SU752828A1 - Printed circuit board checking apparatus - Google Patents

Description

one

The invention relates to radio engineering and can be used in the output control of finished multilayer printed circuit boards.

A device for control of printed circuit boards is known, which contains a contact block with spring-loaded pins, a diaphragm-switching block and a switch of points connected to measuring devices, a dielectric template with holes corresponding to the controlled points of the circuits 1.

A disadvantage of this device is the presence of a complex dial-up unit that determines the complexity of the entire device.

It is also known a device for control of printed circuit boards, containing two contact fields, a program block made in the form of a perforated pattern, each hole of which corresponds to one point (usually the beginning) of a controlled circuit of a printed circuit board, relay switching unit, a step relay and a measuring unit

2 ..

During control of the printed circuit board, the board is connected to the measuring unit with the help of a connecting pin.

block, and on the other contact field, a perforated template is installed, corresponding to the type of board being tested,

5 When the template is installed, the pins of the contact block located at the perforation sites sink and connect to the contact sockets electrically connected to the relay switching unit.

In monitoring the integrity of the printed conductors, the step relay makes it possible for the measuring device to be connected to the circuit points for

15 connections with the starting points of each circuit connected at the perforations through the contacts of the relay switching unit to the case.

In the control of electrical strength and insulation resistance, the step relay is set to free contact, and the relay switching unit alternately connects one circuit to the corresponding measuring unit, while all the other circuits are connected to the housing at this time.

Disadvantage: 1And this device con. Trol boards are the need for a separate contact block to install a template that is structurally complex and expensive, as well as low reliability of the device due to the large number of switching elements-relays.

The purpose of the invention is to increase the reliability of the device and simplify the design.

This goal is achieved by the fact that in a device for testing printed circuit boards, comprising a contact unit with spring-loaded pins, a relay switching unit and a point switch connected to measuring devices, and a dielectric template with holes, around each opening of the dielectric pattern corresponding to the starting point of the circuit under test, the metallized platform is made, and the pins of the contact block are equipped with additional springs, moreover, the metalized platforms and additional electric springs cally connected with relay-switching unit.

FIG. 1 shows the proposed device, in FIG. 2 - dielectric pattern.

The device for testing printed circuit boards contains a contact unit 1 with spring-loaded pins 2 equipped with additional springs 3, a dielectric pattern 4 made in the form of a printed circuit board with holes 5 corresponding to test points / and holes 6 around which metallized surfaces are made, corresponding to the starting points of the monitored circuits, the relay switching unit .7, the switchboard 8 points (for example, a step relay) and measuring devices 9 and 10. The springs 3 and the metallized areas are electrically connected us with relay-kommutatsioynym unit 7, the switch points and 8-relay switching unit 7 are connected to izmeritelnvch devices 9 and 10.

The device works as follows.

: The contact block 1 is sequentially installed a pattern 4, corresponding to the type of the board being tested, and a controlled multilayer printed circuit board 11, while the spring-loaded pins 2 sink into holes 5 and 6 and are connected to the contact pads of the tested board 11, and the additional springs 3 through The metallized sites on the template 1 connect the starting points of the monitored circuits to the relay switching unit 7.

The device performs two kinds of work: monitoring the integrity of the printed conductors and monitoring the electrical strength of the insulation resistance of disconnected circuits.

When monitoring the integrity of the printed conductors all the contacts of the relay switching unit 7 are closed to the case. The control is carried out by a measuring device 9, to which, using a switch of 8 points, all the monitored points of the chains are alternately connected for the presence of a connection with the starting points of each circuit connected at the places of the metallized holes b through additional

spring 3 on the body.

When monitoring the electrical strength and insulation resistance of disconnected circuits, the switch of points 8 is set to free contact, and

relay switching unit 7 alternately connects one circuit to the measuring device 10. All other circuits at this moment are connected to the housing.

The use of the proposed device for control of printed circuit boards makes it possible to exclude a contact block for installing a perforated pattern and to increase its reliability by reducing the number of relays in the switching and switching unit.

Claims (2)

1. USSR author's certificate No. 347957, cl, H 05 K 3/00, 1970. 2. Medvedev A.M. Control and testing of printed circuit boards, M., 1975, p. 134-136 (prototype).