DD276217A3 - Method and device for non-destructive dielectric strength testing - Google Patents

Abstract

The method is used for non-destructive dielectric strength testing of electronic components, assemblies and devices. By means of a test arrangement, the execution of the o. G. Method in two steps, firstly a high-voltage pre-test with required Pruefspannung and energy limitation of the fault current to a value of 10% of the otherwise usual for dielectric strength tests current and secondly a high-voltage Hauptpruefung with the required Pruefspannung without energy limit. Each time the test voltage is switched off, a soft discharge of the test sections or the test piece takes place. Fig. 1

Description

For this 3 pages drawings

Field of application of the invention

The invention relates to a method for the non-destructive dielectric strength test of electronic components, assemblies and devices for dielectric strength.

Characteristic of the known technical solutions There are devices or testing devices known that perform manual or automatic Throughput tests are used, ¹ Yes the testing of assemblies and printed circuit boards, which increasingly

have an ever higher degree of integration.

The safety requirements require a high dielectric strength, which nachgewieoen with very high test voltages

must become.

At the time of the dielectric strength test, the proportion of objectified work on the test object is very large. There are no known solutions that effectively protect alier components, circuits and high-quality electronic Assemblies guarantee if flashover occurs during the breakdown test. In such cases, very often the destruction of semiconductor devices, even if they are not directly in the Test track lie. For example, a flashover can be generated via a separation point realized by optocouplers. The The cause is the defective optocoupler, and as a result of the rollover, further semiconductor components are destroyed. Troubleshooting, repair and retest mean in this case a high economic damage

additional labor and material costs.

Furthermore, according to copyright SU 570854 a method is known, which in the examination of Thin-film capacitors application finds. It is based on the fact that micro-breakdowns with increasing test voltage as long

be generated until the thin-film capacitors are voltage resistant. Several successive Mikrodurchschlä | e improve the dielectric strength of the tested capacitors.

However, this method is not applicable in the testing of assemblies with semiconductor devices, since by the Generation of punches no improvement in dielectric strength can be achieved, but the Dielectric strength decreases, and the risk of destruction of semiconductor devices increases. In addition, the Number of approved high voltage tests limited. Object of the invention

The invention pursues the goal of a non-destructive dielectric strength test of electronic components, assemblies and devices as well as the rationalization of the testing process and the associated increase in the

Labor productivity and increase the reliability of the test. Explanation of the essence of the invention Dor invention is based on the object, the probability of destruction of semiconductor devices during the To prevent or avoid penetration test. According to the object is achieved in that by means of a method, the dielectric strength of electronic

Devices, assemblies and equipment is tested in two consecutive steps, by a high voltage pre-test with required test voltage and an energy limitation of the fault current to a value of <10% of the usual for dielectric strength tests current as the second step by a high-voltage main test with the required Test voltage as the third process step, the energy limit after the error-free pre-test increases the limit and threshold of the fault current, so that the full energy is available for the dielectric strength test.

Advantageously, a first method step, which includes the contact and continuity test, as well as a last method step, in which after each switching off of the test voltage, a soft discharge of the capacitances of the specimen or the test sections.

embodiment

The invention will be explained in more detail below with reference to an embodiment: In the accompanying drawings:

Fig. 1: Representation of the functional groups of the device for performing djs method Fig. 2: Representation of the test voltage and the fault current in the breakdown in the high-voltage pre-test Fig.3: Representation of the test voltage and the fault current in the breakdown in the high-voltage main test. The device consists essentially of the following functional groups: DUT 1, high-voltage switch panel 2, contact and continuity test 3, high-voltage generator 4, Fault detection 5, power limitation 6, display field 7, power supply 8 and control unit 9. All functional groups are arranged in a cabinet-like housing. With the connection of the power supply 8 begins

the control unit 9 with the execution of the specified program steps for the respective Prüflingstyp.

First, via the function group contact and continuity test 3 and high-voltage panel 2 the

Proper contacting of the test specimen holder 1 has been proven. By means of high-voltage switch panel 2, the test section to be tested in the respective test step is switched through by means of special switches.

After the contact test has been completed, the contact and continuity test function group 3 is switched from the through-connected Trial line and the test voltage required for the breakdown test High voltage generator 4 applied to the Prüflingsaufnahme 1 and displayed in the display panel 7. For the duration of the process step high-voltage pre-test, the energy limitation 6 acts Limitation and evaluation of the fault current to 10% of the otherwise usual in breakdown tests current,

wherein the applied test voltage of the required height of the voltage value for the actual

Dielectric strength test corresponds. In the event of a fault! the test is interrupted by the error detection 5 and acoustically / optically signaled. By the Effectiveness of energy limitation β destruction of semiconductor devices is largely avoided. The biggest Part of the dielectric strength error is detected in the phase of high voltage pre-test, since at this time already

the full test voltage is applied.

If there is no error, the limitation and response threshold of the Fdhlerstromes suppressed by the energy limit β, so that the usual in Durchachlagsfestigkeitüffungungon energy

is available.

FIG. 2 shows the voltage conditions and the fault current in the high-voltage preliminary test. At the time

between to and ti, the test voltage increases to the required value Uh ₁₁₁ . If the test specimen is faulty, a breakdown occurs, and a current (fault current) flows in the time interval tj / tj, whose magnitude amounts to S10% of the otherwise

Dielectric strength tests normal current is lowered (Engery limit 6 is effective). At the time tj

the exam is aborted.

Fig. 3 shows the voltage and current conditions in the high-voltage main test. The test voltage U _Hlp has di6 same Height as in the high-voltage preliminary test, the current in the event of a punch corresponds to the usual values Dielectric strength tests and leads to the destruction of various semiconductor devices. After each shutdown of the high voltage generator 4 rin soft unloading of the test section takes place. In all method steps, the fault detection 5 is used to evaluate the test result. With the Anzoigef'd 7

All test steps, method steps and error states or the end of the error-free Piüfumj be signaled.

Claims (3)

1. A method and apparatus for non-destructive dielectric strength testing of electronic components, assemblies and devices by means of a device consisting of the functional groups Prüflingsaufnahme, contact and continuity test, fault detection, power supply and control unit, characterized in that after the first process step done _f known contact - And continuity test with a second step, a high-voltage pre-test with required test voltage is performed by the test voltage required for the dielectric strength is applied to the device under test, for the duration of the process step, an energy limit (6) limits the fault current, with a third step High voltage main test with the. After the error-free pre-test time, the limitation and response threshold of the fault current is raised by the energy limitation (6), so that the full energy is available for the dielectric strength tests. 2. The method according to item 1, characterized in that as a contact test each test section is adapted twice on the test specimen with a subsequent continuity test. 3. The method according to item 1, characterized in that after each shutdown of the test voltage, a soft discharge of the capacitances of the specimen or the test sections.