Probe level adjustment mechanism applied to wafer testing

Abstract

The utility model provides probe horizontal adjusting mechanism applied to wafer test, aims at solving the problem of low precision and poor efficiency caused by the naked eye judgment of the probe level in the prior art, and the mechanism includes the spectroscope of bearing platform bottom side, the laser transmitter of spectroscope bottom side, the silicon strip of test probe bottom end and the identification board of spectroscope outside, bearing platform is equipped with the via hole for laser to pass through, the spectroscope is fixedly inclined 45 DEG through the lens mounting base, and one side of identification board is equipped with the grid line, when working, laser is refracted through the spectroscope, projects to the silicon strip through the via hole, forms the light spot after reflecting again and refracting through the spectroscope to identification board, can accurately judge and adjust the probe level with the help of the grid line. The mechanism realizes non - contact detection by utilizing the optical principle, effectively improves the adjustment precision and efficiency, and is suitable for the scene of higher probe level requirement in wafer test.

Description

Technical Field

[0001] This utility model relates to wafer testing technology, and in particular to a probe leveling mechanism used in wafer testing. Background Technology

[0002] In the field of wafer testing, capacitance testing is an indispensable step. Currently, a Chinese invention patent (CN118483287A) proposes a mercury transfer device for wafer surface performance testing, comprising a support platform, a probe mechanism, and a mercury exchange mechanism. The support platform supports the wafer; the probe mechanism includes a positioning base, a lifting slide, a support arm, and a probe holder. The rear end of the support arm moves vertically via the lifting slide on the positioning base, while the front end of the support arm houses the probe holder. The lower end of the probe holder is used to absorb the mercury, and a conductive metal wire is installed in a through-hole in the center of the probe holder, ensuring electrical connection between the conductive metal wire and the mercury droplet absorbed by the probe holder. Simultaneously, the probe holder carrying the mercury is transferred to the wafer on the support platform, achieving contact between the mercury and the wafer surface. Capacitance measurement is then performed by applying pressure and electricity. The entire device effectively absorbs and transfers mercury droplets, simultaneously improving testing efficiency.

[0003] However, in practical use, it has been found that during the mercury loading process, a certain gap must be maintained between the probe tip and the wafer surface. This gap must allow air to pass through without causing the surface tension-sensitive molten mercury to overflow. This places high demands on the levelness of the probe installation. Currently, the levelness is often determined subjectively by placing a silicon strip at the bottom of the probe as a reference point and comparing it with the wafer surface, relying on the naked eye. This leveling method has poor accuracy and low efficiency, making it difficult to meet actual testing requirements.

[0004] Therefore, in view of the shortcomings of the existing technology, it is necessary to design a probe level adjustment mechanism for wafer testing to solve the above problems. Utility Model Content

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide [the following].

[0006] To achieve the above and other related objectives, the technical solution provided by this utility model is: a probe leveling mechanism applied in wafer testing, wherein wafer testing employs a test probe and a support stage, and the probe leveling mechanism includes: The beam splitter is located on the bottom side of the support stage; A laser emitter is located on the bottom side of the beam splitter and is used to emit laser light toward the beam splitter. A silicon strip, located at the bottom of the test probe and on the top side of the support platform, is used to reflect the laser. An identification plate, located on the outside of the beam splitter, is used to receive the light spot formed after the laser is refracted by the beam splitter; the identification plate is provided with grid lines to determine the position accuracy of the test probe.

[0007] A preferred technical solution is that the support platform is provided with a through hole, which is correspondingly arranged with the silicon strip and the laser emitter to allow the laser to pass through.

[0008] A preferred technical solution is that it further includes a lens mounting base, wherein the beam splitter is fixed in the lens mounting base and is inclined at 45°.

[0009] A preferred technical solution is as follows: the lens mounting base has a 45° inclined mounting surface, the mounting surface is provided with a through hole communicating with the bottom, the laser emitter is located on the bottom side of the lens mounting base, and the through hole allows the laser emitted by the laser emitter to pass through.

[0010] The preferred technical solution is that the label plate is set vertically, and the side with the grid lines faces the side of the beam splitter.

[0011] Due to the application of the above technical solution, the beneficial effects of this utility model are as follows: The probe leveling mechanism provided by this utility model for use in wafer testing significantly improves the adjustment accuracy: by utilizing the high directionality of the laser and the precise refraction of the beam splitter, combined with the grid lines on the marking plate, the judgment of the probe's level can be transformed into a direct observation of the light spot position, avoiding the errors of traditional subjective judgment by the naked eye, greatly improving the accuracy of leveling adjustment, meeting the stringent requirements for the gap between the probe and the wafer surface in wafer testing, and ensuring the accuracy of test data such as capacitance. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the probe horizontal adjustment mechanism involved in this utility model. Detailed Implementation

[0013] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0014] Please see Figure 1It should be noted that in the description of this utility model, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. These terms are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "horizontal," "vertical," and "suspended," etc., do not indicate that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0015] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example

[0016] like Figure 1 As shown, according to a general technical concept of this utility model, a probe leveling mechanism for use in wafer testing is provided. The wafer testing employs a test probe 100 and a support stage 200. The probe leveling mechanism includes: The beam splitter (not shown) is located on the bottom side of the support stage 200; Laser emitter 1 is located on the bottom side of the beam splitter and is used to emit lasers toward the beam splitter; A silicon strip (not shown) is located at the bottom of the test probe 100 and on the top side of the support stage 200, and is used to reflect the laser. The label plate 2 is located on the outside of the beam splitter and is used to receive the light spot formed after the laser is refracted by the beam splitter. The label plate 2 is provided with grid lines to determine the position of the test probe 100.

[0017] like Figure 1 As shown, in an exemplary embodiment of this utility model, the support platform 200 is provided with a light-transmitting hole 201, which is correspondingly arranged with the silicon strip and the laser emitter 1 to allow the laser to pass through.

[0018] like Figure 1 As shown, in an exemplary embodiment of this utility model, a lens mounting base 3 is also included, and the beam splitter is fixed in the lens mounting base 3 and tilted at 45°.

[0019] like Figure 1 As shown, in an exemplary embodiment of this utility model, the lens mounting base 3 has a 45° inclined mounting surface 31, and the mounting surface 31 is provided with a through hole 32 communicating with the bottom. The laser emitter 1 is located on the bottom side of the lens mounting base 3, and the through hole 32 allows the laser emitted by the laser emitter 1 to pass through.

[0020] like Figure 1 As shown, in an exemplary embodiment of this utility model, the label plate 2 is vertically arranged, with the side having the grid lines facing the side of the beam splitter.

[0021] The working process of the probe leveling mechanism is as follows: First, a double-polished silicon wafer is placed on the support stage 200. After the double-polished silicon wafer is vacuum-adsorbed, its lower surface is aligned with the support stage 200. The laser beam passes through the light-transmitting hole 201 on the support stage 200 and irradiates the back of the double-polished silicon wafer. The reflected light spot passes through the light-transmitting hole 201 on the support stage 200 again and is reflected and projected onto a reference point on the marker plate 7. Then, the double-polished silicon wafer is removed, and a leveling silicon strip is vacuum-adsorbed on the probe test surface. The support stage 200 is moved so that the leveling laser irradiates the silicon strip adsorbed on the lower surface of the test probe 100. The reflected laser spot passes through the light-transmitting hole 201 on the support stage 200 and is reflected by the beam splitter 6 and projected onto the same point on the marker plate 7. In this way, the test surface of the test probe 100 is parallel to the support stage 200. When the laser emitter 1 is pre-installed, it is ensured that after reflection from the double-polished silicon wafer on the support stage 200, it reaches the beam splitter 6. The emitted and reflected light spots on the surface of the beam splitter 6 coincide, so that the laser is perpendicular to the support stage 200, which reduces the offset of the reflected light spot caused by changes in the distance to the reflective surface. The beam splitter 6 has its splitting surface facing upwards, and the splitting ratio can be 1:1 or 1:2, depending on the incident light intensity and reflectivity. The beam splitter needs to be made of thin sheet to reduce ghosting and affect the leveling accuracy. The coordination between the laser and the laser lens group needs to ensure that the light spot is minimized when the laser is focused onto the marking plate 7 (for example, if a focused beam is used, the focusing distance is adjusted to cover the optical path of all incident and reflected paths), thereby improving the resolution accuracy.

[0022] By observing the position of the light spot on the grid line, the levelness of the test probe 100 can be determined: if the light spot deviates from the preset reference grid position, it indicates that the test probe 100 has a level deviation. At this time, adjust the position of the test probe 100 until the light spot falls within the reference grid, and the level calibration of the test probe 100 can be completed.

[0023] It should be noted that previously, the tilt level was observed by the naked eye, and the degree of tilt could not be quantified. However, the laser leveling function can quantify the tilt angle each time. The tilt angle can be obtained by dividing the spot offset by the arcsine of the optical path. Another advantage is that the movement of a spot in a two-dimensional plane provides feedback on the left-right and forward-backward tilt of the probe.

[0024] Therefore, this utility model has the following advantages: Significantly improves adjustment accuracy: By leveraging the high directionality of the laser and the precise refraction of the beam splitter, along with the grid lines on the marking plate, the judgment of the probe's level can be transformed into a direct observation of the spot position. This avoids the errors of traditional subjective judgment by the naked eye, greatly improving the accuracy of level adjustment. It can meet the stringent requirements for the gap between the probe and the wafer surface in wafer testing, ensuring the accuracy of test data such as capacitance.

[0025] Effectively improve adjustment efficiency: During the adjustment process, the correspondence between the spot position and the probe level is clear and unambiguous. Operators can quickly locate the deviation direction and make adjustments based on the spot's deviation from the grid reference, without having to repeatedly compare or rely on experience. This significantly shortens the time required for level adjustment and improves the overall efficiency of wafer testing.

[0026] Achieving non-contact testing: The combination of laser and optical systems forms a non-contact testing mode, avoiding direct contact between the mechanical structure and the probe and wafer during the adjustment process, reducing potential damage to the test components, while also reducing the impact of external mechanical interference on the adjustment accuracy and enhancing the stability of the mechanism operation.

[0027] The structure is simple and easy to operate: the overall mechanism forms a complete optical detection link through the reasonable layout of the beam splitter, laser emitter, silicon strip and marking plate. Each component is closely matched and has a clear function. The design of the beam splitter with a 45° tilt and the corresponding light transmission hole ensures the stability of the laser path. With the intuitive reference of the grid line, the operator can quickly get started without professional optical knowledge, which is convenient for promotion and application in actual production.

[0028] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A probe leveling mechanism applied in wafer testing, wherein the wafer testing employs a test probe and a support stage, characterized in that, The probe leveling mechanism includes: The beam splitter is located on the bottom side of the support stage; A laser emitter is located on the bottom side of the beam splitter and is used to emit laser light toward the beam splitter. A silicon strip, located at the bottom of the test probe and on the top side of the support platform, is used to reflect the laser. An identification plate, located on the outside of the beam splitter, is used to receive the light spot formed after the laser is refracted by the beam splitter; the identification plate is provided with grid lines to determine the position accuracy of the test probe.

2. The probe leveling mechanism for wafer testing according to claim 1, characterized in that: The support platform is provided with through holes, which are corresponding to the silicon strip and the laser emitter, and are used to allow the laser to pass through.

3. The probe leveling mechanism for wafer testing according to claim 1, characterized in that: It also includes a lens mounting base, in which the beam splitter is fixed and tilted at 45°.

4. The probe leveling mechanism for wafer testing according to claim 3, characterized in that: The lens mounting base has a 45° inclined mounting surface, and the mounting surface is provided with a through hole that connects to the bottom. The laser emitter is located on the bottom side of the lens mounting base, and the through hole allows the laser emitted by the laser emitter to pass through.

5. The probe leveling mechanism for wafer testing according to claim 1, characterized in that: The signboard is set vertically, with the side having the grid lines facing the side of the beam splitter.

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