JPH11233321A - Resistor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately adjust the resistance characteristic of a resistor element to be incorporated in an electronic tube through trimming. SOLUTION: A resistor element is constituted in such a way that a plurality of electrodes 43a, 43b, 43c, 44, and 45, are formed on an insulating substrate 41, and at the same time, a resistor layer 46 which connects the electrodes 43a, 43b, 43c, 44, and 45 with each other is formed on the substrate 41. In the resistor layer 46, trimming sections 47 for adjusting the splitting ratio are formed. Then the resistance characteristic of the resistor element is adjusted by forming removed sections in the trimming sections 47 with a laser beam. Therefore, the resistance characteristic of the resistor element can be adjusted accurately, without producing dust trimming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a resistor element capable of adjusting a resistance characteristic by trimming.

[0002]

2. Description of the Related Art Conventionally, as an electron tube, for example, in a color cathode ray tube used for a color television receiver, a high voltage needs to be supplied to a convergence electrode and a focus electrode in addition to an anode voltage.

In such a case, if a high voltage is supplied from the stem portion of the color cathode ray tube, a problem occurs in terms of withstand voltage. Therefore, a resistive element for voltage division is incorporated in the color cathode ray tube together with an electron gun, and the resistive element is A method has been proposed in which the anode voltage is divided to supply a high voltage to each electrode.

A resistor element (a resistor for a built-in electron tube) incorporated in such a color cathode ray tube is, for example, shown in FIG.
It is configured as shown in (a), (b) and (c). 8A is a plan view of the resistive element viewed from above the insulating coating layer, FIG. 8B is a cross-sectional view taken along line A1-A2 of FIG. 8A, and FIG. It is.

That is, the resistor element 1 is formed by printing, drying, and drying an electrode material composed of a metal oxide containing ruthenium oxide and lead silicate glass on a ceramic insulating substrate 2 such as aluminum oxide. A plurality of fired electrodes 3 are formed, and between the electrodes 3, a resistance material composed of a metal oxide containing ruthenium oxide and lead borosilicate glass is formed in a shape such that a predetermined resistance value can be obtained. To form a resistor layer 4 printed, dried and fired.
Similarly to the resistor layer 4, a trimming portion 5 for adjusting a division ratio is formed. An insulating coating layer 6 is formed so as to cover the resistor layer 4. A lead terminal 7 is connected to each electrode 3.

[0006] The condition required for such a resistor element 1 is that it be stable in the pressure resistance treatment and the heating step in the color CRT manufacturing process. Resistance change and outgassing due to Joule heat generated during operation are small. Do not become a secondary electron emission source when scattered electrons hit. Disturbing the electric field portion of the electron gun so as not to displace the discharge or the trajectory of the electrons.

In general, in an electron tube to which a high voltage is applied, in order to improve the withstand voltage characteristics, a high voltage having a peak voltage of about 2 to 3 times the normal operating voltage after the exhaust in the manufacturing process is completed. Is applied, and a forcible discharge is performed to remove burrs and deposits on the electrodes of the electron gun which cause a decrease in the withstand voltage by forced discharge. When this withstand voltage processing is applied to a color cathode ray tube in which the resistor element 1 is disposed, a deposition film made of a metal ring of the electron gun is deposited on the insulating coating layer 6 of the resistor element 1 thereunder, and the deposited film is charged. Discharge occurs due to the potential difference between the applied potential and the resistor layer 4,
The resistor layer 4 is disconnected or damaged.

As a result, in the case of disconnection, voltage division becomes impossible, causing a fatal failure. In the case of damage, the resistance value and the division ratio of the resistor element 1 change. Since the numerical tolerance of the division ratio of the resistor element 1 is strict, it must be adjusted to ensure that the division ratio tolerance at the time of production falls within the standard.

For this purpose, the resistor element 1 is provided with a trimming portion 5 in each resistor layer 4 for adjusting the division ratio.
The cutting ratio is adjusted by shaving the trimming portion 5 by a sand blast method.

[0010]

However, when the division ratio is adjusted by the sandblast method as in the prior art,
Since dust is generated, a measurement error or equipment failure occurs due to the dust, and stable split ratio adjustment cannot be performed, and a demand for a tight split ratio tolerance cannot be satisfied.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resistor element capable of precisely adjusting a resistance characteristic by trimming without generating dust as in the related art.

[0012]

According to the present invention, there is provided a resistor element comprising:
An insulating substrate, a plurality of electrodes formed on the insulating substrate, a resistor layer connected to the electrodes, formed on the insulating substrate, and having a trimming portion in at least a part thereof, and a laser formed on the trimming portion. And a removing unit formed by beam processing.

Thus, in the trimming portion of the resistor layer,
By forming the removed portion by laser beam processing and performing trimming, it is possible to accurately adjust the resistance characteristics without generating dust as in the related art during trimming.

Further, since the trimming portion is formed in a separate step for the resistor layer, required resistance characteristics can be easily obtained.

Further, the removal part of the trimming part is made of CO ₂
Even if the thickness of the trimming part is thinner than the wavelength of the laser beam, it is removed by heat from the CO ₂ laser to a part of the insulating substrate, and the resistor layer of the trimming part is securely formed Can be trimmed.

Further, the trimming portion removing portion is formed in at least one of a ladder shape and a lattice shape, and can reduce the thermal effect of a CO ₂ laser or the like.

Further, the insulating substrate is formed of a ceramic material, and the resistor layer and the trimming portion are formed of a resistor containing a glass component. It can be implemented reliably.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 6 show a first embodiment. FIG. 1 is a plan view seen from above an insulating coating layer of a resistor element. FIG. 2 is a sectional view taken along line B1-B2 of FIG. 3 is an enlarged plan view of the trimming portion, FIG. 4 is a side view of the electron gun, FIG. 5 is a perspective view of the electron gun, and FIG. 6 is a sectional view of the color cathode ray tube.

In FIG. 6, the color cathode ray tube has an envelope (vacuum vessel) composed of a panel 11 and a funnel 12, and has a three-color fluorescent light emitting blue, green and red on the inner surface of the panel 11. A phosphor screen 13 composed of a body layer is formed, and a shadow mask 14 having a large number of electron beam passage holes is arranged inside the phosphor screen 13 so as to face the phosphor screen 13. On the other hand, the funnel 12 neck
An electron gun 17 that emits three electron beams 16B, 16G, and 16R is arranged in 15a.

The three electron beams 16B, 16G and 16R emitted from the electron gun 17 are deflected by a magnetic field generated by a deflection yoke 18 mounted on the outside of the funnel 12, so that the phosphor screen 13 is horizontally and vertically. It is formed in a structure for displaying a color image by scanning.

4 and 5, an electron gun structure of an electron gun 17 is disposed in a neck portion 15a of the funnel 12, and the electron gun structure has a first grid electrode common to three cathodes. G1, the second grid electrode G2, the third grid electrode G3, the fourth grid electrode G4, the fifth grid electrode G5,
The sixth grid electrode G6, the seventh grid electrode G7, and the eighth grid electrode G8 are sequentially arranged coaxially, and the eighth grid electrode G8
The convergence electrode 21 is arranged at the subsequent stage.

The grid electrodes G1 to G8 are mechanically held by a bead glass 22 while maintaining a predetermined positional relationship with each other. Further, the third grid electrode G3 and the fifth grid electrode G5 are electrically connected by a conductive wire 23, and the convergence electrode 21 is electrically connected to the eighth grid electrode G8 by welding.

A resistor element (a resistor for incorporating an electron tube) 24 is attached to such an electron gun assembly, and high-voltage extraction terminals 25a and 25b provided on the resistor element 24 are provided.
, 25c are the seventh grid electrode G7 and the sixth grid electrode G
6 and the fifth grid electrode G5. Further, an extraction terminal 26 to the convergence electrode 21 is connected to the convergence electrode 21, and an extraction terminal 27 on the ground side is connected to the ground electrode pin 28.

On the other hand, on the inner wall of the funnel portion 15b of the funnel 12, a graphite conductive film 29 extending to the inner wall of the neck portion 15a is adhered. The anode voltage is supplied through a power supply (not shown). The convergence electrode 21 is provided with a conductive spring 30. When the conductive spring 30 contacts the graphite conductive film 29, the convergence electrode 21, the eighth grid electrode G8, and the lead-out terminal 26 of the resistor element 24 are formed. The anode voltage is supplied to the high-voltage output terminals 25a, 25b, and 25c, and the divided voltage is applied to the seventh grid electrode G7 and the sixth grid electrode.
G6 and the fifth grid electrode G5.

Further, in order to stabilize the potential distribution in the neck portion 15a, a metal ring 31 is provided so as to surround the bead glass 22 and the resistor element 24 from an intermediate portion of the third grid electrode G3. The metal ring 31 is heated by high frequency heating or the like to form a deposited film on the inner wall of the neck 15a.

1 to 3, the resistance element 24
Has an insulating substrate 41 made of ceramics such as aluminum oxide (alumina), and a plurality of substrate through holes 42 are formed in the insulating substrate 41.

On the insulating substrate 41, electrodes 43a, 43b, and 43c are formed at an intermediate portion corresponding to the position of each substrate through-hole 42, and electrodes 44 and 45 are formed at both ends. . These electrodes 43, 43b, 43c, 44, 45
An electrode paste material composed of, for example, a metal oxide containing ruthenium oxide and lead borosilicate glass is printed, dried, and fired.

Further, on the insulating substrate 41, the electrodes 43a, 43
The resistor layer 46 in contact with b, 43c, 44, and 45 is formed in a pattern set so as to obtain a predetermined resistance value. At the same time, a trimming portion 47 for adjusting the division ratio is formed on each part or part of the resistor layer 46 for adjusting even when the ratio is deviated from a predetermined division ratio, and the division ratio can be adjusted even after resistance firing. I can do it. The resistor layer 46 and the trimming portion 47 are formed by printing, drying, and firing a resistor paste material composed of, for example, a metal oxide containing ruthenium oxide and lead borosilicate glass, so that the total resistance value is 1.0 × It is formed to be 10 ⁹ Ω.

Further, an insulating coating layer 48 is formed on the insulating substrate 41 so as to cover the resistor layer 46 and avoid the electrodes 43a, 43b, 43c, 44 and 45.

Further, the metal terminals 25a corresponding to the electrodes 43a, 43b, 43c, 44, and 45 not covered with the insulating coating layer 48.
, 25b, 25c, 26, 27 are fixedly connected by caulking.

The adjustment of the division ratio of the resistor element 24 will be described.

In this embodiment, a trimming portion 47 is formed in each portion of the resistor layer 46, and a part of the trimming portion 47 is removed by laser beam processing.
A plurality of removal portions 49 are formed in a ladder-like pattern, and the division ratio is adjusted.

As described above, the trimming portion 47 of the resistor layer 46 is formed.
In addition, by forming the removed portion 49 by laser beam processing and performing trimming, it is possible to accurately adjust the division ratio without generating dust as in the related art during trimming.

When a commonly used YAG laser (wavelength: 1.06 μm) is used in laser beam processing, the thickness of the resistor layer portion of the trimming portion 47 is smaller than the wavelength of the laser. A small amount of the resistor remains on the surface 41, and the underlying insulating substrate 41 must be heated to remove that portion of the resistor. However, the heat is absorbed by the insulating substrate 41 in the case of the YAG laser. It remains and cannot be removed. On the other hand, a CO ₂ laser (wavelength 1
In the case of 0.6 μm), similarly to the YAG laser, it is not possible to remove the resistor of the trimming portion 47 having a wavelength equal to or less than the wavelength, but it is possible to heat the base insulating substrate 41 and remove even a part of the insulating substrate 41. The trimming portion 47 can be reliably removed.

Also, a trimming unit using this CO ₂ laser
When removal of 47 was performed, high heat was applied by the CO ₂ laser to the conductive portion of the resistor in the trimming portion 47.
Depending on the shape of 49, stable division ratio adjustment could not be performed.

Therefore, the shape of the removal portion 49 of the trimming portion 47 is formed in a ladder shape, and for the plurality of resistor elements 24, the division ratio of the resistor elements 24 is adjusted and four items of characteristic evaluation (accelerated life test, voltage characteristic test, Temperature characteristic test, high-temperature storage test).

In the division ratio adjustment, the variation after the division adjustment is 0.7% in the comparative example (an example in which the shape of the removing portion 49 is not a ladder), whereas the variation after the division ratio adjustment is 0.7% in the ladder shape. Was within 0.3%, and good products were obtained within tight tolerance standards and within all specifications.

In the evaluation of characteristics, in the comparative example, the change in the division ratio was excessively large due to the heat generated by the CO ₂ laser, which was a problem. That is, in the accelerated life test, the applied voltage was set to 40 kV so as to become twice the load in the actual operation,
In the test applied to time, the change was 0.3% in the case of the ladder shape, compared with the change of 1.0% in the comparative example. In the voltage characteristic test, the voltage applied to the resistor element 24 was changed from 1 kV to 30 kV.
In a test in which the change was performed to kV and the change in the split ratio at that time was confirmed, the change was 1.3% in the ladder-like case, compared with the change of 1.3% in the comparative example. The temperature characteristic test is a test for confirming a change in the division ratio of the resistor element 24 in a high-temperature layer from normal temperature to 300 ° C. It became. In the high-temperature storage test, the resistor element 24 was left in a high-temperature layer at 400 ° C. with no load for 10 hours.
In a test for confirming a change in the split ratio after 10 hours, the change was 0.8% in the comparative example, and was 0.2% in a ladder shape.

Therefore, based on the above results, by setting the shape of the removing portion 49 of the trimming portion 47 to a ladder shape, CO
₂ It was demonstrated that the thermal effect of the conductive part of the resistor by the laser can be reduced.

In this embodiment, the trimming section 47
The shapes of the removing portions 49 are ladder-shaped, but are not limited to these shapes, and they can be arbitrarily selected according to the required accuracy of the division ratio. That is, FIG.
As shown in the second embodiment, even in the case of a lattice shape, the thermal effect of the CO ₂ laser can be reduced as in the case of the ladder shape.

In this embodiment, the resistor layer 46 is printed simultaneously with the trimming section 47. However, if simultaneous printing is impossible due to the required total resistance value, the sheet resistance value differs. Even when printing is performed by separating the resistance paste, a stable division ratio adjustment can be similarly performed.

The resistor element 24 is not limited to a color cathode ray tube, but can be applied to other electron tubes requiring a voltage dividing resistor.

[0044]

According to the resistor element of the present invention, by removing and trimming the trimmed portion of the resistor layer by laser beam processing, dust is generated at the time of trimming as in the prior art. And the resistance characteristics can be adjusted accurately.

Further, by forming the trimming portion in a separate step for the resistor layer, required resistance characteristics can be easily obtained.

Further, the removal part of the trimming part is made of CO ₂
By laser beam processing with a laser, even if the film thickness of the trimming portion is smaller than the wavelength of the laser beam, C
A part of the insulating substrate is removed by heat generated by the O ₂ laser, so that the resistor layer at the trimming portion can be surely trimmed.

Furthermore, by forming the removed portion of the trimming portion in at least one of a ladder shape and a lattice shape, it is possible to reduce the thermal effect of the CO ₂ laser or the like.

Further, the insulating substrate is formed of a ceramic material, and the resistor layer and the trimming portion are formed of a resistor containing a glass component. Adjustment can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a plan view of a resistor element according to a first embodiment of the present invention, as seen through from an insulating coating layer.

FIG. 2 is a sectional view taken along line B1-B2 of FIG.

FIG. 3 is an enlarged plan view of the trimming unit according to the first embodiment;

FIG. 4 is a side view of the electron gun.

FIG. 5 is a perspective view of the electron gun.

FIG. 6 is a sectional view of the color CRT according to the first embodiment;

FIG. 7 is an enlarged plan view of a trimming unit according to a second embodiment of the present invention.

8A and 8B show a conventional resistor element, wherein FIG. 8A is a plan view of the resistor element as seen through from an insulating coating layer, and FIG. 8B is a plan view of FIG.
FIG. 2 is a sectional view taken along line A1-A2, and FIG.

[Explanation of symbols]

 41 Insulating substrate 43a, 43b, 43c, 44, 45 Electrode 46 Resistor layer 47 Trimming section 49 Removal section

Claims (5)

[Claims] An insulating substrate; a plurality of electrodes formed on the insulating substrate; a plurality of electrodes formed on the insulating substrate connected between the electrodes;
A resistor element comprising: a resistor layer having a trimming portion in at least a part thereof; and a removing portion formed by laser beam processing in the trimming portion. 2. The resistor element according to claim 1, wherein the trimming portion is formed in a separate step for the resistor layer. 3. The resistor element according to claim 1, wherein the trimming portion is removed by laser beam processing using a CO ₂ laser. 4. The resistor element according to claim 1, wherein the trimmed portion is formed in at least one of a ladder shape and a lattice shape. 5. The electronic substrate according to claim 1, wherein the insulating substrate is formed of a ceramic material, and the resistor layer and the trimming portion are formed of a resistor containing a glass component, and are used for incorporating an electron tube. 4. The resistor element according to any one of 4.