JP2989936B2 - Glass frit, resistor paste and wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass frit, a resistor paste and a wiring board used for a paste for producing a thick film resistor.

[0002]

2. Description of the Related Art As a substrate material used for a wiring substrate of electric / electronic equipment, a material which can be fired at a low temperature has been developed.
Simultaneous and integral firing can be performed at a low temperature of 00 ° C. or less.

[0003] A resistor paste is usually composed of conductive particles, glass frit, a vehicle, and the like, and is formed into a thick-film resistor by firing after printing on a substrate.

As the conductive particles used for the resistor paste, pyrochlore compounds such as ruthenium dioxide or lead ruthenate are frequently used.

The glass frit used for the resistor paste has a softening point of 450 to 800 ° C. and a softening point of 40 to 290 ° C.
In general, a lead borosilicate amorphous glass having an average coefficient of thermal expansion of about 5 to 8 × 10 ⁻⁶ deg ⁻¹ is used.

The characteristics required for the thick film resistor include a temperature coefficient (TCR) of the resistance value close to 0 and low noise. For example, the thermal expansion coefficient of the substrate and the thick film resistance It is known that the TCR characteristic can be improved by making the thermal expansion coefficient close to the thermal expansion coefficient.

However, since the conventional glass frit such as lead borosilicate amorphous glass has a high coefficient of thermal expansion as described above, the coefficient of thermal expansion of the substrate and the coefficient of thermal expansion of the thick film resistor are brought close to each other. It is difficult.

For this reason, a TCR regulator is added to the resistor paste to reduce the TCR.

However, since the amount of the TCR regulator added is extremely small, it is difficult to mix uniformly, and it is difficult to produce the TCR regulator, and characteristics of the product tend to vary. In addition, there is a risk that the addition of the TCR regulator may adversely affect the resistance trimming property and the electrical characteristics other than the TCR.

If the coefficient of thermal expansion of the resistor is high, the substrate having a relatively low coefficient of thermal expansion, especially containing glass and an oxide aggregate such as alumina, is caused by the difference in the coefficient of thermal expansion between the resistor and the substrate. In the case of (1), cracks are easily generated in the resistor after firing.

Furthermore, since lead borosilicate glass has high fluidity when fired, when a resistor pattern is printed and fired on the external conductor pattern, the glass in the external conductor reacts with the glass in the resistor. There is a problem that a bleed-out phenomenon occurs in which the glass of the conductor is extruded, which adversely affects the electrical characteristics of the resistor. In particular, in a high-density wiring substrate having a fine wiring pattern and a thin film thickness, a short circuit easily occurs due to the bleed-out phenomenon.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a thick film resistor, which is used in a paste.
The characteristics can be improved and the occurrence of cracks in the resistor can be prevented.
Moreover, it is an object of the present invention to provide a glass frit capable of preventing a bleed-out phenomenon, a resistor paste, and a wiring board using such a resistor paste.

[0013]

This and other objects are achieved by the present invention which is defined below as (1) to (8).

(1) A binder glass of a resistor paste, wherein ZnO ₂ is 40 to 70% by weight and B ₂ O ₃ is 1
0-30 wt%, a SiO ₂ 5 to 15 wt% and Mn
O ₂ and 5-15 wt% (but not including 5 wt%) glass frit, characterized in that it contains. (2) The average coefficient of thermal expansion α at 40 to 290 ° C. is 3 to 5
The glass frit according to the above (1), which has × 10 ⁻⁶ deg ⁻¹ . (3) A resistor paste comprising the glass frit according to (1) or (2) and conductive particles. (4) The resistor paste according to (3), wherein the conductive particles contain at least one of ruthenium dioxide, lead ruthenate and bismuth ruthenate as a main component. (5) The resistor paste according to (3) or (4), wherein the content of the glass frit with respect to the entire glass frit and the conductive particles is 60 to 90% by weight. (6) A wiring board, wherein a thick-film resistor is formed using the resistor paste according to any of (3) to (5). (7) The wiring substrate according to (6), wherein the thick film resistor is formed on a substrate containing glass and an oxide aggregate. (8) The wiring board according to (6) or (7), wherein an external conductor is formed in contact with the thick film resistor.

[0015]

The glass frit of the present invention has a ZnO ₂ content of 40 to
70 wt%, B ₂ O ₃ 10 to 30% by weight, containing SiO ₂ 5 to 15 wt% and MnO ₂ 1 to 15 wt%. Since glass of this composition is crystallized by firing, when used in a resistor paste, the presence of a crystal phase can suppress the reaction between the glass component in the external conductor and the glass component in the resistor. The bleed-out phenomenon of the glass in the resistor or conductor is prevented.

As a result, deterioration of the electrical characteristics can be prevented, and short circuiting can be effectively prevented even in a high-density wiring board in which the pattern of the external conductor layer is a thin line pattern of, for example, 200 μm or less and the film thickness is reduced. You.

Further, the glass of the above composition has a temperature of 40 to 290 ° C.
Has a low average thermal expansion coefficient α (hereinafter referred to as α) at about 3 to 5 × 10 ⁻⁶ deg ⁻¹ , for example.
Can be reduced, for example, to about 4 to 6 × 10 ⁻⁶ deg ⁻¹ . Therefore, α of the substrate matches or approaches α of the resistor, and the temperature coefficient of resistance (TCR) decreases. In this case, TC
Since R is sufficiently low, there is no need to add a TCR adjuster, so that there is no adverse effect on trimming properties and electrical characteristics other than TCR, and a product which is easy to produce and has little variation can be obtained.

Further, even when a substrate having a relatively low α containing glass and oxide aggregate is used, it is possible to make α of the resistor equal to α of the substrate or to make α of the resistor smaller than α of the substrate. In addition, since a crystal phase is precipitated in the glass of the resistor, the strength of the resistor is improved. For this reason, the occurrence of cracks in the resistor can be effectively prevented.

[0019]

[Specific Configuration] Hereinafter, a specific configuration of the present invention will be described in detail. The glass frit of the present invention is a glass binder of a resistor paste, and has ZnO ₂ , B
Contains ₂ O ₃ , SiO ₂ and MnO ₂ .

The content of ZnO _{2 in} the glass frit is:
It is 40 to 70% by weight, preferably 50 to 65% by weight. If it is less than the above range, crystallization during firing does not proceed, and the effect of the present invention is low. If it exceeds the above range, vitrification becomes difficult.

The content of B ₂ O ₃ is 10 to 30% by weight,
Preferably, it is 15 to 25% by weight. If it is less than the above range, it becomes difficult to vitrify. If it exceeds the above range, bubbles are likely to be generated in the resistor after firing.

The content of SiO ₂ is 5 to 15% by weight, preferably 10 to 15% by weight. If it is less than the above range, the glass softening point is lowered, and the bleed out phenomenon is likely to occur. If it exceeds the above range, the glass softening point increases, and it is difficult to obtain a dense sintered body.

The content of MnO ₂ is 5 to 15% by weight, preferably 5 to 10% by weight. If it is less than the above range, the adhesive strength between the resistor and the substrate after firing is reduced. If it exceeds the above range, vitrification is inhibited.

In this case, MgO,
One or more of CaO, SrO, BaO and the like may be contained in an amount of about 5% by weight or less.

The glass frit having the above composition is usually amorphous before firing, but crystallizes by firing.

Further, the glass frit of the present invention is preferably a glass having a softening point of 400 to 700 ° C., particularly about 500 to 600 ° C. When the thickness is less than the above range, the bleed-out phenomenon easily occurs. When the thickness exceeds the above range, the noise characteristics of the resistor deteriorate when a thick-film resistor is formed. The softening point was about 5 mm x 5 mm x 10 mm using a sample with a load of 10 g.
May be measured using a differential thermal dilatometer.

The average thermal expansion coefficient α of the glass frit at 40 to 290 ° C. is preferably 3 to 5 × 10 ⁻⁶ deg ⁻¹ , particularly preferably about 3.5 to 4.0 × 10 ⁻⁶ deg ⁻¹ . If the value is less than the above range, α of the resistor becomes too small compared to α of the substrate, and the TCR characteristic deteriorates. If it exceeds the above range, α of the resistor cannot be sufficiently reduced. For this reason, there is a risk that a crack may occur in the resistor, and the TCR characteristic deteriorates. In the present invention, a glass frit having the above α is realized.

The average particle size of the glass frit of the present invention is not particularly limited, but is preferably about 5 μm or less. If it exceeds the above range, the particle diameter of the glass component becomes large, so that the screen printability deteriorates.

The resistor paste of the present invention contains the above glass frit, conductive particles, and a vehicle.

The composition of the conductive particles is not particularly limited. For example, RuO ₂ , Pb ₂ Ru ₂ O ₇ , Bi ₂ Ru ₂ O ₇ ,
CdBiRu ₂ O ₇ , NdBiRu ₂ O ₇ , BiInR
u ₂ O ₇ , Bi ₂ IrRuO ₇ , GdBiRu ₂ O ₇ ,
BaRuO ₃ , Ba ₂ RuO ₄ , SrRuO ₃ , CaR
uO ₃ , Co ₂ RuO ₄ , LaRuO ₃ , LiRuO ₃ ,
SnO ₂ , LaB ₆ , Pd-Ag, CoCrO ₄ , Ni
CrO ₄ , SiC, TaC, CaB ₆ , BaB ₆ , Sr
B ₆ , LaB ₆ , YB ₆ , Ta ₂ N, TiSi ₂ , VS
i ₂ , CrSi ₂ , TaSi ₂ , MoSi ₂ , WSi ₂
For example, various ruthenium compounds, other conductive compounds, or various alloys can be used, but at least one of ruthenium dioxide, lead ruthenate, and bismuth ruthenate in terms of good TCR characteristics and noise characteristics can be used. Those having a main component are preferred.

In this case, as ruthenium dioxide, lead ruthenate and bismuth ruthenate, Ru is usually used.
_{O 2, Pb 2 Ru 2 O} 7 and Bi ₂ Ru ₂ O ₇ is used those represented by, but may be a composition which now has somewhat biased, mixtures of those biasing the composition, or biasing the composition It may be a mixture of one another.

The conductive particles containing at least one of ruthenium dioxide, lead ruthenate and bismuth ruthenate as a main component mean that their total content is 90% by weight or more. For example, conductive materials other than the various Ru compounds described above and conductive materials such as various alloys may be included.

The average particle size of the conductive particles is 0.05 to 1.0 μm
m is preferred. Below the range, the dispersion of the particles in the paste becomes insufficient due to the small particle size of the conductive particles,
The fluidity of the resistor paste deteriorates. Exceeding the above range adversely affects noise characteristics and the like.

The content ratio of the glass frit and the conductive particles in the resistor paste is not particularly limited and may be appropriately determined according to the required resistance value. The content is
It is preferably from 60 to 90% by weight, particularly preferably from 70 to 85% by weight.
When the weight ratio is less than the above range, it is difficult to control the resistance value due to excessive conductive particles, and the TCR characteristic is extremely deteriorated. If the weight ratio exceeds the above range, the conductive particles cannot form a conductive network due to too much glass, and tend to be insulated.

Examples of the vehicle include binders such as ethyl cellulose, polyvinyl butyral, methacrylic resin, and butyl methacrylate, terpineol, butyl carbitol, butyl carbitol acetate, acetate, and the like.
Examples of the solvent include solvents such as toluene, alcohol, and xylene, various dispersants, activators, plasticizers, and the like. Any of these can be appropriately selected depending on the purpose. As described above, in the present invention, a TCR sufficiently close to 0 can be obtained without adding a TCR adjuster. Therefore, preferably, a TCR adjuster is not added, but if necessary, CuO, MnO
₂ , V ₂ O ₅ , Nd ₂ O ₅ , MgO, ZnO, etc.
A CR modifier may be added. The addition amount of the TCR regulator is preferably about 0.1 to 6 parts by weight based on 100 parts by weight of the total amount of the conductive particles and the glass frit. The added amount of the vehicle is preferably about 5 to 30 parts by weight based on 100 parts by weight of the total amount of the conductive particles and the glass frit.

The resistor paste of the present invention comprises conductive particles,
It is obtained by mixing a glass frit, further adding the above-mentioned vehicle, kneading them using a usual three-roll or the like, and forming a paste.

The resistor paste of the present invention is used after being printed in a predetermined pattern on a substrate and baked.

FIG. 1 shows an example of the configuration of a multilayer wiring board in which the resistor paste of the present invention is used as a thick film resistor. FIG. 1 is a partial cross-sectional view of the multilayer wiring board.

As shown in the figure, a multilayer wiring board 1 is composed of an insulating substrate 4 having a plurality of layers stacked and integrated by firing.
The internal conductor 2 having a predetermined pattern is formed inside the substrate 4, and the external conductor 3 is formed at a portion where the internal conductor 2 is exposed on the surface of the substrate 4.

The material of the substrate 4 is not particularly limited.
Alumina-borosilicate glass, alumina-lead borosilicate glass, alumina-barium borosilicate glass, alumina-
A low-temperature sintering material containing an oxide aggregate such as calcium borosilicate glass, alumina-strontium borosilicate glass, and alumina-magnesium borosilicate glass and glass is preferable.

In such a substrate material, the glass content is generally preferably about 50 to 80 wt%.

The average thermal expansion coefficient α of the alumina substrate at 40 to 290 ° C. is about 7 to 8 × 10 ⁻⁶ deg ⁻¹ , and a substrate using a low-temperature sintering material containing an oxide aggregate and glass is used. Has an average coefficient of thermal expansion α at 40 to 290 ° C. of 5 to 5.
It is about 6.5 × 10 ⁻⁶ deg ⁻¹ .

The internal conductor 2 is usually multilayered and
Are electrically connected to each other via a through hole 5 formed in the thickness direction of the first and second electrodes.

The outer conductor 3 is formed on the surface of the substrate 4,
It is used for conduction to the resistor 8 or used as a pad for soldering chip components such as chip inductors and chip capacitors and surface mounting components 7 such as semiconductor integrated circuit devices and devices such as diodes with solder 6. . Note that an insulating coating layer may be formed so as to cover the surface.

The resistor paste of the present invention comprises the above resistor 8
Applied to form

The thickness of the resistor 8 is not particularly limited, but is usually 4 to 25 μm, particularly about 8 to 15 μm. Also,
The resistance value of the resistor 8 is not particularly limited and is appropriately selected depending on the purpose and the like, but is usually about 10 Ω / □ to 1 MΩ / □. The resistor 8 has a temperature coefficient of resistance (TC
R) is low. Specifically, using a low-temperature firing material containing an oxide aggregate such as alumina and glass as a substrate constituent material,
Moreover, even when the TCR regulator is not added, -50 to 2
-5 to 10 ppm / ° C at 5 ° C, especially -30 to 0 pp
The TCR falls within the range of 0 to 50 ppm / ° C at m / ° C and 25 to 125 ° C, particularly 0 to 30 ppm / ° C. In addition,
The average thermal expansion coefficient α of the resistor 8 at 40 to 290 ° C. is about 6 × 10 ⁻⁶ deg ⁻¹ or less, particularly 4 to 5.5 × 10 ⁻⁶ de.
It is about g ^-1 .

As the inner conductor 2, it is preferable to use conductive particles mainly composed of Ag, particularly Ag, from the viewpoint of giving priority to good conductivity. The internal conductor paste contains conductive particles, glass frit of about 1 to 5% by weight based on the conductive particles, and a vehicle.

The thickness of the inner conductor 2 is usually 5 to 20.
It is about μm. The conduction resistance of the internal conductor is generally preferably about 2 to 10 mΩ / □, though it depends on the composition.

The outer conductor 3 has migration resistance,
It is preferable to use conductive particles mainly composed of Ag, particularly conductive particles containing Ag and Pd and / or Pt in terms of solder wettability and solder wettability. The external conductor paste contains conductive particles, glass frit of about 1 to 5% by weight based on the conductive particles, and a vehicle. Further, the content of the vehicle is generally about 3 to 10% by weight in the outer conductor paste.

The glass composition of the glass frit is P
_{bO-B 2 O 3 -SiO 2} , B 2 O 3 -SiO 2 -Zn
_{O, PbO-B 2 O 3} -SiO 2 -ZnO, and the like. Further, the average thermal expansion coefficient α of the glass frit at 40 to 290 ° C. is about ^{6 to} 8 × 10 ⁻⁶ deg ⁻¹ and the softening point is 4
About 00-600 degreeC is preferable.

Even if such a glass frit is used, the bleed-out phenomenon can be effectively prevented by the present invention.

The glass is used as a powder having an average particle size of 0.1 to 10 μm. If the average particle size is less than 0.1 μm, impurities are significantly mixed during pulverization, and
If it exceeds m, the printability tends to deteriorate.

Further, additives other than the glass frit include Al ₂ O ₃ , Cr ₂ O ₃ , CuO, TiO ₂ , C
oO, Bi ₂ O _{3 and the} like. Among them, Bi ₂ O ₃ vitrifies during firing,
In some cases, it may be added by vitrification.

The thickness of the outer conductor 2 is usually about 5 to 20 μm. The conduction resistance of the outer conductor is generally preferably about 2 to 10 mΩ / □ although it depends on the composition.

Such a multilayer wiring board is manufactured, for example, as follows.

First, a green sheet as a substrate material is prepared.

In this green sheet, a predetermined amount of an aggregate such as alumina powder, which is a raw material of the substrate, and a glass powder (for example, borosilicate glass) are mixed, a binder resin, a solvent, etc. are added thereto, and these are kneaded. Then, a predetermined number of green sheets are produced by, for example, a doctor blade method.

Next, a through hole 5 is formed in the green sheet by using a punching machine or a die press, and then, an internal conductor paste is printed on each green sheet by, for example, a screen printing method to form a predetermined pattern of the internal conductor 2. Is formed and the inside of the through hole 5 is filled.

Next, the green sheets are superimposed, and hot pressed (about 40 to 120 ° C., 50 to 1000 kgf / cm ² ) to form a green sheet laminate. Perform formation and the like.

Thereafter, the green sheet laminate is usually fired and integrated at a temperature of about 800 to 1000 ° C. in air to obtain a multilayer wiring board having the internal conductor formed on the substrate 4. Then, the external conductor paste is printed by a screen printing method or the like and fired to form the external conductor 3.

Further, the resistor material paste is printed and baked to form the resistor 8. In this case, preferably, the external conductor 3 and the resistor 8 are formed by simultaneous firing with the substrate 4.

The sintering of the resistor 8 is usually performed in air for 10 minutes.
About 100 ° C or less, especially about 800 to 1000 ° C,
It is preferable to carry out for about an hour, and to maintain the maximum temperature for about 5 to 20 minutes. By this firing, the resistor 8
The glass frit inside is crystallized, and the bleed-out phenomenon is effectively prevented.

Thereafter, a predetermined surface mount component 7 is soldered to the external conductor 3 and, if necessary, an insulating coating layer is formed to obtain the multilayer wiring board 1 shown in FIG.

In the above, an example in which the present invention is applied to a multilayer wiring board has been described. However, the present invention is not limited to this, and may be applied to a single-layer board such as an alumina board or an AlN board. be able to.

[0065]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

R having an average particle diameter of 0.05 μm as conductive particles
15 parts by weight of uO ₂ particles, 70 parts by weight of a glass frit having an average particle size of 2 μm, and 15 parts by weight of a vehicle were kneaded with three rolls to form a paste. 1
-No. 4 was obtained. For the vehicle, ethyl cellulose was used as a binder and terpineol was used as a solvent. Note that no TCR preparation was used. The glass composition of the glass frit, the average coefficient of thermal expansion α at 40 to 290 ° C., and the softening point are as follows.

Resistor paste No. 1 (Invention) Glass composition ZnO ₂ : 60 wt% B ₂ O ₃ : 20 wt% SiO ₂ : 10 wt% MnO ₂ : 10 wt% α: 3.8 × 10 ⁻⁶ deg ⁻¹ Softening point: 580 ° C. Resistor paste No. 2 (Invention) Glass Composition ZnO ₂ : 50 wt% B ₂ O ₃ : 25 wt% SiO ₂ : 15 wt% MnO ₂ : 10 wt% α: 4.5 × 10 ⁻⁶ deg ⁻¹ Softening point: 600 ° C. Resistor paste No. 3 (Comparison) Glass composition PbO: 54 wt% B ₂ O _3: 13 wt% SiO _2: 30 wt% Al ₂ O _3: 3 ^{wt% α: 6.2 × 10 -6 deg} -1 softening point: 580 ° C. Resistor paste No. 4 (Comparative) Glass composition ZnO ₂ : 40 wt% B ₂ O ₃ : 40 wt% SiO ₂ : 3 wt% MnO ₂ : 17 wt% α: 5.0 × 10 ⁻⁶ deg ⁻¹ Softening point: 520 ° C.

Next, Ag particles having an average particle size of 10 μm: 8
5 parts by weight, Pd particles having an average particle size of 1 μm: 15 parts by weight, glass frit having an average particle size of 2 μm: 3 parts by weight, average particle size of 2
The 1 μm Bi ₂ O ₃ particles and 4 parts by weight of vehicle were kneaded with three rolls to form a paste, which was used as an external conductor paste. The glass composition of the glass frit is Pb
O: 50 parts by weight, B ₂ O ₃ : 25 parts by weight, Al ₂ O ₃ :
15 parts by weight, SiO ₂ : 10 parts by weight, α at 40 to 290 ° C. was 6.5 × 10 ⁻⁶ deg ⁻¹ , and softening point was 540 ° C.

Next, the following substrate materials were mixed, and the above-mentioned vehicle was added thereto to obtain a substrate paste.

Substrate constituent glass 60 parts by weight (average diameter 1.9 μm) SiO ₂ : 52.2% by weight Al ₂ O ₃ : 11.4% by weight B ₂ O ₃ : 3.9% by weight SrO: 27.6% % By weight CaO: 3.1% by weight MgO: 1.8% by weight 40 parts by weight of Al ₂ O ₃ (average particle size 3.5 μm)

Using this substrate paste, a substrate green sheet having a thickness of 0.2 mm was prepared by a doctor blade method.

Next, after the Ag internal conductor paste was printed on the substrate green sheets, they were laminated by hot pressing to obtain a green sheet laminate. And after degreasing this laminate,
A multilayer wiring board which was simultaneously fired in air at 900 ° C. was obtained.

An external conductor paste was printed on the multilayer wiring board by screen printing, and baked at 850 ° C. in air to form an external conductor having a fine line pattern. In addition, when a substrate was separately manufactured in the same manner, 40
The average coefficient of thermal expansion α at 290 ° C. is 6.4 × 10 ^-6
deg.

Then, a resistor paste is printed on the tip of the outer conductor to a thickness of 20 μm wider than the outer conductor, and then baked at 850 ° C. for 60 minutes in the air to obtain 2 μm ×
A resistor having a thickness of 2 μm and a thickness of 10 μm was formed. Thus, the resistor paste No. No. 1 to No. 4, the multilayer wiring board sample No. 1-4 were obtained.

The obtained multilayer wiring board sample No. 1 to
The average thermal expansion coefficient α at 40 to 290 ° C. and the resistance of the resistor formed in No. 4 were as shown in Table 1.

Next, the following evaluation was performed on each sample. (1) Temperature coefficient of resistance (TCR) of low antibody The TCR is the TCR (cold) at −50 to 25 ° C.
TCR) and TCR at 25 to 125 ° C. (hot
TCR).

(2) Crack resistance After firing and thermal shock test (held at 125 ° C. for 30 minutes,
After holding at −40 ° C. for 30 minutes and 23 cycles), the resistor was observed with an optical microscope, and evaluated by the following four grades of ◎, △, Δ, and ×. Evaluation criteria ◎: No crack after firing and thermal shock test ○: No crack after firing, crack after thermal shock test △: Some crack after firing, crack after thermal shock test ×: Crack after firing, thermal shock Crack after test

(3) Presence or Absence of Bleed-Out Phenomenon The end portion of the thin wire outer conductor pattern near the resistor was observed with an optical microscope, and evaluated by the following four grades of ◎, Δ, ×, XX. Evaluation criteria ◎: No bleed-out at all △: Bleed-out observation at a distance of 10 μm or less ×: Bleed-out observation at a distance of 50 μm or less XX: Bleed-out observation at a distance exceeding 50 μm These results are as shown in Table 1. is there.

[0079]

[Table 1]

From the results shown in Table 1, the effect of the present invention is clear.

The conductive particles were made of Pb ₂ Ru ₂ O ₇ , Bi
_When the same evaluation as above was performed in place of ₂ Ru ₂ O ₇ , equivalent results were obtained.

[0082]

The thick film resistor formed by using the resistor paste of the present invention has a low temperature coefficient of resistance (TCR). In addition, it is possible to prevent the occurrence of cracks in the resistor due to a difference between the coefficient of thermal expansion α of the substrate and α of the resistor. Moreover, the occurrence of the bleed-out phenomenon can be prevented, and the short circuit between the wirings and the deterioration of the electric characteristics can be prevented.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a multilayer wiring board manufactured using a resistor paste of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multilayer wiring board 2 Inner conductor 3 Outer conductor 4 Substrate 5 Through hole 6 Solder 7 Surface mount component 8 Resistor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Taiji Miyauchi 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (56) References JP-A-2-321201 (JP, A) JP-A-3 -167801 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01C 7/00 C03C 8/04 C03C 8/24 H05K 1/16

Claims (8)

(57) [Claims] 1. A binder glass of the resistor paste, the ZnO ₂ 40 to 70 wt%, the B ₂ O ₃ 10 to 30 wt%, a SiO ₂ 5 to 15 wt% and MnO _2. 5 to
A glass frit characterized by containing 15% by weight (but not including 5% by weight). 2. The glass frit according to claim ¹ , wherein the average thermal expansion coefficient α at 40 to 290 ° C. is 3 to 5 × 10 ⁻⁶ deg ^{- 1} . 3. A resistor paste comprising the glass frit according to claim 1 and conductive particles. 4. The resistor paste according to claim 3, wherein the conductive particles contain at least one of ruthenium dioxide, lead ruthenate and bismuth ruthenate as a main component. 5. The content of the glass frit in the glass frit and the whole of the conductive particles is 60 to 9%.
5. The resistor paste according to claim 3, which is 0% by weight. 6. A wiring board, wherein a thick film resistor is formed using the resistor paste according to claim 3. Description: 7. The wiring board according to claim 6, wherein the thick-film resistor is formed on a substrate containing glass and an oxide aggregate. 8. The wiring board according to claim 6, wherein an external conductor is formed in contact with said thick film resistor.