JPH08124729A - Film resistor for trimming, its mounting structure, and its trimming method - Google Patents

Abstract

PURPOSE: To reduce the area occupied by a film resistor for high-accuracy trimming. CONSTITUTION: After forming an insulating film 3 on a resistor 2 for rough adjustment formed on a substrate, a resistor 7 for fine adjustment connected in series through a conductor 4 is provided on the insulating film 3. After the resistor 2 for rough adjustment is trimmed toward a direction changing point (c) from a starting point (b), the resistor 7 for fine adjustment are trimmed toward an ending point (d) after the direction of the resistors 7 is changed by 90 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimming film resistor, its mounting structure and its trimming method, and more particularly to a trimming film resistor formed on a part of a hybrid integrated circuit board, its mounting structure and trimming. Regarding the method.

[0002]

2. Description of the Related Art Referring to Japanese Utility Model Laid-Open No. 61-22304, which describes a conventional trimming film resistor, as shown in FIG. 8, first and second electrodes formed on a main surface of an insulating substrate. On both ends of the electric conductors 5 and 6, the rough adjusting portion resistor 9 and the fine adjusting portion resistor 10 are formed as one projecting region 8.

Here, the right side of one protruding region 8 is rectangular and is coated with a resistance material having a uniform thickness. Therefore, the resistance value per square is uniform everywhere, and the fine adjustment part resistance is Form 10. A resistor having the same resistance value extends from the lower right corner of the resistor 10 to the right, and the second conductor 6
The left side of the resistor 10 continues to the right side of the coarse adjustment unit resistor 9 as it is. The rough adjustment portion resistor 9 has four openings 11, and no resistance material is deposited on the openings 11 to expose the lower insulating substrate. The resistor 9 has a rectangular shape as a whole, and a resistor having the same resistance value extends from a lower left corner thereof and is connected to an end of the first conductor 5, and the right side of the rectangle continues to the fine adjustment unit resistor 10 as it is. .

The resistor constructed and constructed as described above exhibits a resistance value lower than an actually required resistance value, and is set to a desired resistance value in the trimming step to be performed next.

In the trimming process, the surface of the resistor is irradiated with a laser beam while scanning, and the resistor in the irradiated portion is removed as droplets by the energy of the laser beam. The insulating substrate is exposed at the removed portion, and this portion is electrically insulated. Laser beam scanning is performed manually or automatically by preprogrammed numerical control.
A probe (not shown) is provided on each of the second conductors 5 and 6.
Touches each other and can proceed while constantly monitoring the resistance value. Here, a laser beam is applied from below to above so as to traverse the plurality of openings 11, and the resistor is cut until it reaches a constant value slightly smaller than a desired resistance value.

Here, as shown by the laser beam locus 20, when the resistance value becomes a constant value slightly smaller than a desired value, the laser beam is scanned from the left side to the right side. Further, the laser beam is scanned from the upper side to the lower side to perform the final fine adjustment. The region surrounded by the laser beam locus 20 is electrically insulated and therefore does not need to be removed, and the scanning of the laser beam is finished at the position where the desired resistance value is exhibited and the region is removed. The splashed body is cleaned and the trimming process is completed.

After that, electronic components electrically connected to the first and second conductors 5 and 6 are mounted on this substrate.

The necessary number of trimming film resistors as described above are formed on the insulating substrate.

[0009]

In such a conventional trimming film resistor, the rough adjusting portion resistor 9 and the fine adjusting portion resistor 1 are used.
Since 0 and 0 are formed adjacent to each other on the plane, there is a problem that the film resistor occupies a large area on the plane and cannot be mounted at high density. In particular, it is impossible to form such a large number of film resistors on a limited substrate,
If it is forcibly formed, the space between the film resistors will become small, so that capacitive coupling etc. via the insulating substrate cannot be neglected, and a stable desired state such as an oscillation phenomenon occurring in the mounted amplification element will occur. There was a problem that the characteristics of No. 1 could not be obtained. After trimming the resistor 9, the resistor 1
It was necessary to move to the trimming start point of 0, and time was lost during this time.

In view of the above problems, the present invention has the following problems.

(1) To reduce the area occupied by the film resistor.

(2) To provide as many film resistors and electronic components as possible on a limited insulating substrate.

(3) The electrical coupling between the film resistors should be negligibly small.

(4) To make the incorporated electronic parts stably operate with desired characteristics.

(5) To improve the degree of freedom of layout on the insulating substrate.

(6) Trimming so that the resistance value can be adjusted with high accuracy.

(7) Trimming work should be performed continuously.

[0018]

The first structure of the present invention is as follows.
In a trimming film resistor formed on an insulating substrate, a film resistor including a rough adjusting resistor having an opening and a fine adjusting resistor is stacked on the insulating substrate. As described above, the coarse adjustment resistor and the fine adjustment resistor are formed via an insulating film, in particular, the coarse adjustment resistor and the fine adjustment resistor, The film resistor for trimming according to claim 1, wherein the film resistor is electrically connected via a conductor.

A second structure of the present invention is a trimming film resistor formed by forming, on an insulating substrate, a film resistor including a rough adjusting resistor having an opening and a fine adjusting resistor. In the body, the rough adjustment resistor and the fine adjustment resistor are stacked on the insulating substrate so that the main surfaces thereof are in direct electrical contact with each other.

The mounting structure of the present invention is characterized in that the trimming film resistor of the first or second configuration is connected to an external terminal of an operational amplifier.

In the trimming method of the present invention, the trimming operation of the trimming film resistor according to claim 1 or 3 connected to the external terminal of the operational amplifier does not put the operational amplifier into an operating state and the characteristics of the amplifier. It is performed while monitoring.

Further, in the trimming method of the present invention, in the trimming step of the trimming film resistor having the first or second structure, after the rough adjustment resistor is trimmed, the trimming direction is changed and the trimming method is continuously performed. The trimming of the fine adjustment resistor is started.

[0023]

1 is a plan view of a trimming film resistor according to a first embodiment of the present invention and FIG. 2 is a sectional view taken along the line aa 'thereof. A fine adjustment resistor 7 is partially formed on the upper surface of the resistor 2 with an insulating film 3 interposed therebetween.

The coarse adjustment resistor 2 has a rectangular shape and has five rectangular openings 11 therein, the upper left corner of which is connected to the first conductor 5, and the upper right corner of which is an intermediate conductor. The body 4 is connected. The fine adjustment resistor 7 has a rectangular shape, the conductor 4 is connected to its upper side, and the second conductor 6 is connected to its lower side.

As shown in FIG. 2, the insulating film 3 is preferably formed by a screen printing method between the upper resistor 7 and the lower resistor 2 and between the lower resistor 2. The insulating film 3 is formed to have a predetermined thickness and is slightly wider than the upper resistor 7 in order to secure the electrical insulation of the upper and lower resistors 7 and 2, but protects the lower resistor 2. As described above, the resistor 2 may be formed so as to cover the entire surface thereof. It is preferable that the resistor 7 or 2 is formed in a later step of the conductors so as to come into contact with the side surfaces and the upper surfaces of the end portions of the conductors 4, 5, and 6.

The preferred materials for the components of this embodiment are:
It is as follows.

In the case of a thin film substrate; the insulating substrate is ceramic, the conductors 4, 5 and 6 are thin film tantalum, the resistors 2 and 7 are tantalum nitride, and the insulating film 3 is glass ceramic. The conductors 4, 5, 6 and the resistors 2, 7 are formed by a sputtering method and have a thickness of about 1 μm.

In the case of a thick film substrate; the substrate is ceramic, the conductors 4, 5 and 6 are silver palladium, the resistors 2 and 7 are ruthenium oxide, and the insulating film 3 is glass ceramic. Both are formed by screen printing.

In the trimming process of the film resistor of this embodiment, as shown by the laser beam locus 20, starting from the starting point a, scanning is performed downward, and the resistance between the openings 11 of the coarse adjustment resistor 2 is reduced. Opening 1 where the body is cut one after another and the resistance value becomes smaller than the desired value.
Stop at direction change point c in 1 and then scan to the right. At this time, the beam is cut so as to traverse the fine adjustment resistor 7, and is stopped at the end point d when the resistance value reaches a desired value.

Further, when fine adjustment is necessary, the beam may be scanned upward from the end point d.

At this time, there is a concern that the resistor 2 in the lower layer may be disconnected at the same time, but since the resistor 2 has already been disconnected between the starting point b and the direction change point c, the variation in the resistance value due to the disconnection of the resistor 2 Can be ignored.

In the description of the structure and the trimming process of this embodiment, the description common to the above-mentioned prior art is omitted.

In this embodiment, since the fine adjustment resistor 7 is arranged on the upper layer of the coarse adjustment resistor 2, the occupied area is reduced by about 30%, and depending on the configuration, it may be up to 50%.
It can be reduced to nearly%.

From the start point b to the direction change point c, the resistance value of the coarse adjustment resistor 2 increases stepwise,
The resistance value of the fine adjustment resistor 7 does not change. Since it is preferable for the work efficiency to immediately start trimming of the fine adjustment resistor 7 from this direction change point c, the distance e between the left side of the fine adjustment resistor 7 and the straight line from the start point b to the direction change point c is It is preferable to perform trimming by bringing the laser beam close to the left side of the resistor 7 so as to be as small as possible. During trimming from the direction change point c to the end point d, the resistance value of the coarse adjustment resistor 2 remains unchanged. As described above, one of the features is that the trimming end point of the coarse adjustment resistor 2 immediately becomes the trimming start point of the fine adjustment resistor 7.

The fine adjustment resistor 7 is formed via the insulating film 3 so as to cover the entire surface of the coarse adjustment resistor 2 except for the straight line connecting the starting point b and the direction changing point c. May be. Although the conductors 5 and 6 extend in the left-right direction, they can be extended in the required direction such as the up-down direction. For effective trimming, the intermediate conductor 4 is more preferably formed on the same side as the conductor 5, that is, on the upper side of the drawing. That is, it is preferable that the resistor 7 has both poles formed in a direction crossing the resistor 2 between the openings 11.

Further, although the rough adjustment resistor 2 is arranged in the lower layer of the fine adjustment resistor 7, it may be arranged in the opposite upper layer.

As described above, since the area occupied by the film resistors can be reduced, more film resistors can be arranged, and the distance between the film resistors can be increased. Unnecessary electrical coupling is small, so stable operation of electronic components can be ensured. In addition, the degree of freedom of component layout on the main surface of the insulating substrate is improved. Since the conductor 4 is interposed between the coarse and fine adjustment resistors 2 and 7, there is also an advantage that the resistor 7 can be appropriately laid out at a position where trimming work of the fine adjustment resistor 7 can be easily performed. is there.

In this embodiment, the upper and lower resistors 7,
Even if 2 is the reverse layer, the same effect can be obtained.

Referring to FIG. 3 showing the film resistor of the second embodiment of the present invention, in this embodiment, the conductor 4 of the first embodiment is not provided, and the right side of the coarse adjustment resistor 2 remains unchanged. It is common to the first embodiment except that it is connected to the right side of the fine adjustment resistor 7 and that the conductor 6 is not connected to the bottom and is output from above. The description of the part is omitted.

The trimming method of this embodiment is the same as the first method described above.
It is common with the embodiment of.

In addition to the effect of the first embodiment, the effect of this embodiment is that the occupying area is further reduced because there is no intermediate conductor, and the manufacturing method is further simplified.

Referring to FIG. 4 which is a plan view of the film resistor of the third embodiment of the present invention, this embodiment does not include the insulating film 3 of the first and second embodiments, but has upper and lower layers. Resistors 7, 2
And are in direct contact with each other on the main surfaces. In this embodiment, the resistance value of the resistor 2 in the lower layer is the same as that of the resistor 7 in the upper layer.
The film thickness and the material are selected so as to be about 1/10 of the resistance value of. The laser beam locus 20 travels in the up-and-down direction at approximately one-half on the left side, and travels to the right at a predetermined position in the opening. Further, if necessary, the process proceeds upward to end the trimming.

In this embodiment, the upper and lower resistors 7, 2 are
Is used for rough adjustment, and for fine adjustment in the opening having only the resistor 7 in the upper layer.

In this embodiment, the upper and lower resistors 7, 2
Is used for rough adjustment, and the increase in the resistance value of the resistor 2 in the lower layer is dominant, whereas the increase in the resistor 7 in the upper layer is small.

During the trimming of only the upper resistor 7, the change of the resistor 2 is small, and the increase of the resistance value of the resistor 7 becomes dominant. This embodiment also has an advantage that fine adjustment can be immediately (continuously) performed by changing the trimming direction by 90 °.

The effect of this embodiment is that the occupied area is smaller than that of the above embodiment and the manufacturing method is simple.

In this embodiment, the upper and lower resistors 7,
Even if 2 is the reverse layer, the same effect can be obtained. In the above third embodiment, what is common to the first embodiment is that
The description is omitted.

In the second embodiment, the upper layer resistor 7 may be formed to have substantially the same size as the lower layer resistor 2. In the third embodiment, the resistor 7 may be formed on the resistor 2. It may be formed partially.

The number of openings 11, the vertical and horizontal dimensional ratios of the resistors 2 and 7, the film thickness of the resistors 2 and 7, the direction in which the conductors 5 and 6 are drawn out, etc. are limited to those in each of the above embodiments. Not something
It can be changed as needed.

Referring to FIG. 5 showing an electronic component to which any one of the film resistors of the first, second and third embodiments described above is connected, a DC amplifier as an example of an operational amplifier (operation amplifier). A (DC amplifier) 21 is shown, a resistor 29 is connected between the output terminal 26 and the positive-phase input terminal 24, and a resistor 28 is connected between the input terminal 27 and the resistor 29.
Are connected, and the negative-phase input terminal 25 is grounded. Since the amplification factor is determined by the resistance value ratio of the resistor 28 and the resistor 29, it is preferable to use the above-described highly accurate trimmed film resistor. In this case, one of the resistors 28 and 29 made of the above film resistor may be a trimmed film resistor, and the other resistor may not be trimmed. The trimming of this membrane resistor is D
Before connecting C amplifier 21, it is desirable, but DC amplifier 2
When the variation in the characteristics within 1 affects the amplification degree, the DC amplifier 21 is mounted, the power is turned on, the operating state is set, and then the voltages of the input terminal 27 and the output terminal 26 are monitored. Trimming resistor 28 or 29,
It is preferable to perform fine adjustment to a desired amplification degree. The DC amplifier 21 is preferably separated between the resistors 28 and 29 for the purpose of preventing oscillation, and in that sense, the film resistor is preferably used.

Further, referring to FIG. 6 showing another electronic component to which any one of the film resistors of the above-mentioned embodiment is connected, this application example is applied to the adder 22, and the positive phase input terminal 3 is applied.
The resistor 33, the first, the second, and the third between 0 and the output terminal 32.
Resistors 34, 35 and 36 are connected between the input terminals 37, 38 and 39 and the positive phase input terminal 30, respectively. The negative phase input terminal 31 is grounded. The respective voltages applied to the first, second, and third input terminals 37, 38, 39 are output as the inverted value of the added output terminal 32.

Here, the resistors 34, 35 and 36 are formed of the above film resistor so as to match the resistance value of the resistor 33.
Trimming is adjusted. In this adder 22, the resistance 33
May oscillate if placed near the resistors 34, 35, 36, the above-mentioned embodiment in which the area occupied by the resistors is small is used, and at least the reduced area is placed apart from each other. I hope that.

When the effect of the characteristics of the adder 22 on the addition performance cannot be ignored, the adder 22 is connected to bring it into an operating state, and the resistors 34 and 3 are connected by the laser beam.
Trim 5,36. At this time, the input terminals 37, 3
It is more desirable to proceed with the trimming while monitoring the input voltages of 8 and 39 and the output voltage of the output terminal 32.

Further, referring to FIG. 7 showing a circuit of a differential amplifier (differential amplifier) to which any one of the film resistors of the above-mentioned embodiment is connected, an output terminal 42 of this differential amplifier 23 and a positive phase input. Resistor 43 between terminal 40 and positive phase input terminal 40
And a first input terminal 47 with a resistor 45, a negative-phase input terminal with a ground, and a second input terminal 48 with a resistor 44, a resistor 4
6 are connected to each other. Where all resistors 3
If the resistance values of 3, 34, 35 and 36 are made equal to each other,
Since a differential output of the input (E1-E2) is obtained in principle, one of these resistors is used as a reference and the other three resistors are trimmed and adjusted. The condition setting at the time of trimming is the same as that in the case of FIGS.

The various operational amplifiers shown in FIGS. 5, 6 and 7 are more preferably operated from DC to several tens of KHz, and can be operated with other circuit configurations.

[0056]

As described above, according to the present invention,
Since the coarse and fine adjustment resistors have a stacked structure and the area occupied by the film resistor is reduced, the above-mentioned respective problems are achieved, and in particular, it is easy to use as an external resistance of an operational amplifier, and the degree of freedom in design and application are improved. The number of ranges and the like can be expanded, and trimming can be continuously performed in a short distance.

[Brief description of drawings]

FIG. 1 is a plan view showing a trimming film resistor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line aa ′ of FIG.

FIG. 3 is a plan view showing a second embodiment of the present invention.

FIG. 4 is a plan view showing a third embodiment of the present invention.

FIG. 5 is a circuit diagram showing an example in which an embodiment of the present invention is used in a DC amplifier.

FIG. 6 is a circuit diagram showing an example in which an embodiment of the present invention is used in an adder.

FIG. 7 is a circuit diagram showing an example in which an embodiment of the present invention is used in a differential amplifier.

FIG. 8 is a plan view showing a conventional trimming film resistor.

[Explanation of symbols]

1 Insulating Substrate 2 Rough Adjusting Resistor 3 Insulating Film 4, 5, 6 Conductor 7 Fine Adjusting Resistor 8 One Protruding Area 9 Rough Adjusting Part Resistor 10 Fine Adjusting Part Resistor 11 Opening 20 Laser Beam Trajectory 28, 29, 33, 34, 35, 36, 43 to 46
Resistance 21 DC amplifier 22 Adder 23 Differential amplifier 24, 30, 40 Positive phase input terminal 25, 31, 41 Reversed phase input terminal 26, 32, 42 Output terminal 27, 37, 38, 39, 47, 48, 49 Input Terminal b Start point c Direction change point d End point e Interval

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[Procedure amendment]

[Submission date] December 14, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

The rough adjustment resistor 2 has a rectangular shape and has an opening 11 therein, and is connected to the first conductor 5 at the upper left corner thereof and is connected to the intermediate conductor 4 at the upper right corner thereof. ing.
The fine adjustment resistor 7 has a rectangular shape, the conductor 4 is connected to the upper side thereof, and the second conductor 6 is connected to the lower side thereof.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

In the case of a thin film substrate; the insulating substrate is ceramic, the conductors 4, 5 and 6 are gold, the resistors 2 and 7 are tantalum nitride, and the insulating film 3 is polyimide. The conductors 4, 5, 6 and the resistors 2, 7 are formed by a sputtering method and have a thickness of about 1 μm.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 27/04 21/822

Claims (6)

[Claims] 1. A trimming film resistor in which a film resistor including a coarse adjustment resistor having an opening and a fine adjustment resistor is formed on an insulating substrate, wherein the insulating substrate A trimming film resistor, wherein the coarse adjustment resistor and the fine adjustment resistor are formed so as to be stacked on each other with an insulating film interposed therebetween. 2. The trimming film resistor according to claim 1, wherein the coarse adjustment resistor and the fine adjustment resistor are electrically connected via a conductor. 3. A film resistor for trimming, comprising a film resistor provided with a resistor for coarse adjustment having an opening and a resistor for fine adjustment formed on an insulating substrate. A trimming film resistor, wherein the resistor and the fine adjustment resistor are stacked on the insulating substrate so that the main surfaces thereof are in direct electrical contact with each other. 4. A mounting structure for a trimming film resistor, wherein the trimming film resistor according to claim 1 or 3 is connected to an external terminal of an operational amplifier. 5. The trimming work of the trimming film resistor according to claim 1, which is connected to an external terminal of the operational amplifier, is performed while the operational amplifier is in an operating state and the characteristics of the amplifier are monitored. A method for trimming a film resistor for trimming, which comprises: 6. The trimming film resistor trimming step according to claim 1, wherein after the rough trimming resistor is trimmed, the trimming direction is changed to continuously change the fine trimming resistor. A method for trimming a film resistor for trimming, characterized in that the trimming is started.