JPH0714523A - Built-in element for electron tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide built-in elements of an electron tube and their manufacture not abruptly deteriorated with the mechanical strength of metal terminals during use over a long period by specifying the composition of connecting conductor layers formed on a ceramic insulating substrate mainly made of an aluminum oxide and the metal terminals connected to them. CONSTITUTION:A resistive layer 12 is formed on an insulating substrate 11, and metal terminals 16 are electrically connected to the resistive layer 12 via connecting conductor layers 13. The connecting conductor layers 13 are made of a mixed sintered layer containing palladium, silicon, and titanium, and the metal terminals 16 are made of nickel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron tube built-in element suitable for use in, for example, a color cathode ray tube and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, an electron tube, for example, a color cathode ray tube used in a color television receiver is shown in FIGS.
2 shows the whole, and FIG. 3 shows the vicinity of the electron gun. That is, the fluorescent surface 22 is formed on the inner surface of the panel of the glass vacuum envelope 21. On the other hand, an electron gun 24 which emits an electron beam is arranged inside the neck 23, and the electron beam is deflected and scanned by a deflection yoke 28 attached to the cone portion to obtain a fluorescent screen 22. The desired image is displayed on. The electron gun 24 includes a cathode that generates an electron beam, an electrode that applies a low voltage to suppress the generation of the electron beam from the cathode, and an electrode that focuses and accelerates the electron beam emitted from the cathode. A plurality of electrodes composed of
Are arranged at predetermined intervals in the direction.

Generally, an electrode for accelerating an electron beam is
A high-voltage anode voltage is applied from a high-voltage supply button (anode button) 25 provided in the cone portion of the vacuum envelope 21 through the internal conductive film 26. Particularly in a color cathode ray tube, a high voltage of about 20 to 35 KV is applied. Furthermore,
As is clear from FIG. 3, the electron gun 24 in the neck 23 is provided with a built-in element such as a resistance element 29, which is a voltage dividing element. In some electron guns 24, it is necessary to supply a high voltage to the convergence electrode, the focus electrode, etc. in addition to the anode voltage in order to improve the focusing degree of the electron beam. In such cases,
When a high voltage is supplied from the stem portion 27 of the color cathode ray tube, a problem occurs in terms of withstand voltage. Therefore, the anode voltage is divided by the resistance element 29, and the convergence electrode and the convergence electrode are divided.
A predetermined high voltage is supplied to the dust electrode and the like.

A resistance element 29 built in such a color cathode ray tube has been conventionally used, for example, as shown in FIGS.
FIG. 2B is a plan view showing a state of being configured as shown in FIG. 3C, in which FIG. 3A is seen through from the insulating coating layer forming the outer surface portion.
6A is a cross-sectional view taken along line BB ′ of FIG. 7A and seen in the direction of the arrow, and FIG. 7C is a cross-sectional view showing an enlarged main part of FIG.

That is, on a ceramic insulating substrate 31 whose main component is aluminum oxide, a resistor made of lead ruthenate oxide having a predetermined sheet resistance and lead borosilicate glass is used. A resistance layer 33 is formed by printing, drying, and firing a material in a zigzag pattern, and a conductor layer 32 for connection electrically integrated with the resistance layer 33 and a metal terminal 36 joined to the conductor layer 32 for connection are formed. Is provided. Further, the insulating coating layers 34 and 3 are formed so as to cover the resistance layer 33.
5 is formed.

Next, a conventional method of manufacturing a resistance element will be described. First, on one surface of the ceramic insulating substrate 31 containing aluminum oxide as a main component,
The conductor layer 32 for joining is formed. This bonding conductor layer 32
Is formed of a conductor paste containing lead borosilicate glass and containing nickel as a main component. The composition of this conductor paste is
85 to 97 parts by weight of nickel and 3 to 1 of lead borosilicate glass
5 parts by weight and 5 to 10 parts by weight of the organic vehicle. This is printed by a screen printing method so as to have a predetermined shape and a dry film thickness of 60 to 70 μm, and 120 to 150 ° C.
To dry for 10 to 20 minutes to remove the solvent component in the paste.

Next, the conductor layer 3 for bonding on the insulating substrate 31.
A resistance layer 33 is formed on the same surface as 2. Resistance layer 33
Is a resistance material composed of lead ruthenate metal oxide and lead borosilicate glass, and has a sheet resistance value of 10 ⁶
It is formed by using a resistance paste of about 10 ⁷ Ω / □. This is printed in a predetermined shape by a screen printing method and dried at 120 to 150 ° C. for 10 to 20 minutes to remove the solvent component in the paste. At this time, in order to obtain a predetermined total resistance value as the resistance element, 10 ⁶ Ω / □ and 10
Adjust the sheet resistance value of the resistance material by mixing ⁷ Ω / □ resistance paste. Further, the printed pattern of the resistance layer 33 has a zigzag pattern shape so that a predetermined resistance division ratio can be obtained in each electrode portion. Then 840-860
C., heat treatment is performed in an air atmosphere for about 8 to 10 minutes to remove the organic components in the bonding conductor layer 32 and the resistance layer 33, and burn the inorganic components. The resistance layer 33 thus obtained has a total resistance value of 2 × 10 ^{9 to} 3 × 10 ⁹ Ω. At this time, if the resistance division ratio of each metal terminal 36 is not within the predetermined range, the resistance value of each division resistor portion is corrected by the trimming process to adjust the resistance division ratio to the predetermined resistance division ratio.

Next, the insulating coating layers 34 are formed on both surfaces of the insulating substrate 31, respectively. A glass paste containing lead borosilicate glass as a main component and a transition metal oxide such as iron oxide, chromium oxide, or nickel oxide is used. This is printed in a predetermined shape by a screen printing method, and 120 to 15
The solvent component in the paste is removed by drying at 0 ° C. for 10 to 20 minutes. At this time, in order to obtain a predetermined withstand voltage characteristic as the insulating coating layer 34, the surface having the bonding conductor layer 32 and the resistance layer 33 is printed so as to have a film thickness of 200 to 500 μm after firing. On the other side, the film thickness after firing is 5
Printing is performed so as to be 0 to 200 μm.

Next, heat treatment is performed in an air atmosphere at 570 to 630 ° C. for about 8 to 10 minutes to remove the organic components and sinter the inorganic components in the insulating coating layer 34. Next, the insulating coating layer 35 that covers the side surface of the insulating substrate 31 is formed. This is to prevent the unnecessary discharge phenomenon by covering the exposed ceramics portion having a higher secondary electron emission ratio than the insulating coating glass layer. A glass paste containing lead borosilicate glass as a main component and a transition metal oxide such as iron oxide, chromium oxide, or nickel oxide is used. Glass paste is applied to a predetermined part of this by a dispenser method, and 1
The solvent component in the paste is removed by drying at 20 to 150 ° C. for 10 to 20 minutes.

Next, heat treatment is carried out in an air atmosphere at 570 to 630 ° C. for about 8 to 10 minutes to remove the organic components and sinter the inorganic components in the insulating coating layer 35. Then, the metal terminal 36 is fixed to the joining conductor layer 32. Metal terminal 36 is F
e is a main component and is made of a stainless steel-based metal material containing Ni—Cr, and has a thickness of 20 to 200 μm and a width of 1.
It is a ribbon material of 0 to 1.2 mm. The metal terminal 36 is melt-bonded to the bonding conductor layer 32 by laser welding.

In the resistance element obtained as described above, the metal terminal 36 has a high mechanical strength, and a high load test was carried out by applying a voltage 3 to 4 times the actual use condition for 50 hours.
Very good results were obtained, with changes in resistance and partial pressure ratio within ± 0.2%.

[0012]

As described above, in the conventional method of joining the metal terminals 36 in the resistance element, the initial mechanical strength is excellent, but in the long-term use,
In particular, the mechanical strength of the metal terminal 36 is rapidly deteriorated when it is used for 5000 hours or more. For this reason, the metal terminal 36 is disconnected, and a problem that a predetermined voltage cannot be supplied to the electrode of the electron gun 24 occurs, and an urgent countermeasure is desired.

The present invention has been made in view of the above circumstances, and specifies the composition of a bonding conductor layer formed on a ceramic insulating substrate containing aluminum oxide as a main component and the composition of a metal terminal to be bonded thereto. Therefore, it is an object of the present invention to provide a built-in element for an electron tube in which the mechanical strength of a metal terminal does not suddenly deteriorate even during long-term use and a method for manufacturing the same.

[0014]

According to the present invention, a resistance layer is formed on an insulating substrate, a metal terminal is electrically connected to the resistance layer through a bonding conductor layer, and the bonding conductor layer is palladium. It is composed of a mixed sintered layer containing silicon and titanium, and the metal terminal is a built-in element of an electron tube made of nickel.

Further, according to the present invention, when the resistance layer is formed on the insulating substrate and the metal terminal is electrically connected to the resistance layer through the bonding conductor layer, the bonding conductor layer has an average grain size of 0. .2
60 to 85% by weight of palladium powder having an average particle size of 1 to 5 μm, 5 to 10% by weight of silicon powder having an average particle size of 1 to 5 μm, and 10 to 30 titanium hydride powder having an average particle size of 3 to 5 μm.
A conductive paste prepared by kneading 85 parts by weight of inorganic powder containing 15% by weight of organic powder and 15 parts by weight of organic vehicle is printed on an insulating substrate and then fired. The metal terminal is made of nickel having a purity of 99.8% or more. And a thickness of 30 to 60 μm, the metal terminal is bonded to the bonding conductor layer.

[0016]

According to the present invention, the mechanical strength of the metal terminal does not suddenly deteriorate even when it is used for a long time, particularly for a long time exceeding 5000 hours. Therefore, it is possible to obtain an extremely highly reliable built-in element of an electron tube and a method for manufacturing the same, without causing a problem that a predetermined voltage cannot be supplied to the electrodes in the electron tube due to the disconnection of the metal terminals.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. A built-in element such as a resistance element of the electron tube according to the present invention is configured as shown in FIGS. 1A, 1B, and 1C, and FIG. 1A is a state seen through from an insulating coating layer forming an outer surface portion. Is a plan view showing (A) in (a).
A sectional view taken along line -A 'and viewed in the direction of the arrow, (c)
FIG. 7B is a cross-sectional view showing an enlarged main part of FIG.

That is, on a ceramic insulating substrate 11 containing aluminum oxide as a main component, a resistor made of lead ruthenate metal oxide having a predetermined sheet resistance value and lead borosilicate glass. A resistance layer 12 is formed by printing the material in a zigzag pattern, drying and firing. Furthermore, the conductor layer 13 for connection electrically integrated with the resistance layer 12 is formed.
And a metal terminal 16 joined to the joining conductor layer 13. Insulating coating layers 14 and 15 are formed so as to cover the resistance layer 12.

In this case, the bonding conductor layer 13 comprises 60 to 85% by weight of palladium powder having an average particle size of 0.2 to 1 μm, 5 to 10% by weight of silicon powder having an average particle size of 1 to 5 μm, and an average particle size of 85 parts by weight of inorganic powder containing 10 to 30% by weight of titanium hydride powder of 3 to 5 μm and 15 parts by weight of organic vehicle are kneaded, printed on the insulating substrate 11, and then baked and mixed. It consists of a sintered layer.

The metal terminal 16 is made of nickel having a purity of 99.8% or more and has a thickness of 30 to 60 μm, and the metal terminal 16 is melt-bonded to the bonding conductor layer 13. Next, a method of manufacturing the above resistance element will be described. First, a resistance pattern is printed by a screen printing method using a resistance paste on one surface of an insulating substrate 11 made of ceramics containing aluminum oxide as a main component. Then, the solvent in the paste is removed by drying at 120 to 150 ° C. for 10 to 20 minutes to form the resistance layer 12. At this time, the resistance paste is a material composed of a metal oxide containing lead ruthenate and lead borosilicate glass, and has a sheet resistance value of about 10 ⁶ to 10 ⁷ Ω / □. Further, the print pattern is a predetermined zigzag pattern so that a predetermined voltage division ratio can be obtained at each metal terminal 16.

Next, a conductor paste is printed on the same surface as the resistance layer 12 on the insulating substrate 11. After that, 120 ~
By drying at 150 ° C. for 10 to 20 minutes to remove the solvent in the paste, the bonding conductor layer 13 is formed. At this time, the conductive paste contains 6 parts of palladium powder having an average particle size of 0.2 to 1 μm.
0 to 85% by weight, more preferably 65 to 75% by weight
And 5 to 10% by weight of silicon powder having an average particle size of 1 to 5 μm, more preferably 8 to 10% by weight and an average particle size of 3 to 5 μm.
10 to 30% by weight, and a more preferable range is 15 to 25% by weight. This is a conductor paste obtained by kneading 85 parts by weight of an inorganic powder made of these and 15 parts by weight of an organic vehicle made of ethyl cellulose, α-terpineol or the like. The print pattern is printed in a predetermined shape so as to come into contact with the resistance pattern. Further, the printed film thickness is printed such that the film thickness after firing is 40 to 60 μm. This is because the film does not sublime during the laser welding of the metal terminal 16 described later, and the welding is performed well.

Next, the resistance layer 12 and the bonding conductor layer 13 are fired by heating in an air atmosphere at 840 to 860 ° C. for about 8 to 10 minutes. The resistance layer 12 thus obtained has a total resistance value of 2 × 10 ^{9 to} 3 × 10 ⁹ Ω. At this time, when the voltage division ratio at each metal terminal 16 is not within the predetermined range, the resistance layer for resistance value correction provided in each resistance portion of the resistance layer 12 is ground by a sandblast method or the like,
It is corrected so that each partial pressure ratio is within a predetermined range.

Next, a glass paste for insulation coating is printed on predetermined portions of both surfaces of the insulating substrate 11. Then 1
The solvent in the paste is removed by drying at 20 to 150 ° C. for 10 to 20 minutes to form the insulating coating layer 14. At this time, the glass paste is a paste containing lead borosilicate glass as a main component and a mixed material of a transition metal oxide such as iron oxide, chromium oxide and nickel oxide and an organic vehicle. Further, the insulating coating layer 14 is printed so as to have a predetermined film thickness in order to obtain a predetermined withstand voltage characteristic. The film thickness after firing is 200 to 500 μm on the surface side having the resistance layer 12, and 50 to 200 μm on the other both sides.

Next, the insulating coating layer 14 is baked by heating at 570 to 630 ° C. in an air atmosphere for about 8 to 10 minutes. Next, the insulating coating layer 15 that covers the side surface of the insulating substrate 11 is formed. This is to prevent the unnecessary discharge phenomenon by covering the exposed ceramics portion having a higher secondary electron emission ratio than the insulating coating glass layer. A glass paste containing lead borosilicate-based glass as a main component and a transition metal oxide such as iron oxide, chromium oxide, or nickel oxide is used. A glass paste is applied to a predetermined portion of the paste by a dispenser method and dried at 120 to 150 ° C. for 10 to 20 minutes to remove the solvent component in the paste.

Then, heat treatment is performed in an air atmosphere at 570 to 630 ° C. for about 8 to 10 minutes to remove the organic components and sinter the inorganic components in the insulating coating layer 15. Then, the metal ribbon material is bonded by a laser welding method to the conductor layer 13 for joining.
To form the metal terminal 16. This metal terminal 16
Is made of nickel with a purity of 99.8% or more and has a width of 1.0 to
A ribbon material having a thickness of 1.5 mm and a thickness of 30 to 60 μm is used.

The ribbon material is supplied as it is at the time of joining, and after being joined to the joining conductor layer 13, it is cut into a predetermined length by a laser beam. Since the ribbon material is supplied in this way, it is not necessary to mount small metal parts machined to a predetermined length, and it is possible to flexibly cope with metal terminals 16 having different lengths. It has excellent properties.

Regarding the material of the metallic ribbon, the purity is 99.
The material is not limited to nickel of 8% or more, and any material that can be melted, diffused, and bonded to the conductive material used in the bonding conductor layer 13 may be used. Other examples include Ni-Co-Fe alloy, Ni-Fe alloy, Fe-Ni-Cr alloy and the like. The thickness of the metal ribbon is preferably 30 to 60 μm. If the thickness is 30 μm or less, the mechanical strength of the metallic ribbon is insufficient, and the resistance of the resistance element to the electron tube cannot be sufficiently secured. Further, if the thickness exceeds 60 μm, the ribbon is melted, so that it is necessary to increase the output of the laser beam, and the damage to the bonding conductor layer 13 becomes large. Therefore, peeling of the bonding conductor layer 13 may occur.

The laser welding conditions used in this example are shown in Table 1. Further, in this embodiment, the laser welding method under the conditions shown in Table 1 was used, but the joining conductor layer 13 and the metal terminal 1 were used.
The conditions and means are not limited to these as long as it is a method capable of melt-bonding No. 6.

[0029]

[Table 1]

Hereinafter, the manufacturing process of the conventional resistance element is the same. Metal terminal 1 of the resistance element made as described above
No. 6 has a sufficient joint strength of 1.5 to 2.5 kg in the tensile test. In addition, no deterioration was observed in the bonding strength even after the actual operation test for 10,000 hours.

It should be noted that palladium, which is the main component of the conductor paste, is 8% even if fired in an oxidizing atmosphere.
It is difficult to oxidize at a temperature of about 50 ° C. On the contrary, in this temperature range, conductivity is maintained because the oxygen is reduced and oxygen is released. Therefore, the conductor layer made of palladium has sufficient conductivity. However, the cost of palladium alone is high. Further, in order to obtain a sufficient bonding strength, the film is melted and the firing temperature must be 1300 ° C. or higher in order to form a dense film. Therefore, in order to lower the melting point of palladium, silicon is added to form a eutectic alloy to lower the melting point. Palladium and silicon have a eutectic point around 850 ° C. for that reason,
Firing at 850 ° C., which is the standard firing temperature for thick film resistors, is possible. Further, the particle diameters are specified so that palladium and silicon can be easily melted to form a dense conductor layer. Palladium preferably has a particle size of 0.2 to 5 μm. The particle size is more preferably 0.2 to 1 μm. When the particle size is smaller than 0.2 μm, secondary agglomeration is likely to occur, and on the contrary, the particle size becomes apparently large, and the melting temperature varies. On the other hand, if the particle size exceeds 1 μm, the particles are sufficiently melted and sintered, so that it is necessary to prolong the reaction time, which is not preferable in manufacturing. 1 to 10 for silicon
A particle size of μm is preferred. The particle size is more preferably 1 to 5 μm. Since silicon is pulverized into powder, if the particle size is 1 μm or less, it tends to be oxidized during pulverization to contain impurities. Further, since the shape tends to be irregular, the sinterability varies. When the particle size is more than 5 μm, the particles are sufficiently melted and sintered similarly to palladium, so that the reaction time needs to be lengthened, which is not preferable in production.

Titanium hydride improves the adhesion between the bonding conductor layer and the substrate. This is because titanium in titanium hydride reacts with aluminum oxide in the substrate to form a titanium aluminate layer at the interface between the bonding conductor layer and the insulating substrate made of ceramics and firmly adheres to it. By adding titanium in the state of titanium hydride, hydrogen gas is released during firing, and contact between titanium and the oxidizing atmosphere is suppressed. Furthermore, since titanium hydride releases hydrogen in a temperature range higher than the debinding temperature range, it is in the titanium hydride state in the debinding temperature range, so there is little reaction with carbon generated during debinding, and titanium and the atmosphere The effect of suppressing the reaction with the titanium inside is also high. Therefore, aluminum oxide and titanium in the insulating substrate can sufficiently react with each other to form titanium aluminate. Therefore, the bonding conductor layer can have sufficient adhesion strength.

The metal terminal has a thickness of 30 to 6 as described above.
It is made of nickel having a purity of 99.8% or more at 0 μm. Therefore, at the time of fusion bonding, the titanium component and the palladium existing in a portion relatively close to the surface layer in the bonding conductor layer are mutually diffused and alloyed. As a result, the bonding strength is significantly improved as compared with the conventional one, and the sufficient bonding strength can be maintained for a long time.

In the above embodiment, the resistance element is taken as an example of the built-in element of the electron tube, but the built-in element is not limited to the resistance element, and the present invention can be applied to a capacitor and other active or passive elements. It

[0035]

According to the present invention, the conductor layer for joining is made of a mixed sintered layer containing palladium, silicon and titanium hydride, and the metal terminal is made of nickel. The mechanical joining strength between the joining conductor layer and the metal terminal does not suddenly deteriorate. Therefore, it is possible to provide a highly reliable built-in element of the electron tube.

Further, according to the manufacturing method of the present invention, it is possible to prevent the film strength from being lowered due to the film shrinkage cracks while lowering the firing temperature. Further, by producing the paste by mixing titanium hydride powder, it is possible to effectively suppress the oxidizing atmosphere and the reaction between carbon and titanium during firing, and improve the adhesion between the substrate and the conductor film. You can

[Brief description of drawings]

1 (a), (b) and (c) show a built-in element of an electron tube according to an embodiment of the present invention, and (a) shows a state seen through from an insulating coating layer forming an outer surface portion. Plan view,
(B) is a cross-sectional view taken along the line AA 'of (a) and viewed in the direction of the arrow, and (c) is a cross-sectional view showing an enlarged main part of (b).

FIG. 2 is a schematic cross-sectional view showing the whole of a general color CRT.

FIG. 3 is an enlarged cross-sectional view showing a main part (near the electron gun structure) of the color cathode ray tube in FIG.

4 (a), (b), (c) show a built-in element of a conventional electron tube, (a) is a plan view showing a state seen through from an insulating coating layer forming an outer surface portion, (b). Is B- in (a)
Sectional drawing which cut | disconnected along the B'line and was seen in the arrow direction, (c) is sectional drawing which expands and shows the principal part of (b).

[Explanation of symbols]

11 ... Insulating substrate, 12 ... Resistance layer, 13 ... Bonding conductor layer,
14, 15 ... Insulating coating layer, 16 ... Metal terminals.

Claims (2)

[Claims] 1. A built-in element for an electron tube, comprising a resistance layer formed on an insulating substrate, and a metal terminal electrically connected to the resistance layer via a bonding conductor layer, wherein the bonding conductor layer is palladium. An electron tube built-in element comprising a mixed sintered layer containing silicon, titanium, and titanium, and the metal terminal made of nickel. 2. A method of manufacturing a built-in element for an electron tube, comprising forming a resistance layer on an insulating substrate and electrically connecting a metal terminal to the resistance layer via a bonding conductor layer, wherein the bonding conductor layer comprises: 60 to 85% by weight of palladium powder having an average particle size of 0.2 to 1 μm, and an average particle size of 1 to 5 μm
5 to 10% by weight of silicon powder having an average particle size of 3 to 5 μm
The inorganic paste containing 10 to 30% by weight of titanium hydride powder of m and 85 parts by weight of the organic vehicle and 15 parts by weight of the organic vehicle are kneaded and printed on the insulating substrate, and then baked to obtain the above metal. A method for manufacturing a built-in element for an electron tube, characterized in that the terminal is made of nickel having a purity of 99.8% or more and has a thickness of 30 to 60 μm, and the metal terminal is bonded to the bonding conductor layer.