Apparatus and method for managing thermally induced motion of a probe card assembly
View Patent ↗A probe card assembly can include a probe head assembly having probes for contacting an electronic device to be tested. The probe head assembly can be electrically connected to a wiring substrate and mechanically attached to a stiffener plate. The wiring substrate can provide electrical connections to a testing apparatus, and the stiffener plate can provide structure for attaching the probe card assembly to the testing apparatus. The stiffener plate can have a greater mechanical strength than the wiring substrate and can be less susceptible to thermally induced movement than the wiring substrate. The wiring substrate may be attached to the stiffener plate at a central location of the wiring substrate. Space may be provided at other locations where the wiring substrate is attached to the stiffener plate so that the wiring substrate can expand and contract with respect to the stiffener plate.
1. A method of maintaining contact between probes and terminals of semiconductor devices, the method comprising:
coupling utilizing exclusively mechanically stiff components a probe head assembly comprising a plurality of probes for contacting terminals of semiconductor devices to a test system housing in which the semiconductor devices are disposed;
effecting contact between ones of the probes and ones of the terminals of the semiconductor devices;
monitoring an alignment in a plane that is generally parallel to a surface of the semiconductor devices on which the terminals are disposed of the ones of probes with respect to the ones of the terminals of the semiconductor devices; and
causing a substrate of the probe head assembly to which the probes are attached to expand or contract thermally in the plane so that the ones of the probes and the ones of the terminals of the semiconductor devices maintain sufficient alignment to maintain said contact as the semiconductor devices expand or contract thermally.
2. The method of claim 1 , wherein the probe head assembly is part of a probe card assembly, the probe card assembly comprising an electrical interface to a tester for controlling testing of the semiconductor devices, the probe card assembly further comprising electrical connections from the interface to the probes.
3. The method of claim 2 , wherein the monitoring comprises:
capturing images of the ones of the probes and the ones of the terminals of the semiconductor devices; and
determining positions of the ones of the probes and the ones of the terminals in the images.
4. The method of claim 2 further comprising after the effecting contact, testing the semiconductor devices by providing test signals from the tester through the probe card assembly and the ones of the probes to the semiconductor devices, wherein the monitoring and the causing are performed during the testing.
5. The method of 4 further comprising, during the testing, changing a temperature of the semiconductor devices.
6. The method of claim 2 , wherein the causing comprises changing a temperature of the substrate to which the probes are attached.
7. The method of claim 6 , wherein the changing a temperature comprises increasing a temperature of the substrate to cause the substrate to expand.
8. The method of claim 6 , wherein the changing a temperature comprises reducing a temperature of the substrate to cause the substrate to contract.
9. The method of claim 6 , wherein the changing a temperature comprises activating heating elements on or in the substrate.
10. The method of claim 6 , wherein the changing a temperature comprises activating cooling elements on or in the substrate.
11. The method of claim 1 , wherein the mechanically stiff components are metal components.
12. The method of claim 1 , wherein the probe head assembly is coupled directly to a metal stiffener plate.
13. The method of claim 12 , wherein the metal stiffener plate comprises a plurality of metal tabs that are coupled directly to the test system housing.
14. A system for testing semiconductor devices, the system comprising:
a prober configured to hold in contact a plurality of probes and a plurality of corresponding terminals of semiconductor devices disposed within the prober
a probe head assembly comprising a probe substrate to which the probes are coupled, the probe head assembly being coupled to the prober exclusively by mechanically stiff components;
a monitoring mechanism configured to monitor in a plane that is generally parallel to a surface of the semiconductor devices on which the terminals are disposed an alignment of the probes with respect to the corresponding terminals of the semiconductor devices; and
a temperature control device on or in the probe substrate; and
a controller configured to control the temperature control device and thereby expand or contract the probe substrate in the plane so that the probes and the corresponding terminals of the semiconductor device maintain sufficient alignment as monitored by the monitoring mechanism to keep the probes and the corresponding terminals in contact as the semiconductor devices expand or contract thermally.
15. The system of claim 14 , wherein the probe head assembly is part of a probe card assembly, the probe card assembly comprising an electrical interface to a tester for controlling testing of the semiconductor devices, the probe card assembly further comprising electrical connections from the interface to the probes.
16. The system of claim 14 , wherein the temperature control device comprises a heating element.
17. The system of claim 14 , wherein the temperature control device comprises a cooling element.
18. The system of claim 14 , wherein the monitoring mechanism comprises cameras positioned to capture images of the probes and the corresponding terminals of the semiconductor devices.
19. The system of claim 14 , wherein the monitoring mechanism and the controller comprise a processor programmed to monitor the alignment of the probes with respect to the corresponding terminals of the semiconductor devices and control the temperature control device during testing of the semiconductor devices.
20. The system of claim 14 , wherein:
additional probes are attached to a second probe substrate comprising a second temperature control device;
the monitoring mechanism is further configured to monitor an alignment of the additional probes with corresponding additional terminals of the semiconductor devices;
the probe head assembly comprising an attachment structure to which the probe substrate and the second probe substrate are attached, the attachment structure comprising a third temperature control device;
the controller further configured to control the second temperature control device and the third temperature control device and thereby expand or contract the second probe substrate and the attachment structure in accordance with the alignment of the probes and the corresponding terminals and the additional probes and the corresponding additional terminals as monitored by the monitoring mechanism.
21. The system of claim 14 , wherein the mechanically stiff components are metal components.
22. The system of claim 14 , wherein the probe head assembly is coupled directly to a metal stiffener plate.
23. The system of claim 22 , wherein the metal stiffener plate comprises a plurality of metal tabs that are coupled directly to the test system housing.