% by weight of a low expansion ceramic filler powder, and 50 to 30% after firing.
The average coefficient of thermal expansion at 0 ° C. is 80 × 10 ^{−7 to} 110 × 10 ^−7.
/ C, a sealing composition for sealing a panel of a CRT and a funnel. 3. The composition of claim 1, comprising 50 to 100% by weight of the crystalline low melting glass composition powder according to claim 1 and 0 to 50% by weight of the low expansion ceramic filler powder.
The average thermal expansion coefficient at 0 ° C. is 60 × 10 ^{−7 to} 90 × 10 ⁻⁷ /
A sealing composition for sealing a plasma display panel or a fluorescent display tube, which is at 0 ° C. 4. A composition for coating a substrate, comprising 50 to 100% by weight of the crystalline low melting glass composition powder according to claim 1 and 0 to 50% by weight of a low expansion ceramic filler powder. 5. A partition for a plasma display panel or a fluorescent display tube, comprising 50 to 100% by weight of the crystalline low melting point glass composition powder according to claim 1 and 0 to 50% by weight of a low expansion ceramic filler powder. Composition. 6. The crystalline low melting glass composition powder according to claim 1, wherein the inorganic component is 1 to 50% by weight, and the conductive powder is 50 to 9%.
9% by weight and low expansion ceramic filler powder 0-1
Conductive paste consisting of 0% by weight.