JPS6330000A - Method of mounting optimum resistance onto circuit board - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for optimally mounting resistors on a circuit board, and is used to manufacture electronic circuit boards using a chip resistor mounting machine and a function adjusting and measuring machine. .

BACKGROUND OF THE INVENTION Conventionally, semi-fixed resistors are retrofitted to parts of the circuit that require adjustment, and adjustments are made manually or mechanically during the adjustment process.

It is also possible to mount printed resistors or chip resistors and perform functional trimming using a laser trimming device or the like.

Problems to be Solved by the Invention The former method of the prior art requires a step of mounting a semi-fixed resistor, which is an oddly shaped component, and there is concern about the stability of the characteristics after adjustment.

In addition, in the latter case, the resistor to be adjusted is printed and mounted together with other resistors, so only the adjustment man-hours are required, and after adjustment, it becomes a fixed resistance, so the characteristics are stable, but since a laser trimming device is used for adjustment, the equipment The cost will be higher.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides, as a first invention, a function adjustment measuring device for determining the constant of the resistance to be adjusted on a circuit board having a function adjustment location, and a function adjustment measuring device for determining the resistance value to be adjusted. Using a chip resistance mounting machine equipped with a stock of two-chip resistors of the required type □ for each range, and a control device that manages the function adjustment measuring instrument and the chip resistance mounting machine, The device is characterized in that the output is received by the control device to select a necessary combination of chip resistors, instruct it to the chip resistor mounting machine, and mount the selected step resistors on the circuit board. It is.

A second invention, in contrast to the first invention, is such that when the control device instructs the chip resistor mounting machine to select a combination of chip resistors, the actual value of the instructed resistor is measured by the resistance measurement. The value is fed back to the control device, and then the resistances are combined while correcting the resistors to be mounted, and the resistors based on the corrected combinations are mounted by the chip resistance mounting machine. It is characterized by being mounted on a circuit board.

In the first invention, the constant of the resistance to be adjusted on the circuit board where the function adjustment part is located is determined by the function adjustment measuring device, and this data is received by the control device to select the necessary combination of chip resistors. can.

This selection is instructed to the chip resistor mounting machine, which picks up the selected chip resistor from stock and mounts it on the circuit board, making it possible to mount the optimal resistor on the circuit board or individually without trimming.

In the second invention, the actual value of the indicator resistor related to the selected combination of chip resistors in stock is measured by a resistance measuring device, and this measured value is fed back to the control device to determine which chip resistors should be mounted next. The resistor is corrected, and a chip resistor based on the selected combination is mounted on the circuit board while making this correction.The error of the stocked chip resistor is also considered without trimming, and a more appropriate resistor is mounted. can do.

Embodiment To explain the embodiment of the present invention shown in FIGS. 1 to 4, as schematically shown in FIG. Function adjustment measuring instrument 2 that measures constants during optimum function adjustment of the board
The controller 1 receives the data measured by the function adjustment measuring device 2, selects a combination of constants of the chip resistor to be mounted on the board to be measured, and instructs this to the chip resistor mounting machine 3, The selected chip resistor is mounted on the circuit board P. Here, the chip resistor mounting machine 3 is stocked with the necessary types of chip resistors,
Pick up and implement according to the selection command.

Note that one resistor R to be adjusted (Fig. 2) should not be composed of a single resistor, but rather a plurality of resistors R1, R2, and R3 of different ranges connected in series as shown in Fig. 2. If various resistance values are synthesized and selectively used, adjustments can be made without trimming, which is convenient.

Furthermore, if the chip resistor mounting machine has a stock divided into 10 equally spaced parts for each range, it is possible to select resistors that are compatible with each digit of the decimal representation of the value instructed by the control device. . If the optimum resistance value is 123Ω, it can be divided into 10KΩ, 20KQ, and 3Ω.

In order to mount in this manner, the circuit pattern of the circuit board P to be mounted must also be such that multiple chip resistors can be mounted.The chip resistor mounting machine 3 must also have a built-in resistance measuring device. In addition to measuring the actual value of the resistor to be actually mounted and determining whether the resistor is defective, the measurement data is returned to the control device 1 to perform combinations of resistors while correcting the resistor to be mounted next. , a resistor based on this corrected combination can be mounted on the circuit board P by the chip resistor mounting machine 3.

To explain this specifically, if the resistance value R is made up of n resistors, (1) R=Σ rK rK>rK+1 = 1, but in reality each resistor has an error εK.

■ gK=rK rK rK is actually measured data. This error εK is actually measured for the first selected chip resistor, and the next rK+1 is corrected using the error εK at that time, and "K+
, is used instead of rK+1.

■ ``K11=rK+1'' Repeat this method to combine and mount the required number of chip resistors to obtain the required resistance value. FIG. 3 represents an algorithm for such a method.

If the chip resistance error is 10% or less, ε1 is 1 of H.
It is less than 1/0, ε2 is less than 1%, and ε3 is 0.1%.
You can expect the following.

By the method described above, circuit functions can be adjusted with high precision without providing an adjustment step after board assembly and without using expensive equipment such as a laser trimming device.

Furthermore, since the resistance after adjustment is a fixed resistance, the stability of the product is good.

In the method of the present invention, it is necessary to stock many types of chip resistors, but by limiting the range of resistances for adjustment at the circuit design stage, the number of required types of resistors can be reduced.

Furthermore, if there are many types of resistors in stock, it is possible to manufacture a wide variety of products.

FIG. 4 shows an example of a specific apparatus for implementing the method.

In this example, the board P is supplied from the loader 7, and the control device 1 determines the combination of mounted resistances for each board P based on data measured by the function adjustment measuring instrument 2. At the same time, the resistance stocker 8 provided in the chip resistance mounting machine 3 moves, and the rotary mount head 9 of the mounting machine 3 takes out the resistors related to the determined combination from the stocker 8, and the resistance measurement probe 1
With 4.

Once transferred to the position regulating section 10, the chip resistance value is measured.

This measured value is fed back to control device #1 to process defective chips and correct the indicated value of the resistor to be taken out next. During this time, the substrate P is moved from the loader 7 to the table 11 and positioned for mounting. Position regulating section 10
Take out the chip resistor again and place it on the board P on the table 11.
to be implemented.

After that, move the table, show the chip resistance range, measure the resistance value,
The mounting is repeated, and when all the resistors have been mounted, the board is transferred from the substrate pH table 11 to the unloader 12 and unloaded.

Effects of the Invention Since the present invention has the above-described configuration and operation, it is possible to perform functional adjustment by combining a chip resistor mounting machine and a measuring device without using a laser trimming device or the like, thereby reducing equipment costs.

In particular, in the second aspect of the invention, it is possible to more appropriately mount the resistor, taking into consideration the actual measurement error of the resistor to be mounted.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an apparatus for carrying out the present invention; The figure is a flowchart for correcting the resistance value when the above-mentioned resistors are mounted, and FIG. 4 is a plan view showing a specific example of an apparatus implementing the present invention. 1... Control device, 2... Function adjustment measuring device, 3... Chip resistance mounting machine, 14...
Resistance measurement probe, P...Circuit board. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
S1 Figure 2 R Rt>R2> R3

Claims (2)

[Claims] (1) A function adjustment measuring device that determines the constant of the resistance to be adjusted on a circuit board with a function adjustment location, a chip resistance mounting machine equipped with a stock of chip resistors with different resistance values, and the function adjustment measuring device and the chip. A control device that manages the resistor mounting machine is used to select a necessary combination of chip resistors and instruct the chip resistor mounting machine to select a necessary combination of chip resistors by receiving the output from the function adjustment measuring device into the control device. . A method for optimally mounting a resistor on a circuit board, comprising: mounting the selected chip resistor on a circuit board. (2) A chip resistor mounting machine equipped with a function adjustment measuring device that determines the constant of the resistance to be adjusted on a circuit board with a function adjustment point, a stock of chip resistors with different resistance values, and a resistance measuring device, and the above-mentioned function. Using an adjustment measuring device and a control device that manages a chip resistor mounting machine, the control device receives the output from the function adjustment measuring device, selects a necessary combination of chip resistors, and selects the combination of chip resistors. To instruct the mounting machine, the actual value of the specified resistor is measured by the resistance measuring device, the value is fed back to the control device, and then the resistance is measured while correcting the resistor to be mounted. A method for optimally mounting a resistor on a circuit board, characterized in that the resistor based on the corrected combination is mounted on the circuit board by the chip resistor mounting machine.