JPS62132353A - Regulating method for electronic circuit - Google Patents

Abstract

PURPOSE:To reduce a trimming mistake and to insert and mount another sub substrate by retrimming the sub substrate even if the mistake occurs by forming a regulating resistor by screen printing on the sub substrate, and positioning a plurality of regulating resistors on the sub substrate. CONSTITUTION:Through-holes 11' to which comb terminal 11 group of a sub substrate 5 formed integrally with regulating resistors of regulating variable resistors 2 and printed resistors 2' are inserted are opened in an electronic circuit board 1. Measuring cables 10 having characteristic measuring probes are led from predetermined position of the board 1 to a circuit characteristics measuring unit 7 to measure the circuit characteristics. A computer 9 issues a target regulating value to the measuring unit 7, controls a laser trimmer 8 to emit laser light 4 to predetermined positions of regulating resistors 3 to vary resistance values. The sub substrate 5 trimmed at the resistors 3 in response to the variability in characteristics of components is inserted into the holes 11' on the board 1 and mounted by connecting means such as soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention processes a printed resistor formed on a sub-board in order to adjust the characteristics of an electronic circuit to a predetermined target value, and then returns the processed sub-board to a predetermined adjustment target value. The present invention relates to a method for adjusting an electronic circuit mounted on an electronic circuit board.

2. Description of the Related Art A conventional method for adjusting an electronic circuit board is as shown in Fig. 2, in which two semi-fixed resistors are mounted on an electronic circuit board 1, and an adjuster drives the semi-fixed resistors using a screwdriver while looking at an oscilloscope. A method of adjustment was adopted. In addition, as shown in Fig. 3, with the recent trend toward hybridization, resistors 2' are screen printed on ceramic substrates, and after firing, electronic circuit components such as ICs, transistors, diodes, capacitors, and coils are attached to the circuits. A method of trimming the printed resistor using a laser or sandblasting to achieve a predetermined characteristic has also been realized.Problems to be Solved by the InventionHowever, when adjusting by an adjuster, even a skilled worker cannot achieve high precision. The required adjustments took a long time and were extremely inefficient.

In addition, with the method of directly trimming the printed resistor on the ceramic substrate, unless advanced resistor printing technology and trimming technology are used, trimming errors may occur, even if the electronic circuit components other than the adjustment resistor are good. Regardless, the entire electronic circuit board becomes defective, resulting in poor yields.
This method has the disadvantage that productivity is significantly reduced and economic losses are also significant.

The present invention provides a method for adjusting electronic circuits that eliminates the drawbacks of the above-mentioned conventional examples and can improve yield and productivity.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the method for adjusting an electronic circuit according to the present invention provides a method for adjusting an electronic circuit in which a plurality of adjustment resistors are mounted on an electronic circuit board on which a plurality of adjustment resistors are not mounted. The resistors formed on the sub-board corresponding to the adjustment resistances are temporarily connected to the adjustment points on the electronic circuit board, and each resistor is adjusted to a predetermined adjustment target while measuring the characteristics of the electronic circuit with a circuit characteristic measuring device. The trimmed sub-board is then mounted on the electronic circuit board.

By doing the above, even if a trimming error occurs, the entire circuit will not become defective, and component costs can be reduced, making it possible to adjust electronic circuits with high yield and productivity. This also reduces constraints on circuit design.

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

In the figure, 1 is an electronic circuit board, 6 is a sub-board on which a plurality of adjustment resistors 3 to be adjusted are formed on the electronic circuit board by screen printing, etc., and the terminals of the adjustment resistors 3 are inserted into the electronic circuit board 1. The com terminal 11 connected to the com terminal 11 to be fixed and the through-hole hole 11 of the electronic circuit board
' is the unmounted state of the sub-board 6, and in order to configure the circuit, probe contacts (indicated by - in the figure) are attached at both ends.
Connected by a connecting cable with On the other hand, the circuit measuring device 7 is similarly connected to the electronic circuit board 1 by a measuring cable 1o having a contact probe. 8 is a laser beam 4 so that the circuit performance reaches a predetermined value using the circuit characteristic measuring device 7.
This is a laser trimmer that trims the resistor.

The laser trimmer 8 and the circuit characteristic measuring device are controlled by a computer 9.

An outline of the operation in the above configuration will be explained.

The electronic circuit board 1 shown in FIG. 1 has a group of 11 com terminals on a sub-board 5 on which the adjustment resistors 2 and printed resistors 2' shown in the conventional examples shown in FIGS. 2 and 3 are collectively formed. A through-hole hole 11' is bored into which a can be inserted.

The connection cable 6 is connected to the through-hole conductor and the com terminal 11.
The electronic circuits are connected as shown in FIGS. 2 and 3 of the conventional example. On the other hand, a measuring cable 10 having a characteristic measuring probe is led from a required location on the electronic circuit board 1 to a circuit characteristic measuring device 7, so that circuit characteristics can be measured. The computer 9 sends the adjustment target value to the circuit characteristic measuring device 7, and controls the laser trimmer 8 to irradiate the laser beam 4 to required locations on the adjustment resistor 30 to change the resistance value.

The change in resistance of the adjustment resistor results in a change in the circuit characteristics, and when the circuit characteristics reach the adjustment target value given by the computer 9, the circuit characteristics measuring device 7 changes the circuit characteristics to the computer 9.
A signal to stop the irradiation of the laser beam 4 is transmitted to the computer 9, and the computer 9 stops the irradiation of the laser beam 4 from the laser trimmer 8. In this way, the sub-board 5 with each adjustment resistor 3 trimmed is inserted into the through-hole hole 11' on the electronic circuit board 1 and soldered etc. The adjustment of the electronic circuit of the present invention is completed by mounting with the connecting means.

Effects of the Invention According to the present invention, the adjustment resistors can be formed on the sub-board by screen printing, and the positioning of a plurality of adjustment resistors can be performed with respect to the sub-board, so that trimming errors can be reduced. Even if a trimming error occurs, you can re-trim another sub-board and insert and mount it on the electronic circuit board. This will prevent the entire circuit board from becoming defective, as would be the case if a resistor is formed directly on the electronic circuit board and then trimmed. Teshi 1
This brings about a great industrial effect in that the adjustment yield and productivity of electronic circuit boards are significantly improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an adjustment device in an embodiment of the present invention;
FIGS. 2 and 3 are perspective views showing conventional electronic circuit adjustment states. 1...Electronic circuit board, 3...Adjustment resistor, 5...
=・Sub board, 6... Connection cable, 7...
...Circuit characteristics measuring device, 8...Laser trimmer, 9...Computer, 10...Measurement cable, 11...Com terminal, 11'... Through-hole hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] Temporarily connecting resistors formed on a sub-board corresponding to the plurality of adjustment resistors on the electronic circuit board to the adjustment points of the electronic circuit board on the electronic circuit board on which the plurality of adjustment resistors are not mounted;
An electronic circuit characterized in that each resistor is trimmed to a predetermined adjustment target value while measuring the characteristics of the electronic circuit with a circuit characteristic device, and the trimmed sub-board is mounted on the electronic circuit board. How to adjust.