Multi-region replaceable combined probe card for machine state inspection

Abstract

The invention relates to the technical field of semiconductor testing, and discloses a multi-area replaceable combined probe card for machine state inspection, which comprises a disc, the surface of the disc is provided with a wafer surface, and the surface of the wafer surface is provided with a modular MLC structure. According to the modularized MLC structure, a plurality of independent small MLCs are uniformly distributed in a disc range with a 300mm wafer surface size, and the plurality of small MLCs are integrated on a PCB (Printed Circuit Board) and a plurality of probes through being fixedly connected with a conductive piece. A traditional whole ceramic MLC is replaced by a plurality of independent small MLCs, so that the probe card can flexibly adapt to DUTs of different sizes and numbers, various test requirements are met, meanwhile, the small MLCs are easy to manufacture, material loss is reduced, the manufacturing cost is reduced, raw material waste is reduced, the manufacturing cost is remarkably reduced, a single MLC can be independently replaced when damaged, the whole card is prevented from being scrapped, and the cost is reduced. And the limitation of the traditional design on flexibility and cost control is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor testing, and specifically provides a multi-region replaceable combined probe card for machine state inspection. Background Art

[0002] In the semiconductor industry, the accurate inspection of machine state is crucial for ensuring high-quality and high-efficiency chip production. As a key interface connecting the ATE test machine and the semiconductor wafer, the performance of the probe card directly affects the accuracy and efficiency of testing. With the continuous development of chip technology, higher requirements are imposed on the probe card, which needs to have higher flexibility, replaceability, and adaptability.

[0003] Traditional MEMS probe cards usually use a whole piece of ceramic as the MLC structure. This design has limitations in terms of flexibility and cost control. The manufacturing cost of the whole piece of ceramic is relatively high, and it is difficult to adapt to different sizes and quantities of DUTs. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a multi-region replaceable combined probe card for machine state inspection, which solves the problems of limitations in flexibility and cost control.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A multi-region replaceable combined probe card for machine state inspection, comprising: A disk, on the surface of which a wafer surface is provided. On the surface of the wafer surface, a modular MLC structure is provided. The modular MLC structure consists of multiple independent small MLCs evenly distributed within the range of a 300mm wafer surface-sized disk. The multiple small MLCs are integrated into the PCB through conductive fixed connections; Multiple probes, all of which are located on the surface of the small MLC. A reflective surface is provided at the tip of the probe, which is used for optical flatness measurement and simultaneously realizes electrical testing through physical contact with the aluminum wafer. The probe is connected to the test machine interface POGO point of the PCB through a conductive path; A temperature probe, which is distributed in the edge area of the probe card with a measurement accuracy of ±0.1°C and is used to monitor the test environment temperature in real time; A signal transmission module, which is used for signal transmission with a signal transmission impedance ≤ 0.1Ω.

[0006] Preferably, the material of the small MLC is aluminum nitride ceramic, with a single-piece size of 10mm×10mm×0.5mm, an adjacent spacing of 5mm, and an annular array distribution.

[0007] Preferably, the probe is made of beryllium copper alloy, the tip diameter is 50 μm, the thickness of the gold plating layer on the surface is 0.5 μm, and the reflectivity of the reflective surface is ≥90%.

[0008] Preferably, the temperature probe is a micro thermocouple or an infrared sensor, and communicates with the PCB through the SPI interface.

[0009] Preferably, the probe is used to contact the aluminum wafer for electrical testing, and the pressure applied when contacting the aluminum wafer is controlled at 20 - 30 gf through a spring structure.

[0010] Preferably, a reflective surface is provided at the tip of the probe. The material of the reflective surface has a high reflectivity, and the surface roughness is less than 0.1 μm, which is used for optical focusing of the Prober camera to achieve optical flatness measurement, and the optical measurement accuracy can reach ±0.01 mm.

[0011] Preferably, the probe is connected to the PCB by metal welding, and a signal shielding layer is provided on the PCB.

[0012] Preferably, the small MLCs are connected by mechanical buckles, the buckle accuracy is ±0.05 mm, and they are fixed by a combination of screw fastening and glue assistance. The screws are made of high-strength stainless steel.

[0013] Preferably, the conductive path uses a low-resistance graphene material to ensure stable signal transmission.

[0014] Preferably, the probes are distributed in an equilateral triangle on each small MLC, the probe pitch is 2 mm, and the probe distribution positions on adjacent MLCs are staggered.

[0015] Working principle: The probe card uses a disc as the basic carrier platform. The wafer surface on its surface simulates the real wafer test environment. The modular MLC structure consists of multiple small MLCs evenly distributed within the range of a 300 mm wafer surface size disc, and is integrated with the PCB through conductive fixed connections; The small MLCs are made of aluminum nitride ceramic material. Utilize its good thermal conductivity to dissipate the test heat, prevent local overheating from affecting the accuracy, and avoid signal interference between small blocks by virtue of electrical insulation. The single block size is 10 mm × 10 mm × 0.5 mm, and the adjacent spacing is 5 mm and is distributed in an annular array, which not only effectively covers the wafer surface, but also disperses the test pressure and optimizes the space layout; Multiple probes are arranged on the surface of the small MLC. The material is beryllium copper alloy and gold-plated to ensure conductivity and corrosion resistance. The reflectivity of the reflective surface of the probe tip is ≥90% and the surface roughness is less than 0.1μm. The light emitted by the Prober camera is reflected by the reflective surface, and the optical flatness measurement with an accuracy of ±0.01mm is achieved by analyzing the reflected light. At the same time, the probe contacts the aluminum wafer with a pressure of 20 - 30gf for electrical testing, transmits the test signal and collects the feedback signal. The probes on each small MLC are distributed in an equilateral triangle with a spacing of 2mm. The probe distributions on adjacent MLCs are staggered to reduce signal interference; The temperature probe is located at the edge of the probe card and can be a micro thermocouple or an infrared sensor. The former is based on the thermoelectric effect, and the latter measures the temperature by detecting infrared radiation. The measurement accuracy is ±0.1℃, and the temperature data is transmitted to the PCB through the SPI interface for temperature compensation of test data or adjustment of test parameters; The conductive path uses low-resistance graphene material, and combined with the signal transmission module, the signal transmission impedance ≤0.1Ω to ensure low-loss and distortion-free transmission of various signals; The probe is connected to the PCB by metal welding to ensure stable electrical connection. The signal shielding layer on the PCB blocks external electromagnetic interference. The small MLCs are connected by mechanical buckles with an accuracy of ±0.05mm, and are fixed with high-strength stainless steel screws and glue assistance to ensure the structure is stable, enabling the probe card to operate stably for a long time and realizing accurate inspection of the machine tool state.

[0016] The present invention provides a multi-region replaceable combined probe card for machine tool state inspection. It has the following beneficial effects: 1. By replacing the traditional monolithic ceramic MLC with multiple independent small MLCs, the probe card can flexibly adapt to different sizes and quantities of DUTs to meet diverse test requirements. At the same time, the small MLC is simple to manufacture, reduces material loss, lowers the manufacturing cost, reduces raw material waste, significantly reduces the manufacturing cost, and can be independently replaced when a single MLC is damaged, avoiding the scrapping of the entire card, thus solving the limitations of the traditional design in terms of flexibility and cost control.

[0017] 2. The present invention integrates an optical reflective surface with a reflectivity ≥90% and an electrical contact function on the probe. The contact pressure is 20 - 30gf, and the optical focusing and electrical testing are completed synchronously. The gold-plated layer on the probe surface is 0.5μm and the low-resistance graphene conductive path with a resistivity ≤1×10⁻ 6 Ω·m ensures the stability of the electrical signal transmission, and the contact resistance ≤0.1Ω, enabling the multi-functional probe to realize the integration of the test process.

[0018] 3. The temperature probe of the present invention monitors the ambient temperature in real time with a high precision of ±0.1°C, compensates or adjusts the test to avoid the influence of temperature. The impedance of the signal transmission module is ≤0.1Ω to ensure stable signal transmission. Each component is integrally designed to optimize the spatial layout and strengthen the mechanical and electrical connections, comprehensively ensuring the accuracy and stability of the inspection of the machine tool status. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a three-dimensional layout diagram of small MLCs of a multi-region replaceable combined probe card for machine tool status inspection according to the present invention; Figure 2 FIG. is a top view schematic diagram of the layout of small MLCs of a multi-region replaceable combined probe card for machine tool status inspection according to the present invention; Figure 3 FIG. is a plan view schematic diagram of the layout of small MLCs of a multi-region replaceable combined probe card for machine tool status inspection according to the present invention; Figure 4 FIG. is a schematic diagram of a disc of a multi-region replaceable combined probe card for machine tool status inspection according to the present invention; Figure 5 FIG. is a schematic diagram of a probe of a multi-region replaceable combined probe card for machine tool status inspection according to the present invention.

[0020] Among them, 1. Small MLC; 2. PCB; 3. Probe; 31. Reflective surface; 4. Temperature probe; 5. Disc; 6. Wafer surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Please refer to the attached Figure 1 - attached Figure 5 , the embodiment of the present invention provides a multi-region replaceable combined probe card for machine tool status inspection, including: A disc 5, on the surface of the disc 5 is provided a wafer surface 6, on the surface of the wafer surface 6 is provided a modular MLC structure, the modular MLC structure is composed of a plurality of independent small MLCs 1 evenly distributed within the range of the disc 5 with a size of 300 mm wafer surface 6, and the plurality of small MLCs 1 are integrated on the PCB 2 through conductive fixed connections; The disc 5 serves as the basic support structure for the entire probe card, providing a stable installation plane for each component. The wafer surface 6 simulates the actual wafer test scenario to ensure the consistency of the test environment. The design of the modular MLC structure enables the probe card to flexibly adjust the number and layout of the small MLCs 1 according to different test requirements. The number of small MLCs 1 can be selected according to needs, such as 9, 17, 21 or more. Multiple small MLCs 1 are evenly distributed within the range of the disc 5 with a size of 300 mm wafer surface 6, which can cover a large test area and improve the test efficiency. It is integrally connected to the PCB 2 through conductive fixation to achieve effective transmission and processing of electrical signals; Multiple probes 3, all of the multiple probes 3 are located on the surface of the small MLC 1. The tip of the probe 3 is provided with a reflective surface 31, and the reflective surface 31 is used for optical flatness measurement. At the same time, electrical tests are realized through physical contact with the aluminum wafer. The probe 3 is connected to the test machine interface POGO point of the PCB through a conductive path; The multiple probes 3 are the key components to realize various test functions and are located on the surface of the small MLC 1, which is convenient for close contact with the object under test. The reflective surface 31 at the tip of the probe 3 works based on the principle of optical reflection. When the Prober camera emits light to the reflective surface 31, the reflected light carries information about the relative position between the tip and the wafer surface. By analyzing the reflected light, the optical flatness of the wafer can be accurately measured. At the same time, the probe 3 realizes the transmission and acquisition of electrical signals through physical contact with the aluminum wafer to complete the electrical test, and is connected to the test machine interface POGO point of the PCB through a conductive path to ensure that the test signal can be transmitted to the test equipment for analysis and processing; The temperature probe 4, the temperature probe 4 is distributed in the edge area of the probe card, and the measurement accuracy is ±0.1 °C, which is used to monitor the test environment temperature in real time; The temperature probe 4 is arranged in the edge area of the probe card. In this way, it does not affect the normal operation of other components and can effectively sense the temperature change of the test environment. The measurement accuracy reaches ±0.1 °C, which can capture the minute fluctuations of the ambient temperature. Since temperature has a significant impact on the electrical and optical properties of semiconductor materials, real-time monitoring of the test environment temperature can timely detect temperature anomalies and accordingly perform temperature compensation on the test data or adjust the test parameters to ensure that the inspection results of the machine tool state are not interfered by temperature changes; The signal transmission module, the signal transmission module is used for signal transmission, and the signal transmission impedance ≤ 0.1 Ω.

[0023] The material of the small MLC 1 is aluminum nitride ceramic, the single-piece size is 10 mm × 10 mm × 0.5 mm, the adjacent spacing is 5 mm, and it is distributed in a circular array.

[0024] Aluminum nitride ceramic is selected as the material for the small piece MLC1 because it has excellent thermal conductivity and electrical insulation. Good thermal conductivity can effectively dissipate the heat generated during the test, avoiding local overheating and affecting the test accuracy. Electrical insulation prevents the mutual interference of electrical signals between small pieces. The setting of the single-piece size of 10mm×10mm×0.5mm takes into account both space utilization and structural stability. The adjacent spacing of 5mm ensures sufficient electrical isolation and leaves a reasonable space for signal transmission lines and mechanical connections. The annular array distribution helps to evenly cover the wafer surface 6 and is convenient for wiring and installing other components, improving the compactness and rationality of the overall structure.

[0025] The material of the probe 3 is beryllium copper alloy, the tip diameter is 50μm, the thickness of the gold plating layer on the surface is 0.5μm, and the reflectivity of the reflective surface 31 is ≥90%.

[0026] Beryllium copper alloy is selected as the material of the probe 3 because it has high strength, high elasticity and good electrical conductivity. High strength and high elasticity ensure that the probe is not easily deformed when contacting the object to be measured multiple times and can maintain a stable contact pressure. Good electrical conductivity reduces the resistance loss during signal transmission and ensures the accuracy of electrical test signals. The tip diameter of 50μm can achieve precise physical contact without damaging the surface of the object to be measured. The thickness of the gold plating layer on the surface is 0.5μm, which further enhances the electrical conductivity and corrosion resistance and extends the service life of the probe. The reflectivity of the reflective surface 31 is ≥90%, which ensures the intensity of the optical reflection signal and improves the accuracy and reliability of the optical flatness measurement.

[0027] The temperature probe 4 is a micro thermocouple or an infrared sensor and communicates with the PCB through the SPI interface.

[0028] Both the micro thermocouple and the infrared sensor are commonly used high-precision temperature measurement components. The micro thermocouple works based on the thermoelectric effect, can quickly respond to temperature changes, and directly converts temperature into an electrical signal output. The infrared sensor measures temperature by detecting the infrared radiation emitted by the object and has the advantages of non-contact measurement and fast response speed. Communicating with the PCB through the SPI interface, the SPI interface has the communication characteristics of high speed, synchronization, and full duplex, ensuring that the temperature data collected by the temperature probe 4 is transmitted to the PCB for subsequent real-time processing and analysis of the temperature data.

[0029] The probe 3 is used to contact the aluminum wafer for electrical testing, and the pressure applied when contacting the aluminum wafer is controlled at 20 - 30 gf through the spring structure.

[0030] When the probe 3 contacts the aluminum wafer for electrical testing, the applied pressure needs to be controlled between 20 - 30 gf. If the pressure is too small, it will lead to poor contact between the probe and the aluminum wafer, generating contact resistance and affecting the accuracy of the electrical test results. If the pressure is too large, it will cause scratches or damage to the surface of the aluminum wafer. By using a spring structure to control the pressure, while ensuring good electrical contact, it can avoid damaging the object under test and ensure the stability and reliability of the electrical test process.

[0031] A reflective surface 31 is provided at the tip of the probe 3. The material of the reflective surface 31 has a high reflectivity and a surface roughness less than 0.1 μm, which is used for the optical focusing of the Prober camera to achieve optical flatness measurement, and the optical measurement accuracy can reach ±0.01 mm.

[0032] The material of the reflective surface 31 at the tip of the probe 3 has a high reflectivity, ensuring that the intensity of the reflected light is sufficient for the Prober camera to capture. The surface roughness is less than 0.1 μm, making the reflected light more regular and reducing the error caused by diffuse reflection. The Prober camera uses the light reflected by the reflective surface 31 for optical focusing. Based on the principle of optical imaging, it measures the relative position relationship between the probe tip and the wafer surface, thereby achieving optical flatness measurement. The optical measurement accuracy can reach ±0.01 mm, which helps to detect potential flatness problems of the machine in a timely manner.

[0033] The probe 3 is connected to the PCB 2 by metal welding, and a signal shielding layer is provided on the PCB 2.

[0034] The probe 3 is connected to the PCB 2 by metal welding. Metal welding can form a firm physical connection and good electrical conduction. This connection method has high stability and can withstand the vibration and stress during multiple tests, ensuring a firm electrical connection between the probe 3 and the PCB 2. The signal shielding layer provided on the PCB 2 can effectively block the influence of external electromagnetic interference on the test signal. In a complex electromagnetic environment, the signal shielding layer can prevent external electromagnetic fields from coupling into the test signal line, ensuring the purity of the test signal during transmission.

[0035] The small MLC 1s are connected by mechanical buckles with a buckle accuracy of ±0.05 mm, and are fixed by a combination of screw fastening and glue assistance. The screws are made of high-strength stainless steel.

[0036] The small MLC1s are mechanically snapped together with a snap accuracy of ±0.05 mm. The high-precision snaps ensure the accuracy of the relative positions between the small MLC1s, which is beneficial to the stability and consistency of the overall structure. The screw fastening provides the main connection force. The screws made of high-strength stainless steel have good corrosion resistance and high strength, and can maintain the fastened state during long-term use. The glue-assisted fixation further enhances the tightness of the connection, fills the tiny gaps existing between the mechanical snaps and the screw connections, prevents relative displacement between the small MLC1s due to vibration or external forces, ensures the stability of the entire modular MLC structure, and guarantees the long-term stable operation of the probe card.

[0037] The conductive path uses a low-resistance graphene material to ensure stable signal transmission.

[0038] The conductive path is selected to use a low-resistance graphene material. Graphene has excellent electrical properties and a two-dimensional crystal structure, which endows it with extremely high electron mobility and ultra-low resistance characteristics. This enables the test signals to have extremely small energy loss and negligible signal attenuation when transmitted in the conductive path, effectively avoiding signal distortion. Thus, it ensures that the electrical and optical test signals collected from the probe 3, as well as the temperature signals transmitted by the temperature probe 4, can be stably and accurately transmitted to the PCB for processing and analysis.

[0039] The probes 3 are distributed in an equilateral triangle pattern on each small MLC1, with a probe pitch of 2 mm, and the distribution positions of the probes 3 on adjacent MLCs are staggered.

[0040] The probes 3 are distributed in an equilateral triangle pattern on each small MLC1. This distribution pattern has a high space utilization rate and can reasonably arrange multiple probes on the surface of the limited small MLC1s. The geometric structure of the equilateral triangle enables the probes to support each other, enhancing the measurement stability and at the same time helping to reduce the electromagnetic interference between the probes. The probe pitch of 2 mm ensures sufficient electrical isolation between the probes and does not cause the pitch to be too large to affect the comprehensiveness of the measurement. The distribution positions of the probes 3 on adjacent MLCs are staggered, further reducing the signal interference between the probes on different small MLC1s, enabling each probe to independently obtain measurement data.

[0041] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art 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 appended claims and their equivalents.

Claims

1. A multi-region replaceable combined probe card for machine state inspection, characterized in that, Including: A disk (5), on the surface of which there is a wafer surface (6), on the surface of which there is a modular MLC structure. The modular MLC structure consists of multiple independent small MLCs (1) evenly distributed within the range of the disk (5) with a size of 300 mm wafer surface (6). The multiple small MLCs (1) are integrated into the PCB (2) through conductive fixed connections; Multiple probes (3), all of the multiple probes (3) are located on the surface of the small MLC (1). The tip of the probe (3) is provided with a reflective surface (31). The reflective surface (31) is used for optical flatness measurement and at the same time realizes electrical testing through physical contact with the aluminum wafer. The probe (3) is connected to the test machine interface POGO point of the PCB through a conductive path; A temperature probe (4), which is distributed in the edge area of the probe card, with a measurement accuracy of ±0.1 °C, and is used to monitor the test environment temperature in real time; A signal transmission module, which is used for signal transmission, and the signal transmission impedance ≤ 0.1 Ω.

2. The multi-region replaceable combined probe card for machine tool status inspection according to claim 1, wherein: The material of the small MLC (1) is aluminum nitride ceramic, with a single-piece size of 10 mm × 10 mm × 0.5 mm, an adjacent spacing of 5 mm, and is distributed in a circular array.

3. The multi-region replaceable combined probe card for machine tool status inspection according to claim 1, wherein: The material of the probe (3) is beryllium copper alloy, the tip diameter is 50 μm, the thickness of the gold plating layer on the surface is 0.5 μm, and the reflectivity of the reflective surface (31) ≥ 90%.

4. The multi-region replaceable combined probe card for machine tool status inspection according to claim 1, wherein: The temperature probe (4) is a micro thermocouple or an infrared sensor, and communicates with the PCB through the SPI interface.

5. The multi-region replaceable combined probe card for machine platform status inspection according to claim 1, wherein: The probe (3) is used to contact the aluminum wafer to realize electrical testing, and the pressure applied when contacting the aluminum wafer is controlled at 20 - 30 gf through a spring structure.

6. The multi-region replaceable combined probe card for machine platform status inspection according to claim 1, wherein: The tip of the probe (3) is provided with a reflective surface (31). The material of the reflective surface (31) has a high reflectivity, and the surface roughness is less than 0.1 μm, which is used for optical focusing of the Prober camera to realize optical flatness measurement, and the optical measurement accuracy can reach ±0.01 mm.

7. The multi-region replaceable combined probe card for machine platform status inspection according to claim 1, characterized in that: The probe (3) is connected to the PCB (2) through metal welding, and a signal shielding layer is provided on the PCB (2).

8. The multi-region replaceable combined probe card for machine tool status inspection according to claim 1, wherein: The small MLCs (1) are connected by mechanical buckles, the buckle accuracy is ±0.05 mm, and they are fixed by a combination of screw fastening and glue assistance. The screws are made of high-strength stainless steel.

9. The multi-region replaceable combined probe card for machine tool status inspection according to claim 1, wherein: The conductive path uses a low-resistance graphene material to ensure stable signal transmission.

10. A multi-region replaceable combined probe card for machine tool status inspection according to claim 1, characterized in that: The probes (3) are distributed in an equilateral triangle on each small MLC (1), the probe spacing is 2 mm, and the distribution positions of the probes (3) on adjacent MLCs are staggered.

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