Method and arrangement for positioning a probe card
View Patent ↗A method for perpendicular positioning of a probe card relative to a test substrate, includes storing a separation position approached in a first positioning step as a distance between the needle tips of the probe card and the substrate, storing a contact position approached in a second positioning step until the probe card contacts the substrate, and displaying an image of the needle tips. For avoiding erroneous operation after a probe card has been changed, when imaging the needle tips, the stored contact position is imaged and is changed until presentation of this contact position corresponds to actual height of the tips appropriate for the respective probe card and this setting is then stored as a new contact position. A display device presents the needle tips and the stored contact position and is connected to a memory, a recording device and an input device which changes the contact position.
1. A method for positioning a probe card with probe needles, the needles having needle tips, relative to a surface of a substrate to be tested, in a direction perpendicular to the surface of the substrate, comprising:
measuring and storing a separation position wherein the needle tips are separated from the surface of the substrate, measuring and storing a contact position wherein the needle tips are in contact with the surface of the substrate, recording an image of the needle tips along at least one horizontal imaging direction, which direction is essentially parallel to the surface of the substrate, displaying the recorded image of the needle tips along with the stored contact position or an absolute height of the needle tips which corresponds to the stored contact position, changing the displayed contact position or the displayed absolute height of the needle tips to a new contact position corresponding to a height of the needle tips displayed, storing the new contact position.
2. Method according to claim 1 , wherein a new height of the separation position is calculated from the stored new contact position or is calculated using the stored height of the needle tips over a predefined distance and is stored.
3. Method according to claim 1 , wherein, when displaying the recorded image of the needle tips, the stored separation position is displayed, and the displayed separation position is changed to a new separation position corresponding to a height of the needle tips displayed, and the new separation position is stored.
4. Method according to claim 1 , wherein removal of the probe card from a probe card holder is detected and the stored contact position is displayed when removal has been determined.
5. Method according to claim 4 , wherein removal of the probe card is detected if a distance between the probe card and the probe card holder is exceeded.
6. Method according to claim 1 , wherein position of the needle tips is electronically determined from imaging of the needle tips and is stored.
7. Method according to claim 6 , wherein the new contact position is calculated from the stored position of the needle tips and is stored.
8. Method according to claim 7 , wherein the separation position is calculated from the stored position of the needle tips or from the calculated contact position and is stored.
9. Method according to claim 4 , wherein, when removal is detected, an error signal is output if a defined difference between the position of the needle tips and the stored contact position is exceeded.
10. Arrangement for positioning a probe card with probe needles, which needles have needle tips and are arranged on the probe card such that the needles are oriented in position, comprising: a substrate holder for holding a substrate to be tested by the probe needles of the probe card, a setting device for adjusting the substrate holder relative to the probe card, an image recording device with a recording axis directed at the probe needles and essentially parallel to a surface of the substrate, the setting device including a drive device having a memory that stores a contact position wherein the needle tips are in contact with the substrate and a separation position wherein the needle tips are separated from the substrate, and a display device that displays a recorded image of the needle tips and the stored contact position and is connected to the memory and to the recording device and has an input means for changing displayed contact position.
11. Arrangement according to claim 10 , further comprising means which detects removal of the probe card and is connected to the recording device.
12. Arrangement according to claim 11 , further comprising means which detects distance between the probe card and a probe card holder.
13. Arrangement according to claim 11 , wherein an opening which is connected to a compressed air source or to a vacuum source by a pressure line is arranged in the probe card holder, said opening being closed when the probe card is inserted in the probe card holder and being open when the probe card has been removed, and the pressure line is connected to a pressure measuring device which detects a pressure difference in the pressure line and, is connected to an evaluation unit which determines a pressure difference.
14. Arrangement according to claim 13 , wherein the probe card holder is provided with a sliding piece which locks the probe card and has a position which unlocks the probe card and in which the opening is open and a position which locks the probe card and in which the opening is closed.