Probe Card Structure and Probe Card Testing Method

Abstract

The present application provides a probe card structure and a probe card testing method. Among them, the probe card structure is arranged opposite to the wafer stage, and includes a top component, a PCB board, and probes arranged in three layers in sequence. The top component is arranged above the PCB board through ceramics, and the probes are arranged below the PCB board through epoxy resin; the probe card structure further includes: a gas gathering ring is additionally provided at the ceramic position in the inner ring direction of the probe and extends towards the wafer stage; a plurality of air holes penetrating the PCB board are arranged around the epoxy resin corresponding to the probes; a gas gathering wall is arranged around the air holes; among them, nitrogen gas flows through the main air flow holes penetrating the PCB board between the probes in the air storage chamber in the top component and is blown towards the wafer stage direction by the constraint of the gas gathering ring; nitrogen gas also flows through the air holes and is blown towards the periphery of the wafer stage by the constraint of the gas gathering ring and the gas gathering wall, so that nitrogen gas covers the probe testing area and the periphery area of the probe testing. By ensuring a uniform pressure atmosphere in the testing area, the withstand voltage is improved to meet the testing requirements.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and particularly to a probe card structure and a probe card testing method. Background Art

[0002] A probe card is used to test the performance of a device. Especially when the device works in environments such as high voltage and high temperature, it is necessary to ensure that the device can work properly. An important indicator for the normal operation of the device is the breakdown voltage, which can be as high as several thousand volts, etc. If abnormal discharge occurs in the probes of the probe card during the testing process, the testing equipment and the wafer under test will be damaged instantly.

[0003] For example Figure 1 In the prior art, when the test voltage is above 1200V, a sparking phenomenon occurs at the edge of the window area of the SiC wafer during the testing process of the existing probe card, and this sparking phenomenon is positively correlated with the test voltage. That is, as the test voltage increases, the sparking phenomenon increases exponentially (see Figure 2 ), and at the same time, it causes damage to the probe card and the wafer (see Figure 3 ). For example Figure 2 It can be seen that when the test voltage is greater than 1100V, the product yield decreases and the sparking phenomenon becomes more obvious. As shown in Figure 3 , a spark occurs during the detection at the circled area, causing damage to the wafer. Therefore, the detection process of the prior art not only increases the test cost and reduces the product yield, but also encounters test problems, making it impossible to meet the current test requirements.

[0004] Therefore, a new probe card solution is needed. Summary of the Invention

[0005] In view of this, embodiments of this specification provide a probe card structure and a probe card testing method, which are applied to the process of testing the performance of semiconductor devices.

[0006] Embodiments of this specification provide the following technical solutions:

[0007] Embodiments of this specification provide a probe card structure. The probe card structure is oppositely arranged with a wafer stage, and includes a top component, a PCB board, and probes arranged in three layers in sequence. The top component is arranged above the PCB board through ceramics, and the probes are arranged below the PCB board through epoxy resin. The probe card structure further includes: a gas gathering ring is added and extended towards the wafer stage at the ceramic position in the inner ring direction of the probes; a plurality of air holes penetrating the PCB board are arranged around the epoxy resin corresponding to the probes; a gas gathering wall is arranged below the PCB board around the air holes; among them, nitrogen flows through the main air flow holes penetrating the PCB board between the probes from the gas chamber in the top component, and is blown towards the wafer stage direction by the constraint of the gas gathering ring. Nitrogen also flows through the air holes and is blown towards the periphery of the wafer stage by the constraint of the gas gathering ring and the gas gathering wall, so that nitrogen covers the probe testing area and the peripheral area of the probe testing.

[0008] The embodiments of this specification also provide a probe card testing method. The probe card testing method adopts the probe card structure of any technical solution in the embodiments of this specification. The probe card testing method includes:

[0009] If it is detected that a wafer is placed on the wafer stage, the air flow input valve is opened, and the air flow passes through each air hole and respectively covers and blows towards the test area and the test peripheral area;

[0010] If it is detected that no wafer is placed on the wafer stage, the air flow input valve is closed.

[0011] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

[0012] By providing a plurality of air holes, and air-gathering rings, air-gathering walls, etc. that constrain the air flow, not only the main air flow in the test area is gathered to form a uniform gas environment, but also a covering gas environment is formed in a certain area of the test periphery in the form of an air curtain through structures such as each air hole, so as to form a uniformly covered gas environment in the detection area and the peripheral area. That is, by increasing the gas pressure in the test area and the test peripheral area, the test withstand voltage is improved, which not only meets the test requirements but also avoids the occurrence of arcing phenomena and damage to the wafer, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0014] Figure 1 It is a schematic diagram of the arcing phenomenon at the edge of the wafer window area during the probe card testing process of the prior art;

[0015] Figure 2 It is a schematic diagram showing the positive correlation between the arcing phenomenon and the voltage in the prior art;

[0016] Figure 3 It is a schematic diagram of the wafer damaged by the arcing phenomenon in the prior art;

[0017] Figure 4 It is a schematic diagram showing the positive correlation between the atmospheric pressure, the electrode distance and the breakdown voltage in the arcing phenomenon;

[0018] Figure 5 It is a schematic diagram of the probe card structure of the prior art;

[0019] Figure 6 It is a schematic diagram of the use of the probe card of the prior art;

[0020] Figure 7 It is a schematic diagram of a probe card structure in this application;

[0021] Figure 8 It is a flowchart of a probe card testing method in this application. Specific Embodiments

[0022] The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0023] The following illustrates the implementation manners of this application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. This application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0024] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on this application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0025] It also needs to be noted that the drawings provided in the following embodiments only illustrate the basic concept of this application schematically. The drawings only show the components related to this application rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0026] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the examples can be practiced without these specific details.

[0027] During the prior art wafer testing process, when the test voltage is higher than 1200V, arcing occurs at the edge of the SiC wafer window area, that is, the prior art testing cannot meet the requirements for voltages greater than 1200V and above. Additionally, as the test voltage increases, the arcing phenomenon in this wafer window area increases exponentially, making the testing more difficult, increasing the testing cost, and even unable to meet the testing requirements.

[0028] In view of this, the inventors learned from Paschen's curve theory that the electrode distance, atmospheric pressure, and breakdown withstand voltage are positively correlated. Referring to the theoretical relationship diagram of breakdown voltage and pressure Figure 4 , where U0 is the breakdown voltage, P is the gas pressure, and d is the distance. As Figure 4 can be seen, the left side of the curve is close to a vacuum environment. Therefore, the right side area of the curve, such as the right side area circled by the box, is used during the testing process. It is found that by increasing the pressure P, the spark (breakdown) voltage can be increased. Through multiple experimental investigations, it is concluded that each wafer manufacturing factory solves the problem of SiC testing arcing by adding N2 (i.e., increasing the pressure P) during CP (Chip Probe) testing.

[0029] Based on this, the embodiments of this specification propose a probe card solution: as Figure 7 shown, based on the probe card structure of the prior art, a gas gathering ring is arranged at the inner ring position of the probe, and multiple air holes and gas gathering walls are arranged around the probe. This not only increases the pressure in the detection area, comprehensively improves the uniform gas environment in the test area and the test peripheral area, ensures that the wafer testing during the test process is evenly covered by a higher gas environment, thereby increasing the test withstand voltage and meeting the test requirements for higher voltages, but also avoids the occurrence of arcing phenomena and damage to the wafer, etc.

[0030] The following describes the technical solutions provided by the embodiments of this application in conjunction with the accompanying drawings.

[0031] As Figure 7 shown, the embodiments of this specification provide a probe card structure. This probe card structure is oppositely arranged with the wafer stage 20 and includes three layers arranged in sequence: the top component 10, the PCB board 11, and the probe 12. The top component is arranged above the PCB board through the ceramic 13, and the probe 12 is arranged below the PCB board through the epoxy resin 14; this probe card structure further includes: a gas gathering ring 15 is extended and added in the direction of the inner ring of the probe at the ceramic position towards the wafer direction, multiple air holes 16 penetrating the PCB board are arranged around the epoxy resin corresponding to the probe, and a gas gathering wall 17 is arranged outside the air holes. Specifically, nitrogen flows through the air storage chamber 18 in the top component 10, passes through the main air flow holes 19 in the probe and penetrating the PCB board, and is blown towards the wafer stage direction by the constraint of the gas gathering ring 15. Nitrogen also flows through the air holes 16 and is blown towards the periphery of the wafer stage by the constraint of the gas gathering ring 15 and the gas gathering wall 17, so that nitrogen covers the probe test area and the probe test peripheral area. The top component also includes connectors, cables, etc.

[0032] In the embodiments of the present specification, the air chamber space can be increased. After the air flow passes through the main air holes (such as honeycomb holes arranged on the air flow column), it is blown towards the needle insertion detection area by the air gathering ring. At the same time, the air flow passes through multiple air holes outside the probe and blows towards the test peripheral area in the form of an air curtain. By setting an appropriate air flow in the test peripheral area, it is ensured that the test area is completely covered by the air flow, thereby increasing the detection test voltage, that is, improving the withstand voltage of the test to meet the test requirements. At the same time, an air gathering wall is added outside the air curtain, which can not only lock the air flow in the test area to make the air flow fully cover the test area, but also shorten the distance between the air gathering ring and the wafer to avoid interference with the test. However, after the probe inserts the needle, it can maximize the imitation of the detection area and the detection peripheral area as a closed space, thereby achieving the effect of increasing the air pressure and increasing the test voltage.

[0033] In some embodiments, such as Figure 7 shown, a sensor 30 is added to the probe card structure. The sensor 30 is connected to the air flow input valve 40 and is used to open or close the air flow input valve according to the placement of the wafer on the wafer stage. The probe card structure also includes an acrylic cover 50. The sensor 30 is arranged outside the acrylic cover 50. If it is detected that a wafer is placed on the wafer stage, the air flow input valve 40 is opened; if the sensor 30 detects that no wafer is placed on the wafer stage, the air flow input valve 40 is closed. If the wafer is removed or moved from the wafer stage, the air flow input valve is closed. It can ensure that the wafer is not blown away by the air flow during test wafer changing / removing, ensure the safety of the wafer, and prevent damage to the wafer. If a wafer is placed on the wafer stage, whether the needle is inserted or not, the air flow input valve is in the open state to maintain the air flow blowing for the wafer. It ensures that a large amount of gas fully covers the wafer area during the test and ensures the gas environment for high voltage use during the detection process.

[0034] In some embodiments, 12 air holes passing through the PCB board are evenly arranged, and the total diameter of the main air holes (such as honeycomb holes arranged on the air flow column) is greater than the diameter of each air hole.

[0035] Such as Figure 7 shown, 12 air holes 16 are evenly arranged through the PCB board located outside the probe, and the diameter of each air hole is smaller than the total diameter of the main air holes (not shown). So that during the detection process, the air flow not only blows towards the detection area through the main air holes, but also forms an air curtain through each air hole to cover an appropriate range of the detection peripheral area. By setting the air holes, the air gathering ring and the air gathering wall around the air holes, the function of the air curtain is simulated, and the loss of gas in the air gathering ring is reduced as much as possible, so as to ensure that both the detection area and the detection peripheral area are in a gas environment fully covered during the test process, to increase the detection voltage to meet the test requirements, and also avoid the occurrence of sparking and damage to the wafer, etc.

[0036] In some embodiments, the diameter of the gas-gathering ring is greater than the diameter of at least one wafer-cut chip; the diameter of the gas-gathering ring is 10 mm.

[0037] In this embodiment, the inner diameter of the gas-gathering ring is greater than the diameter of at least one wafer-cut chip, so as to ensure that each wafer-cut chip is in a proper high-pressure gas environment during the test, realize the safe progress of the high-voltage test, prevent the wafer from being damaged, and meet the requirements of testing high voltage. In some embodiments, the opening diameter of the gas-gathering ring is 10 mm, the blowing area is larger than the area of the wafer-cut chip, the air flow passes through the detection area and the detection peripheral area. When the probe needles, the gas-gathering ring is closer to the wafer than the acrylic cover arranged outside the overall structure, making it easier for the air flow to gather, ensuring that there is enough nitrogen flow in the test area, thereby increasing the test voltage to meet the test requirements. In some embodiments, the diameter of the gas-gathering ring can also be the inner ring diameter, the outer ring diameter, and the average diameter of the inner and outer ring diameters according to actual needs as the diameter of the gas-gathering ring.

[0038] In some embodiments, the height of the gas-gathering ring is greater than the height of the gas-gathering wall.

[0039] In this embodiment, the height of the gas-gathering ring 15 is greater than the height of the gas-gathering wall 17. For example, the width of the annular gas-gathering wall is 5 mm, the height is 4.5 mm, the outer diameter is 50 mm, and the inner diameter is 40 mm. The width of the annular engineering plastic gas-gathering ring is 5 mm, the height is 5 mm, the outer diameter is 20 mm, and the inner diameter is 10 mm.

[0040] In this description embodiment, the height of the engineering plastic gas-gathering ring is greater than the height of the gas-gathering wall, ensuring that there is no unnecessary influence on the detection area during the detection process, and it can also combine with the gas-gathering wall to gather the gas near the wafer to maintain the air flow in the detection gas environment, thereby increasing the test voltage. At the same time, the height of the gas-gathering ring is greater than the height of the gas-gathering wall, reducing the diffusion of the air flow gathered in the gas-gathering ring, and also ensuring the high-pressure gas environment in the appropriate range of the test peripheral area, realizing the full coverage of the test area and the test peripheral area by the gas, thus meeting the high-voltage requirements of the test and avoiding the occurrence of sparking and damage to the wafer, etc.

[0041] In some embodiments, the height of the gas-gathering wall is 0.5 mm less than the height of the probe tip; the height of the gas-gathering wall is 4.5 mm.

[0042] For example, the height of the gas-gathering wall is 4.5 mm, and the height of the gas-gathering wall is 0.5 mm lower than the height of the probe tip, so as to simulate the function of the gas wall, so that the air flow is restricted by the gas-gathering ring and the gas-gathering wall after passing through each air hole, and the nitrogen gas is retained in the gas-gathering wall, especially gathering in an appropriate range outside the detection area to form a high-pressure gas environment that meets the test requirements, so as to ensure the full coverage of the test area and the test peripheral area by the gas during the test process and realize the high-voltage requirements of the test.

[0043] In some embodiments, when the probe tip does not contact the wafer, the distance between the probe tip and the gas focusing ring in the vertical direction is 150 um; when the probe tip contacts the wafer, the distance between the probe tip and the gas focusing ring in the vertical direction is 100 um.

[0044] In this embodiment, the distance from the tip to the gas focusing ring is designed to be about 150 um. If the vertical distance between the gas focusing ring and the probe tip after the probe needles into the wafer is 100 um. Therefore, while ensuring detection safety, by increasing the gas pressure, the withstand voltage of the detection environment is increased, that is, the detection voltage is increased, thereby avoiding the occurrence of arcing and damage to the wafer, etc.

[0045] In some embodiments, the test voltage is greater than or equal to 1600V. In some embodiments, the test voltage is greater than 2000V. Combining the above embodiments, using the probe card structure of the present application as Figure 7 for probe testing, by increasing the nitrogen gas pressure, the test voltage is increased to 1600V, and in some cases, the test voltage is even increased to 2000V.

[0046] In the prior art, the design dimensions of the circular acrylic sealing cover such as length, width and height are 80mm, 80mm, 25mm respectively. The size of the CDA (compressed air) or nitrogen gas filling port is a 6mm tube. The dimensions of the square air chamber in terms of length, width and height are 50mm, 50mm, 15mm respectively. The width of the square honeycomb air column is 50mm and the height is 7mm, arranged in a 6*6 matrix (the diameter of each honeycomb hole is 3mm). The width and height dimensions of the annular ceramic Ring are 5mm and 3mm respectively, the outer diameter is 20mm and the inner diameter is 15mm. The width and height dimensions of the annular epoxy resin are 5mm and 3mm respectively, the outer diameter is 20mm and the inner diameter is 15mm. The length, width and height dimensions of the long-shaped PCB are 114mm, 128mm and 3.5mm respectively. The probe card structure of the embodiments of this specification compared with the probe card structure of the prior art (see Figure 5 the structure and Figure 6 the usage examples, Figure 6 part a) in Figure 6 is the usage example diagram combined with the wafer stage, Figure 6 part b) in Figure 6 is the physical example of the prior art probe card), the embodiments of this specification increase the space of the square air chamber, so that the gas flows through the main air holes and evenly blows to the detection area to increase the pressure, thereby increasing the withstand voltage; by designing auxiliary air holes, gas focusing rings and gas retaining walls, the gas flowing through each air hole blows to the test peripheral area, and the designed gas retaining wall locks the gas, shortening the distance from the gas focusing ring to the wafer. After the needles are inserted, it maximally mimics a closed space, so that the test area and a certain test peripheral area are covered by gas and in a gas environment with a relatively high pressure, thereby increasing the test withstand voltage, avoiding the occurrence of arcing during the test and also avoiding damage to the wafer, etc. Thereby improving the test efficiency and product yield, etc.

[0047] Combined with the above embodiments, a probe card testing method of the present application is as follows Figure 8 shown. This probe card testing method may include steps S210 to S220. Among them, in step S210, if it is detected that a wafer is placed on the wafer stage, the air flow covers and blows towards the detection area and the test peripheral area, and the wafer is tested. In step S220, if it is detected that no wafer is placed on the wafer stage, the air flow input valve is closed.

[0048] Combined with Figure 7 the probe card structure of the present application, an inductor is added to detect whether a wafer is placed on the wafer stage, so as to control the opening or closing of the air flow input valve.

[0049] Specifically, in step S210, if the inductor detects that a wafer is placed on the wafer stage, the air flow input valve is opened, and the air flow passes through the air chamber of the top component, flows through the main air holes and each air hole on the PCB board, and is respectively blown towards the covered test area and the test peripheral area by the air gathering ring and the air gathering wall to test the wafer. Ensure that the test area and the test peripheral area are both in a uniform high-pressure nitrogen environment during the probe test process, so as to improve the test withstand voltage, avoid the occurrence of arcing and damage to the wafer, etc. Furthermore, ensure the safety of the wafer and improve the test efficiency.

[0050] In step S220, if the inductor detects that no wafer is placed on the wafer stage, the air flow input valve is closed. In this embodiment, if no wafer is placed on the wafer stage, closing the air flow input valve can prevent the wafer from being blown off by the air flow during wafer replacement / retraction.

[0051] In this embodiment, by using the inductor to detect whether a wafer is placed on the wafer stage, it can be ensured that the wafer is not blown away by the air flow during test wafer replacement / retraction, ensure the safety of the wafer, and prevent damage to the wafer. If a wafer is placed on the wafer stage, whether the needles are inserted or not, the air flow input valve is in the open state to maintain the air flow blowing for the wafer. Ensure that a large amount of gas fully covers the wafer area during the test, and ensure the gas environment for high-voltage use during the detection process.

[0052] In this specification, for the same or similar parts between various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the descriptions are relatively simple, and the relevant parts can refer to the partial descriptions of the system embodiments.

[0053] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A probe card structure, the probe card structure is arranged opposite to the wafer stage, and includes a top component, a PCB board, and probes arranged in sequence in three layers. The top component is disposed above the PCB board through ceramics, and the probes are disposed below the PCB board through epoxy resin; characterized in that, The epoxy resin is disposed under the PCB board at the position of the ceramic; The probe card structure further includes: A gas gathering ring is added and extends towards the wafer stage at the ceramic position in the inner ring direction of the probe; A plurality of air holes penetrating the PCB board are provided around the epoxy resin corresponding to the probe; A gas gathering wall is provided under the PCB board outside the air holes; The gas gathering ring is located inside the area surrounded by the gas gathering wall; Wherein, nitrogen flows through the main air holes penetrating the PCB board between the probes from the air storage chamber in the top component and is blown towards the wafer stage direction by the restraint of the gas gathering ring. Nitrogen also flows through the air holes and is blown towards the periphery of the wafer stage by the restraint of the gas gathering ring and the gas gathering wall, so that the nitrogen covers the probe test area and the periphery area of the probe test.

2. The probe card structure according to claim 1, wherein An inductor is added. The inductor is connected to the air flow input valve and is used to open or close the air flow input valve according to the placement of the wafer on the wafer stage. The probe card structure further includes an acrylic cover, and the inductor is disposed outside the acrylic cover.

3. The probe card structure according to claim 1, wherein The 12 air holes penetrating the PCB board are evenly arranged; the total diameter of the main air holes is larger than the diameter of each air hole.

4. The probe card structure according to claim 1, wherein, The diameter of the gas gathering ring is larger than the diameter of at least one wafer diced chip; the diameter of the gas gathering ring is 10 mm.

5. The probe card structure according to claim 4, wherein, The height of the gas gathering ring is greater than the height of the gas gathering wall.

6. The probe card structure according to claim 5, wherein, The height of the gas gathering wall is 0.5 mm less than the height of the probe tip; the height of the gas gathering wall is 4.5 mm.

7. The probe card structure according to claim 1, wherein When the probe tip does not contact the wafer, the vertical distance between the probe tip and the gas gathering ring is 150 um; when the probe tip contacts the wafer, the vertical distance between the probe tip and the gas gathering ring is 100 um.

8. The probe card structure according to claim 1, wherein The test voltage is greater than or equal to 1600 V.

9. The probe card structure according to claim 1, characterized in that, The test voltage is greater than 2000 V.

10. A probe card testing method, characterized in that, The probe card testing method uses the probe card structure as described in any one of claims 1-9. The probe card testing method includes: If it is detected that a wafer is placed on the wafer stage, the air flow input valve is opened, and the air flow covers and blows towards the test area and the test peripheral area, and the wafer is tested; If it is detected that no wafer is placed on the wafer stage, the air flow input valve is closed.

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