Probe for testing thin wafer
By designing a probe including shock absorbing springs and spherical contacts, the problem of difficult to control the drop stroke of the probe when testing the thin wafer is solved, and the protection of the wafer aluminum layer is achieved, avoiding device function failure.
Patent Information
- Application Number
- CN202421375517.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-05-20
- Estimated Expiration
- 2034-06-17
AI Technical Summary
When testing thin wafers, the probe is difficult to effectively control the drop stroke, which easily damages the aluminum layer and oxide layer on the wafer gate surface, resulting in device function failure.
A probe including a probe arm, shock absorbing spring, probe rod, probe head and contacts is designed. The probe arm is an L-shaped structure, with a shock absorbing spring in the middle, the probe head is a circular plate-shaped structure, and the contact is a semispherical structure with a height of 1um. Through the design of shock absorbing spring and spherical contacts, the contact contact and puncture depth of the wafer are controlled.
Through the primary shock absorption spring and the spherical contact design, the pressure of the probe is effectively reduced, the contact puncture depth of the aluminum layer is controlled, the gate oxide layer is protected, and the device function failure is avoided.
Smart Images
Figure CN222887701U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor power device testing, and particularly relates to a probe for testing thin wafers. Background Technique
[0002] Semiconductor power devices are mainly used for signal amplification and switching. In the power conversion process, a relatively large current flows through the device. In order to reduce power consumption, it is necessary to reduce the on-resistance inside the device, and the wafer is often made very thin. The final thickness of an insulated gate bipolar transistor (IGBT) wafer can be made dozens of micrometers. The gate of the insulated gate bipolar transistor is very thin. When testing the product CP, the test probe needs to pierce the aluminum layer on the surface of the gate to ensure good contact between the device and the probe, so that its electrical parameters can be correctly collected by the tester. At the same time, the piercing stroke of the test probe should not damage the oxide layer under the aluminum layer to avoid device function failure. Therefore, it is very important to control the overall stroke of the test probe when it falls. In order to save manufacturing costs, probe card testing is often used for products with a large test current, while independent probe testing is still used for products with a small test current. It is relatively difficult to control the falling stroke of an independent probe compared to a probe card. Summary of the Utility Model
[0003] The purpose of the utility model is to provide a probe for testing thin wafers to solve the above problems.
[0004] To achieve the above purpose, the following technical solutions are provided:
[0005] A probe for testing thin wafers, used in cooperation with a wafer, includes a probe arm, a shock-absorbing spring, a probe rod, a probe head, and a contact. The probe arm is of an L-shaped structure, and a shock-absorbing spring is provided in the middle of one section. One end of the probe arm where the shock-absorbing spring is provided is fixedly connected to a probe rod. The bottom end of the probe rod is fixedly connected to the probe head, and a certain number of contacts are provided on the bottom surface of the probe head.
[0006] Preferably, the probe head is of a circular plate structure, and the contact is of a hemispherical structure.
[0007] Preferably, the height of the contact is 1um.
[0008] Preferably, the probe head and the probe rod are fixedly connected by bolts.
[0009] The beneficial effects of the utility model are:
[0010] This utility model uses a shock-absorbing spring for primary shock absorption to reduce the pressure exerted by the contact on the aluminum layer of the wafer gate surface when the probe arm drops. At the same time, by setting spherical contacts, it ensures an increased contact area between the contacts and the aluminum layer of the wafer gate surface. The height of the contacts is set at 1um, thereby controlling the piercing depth of the contacts into the aluminum layer of the wafer gate surface and protecting the gate oxide layer from being damaged. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 is a schematic structural diagram of this utility model;
[0012] Figure 2 is a schematic structural diagram of the probe head and contacts of this utility model;
[0013] The reference numerals shown in the figures are: 1 - probe arm, 2 - shock-absorbing spring, 3 - probe rod, 4 - probe head, 5 - contact, 6 - bolt; DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The following details this design solution in conjunction with the accompanying drawings.
[0015] As Figure 1-2 shown, a probe for testing thin wafers, used in conjunction with wafers, includes a probe arm 1, a shock-absorbing spring 2, a probe rod 3, a probe head 4, and contacts 5. The probe arm 1 has an L-shaped structure, with the middle section of its downward-bent part being truncated. A shock-absorbing spring 2 is provided at the truncated part for connecting the other broken end. The upward-bent part is used to connect to the testing machine. One end of the probe arm 1 where the shock-absorbing spring 2 is provided is fixedly connected to a probe rod 3. The shock-absorbing spring 2 provides the effect of primary shock absorption. The bottom end of the probe rod 3 is fixedly connected to the probe head 4. The bottom surface of the probe head 4 is provided with five evenly distributed contacts 5.
[0016] In some embodiments, the probe head 4 has a smooth and burr-free circular plate-like structure, the contacts 5 have a smooth and burr-free hemispherical structure, and the height of the contacts 5 is 1um.
[0017] In some embodiments, the probe head and the probe rod are fixedly connected by bolts, and different-sized probe heads can be replaced according to the different sizes of the wafer pads.
[0018] Embodiment
[0019] As Figure 1-2As shown, the overall design of the probe uses a shock-absorbing spring 2 for primary shock absorption to reduce the pressure exerted by the contact 5 on the aluminum layer on the surface of the wafer gate when the probe arm 1 drops. At the same time, the probe head 4 adopts a circular design and is equipped with 5 contacts 5 with a height of 1 um to ensure an increased contact area between the contact 5 and the aluminum layer on the surface of the wafer gate. When the contact 5 pierces the aluminum layer on the surface of the wafer gate and then moves downward, the probe head 4 contacts the aluminum layer, and the probe head 4 will be lifted upward by the reaction force, thereby reducing the pressure exerted by the contact 5 on the aluminum layer on the surface of the wafer gate and protecting the gate oxide layer from being damaged.
[0020] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.
Claims
1. A probe for testing a thin wafer, used in conjunction with the wafer, characterized in that: It includes a probe arm, a shock-absorbing spring, a probe rod, a probe head and contacts. The probe arm is an L-shaped structure, a shock-absorbing spring is provided in the middle of one section, one end of the probe arm provided with the shock-absorbing spring is fixedly connected to the probe rod, the bottom end of the probe rod is fixedly connected to the probe head, and a certain number of contacts are provided on the bottom surface of the probe head.
2. A probe for testing a thin wafer according to claim 1, characterized in that: The probe head is a circular plate-shaped structure, and the contact point is a hemispherical structure.
3. The probe for testing a thin wafer according to claim 2, characterized in that: The height of the contact is 1 um.
4. The probe for testing a thin wafer according to claim 1, characterized in that: The probe head is fixedly connected to the probe rod by means of bolts.