SU1413557A1 - Device for inspecting the quality of metal-coating of holes of printed-circuit boards - Google Patents

Abstract

The invention relates to instrumentation technology and can be used to control the quality of the metallization of holes in printed circuit boards. The purpose of the invention, the enhancement of functionality, is achieved by increasing the number of

Description

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honest controlled parameters of printed circuit boards. The device implementing the invention contains a current stabilizer 1, an upper 2 and a lower 3 contact heads, probes 4, drives 5 and 6 for feeding printed circuit boards, a drive 7 for feeding heads, a control unit 8, a control panel 9, a signal meter 10, a block 11 automatic control, register 12, software control unit 13, photo-reading unit 14, switch 15, reference metallization sensor 16, operating mode switch 17, comparison unit 18, electronic key 19, contact pad 20, controlled printed circuit board 21 and linear block 22 cheating with the current. 2 z.p, f-ly, 2 silt,

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The invention relates to an instrumentation technique and can be used to control the quality of the metallization of holes in printed circuit boards. .

The aim of the invention is to expand the functionality by increasing the number of monitored parameters of printed circuit boards.

Fig, 1 shows the functional diagram of the device; Fig. 2 is a functional block diagram of a linearly varying current.

The device contains a current stabilizer 1, the top 2 and bottom 3 contact heads, probes 4, the first 5 and second 6 print feed drives 1x boards, the contact head feed drive 7, control unit 8, control panel 9, signal meter 10, block 11 control automation, recorder 12, software control unit 13, photo-reading unit 14, switch 15, reference metallization sensor 16, operation mode switch 17, comparison unit 18, electronic 19, pad 20, controlled printed circuit board 21, linearly variable current And what is the first switched input of the switch 19 connected to the output of the stabilizer 1, the input of which is connected to the first output of the sensor 16, the input of which is connected to the first output of the switch 15, the second and third outputs of which are connected respectively to the first and second inputs of the switch 17, the third and fourth inputs of which are connected respectively with. the second and third pins of the switch 15, the fourth and fifth

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10 5 0 5

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the findings of which are connected to the first Outputs, respectively, of the key 19 and the block 11, the second output of which is connected to the input of the recorder 12, and the third is connected to the first input of the block 13, the second input of which is connected to the output of the block 14, and the output to the first input of the block 8, the second input of which is connected to the fourth output of block P, the first input of which is connected to the first output of block 8, the second and third outputs of which are connected to the inputs of the first 5 and second 6 respectively, the fourth to the input of the drive 7, and the third input to the output of the console 9, fifth exit blo and 1 is connected to the second switched input of the switch 19, the switching of which is connected to the input of the meter 10, the output of which is connected to the input of the block 18, the output of which is connected to the second input of the block 11, the test and the seventh conclusions of the switch 13 are connected respectively to the first and second pins contact head 2, and the eighth and ninth, respectively, with the first and outputs of the contact head 3, the input unit 22 is connected to the sixth output unit 11, and the first and second outputs, respectively, with the tenth and eleventh output switch 15.

Unit 22 contains (FIG. 2) and an integrator 23, a level converter 24, a voltage converter 25 (direct to current, comparator 26, first 27 and second 28 controlled voltage dividers, work type switch 29, logic element 4ID-NE 30 , button 31, ammeter 32 and indicator 33, to the input

314

which is connected to the first output of the element 4И-НЕ 30, to the inputs of which the first output of the comparator is connected, 26, to the first input of which the first output of the block 22 and the first output of the converter 25 are connected, the input of which is connected to the output of the divider 27 whose input is connected to the output of the converter 2A, the input of which is connected to the output of the integrator 23, the input of which is connected to the second output of the comparator 26, to the second input of which the output of the divider 28 is connected, the second output of the converter 25 is connected to the first output of the ammeter 32, the second output of which It is connected to the second output of block 22, the input of which is connected to the input of switch 29, the output of which is connected to the third. entrance {samparatora 26.

The device works as follows.

Probes 4 are installed on the pads 20 of the metallized opening of the printed circuit board 2. The mode switch 17 is set to the Calibration position, and the key} 9 is opened along a closed circuit: a stabilizer, a key 19, normally closed contacts of the switchpads of the switches 5, the sensor 16 flows through the reference current. Since the value of the ohmic resistance of the sensor 16 is known, the measuring path of the device is calibrated by the meter 10. Then the switch 17 is moved to the Measurement position and the key 19 is closed. In this position of the switch 17, the key 19 opens and closes only under the condition that the probes 4 of the heads 2 and 3 are in contact with the contact pad 20 of the printed circuit board 21. After the next measurement by the signal of the block 11, the key 19 is first closed, and C is the lifting of the contact heads 2 and 3. It prevents scorching1 | Probes 4.

At the command of unit 8, the actuators 5 and 6 set the state 21 to the initial position, coinciding with the origin of the area.

Further operation of the device is carried out according to the program. In block 14, the program is read and processed in block 13, from where it is supplied as commands to block 8. Drives 5 and 6

7

carry out the testing of the specified program for moving the board.

After that, according to the signal of the block B, the clock system of the block 11 is started. By the signal of the block 11, the stepper drive 7 is started. The contact heads 2 and 3 are lowered onto the contact pad 20 of the metallized hole. Contact: The probe pressure is adjusted by changing the number of pulses delivered from block 8.

The signal of the clock system of the block P opens the key 19. Through the probes 4

and the metallized opening. current of a certain size flows. The voltage taken from another pair of probes 4, through the switch 17, is fed to the meter 10 signals. With unchanged

current through the metallized hole, the voltage drop is proportional to the ohmic resistance of the metallization of the hole, i.e. the largest voltage judged on the quality of metallization .-

An increase in ohmic resistance is shown as a voltage increase, i.e. metallization in the hole is defective.

The result of measurements in a binary-decimal code is removed from the meter 10 and is stored in block 18. According to the signal of the clock system of block 1, all contact groups of the first relay switch 15 switch to the second position. The stabilizer 1 is connected to another pair of contact probes 4 and a second measurement is made without changing the position of the probes on the board. The result of the second measurement goes to block 18.

If the measurements coincide, block 11 closes key 19 and all contact groups of the second relay

switch 15 switches to tEo second position, and block 22 is connected to contact probes 4, through probes 4 and the metallized hole flows a linearly increasing current of a certain magnitude AND duration, which are set by block 22, which can work both in automatic mode and in manual mode depending on the position of the switch

chatel 29. If switch 29 is in the Avomat position, then when a signal is received from block 11 in integrator 23 of block 22, the linearly varying

over time, the voltage supplied to the converter 24. Depending on the diameter of the controllable hole, the voltage level is set, which through the converter 25 is converted into a proportional amount of current required to test for resistance to a short-term current load of the specified metallized hole. Video current, trojkho through probes 4, a metallized hole, creates a voltage drop, which amplifies and arrives at the comparator 26. When a certain voltage value is reached, a comparator 26 is triggered at the output of which a signal appears that turns off the integrator, and the indicator 33 goes out, and the AND block of this signal brings the relay switches of the switch 15 to the initial state; the key 19 opens. After checking the metallized hole with a short-term current load of a certain size, the ohmic resistance of the metallization of this hole is measured again. The result of the second measurement will go to block 18. When the measurements coincide, block 1 closes the key .19 and blocks 8 and 13 receive a command to raise the contact heads 2 and 3 and enter the next program frame. The results of the first and second measurements are also supplied to block 11, where they are compared with the installation, and if they are higher than the setpoint voltage, the recorder 2 is turned on and the order number of the measurements is printed out, the hole coordinates and the ohmic resistance of the metallization, i.e. on the tape, the data on the defect of the metallized hole and its coordinates are recorded.

Unit 22 can operate in manual mode with the position of the switch 29 Manual. The launch of the block in this case is performed by button 31.

Similarly, all metallized holes of the monitored printed circuit board are tested.

Claims (3)

1. Device for checking the quality of metallization of the holes of printed circuit boards, containing a current stabilizer. five 0 five 0 five 0 five upper and lower contact heads, two PCB feed drives, contact head feed drives, control unit, control panel., signal meter, control automation unit, recorder, program control unit, photo reading unit, switch, reference metal sensor, operating mode switch, the electronic key, the first switch its input of the electronic key is connected to the output of the current stabilizer, the input of which is connected to the first output of the reference metallization sensor, the input of which is connected to the first the output of the switch, the second and third outputs of which are connected respectively to the first and second inputs of the operating mode switch, the third and fourth inputs of which are connected respectively to the second and third terminals of the coaxial, fourth and fifth outputs: which are connected to the first outputs, respectively the key of the automation control unit, the second output of which is connected to the recorder input, and the third to the first input of the program control unit, the second input of which is connected to the output of the photo-reading unit, and the output is connected to the first input of the control unit, the second input of which is connected to the fourth output, the progress of the control automation unit, the first input of which is connected to the first output of the control unit, the second and third outputs of which are connected to the inputs of the first and second drives of the printed circuit boards, respectively the fourth is connected to the input of the feed drive; it is contact: x heads, and the third input is connected to the output of the control panel; the fifth output of the automatic control unit is connected to the second commutator No.1M input of the electronic key, which connects The sixth and seventh terminals of the switch are connected to the first and second terminals of the upper contact plate, the eighth and ninth, respectively, to the first one, respectively. and the second pins of the lower contact plate, that is, so that, in order to expand the functionality of the possibilities due to a twofold definition of the number of monitored parameters of printed circuit boards, a linear varying a current input coupled to a sixth output automation control unit, and the first and second output -, respectively, tenth and eleventh switch terminals. 2. The device according to claim 1, about tl and - that the switch contains two relay switches, each of which consists of four contact groups, with the first contacts of the contact groups of the first burdock switch connected respectively to the first, the second, third, and fourth terminals of the switch, and the switching contacts of the second, respectively, with the sixth, seventh, eighth, and ninth terminals of the switch, the second terminals of the first and second contact groups of the first relay switch, and the third and fourth - with the eleventh output of the switch, the switching contacts of the contact groups of the first burl switch are connected to the corresponding first terminals of the second relay switch, while the first terminals of the first and third contact groups of the second burr terminal are connected to the second terminals, and the second terminals, respectively, to the first terminals of it second and fourth contact groups. 3. The device according to claim 1, which means that the linearly varying current block contains an integrator, a level converter, a voltage-to-current converter, a comparator, two controllable dividers voltage, the switch of the type of work, the logic element 4I-NOT, the button, the ammeter and the indicator, the input of which is connected to the output of the logic element 4I-NOT, the inputs of which are connected to the first computer output 1 $ ator. The first input of which is connected to the nepBbul output of the unit and the first output of the voltage converter to the current, the input of which is connected to the output of the first controlled voltage divider, the input of which is connected to the output of the level converter, the input of which is connected to the output of the integrator, the input of which is connected to the second output a comparator, to the second of which the output of the second controlled voltage divider is connected, the second output of the voltage to current converter is connected to the first the output of the ammeter, the second output of which is connected to the second output of the unit, the input of which is connected to the input of the switch of the kind of work, the output of which is connected to the third input of the comparator.