JPH02178961A - Regulator for electronic circuit - Google Patents

Abstract

PURPOSE:To conduct adjustment with high accuracy by constituting an adjusting resistor in the series connection of a printed resistor and a chip resistor, selecting the value of the chip resistor so that the quantity of trimming is reduced to the printed resistor and loading the chip resistor. CONSTITUTION:An adjusting resistor 8 is composed in the series connection of a printed resistor 3 and a chip resistor 4, and the chip resistor 4 is not mounted previously. The value of the adjusting resistor 8, by which a specified adjusting target value is acquired, and the resistance value of the printed resistor 3 are measured by a resistance measuring instrument 10, and the chip resistor 4 by which the difference of the value of the adjusting resistor 8 and the value of the printed resistor 3 is reduced extremely is selected and loaded. Trimming is conducted to the printed resistor 3 so that an output obtained from the adjusting resistor 8 consisting of the printed resistor 3 and the chip resistor 4 is brought to the adjusting target value. Consequently, the quantity of trimming to the printed resistor 3 can be lowered. Accordingly, adjustment can be performed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic circuit adjustment device for trimming the characteristics of an electronic circuit of a functional module such as a hybrid integrated circuit to a predetermined adjustment target value with high precision and high reliability.

2. Description of the Related Art A conventional method for adjusting an electronic circuit is as shown in FIG.
The adjuster was operating the equipment so that the instructions would match the adjustment target value.

However, this method requires the cost and adjustment time of the semi-fixed volume 2, and there are variations in adjustment.
It was difficult to pursue accuracy and productivity.

In addition, in recent years, hybrid integrated circuits have come into use, in which conductors and resistors are screen printed on a ceramic substrate, and after firing, electronic circuit components such as ICs, transistors, diodes, capacitors, and coils are attached. A method has been realized in which printed resistors are trimmed using laser beams, sandblasting, etc. so that the circuit characteristics obtain a predetermined performance.

Problems to be Solved by the Invention Variations in electronic circuit components, particularly variations in characteristics of integrated circuits, have expanded the variable range of the adjustment resistor. On the other hand, a printed resistor is formed by firing a resistor paste, and it is extremely difficult to suppress the variation to less than a factor of 10, and generally an error of about ±20 qb occurs.

Such a high cut magnification (
The ratio of the resistance value after trimming to the initial resistance value) not only does not allow highly accurate trimming, but also
Deterioration over time, such as drift after trimming, is more likely to occur. In addition, if you try to use printed resistors alone to function as adjustment resistors, if you make a printing mistake, the entire electronic circuit board will be defective, regardless of the quality of the electronic circuit components other than the adjustment resistors, resulting in lower yields. There was a problem in that the performance was poor and productivity was significantly reduced.

The present invention aims to solve the problem described in 1.The present invention is configured such that the adjustment resistor is connected in series with a printed resistor and a chip resistor, and the value of the chip resistor is set so that the amount of trimming is reduced relative to the printed resistor. The aim is to select and install the following to perform high-precision adjustment.

Means for Solving the Problems In order to solve the above-mentioned problems, the electronic circuit adjustment device of the present invention comprises an adjustment resistor for adjusting characteristic variations of electronic circuit components by a series connection of a printed resistor and a chip resistor. means for measuring the value of the adjusted resistance and the resistance value of the printed resistance to obtain a predetermined adjustment target value with the chip resistor unmounted in advance; Means for selectively mounting a chip resistor to minimize the difference, and trimming the output obtained from the adjustment resistor consisting of the printed resistor and the chip resistor to the adjustment target value with respect to the printed resistor. and means.

By doing the above, the amount of trimming for the printed resistor can be reduced, and not only can highly accurate adjustment be made without reducing the trimming speed, but the shape of the printed resistor can also be made smaller. can be achieved.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows an electronic circuit adjustment device 6 base 7 according to the present invention. It is an explanatory diagram and also a conventional example.

FIG. 2 is a diagram showing the relationship between adjustment resistance and output voltage.

When the adjustment resistor vR2 of the circuit to be adjusted 1 in FIG. 3 is varied, the output voltage V. changes as shown in Figure 2.

Adjusted circuit 1 to obtain the same adjustment target value (VTR, T)
Sample IG, Rx4 for 1, R for sample notification 2
It can be seen that an adjustment resistance value of x2 is required.

Generally, in the adjustment process of electronic circuits in the mass production process, the variable range of the adjustment resistor can be limited (hereinafter, the lower limit is referred to as Rmin and the upper limit is Rmax) due to the degree of variation in component parts, so the adjustment resistor V□ can be changed from the variable range Rmin. Rma
The above RX is varied up to x to obtain the adjustment target value (VTRII)T, and it is sufficient to fix it to Rx2.

FIG. 1 shows one embodiment of the present invention, which will be explained below in conjunction with FIG. 2.

In FIG. 1a, 1 is a circuit board to be adjusted, and 2 is a circuit to be adjusted.Although the circuit board 1 to be adjusted often includes a plurality of circuits 2 to be adjusted, in this embodiment, the circuit to be adjusted 2 is shown as one location. ing. A pattern is formed such that a printed resistor 3 and a chip resistor 4 are connected in series as an adjustment resistor for the circuit to be adjusted 2, but the chip resistor 4 is left unmounted.

A measuring jig 6 is attached to the connecting conductor 6 between the circuit to be adjusted 2 and the chip resistor 4, the connecting conductor 6' between the circuit to be adjusted 2 and the printed resistor 3, and the connecting conductor 6'' between the chip resistor 4 and the printed resistor 3. Connecting.

Connecting gloves 7.7', 7'' are connected to the measuring jig 6 in correspondence with the conductors 5.5', 6'', respectively. First, the adjusting resistor 8 is varied within the range of Rmin to Rmax, and the output voltage V . so that the adjustment target value (VTR, T) can be obtained. After that, the value of the printed resistance is measured with the resistance measuring device 1Q. Next, connection proof completed 77, 7/l
and the conductors 6.6', 6'', turn the switch 9 to the b side, and measure the value of the adjustment resistor 8 with the resistance measuring device 1o.

In the next step, shown in Figure 1, the value of the printed resistor is subtracted from the value of the adjustment resistor 8, and a suitable chip resistor 4 is obtained.The nominal tolerance is calculated from the series such as the El 2.124 series used in the mass production process. Select the value, mount it, and solder 7t\-/.

In the next trimming step, FIG. 1C, the mounted chip resistor 4 and the printed resistor 3 printed in advance are formed as an adjustment resistor, and the adjustment target value (v) is again set as the output voltage v0 to RGT. Trimming 11 is applied to the printed resistor so that the printed resistor is

As described above, according to this embodiment, the adjustment resistance for obtaining the desired adjustment target value of the circuit to be adjusted is measured in advance, and the resistance for obtaining the adjustment resistance is divided into a chip resistor and a printed resistor. , since the chip resistor is mounted with a value selected to minimize the amount of trimming when trimming the printed resistor, the output voltage V. is close to the adjustment target value (VTR,T), and even if the trimming operation is performed at a low speed, the trimming time can be significantly shortened.

Effects of the Invention As described above, according to the present invention, since the amount of trimming is reduced when trimming a printed resistor, which has extremely large manufacturing variations, highly reliable and highly accurate adjustment can be performed.

Even if a trimming error occurs, by remounting the chip resistor according to the value of the printed resistor and performing trimming, a trimming error can cause the entire electronic circuit board to fail, regardless of the quality of the components of the circuit to be adjusted. There will be no need to do so, and this will bring great economic and industrial effects.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the electronic circuit adjustment device of the present invention, Fig. 2 is a diagram showing the relationship between adjustment resistance value and output voltage, and Fig. 3 is a block diagram for explaining electronic circuit adjustment and a conventional example. . 1...Circuit board to be adjusted, 2...Circuit to be adjusted, 3
・Printed resistor, 4...Chip resistor, 61.5",
, 5"... Conductor, 6. Measuring jig, 8 Adjustment resistor, 9 Switch, 10... Resistance measuring device, 11... Trimming trajectory. Name of agent: Patent attorney Shigetaka Awano, 1st person
Figure (CL) (b) Yi (C) b7 also known as J Biao Gu. 2.゛T or ζ4'Ashinuma (-word 1-λsu 5 units 2be; ya 1 thigh shibu chrysanthemum

Claims (1)

[Claims] Adjustment resistors for adjusting characteristics variations in electronic circuit components are constructed by connecting a printed resistor and a chip resistor in series, and the chip resistor is left unmounted in advance to obtain a predetermined adjustment target value. means for measuring the resistance value and the resistance value of the printed resistor; means for selectively mounting a chip resistor to minimize the difference between the adjusted resistance value and the printed resistance value; and the printed resistor and the chip resistor. 1. An electronic circuit adjustment device comprising: a means for trimming an output obtained from an adjustment resistor consisting of a printed resistor so that the output obtained from the adjustment resistor comprising a printed resistor becomes an adjustment target value.