SU856052A1 - Contact device for testing printed circuit boards - Google Patents

Description

54) CONTACT DEVICE FOR THE CONTROL OF PCB

The invention relates to radio engineering and can be used in radio equipment control devices for - determining the correctness of mounting of electronic devices and their operability. A device for control of printed circuit boards is known, comprising a control unit, a switching unit, a comparison unit and contact terminals T. However, this device allows the electrical parameters of printed circuit boards of only one size and cannot be used for automated testing of various types of printed circuit boards with the same contact block. The closest to the proposed technical entity is a contact device for control of printed circuit boards, containing a software control unit connected to a measuring unit and a switch, which is connected to a contact unit made in the form of a dielectric base with uniformly guided holes MI for installing spring-loaded contact elements C 21. The disadvantage of this device is low productivity and reliability. Poor performance is due to the fact that, when monitoring printed circuit boards, the device polls all contacts located in the contact block. As the size of a printed circuit board increases, the number of contacts, the capacity of the switch and the monitoring time increase in square depending on its dimensions, and as a result, the reliability of the entire device decreases (for example, at a pitch of 2.5 mm for a 50x50 mm printed circuit board, you need to have a contact capacity of 400 For a 200V.200 board, the capacity of the switch is 64 pins). The disadvantage of this device is also the lack of registration of the deviation value of the monitored parameter, since the control is conducted on the principle of less - the norm is greater. The purpose of the invention is to increase productivity and reliability. The goal is achieved in that in a contact device for control of printed circuit boards, containing a software control unit, connected to a measuring unit and a switch, which is connected to a contact unit made in the form of a dielectric base with uniformly placed and with a minimum pitch of guide holes , the contact block is equipped with contact tires placed h dielectric base parallel to each other and perpendicular to the contact elements, at this ohm contact tires are interoperable with contact elements and electrically connected to the switch inputs, each switch input is connected to the inputs of the measuring unit.

Moreover .contact elements are removable,

In addition, the contact tires are provided with elastic elements and are mounted so that they can move in a dielectric guide.

Figure 1 is a diagram of a contact device for controlling printed circuit boards; figure 2-4 - constructive execution of the contact block; Figure 5 is a switch diagram.

A contact device for controlling printed circuit boards contains a contact unit 1, a switch 2 connected to contact block 1, a software control unit 3 and a measuring unit 4, contacts 5. A contact block 1 contains a dielectric base made of an upper dielectric guide 6 and a lower one dielectric direction 1in1; her 7, a set of contact of the movable bushes 8 with elastic elements 9, the printed circuit board being tested 10. Switch 2 contains switching elements 11 with contacts 12-19.

The device works as follows.

Before the start of control, according to the control card corresponding to the control program, removable contacts 5 are installed in the contact unit 1 in the apertures of the dielectric guide 6.

The control points of the control object are selected so that there is one contact point along the contact bus (the places of installation of the removable contacts are conventionally crossed out).

With the purpose of contacting at any point of the printed circuit board, the contact tires, 8 are parallel to each other with the minimum grid spacing, and the holes in the dielectric guide along the contact bus are arranged with the minimum grid spacing.

The control object assembled on the printed circuit board 10 is mounted on the contact block 1, thereby connecting the control points of the control object with the inputs of the switch 2 via the removable contacts 5 and the contact buses 8. For reliable contact. The contact tires 8 are movable and spring-loaded with elastic elements 9 The elastic elements 9 create the necessary contacting force, and due to the mobility of the contact tires 8, the irregularities of the monitored sites of the tested board are copied.

To ensure the mobility of the contact tires 8, grooves are made in the upper dielectric guideline 6, and elastic elements 9 are mounted in the lower dielectric guide rail 7.

The program control unit 3, in accordance with the program, is connected in series through the switch 2 control points of the test object to the measuring unit 4. The measurement unit 4 measures the electrical parameters of the test object. Measurement results

5 enters the software control unit 3, which performs diagnostics of the results obtained, compares them with the specified limits and indicates the measurement results with

n tied it to the reference point number or the measurement number only if the measurement result is not within the specified limits. Switch 2 functions as follows. Suppose that it is necessary to rip the correct installation of the semiconductor diode on the printed circuit board. (A diode is connected via contact block 1 to the inputs of switch 2). For this, a positive potential is fed to the input of switch 2 and a negative potential to another input, a short to contacts 18.17 of switching elements 11 of switch 2. In this case, the forward transition is checked. / n diode.

When reverse polarity is applied to the inputs, contacts 16 and 19 of the switching elements 11 are closed and the reverse transition of the semiconductor is checked

0 diode.

To implement a contact block, it is necessary to have only n contact tires arranged parallel to each other with a minimum grid coordinate step, which drastically reduces the capacity of the switch, the number of contacts of monitored points of the respondents. a software control unit, thereby increasing the reliability of the device. In order to control other electronic devices assembled on printed circuit boards, it is necessary to rearrange the removable contacts on the control card according to the control program. Targeting the results to a specific group of measurement and display points

of the measurement result itself, only in the case when the result does not correspond to the specified limit, dramatically improves the device performance, speeding up the elimination of a malfunction in the control object.

Claims (3)

1. A contact device for control of printed circuit boards containing a program control unit connected to a measuring unit and a switch which is connected to a contact unit made in the form of a dielectric base with spaced evenly and with minimal pitch guides for installing contact elements different from that, in order to improve performance and reliability, the contact block is equipped with contact tires placed in a dielectric base parallel to each other and erpendikul koytaktnym angles to the elements, wherein the contact rails INSTALLS. They are interoperable with contact elements and electrically connected to the inputs of the switch, each of which is connected to the inputs of the measuring unit. 2. Device POP.1, characterized in that the contact elements are made removable. 3. A device according to claim 1, characterized in that the contact tires are provided with elastic elements and are mounted with the possibility of remastering in a dielectric guide. five Sources of information taken into account in the examination  USSR author's certificate number 470944, cl. H 05 K 13/08, 1973. 2, USSR author's certificate 0 No. 527037, cl. H 05 K 1/04, 1973. / V IH-J l + i i + 1 j + j 1 + 1 I, I i + l; v, + i 1 + 11 + i 1+ if | i + i i + i 1 + 1; 1 + 1 141 + 11 11 1+; К i + i; ri 1 :; + l + i H-i rfi H-i4 II I, I I,, 1I I W I + l 1 + 1 1 + 1 T r Fig.Z X- / 1 T g     I I 1 I 4iiyJ i Jiir if 1 L L.