Microbump test probe, test device, test method and probe production process

Abstract

This application relates to the field of chip testing technology, and discloses a microbump test probe, testing device, testing method, and probe manufacturing process. The test probe includes a support body and a probe head. The probe head is an elastic clamping structure with a first clamping arm and a second clamping arm arranged opposite each other. The first clamping arm and the second clamping arm form a clamping opening in the free state, and the clamping opening has a convergent smooth curved surface profile that is narrower at the front and wider at the back along the clamping direction. The size of the clamping opening is less than or equal to the diameter of the conductive pillar of the microbump to be tested. The support body is connected to the end of the probe head away from the clamping opening. The support body is an axially elastic deformation structure, and the axial height of the support body is greater than or equal to the sum of the side view height of the probe head and the thickness of the top solder layer of the microbump to be tested. This application can realize non-destructive, low-resistance, and adaptive microbump testing.

Description

Technical Field

[0001] This application relates to the field of chip testing technology, and in particular to a microbump test probe, test device, test method and probe manufacturing process. Background Technology

[0002] In advanced semiconductor packaging, microbumps serve as high-density interconnect structures, with conductive pillars topped by a tin-based solder layer for subsequent bonding. Current testing commonly employs rigid probes (such as vertical probes or thin-film probes) to directly penetrate this solder layer for electrical contact. However, the solder layer has low mechanical strength and poor ductility, making it prone to plastic deformation, breakage, contamination, or residual indentations during repeated penetration. This can lead to poor solder joints, bridging, or interface voids during subsequent thermoforming, severely threatening package reliability. Furthermore, when the chip warps due to temperature changes or process errors during testing, rigid probes struggle to adapt to surface deformation, easily causing poor contact, signal fluctuations, or even device damage. In addition, point contact methods have a small effective area, high and unstable contact resistance, limiting the testing accuracy and consistency of high-speed signals (such as HBM interfaces). Summary of the Invention

[0003] In view of this, embodiments of this application provide a micro-bump test probe, test device, test method, and probe manufacturing process, which can realize non-destructive, low-resistance, and adaptive micro-bump testing.

[0004] In a first aspect, this application provides a micro-bump test probe, comprising: a support and a probe head; The probe head is an elastic clamping structure with a first clamping arm and a second clamping arm arranged opposite to each other. The first clamping arm and the second clamping arm form a clamping opening in the free state, and the clamping opening has a convergent smooth curved surface profile that is narrow at the front and wide at the back along the clamping direction. The size of the clamping opening is less than or equal to the diameter of the conductive post of the micro-protrusion to be measured. The support is connected to the end of the probe head away from the clamping opening. The support is an axially elastic deformation structure, and the axial height of the support is greater than or equal to the sum of the side view height of the probe head and the thickness of the top solder layer of the micro-bump to be tested.

[0005] In an optional embodiment, the clamping working area of ​​the probe tip is provided with a micro-protrusion structure; The micro-protrusion structure includes at least one of the following: spike-like, thread-like, serrated, pyramidal, prismatic, or roughened surface.

[0006] In an optional embodiment, the micro-protrusion structure is distributed on the inner sidewalls of the first clamping arm and the second clamping arm.

[0007] In an optional embodiment, the support is a multi-bend elastic deformation structure; the support includes at least two reverse bending segments, forming a Z-shape or a zigzag shape.

[0008] In an optional embodiment, the probe tip is made of an elastic conductive material.

[0009] In an optional embodiment, after the conductive column is fully inserted into the probe head, the first clamping arm and the second clamping arm form an enveloping contact along the circumference of the conductive column, so that the side surface of the conductive column is in continuous circumferential contact with the inner wall of the probe head.

[0010] Secondly, this application provides a micro-bump testing device, including the aforementioned micro-bump testing probe; the testing probe is electrically connected to an external testing system, and the testing probe establishes an electrical connection with the conductive column of the micro-bump to be tested through the probe head.

[0011] Thirdly, this application provides a micro-bump testing method, including: The probe head of the micro-bump test probe is translated along the direction of the conductive column toward the micro-bump to be tested, so that the probe head wraps around and elastically clamps the conductive column. A low-resistance electrical connection is established through circumferential continuous surface contact between the probe head and the conductive pillar, and the electrical signal test of the micro-bump to be tested is completed.

[0012] In an optional implementation, during the test, when the chip warps, deforms, or becomes uneven, the axial elastic deformation structure of the test probe support compensates for this by vertical elastic deformation, thereby maintaining stable clamping and electrical connection between the probe head and the conductive pillar.

[0013] Fourthly, this application provides a manufacturing process for a microbump test probe, used to fabricate the aforementioned microbump test probe, the manufacturing process comprising: A substrate is provided, and a sacrificial layer is formed on the substrate; Based on the geometric parameters of the multi-bend elastic deformation structure of the support, photolithography and etching are performed stepwise in the sacrificial layer to define the bending morphology mold of the bending section of the support. Based on the narrow front and wide rear convergent profile of the probe head and the distribution range of the micro-protrusion structure in the clamping working area, photolithography and etching are performed in the sacrificial layer to define the probe head clamping cavity and its inner wall microstructure mold. An elastic conductive metal is filled into the complete mold formed by etching, so that the support body and the probe head are integrally formed; the complete mold includes the bending morphology mold and the probe head clamping cavity and its inner wall microstructure mold. Remove all of the sacrificial layers to release a microbump test probe with axial elastic deformation capability, clamping opening size constraint, and micro-bump structure.

[0014] The embodiments of this application have the following beneficial effects: By designing the probe head configuration as a convergent smooth curved surface profile that is narrow at the front and wide at the back, and ensuring that the size of the clamping opening is strictly less than or equal to the diameter of the conductive pillar of the micro-bump to be tested, the conductive pillar can be naturally guided to elastically open and gradually tighten along the pillar surface during the process of entering the clamping opening, thereby achieving a stable and tight contact. At the same time, the support body is clearly defined as an axially elastic deformation structure, and its axial height is structurally set to be no less than the sum of the probe head's side view height and the thickness of the top solder layer. This dimensional constraint physically limits the maximum translational stroke of the probe head, ensuring that it only contacts the conductive pillar under any test conditions, completely avoiding the squeezing, scratching, or puncturing of the top solder layer, thereby eliminating reliability risks in subsequent chip integration. Furthermore, the axially elastic deformation support body in this application can compensate for stroke deviation in real time by autonomous compression or elongation when the chip warps or the surface is uneven, continuously maintaining reliable clamping and electrical connection between the probe head and the conductive pillar, thereby enhancing the accuracy of the testing process. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and therefore should not be considered as a limitation on the scope of protection of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the first structure of the micro-bump test probe according to an embodiment of this application is shown; Figure 2 A schematic diagram of the serrated micro-protrusion structure according to an embodiment of this application is shown; Figure 3 A schematic diagram of the second structure of the microbump test probe according to an embodiment of this application is shown; Figure 4 A top view showing the contact between the needle tip and the conductive column according to an embodiment of this application is shown; Figure 5 This invention provides a schematic diagram showing the relative positions of the probe tip and the conductive column before needle insertion according to an embodiment of the present application. Figure 6 This invention provides a schematic diagram showing the relative positions of the probe tip and the conductive column after needle insertion according to an embodiment of the present application. Figure 7 A schematic diagram of a micro-bump testing device according to an embodiment of this application is shown; Figure 8 A flowchart illustrating the micro-bump testing method according to an embodiment of this application is shown; Figure 9 The illustration shows a scenario with the chip being undeformed and deformed according to an embodiment of this application. Figure 10 A schematic diagram of the manufacturing process of the micro-bump test probe according to an embodiment of this application is shown; Figure 11 A schematic diagram of the manufacturing process of the micro-bump test probe according to an embodiment of this application is shown.

[0017] Explanation of key component symbols: 1-Micro bump test probe; 2-Support body; 3-Probe head; 4-Conductive pillar; 5-External test system; 6-Micro bump structure. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0019] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0021] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0022] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] The microbump test probe 1 will be described below with reference to some specific embodiments. This test probe is suitable for electrical testing of microbumps in the field of advanced semiconductor packaging and testing. For example, it can be used for testing fine microbumps with a pitch of less than 100 micrometers. The test probe of this embodiment can effectively solve the technical problems of damage to the solder layer on the top of the microbump, high contact resistance, and poor contact caused by chip deformation during traditional rigid probe testing. It can achieve stable, low-resistance, and non-destructive testing of the conductive pillar 4 of the microbump, thereby ensuring the reliability of subsequent chip integration and improving test accuracy and consistency.

[0024] Figure 1 A schematic diagram of a micro-bump test probe 1 according to an embodiment of this application is shown. Exemplarily, the micro-bump test probe 1 includes a support body 2 and a probe head 3; the support body 2 and the probe head 3 can be integrally formed, which can ensure the mechanical strength of the overall structure and realize the continuous transmission of electrical signals, avoiding the additional contact resistance caused by the separate connection, which would affect the test signal quality.

[0025] The probe head 3 is an elastic clamping structure with a first clamping arm and a second clamping arm arranged opposite to each other. The first clamping arm and the second clamping arm are symmetrically distributed and form a clamping opening in the free state. The clamping opening has a convergent smooth curved surface profile that is narrow in the front and wide in the back along the clamping direction.

[0026] like Figure 1 and Figure 2 As shown, the convergent smooth curved surface profile of the probe head 3 can be understood as having the smallest size on the side of the clamping opening near the free end, gradually increasing in size on the side connected to the support body 2 along the clamping direction, and its inner wall is smooth. When the conductive column 4 with micro-protrusions enters the clamping opening along the clamping direction, the first clamping arm and the second clamping arm can be elastically opened by squeezing, and then the elastic restoring force can be used to gradually tighten and stably clamp the conductive column 4. At the same time, the smooth curved surface profile is compatible with the cylindrical structure of the conductive column 4, which can lay the foundation for subsequent circumferential continuous surface contact.

[0027] Furthermore, in order to enable the first and second clamping arms to effectively elastically open when squeezed by the conductive column 4 and return to their initial shape after the test, thereby achieving multiple reuses and satisfying the low-resistance conduction of electrical signals in the probe head 3, avoiding test signal attenuation or interference due to poor material conductivity, and improving test accuracy, the probe head 3 in this embodiment needs to be made of an elastic conductive material, which includes, but is not limited to, at least one of nickel-cobalt alloy, nickel-tungsten alloy, and nickel-iron alloy.

[0028] Furthermore, to ensure an interference fit between the probe tip 3 and the conductive post 4, the size of the clamping opening in this embodiment is less than or equal to the diameter of the conductive post 4 of the micro-protrusion to be tested. When the conductive post 4 enters the clamping opening, the first and second clamping arms elastically open to both sides, generating a continuous inward clamping force, thereby firmly holding the conductive post 4 and achieving a tight fit between the probe tip 3 and the conductive post 4. In addition, the interference fit design also enables automatic centering, ensuring that the probe tip 3 is accurately aligned with the conductive post 4 during each test, avoiding test errors caused by positioning deviations, and thus improving test consistency.

[0029] In some embodiments, the size of the clamping opening can be 60%-95% of the diameter of the conductive post 4 of the micro-protrusion to be tested. This range can be flexibly adjusted according to the specific diameter of the conductive post 4 and the material of the probe head 3. The main purpose is to ensure the clamping force while avoiding deformation of the first clamping arm and the second clamping arm due to excessive interference, which would affect the service life of the probe.

[0030] Furthermore, the support 2 is connected to the end of the probe head 3 away from the clamping opening, which provides stable mechanical support for the probe head 3 on the one hand, and serves as a path for electrical signal transmission on the other hand, enabling the probe head 3 to connect with the external testing system 5 via electrical signals.

[0031] The support 2 is an axially elastic deformation structure, and the axial height of the support 2 is greater than or equal to the sum of the side view height of the probe tip 3 and the thickness of the top solder layer of the microbump to be tested. By limiting the axial height of the support 2, this embodiment can structurally ensure that when the probe tip 3 translates and clamps the conductive post 4 towards the microbump to be tested, its overall stroke and clamping height are precisely limited to the conductive post 4 area of ​​the microbump. This ensures that the probe tip 3 only contacts the conductive post 4, completely avoiding the solder layer on top of the microbump. This fundamentally avoids the probe tip 3 squeezing, scratching, or damaging the top solder layer, thereby eliminating reliability problems such as poor bonding, cold solder joints, and short circuits caused by solder layer damage during subsequent chip integration.

[0032] Furthermore, the axial elastic deformation capability of the support 2 allows it to have adaptive floating and buffer space in the vertical direction. This is useful when the chip warps, deforms, or becomes uneven due to factors such as temperature changes or processing errors during testing (e.g., ...). Figure 9 As shown, the support 2 can autonomously undergo elastic deformation up and down with the contact pressure to compensate for the pressure, thereby always maintaining the stable clamping and good electrical contact between the probe head 3 and the conductive pillar 4 of the micro-bump. This effectively avoids poor contact, contact failure or device damage caused by poor chip coplanarity, thereby improving the stability and consistency of the testing process.

[0033] In some embodiments, the clamping working area of ​​the probe tip 3 is provided with a micro-protrusion structure 6. In this embodiment, the micro-protrusion structure 6 is provided mainly to effectively remove the oxide layer and dirt on the surface of the conductive pillar 4 when the probe tip 3 contacts the conductive pillar 4, ensuring low-resistance electrical contact between the probe tip 3 and the conductive pillar 4, and improving the quality and stability of the test signal.

[0034] The micro-protrusion structure 6 can be set up so that the oxide layer and dirt layer formed on the surface of the conductive pillar 4 due to air oxidation and processing residue can be removed through the scraping and piercing action during physical contact, so that the elastic conductive material of the probe head 3 can directly contact the clean surface of the conductive pillar 4, thereby greatly reducing the contact resistance. For example, the micro-protrusion structure 6 can be set as at least one of the following: spike-shaped, thread-shaped, sawtooth-shaped, pyramid-shaped, ridge-shaped, or roughened surface.

[0035] like Figure 2 As shown, Figure 2 A schematic diagram of a microscopic protrusion structure 6 is shown. Figure 2 The micro-protrusion structure 6 is a serrated micro-protrusion structure. This serrated micro-protrusion structure has a continuous tooth-like distribution, which has a large scraping area and good cleaning effect when in contact with the conductive pillar 4. It can be used in test scenarios where the oxide layer on the surface of the conductive pillar 4 is thick. Of course, in other embodiments, a suitable micro-protrusion structure 6 can be selected according to the surface condition of the conductive pillar 4. For example, the contact point pressure of the spike structure is high and can quickly pierce the hard oxide layer, while the threaded structure can achieve all-round surface cleaning through rotation and scraping.

[0036] In addition, the micro-protrusion structure 6 is distributed on the inner sidewalls of the first clamping arm and the second clamping arm.

[0037] Specifically, when the probe head 3 clamps the conductive pillar 4, the conductive pillar 4 needs to enter the probe head 3 from the clamping opening. For example, in this embodiment, the micro protrusion structure 6 can be set in the area extending inward from the edge of the clamping opening to within 1 / 3-1 / 2 of the clamping length. In this way, when the conductive pillar 4 enters the probe head 3 from the clamping opening, it can pass through the micro protrusion structure 6, thereby removing the oxide layer and dirt on the surface of the conductive pillar 4.

[0038] It should be noted that when setting the micro-protrusion structure 6, it is necessary to ensure that the micro-protrusion structure 6 has the ability to scratch and puncture, but will not cause scratches or damage to the surface of the conductive pillar 4 due to excessive size. At the same time, it should be compatible with the fine structure of the micro-protrusions to avoid affecting the fit between the probe head 3 and the conductive pillar 4 due to the excessive size of the micro-protrusion structure 6. The micro-protrusion structure 6 and the probe head 3 are integrally formed and are formed simultaneously with the preparation process of the probe head 3. This can ensure the stability of the structure and the connection strength, and avoid cleaning failure and poor contact caused by the micro-protrusion structure 6 falling off.

[0039] In some embodiments, the support 2 is a multi-bend elastic deformation structure; the support 2 includes at least two reverse bending segments, forming a Z-shape or a zigzag shape. It can be understood that this embodiment, through its multi-bend design, can enhance the axial elastic deformation capability of the support 2, enabling it to generate a large axial deformation under relatively small external forces. This satisfies the stroke compensation requirements during chip warpage and deformation. Simultaneously, the multi-bend structure can disperse the stress on the support 2, preventing stress concentration and subsequent breakage, thereby improving the mechanical strength and service life of the support 2.

[0040] Reference Figure 1 and Figure 3 , Figure 1 The image shows a six-bend Z-shaped elastic deformation structure. Figure 3 A Z-shaped elastic deformation structure with two bends is shown.

[0041] The six-bend Z-shaped structure includes six bends and seven straight segments, while the two-bend Z-shaped structure includes two bends and three straight segments. The bending directions of adjacent bends are opposite, giving the support 2 good axial flexibility. When the probe head 3 is subjected to vertical pressure, each straight segment can oscillate slightly in the vertical direction, achieving overall axial contraction of the support 2 through the elastic deformation of the bends. When the pressure is removed, the elastic restoring force of the bends can drive the straight segments back to their initial positions, allowing the support 2 to return to its initial length. It is understood that the number of bends can be flexibly adjusted according to the chip's maximum deformation and the requirements of the testing scenario. The more bends, the greater the axial deformation of the support 2 and the stronger the stroke compensation capability. This embodiment does not specifically limit this, as long as the support 2 includes at least two opposite bends and possesses axial elastic deformation capability. Furthermore, it should be noted that... Figure 1 and Figure 3 The elastic deformation structure shown is exemplary, and specific configurations can be made as needed.

[0042] Furthermore, the support 2 and the probe tip 3 can be made of the same elastic conductive material, such as nickel-cobalt alloy, nickel-tungsten alloy, or nickel-iron alloy. This ensures continuous and low-resistance conduction of electrical signals between the support 2 and the probe tip 3, while matching the elastic deformation characteristics of the support 2 and the probe tip 3. This allows for coordinated deformation during testing, further improving the overall adaptability of the probe structure. The cross-section of the support 2 can be rectangular, circular, or square. In a preferred embodiment, the cross-section of the support 2 can be rectangular. A rectangular cross-section of the support 2 provides good axial deformation stability and reduces lateral displacement, ensuring that the probe tip 3 always clamps the conductive column 4 vertically, thus improving the positioning accuracy of the test.

[0043] In some embodiments, after the conductive column 4 is fully inserted into the probe head 3, the first clamping arm and the second clamping arm form an enveloping contact along the circumference of the conductive column 4, so that the side surface of the conductive column 4 is in continuous circumferential contact with the inner wall of the probe head 3.

[0044] Reference Figure 4 , Figure 5 and Figure 6 , Figure 4 A top view showing the contact between probe tip 3 and conductive pillar 4 is shown; Figure 5 A schematic diagram showing the relative positions of the probe head 3 and the conductive column 4 before needle insertion is shown; Figure 6 A schematic diagram showing the relative positions of the probe head 3 and the conductive column 4 after needle insertion is shown.

[0045] Specifically, before needle insertion, the clamping opening of the probe head 3 is aligned with the axis of the conductive column 4, and the two are kept coaxial. During needle insertion, the probe head 3 is translated along the direction of the conductive column 4 toward the micro-protrusion to be measured, so that the clamping opening of the probe head 3 is laterally aligned with the conductive column 4, and the conductive column 4 first contacts the free end of the clamping opening. As the probe head 3 continues to translate, the conductive column 4 gradually enters the clamping opening along the clamping direction, and then the first clamping arm and the second clamping arm elastically open to both sides until the conductive column 4 is completely in the clamping working area of ​​the probe head 3. At this time, under the action of elastic restoring force, the first clamping arm and the second clamping arm are tightly attached to the side surface of the conductive column 4 along the circumference, forming an envelope contact, so that the side surface of the conductive column 4 and the inner wall of the probe head 3 achieve circumferential continuous surface contact.

[0046] Compared to the point contact of traditional rigid probes, the circumferential continuous surface contact in this embodiment significantly increases the effective contact area between the probe tip 3 and the conductive pillar 4. This increased contact area significantly reduces contact resistance, minimizing signal attenuation and interference during testing. This allows the external testing system 5 to accurately acquire the electrical signals of the micro-bumps, improving testing precision and accuracy. Simultaneously, the circumferential continuous surface contact ensures that the clamping force of the probe tip 3 on the conductive pillar 4 is evenly distributed across the side surface of the conductive pillar 4. This avoids deformation or damage to the conductive pillar 4 caused by excessive local pressure during point contact, further guaranteeing the structural integrity of the micro-bumps and ensuring the reliability of subsequent chip integration.

[0047] This application also provides a micro-bump testing device, such as Figure 7 As shown, it includes the micro-bump test probe 1 in the above embodiment. The micro-bump test probe 1 is electrically connected to the external test system 5. The test probe establishes an electrical connection with the conductive column of the micro-bump to be tested through the probe head 3, thereby realizing the electrical signal transmission between the external test system 5 and the micro-bump and completing the electrical test of the micro-bump.

[0048] In addition, the external testing system 5 includes, but is not limited to, a signal generation module, a signal acquisition module, a data processing module, and a display module. The signal generation module is electrically connected to the support 2 of the test probe and is used to output a preset test electrical signal to the micro-bump. The signal acquisition module is electrically connected to the support 2 of the test probe and is used to acquire the electrical signal fed back by the micro-bump and transmit the acquired electrical signal to the data processing module. The data processing module is used to filter, amplify, and analyze the acquired electrical signal to obtain the electrical parameters of the micro-bump, such as resistance, capacitance, inductance, and conductivity. The display module is used to display the electrical parameters obtained by the data processing module in the form of numbers, curves, and images for easy observation and recording by the test personnel.

[0049] Furthermore, the testing device also includes a drive module connected to the test probe. This drive module drives the test probe to move in the direction towards the conductive pillar 4, achieving alignment of the probe head 3 with the conductive pillar 4, translation in the direction towards the conductive pillar 4, and resetting. The drive module's motion accuracy can reach the micrometer level, thus ensuring that the probe head 3 can be accurately aligned with the conductive pillar 4, avoiding test errors or device damage caused by positioning deviations. During the test, the drive module can adjust the translation stroke in real time according to the surface morphology of the chip. Combined with the axial elastic deformation capability of the support 2, it can achieve adaptive compensation for chip warpage and deformation, further improving the stability and consistency of the test.

[0050] It should be noted that this microbump testing device can be integrated into semiconductor testing equipment and is suitable for batch testing of microbumps at the wafer or chip level. It can realize automated, high-precision, and non-destructive electrical testing of microbumps, thereby improving testing efficiency and yield, and reducing the cost of advanced semiconductor packaging and testing.

[0051] This application also provides a method for testing micro-bumps, such as... Figure 8 As shown, the method includes steps S10-S20: Step S10: The probe head 3 of the micro-bump test probe 1 is translated along the direction toward the conductive pillar 4 to be tested, so that the probe head 3 wraps around and elastically clamps the conductive pillar 4, and during the wrapping process, the micro-bump structure 6 of the probe head 3 removes the oxide layer or dirt on the surface of the conductive pillar 4.

[0052] In this step, the probe tip 3 of the test probe is first aligned coaxially with the conductive post 4 of the micro-bump to be tested using a precision positioning device. This ensures that the center of the clamping opening coincides with the axis of the conductive post 4, preventing the probe tip 3 from contacting the top solder layer of the micro-bump due to positioning deviation, which could damage the solder layer. After positioning, the test probe is driven by the drive module to translate along the direction towards the conductive post 4 of the micro-bump to be tested. The free end of the clamping opening of the probe tip 3 first contacts the conductive post 4. As the test probe continues to translate, the conductive post 4 gradually enters the clamping opening of the probe tip 3 along the clamping direction. Because the size of the clamping opening is less than or equal to the diameter of the conductive post 4, the conductive post 4 will force the first and second clamping arms to elastically open to both sides, producing elastic deformation.

[0053] During the elastic opening of the first and second clamping arms, the microscopic protrusions 6 on their inner walls make physical contact with the side surface of the conductive pillar 4. Through scraping and piercing, the oxide layer and dirt on the surface of the conductive pillar 4 are removed, allowing the elastic conductive material of the probe head 3 to directly contact the clean metal surface of the conductive pillar 4, thus laying the foundation for establishing a low-resistance electrical connection. When the test probe moves to the preset stroke, the conductive pillar 4 completely enters the clamping working area of ​​the probe head 3, and the probe head 3 completely encloses the conductive pillar 4. Under the action of elastic restoring force, the first and second clamping arms generate a continuous clamping force on the conductive pillar 4, achieving elastic clamping of the conductive pillar 4.

[0054] The preset stroke can be set according to the structural dimensions of the micro-bumps to ensure that the clamping height of the probe head 3 does not exceed the height of the conductive column 4 while completing the wrapping and clamping, and completely avoids the top solder layer of the micro-bumps. Specifically, it can be calculated based on the axial height of the support body 2, the side view height of the probe head 3 and the thickness of the top solder layer. That is, the preset stroke should be less than or equal to the difference between the axial height of the support body 2 and the side view height of the probe head 3.

[0055] In step S20, a low-resistance electrical connection is established through circumferential continuous surface contact between the probe head 3 and the conductive pillar 4, and the electrical signal test of the micro-bump to be tested is completed.

[0056] In this step, after the probe head 3 achieves elastic clamping of the conductive column 4, the first clamping arm and the second clamping arm form an enveloping contact along the circumference of the conductive column 4, which can make the side surface of the conductive column 4 and the inner wall of the probe head 3 in continuous circumferential contact, thereby increasing the effective contact area, reducing the contact resistance, and establishing a low-resistance electrical connection between the probe head 3 and the conductive column 4.

[0057] After the low-resistance electrical connection is established, the external test system 5 can output a preset test electrical signal to the probe head 3 through the support 2 of the test probe. The test electrical signal is conducted to the conductive pillar 4 through the probe head 3, and then to the inside of the chip through the microbump. The circuit inside the chip feeds back the test electrical signal. The feedback electrical signal is conducted back to the external test system 5 through the conductive pillar 4, the probe head 3, and the support 2. The external test system 5 collects, processes, and analyzes the feedback electrical signal to obtain the electrical parameters of the microbump under test, so as to complete the electrical signal test of a single microbump.

[0058] After testing a single microbump, the drive module drives the test probe to reset vertically upwards. The first and second clamping arms of the probe head 3 return to their free state under the action of elastic restoring force, separating from the conductive pillar 4. Then, a precision positioning device moves the test probe to the position of the next microbump to be tested, repeating steps S10-S20 to achieve batch testing of microbumps. The drive module can also drive multiple test probes simultaneously, enabling simultaneous testing by multiple probes.

[0059] Furthermore, during the testing process, when the chip warps, deforms, or has an uneven surface (refer to...), Figure 9 ( Figure 9 'a' indicates that the chip is not deformed. Figure 9 b is the chip tilted upwards, Figure 9 (where c is the chip recess) The axial elastic deformation structure of the test probe support 2 compensates for displacement through vertical elastic deformation to maintain the dynamic coaxial relationship between the center of the probe head 3 clamping opening and the axis of the conductive pillar 4, thereby ensuring the stable clamping and electrical connection of the probe head 3 to the conductive pillar 4.

[0060] Specifically, when the chip is not deformed, the support 2 maintains its initial height, and the probe 3 moves along the conductive pillar 4 towards the micro-bump to be measured to a preset stroke, thus achieving stable clamping of the conductive pillar 4. When the chip tilts upward, the height of the micro-bump to be measured in a local area is higher than the surrounding area. Since the support 2 is an elastic deformation structure, during the movement, as the chip deforms, the support 2 will also adaptively deform up and down to align the probe 3 with the conductive pillar 4, thereby ensuring that the probe 3 can still completely wrap around and clamp the conductive pillar 4. Similarly, when the chip tilts downward, the height of the micro-bump to be measured is lower than the surrounding area. Since the support 2 is an elastic deformation structure, during the movement, as the chip deforms, the support 2 will also adaptively deform up and down to align the probe 3 with the conductive pillar 4, thereby ensuring that the probe 3 can still completely wrap around and clamp the conductive pillar 4.

[0061] The axial elastic deformation compensation of the support 2 is an adaptive process that does not require manual intervention. It can respond to changes in the surface morphology of the chip in real time during the test, and always maintain the stable clamping and low-resistance electrical connection between the probe head 3 and the conductive pillar 4. This effectively avoids test instability problems such as poor contact and signal fluctuation caused by chip warping and deformation, and improves the consistency and yield of the test.

[0062] This application embodiment also provides a manufacturing process for a microbump test probe 1, which is used to fabricate the microbump test probe 1 described in the above embodiment, such as... Figure 10 As shown, the production process includes steps S100-S500: Step S100: Provide a substrate and form a sacrificial layer on the substrate.

[0063] This step is the foundational process for mold fabrication of the probe structure. Through multi-layer oxide layer stacking and step-by-step etching, a complete cavity is provided for the molding of the support 2 and the probe head 3. Specific sub-steps are as follows: Figure 11 S1-S12 in the middle: S1, deposit the first oxide layer on the substrate. The substrate can be a silicon substrate or a glass substrate. In this step, a silicon or glass substrate is first provided as the process carrier substrate. The substrate surface is flat, has stable mechanical properties, and can withstand subsequent photolithography, etching, deposition, and other processes. A first oxide layer (1st oxide layer) can be deposited on the substrate surface using chemical vapor deposition (CVD) or physical vapor deposition (PVD). The oxide layer can be silicon oxide (SiO2). The thickness of the first oxide layer corresponds to the height of the bottom structure of the support 2, providing molding space for the base segment of the Z-shaped support.

[0064] S2, Deposit photoresist and expose / develop. In this step, photoresist is coated on the surface of the first oxide layer. The photoresist is then exposed and developed using a mask to transfer the pattern of the bottom structure of the support 2 to the photoresist layer, forming a photoresist mask that matches the bent section of the bottom layer of the support 2, providing patterned protection for subsequent etching.

[0065] S3, Etching This step can employ a dry anisotropic etching process to etch the area of ​​the first oxide layer not protected by photoresist, forming the initial step structure of the bottom layer of the support 2 within the first oxide layer, thus completing the patterning of the first layer mold of the support 2. After etching, the remaining photoresist is removed to obtain the first oxide layer mold substrate.

[0066] S4, Development, Exposure, Etching This step mainly involves repeatedly performing photoresist coating, exposure, development, and etching processes based on the design parameters of the Z-shaped multi-bend structure of the support 2. The first oxide layer is then patterned a second time, and the reverse bending section cavity of the bottom layer of the support 2 is further etched out to form a bottom bending morphology that matches the Z-shaped support 2, thus providing a structural basis for the elastic deformation of the support 2.

[0067] S5, Deposition of support pillar material - performed in the first oxide layer mold. Exemplary, in the mold cavity of the first oxide layer formed by etching, support pillar material (i.e., elastic conductive metal, such as nickel-cobalt alloy, nickel-tungsten alloy, nickel-iron alloy, etc.) can be filled by electroplating or chemical deposition to form the bottom layer structure of support body 2. After filling, chemical mechanical polishing (CMP) can be performed to make the surface of the support pillar material flush with the surface of the oxide layer, thereby ensuring the flatness of subsequent processes.

[0068] It should be noted that the S1-S5 process can be repeated to stack multiple oxide layers and etch corresponding steps according to the required number of layers of the bending structure of the support 2, so as to obtain Z-shaped support 2 molds with different bending numbers, thereby meeting the warpage compensation requirements of different chips.

[0069] S6, Exposure, Etching - Targeting the first oxide layer In this step, after the bottom structure of the support 2 is formed, photoresist is applied, exposed, and developed. The first oxide layer and the support pillar material are etched a second time to adjust the size and angle of the bottom bending section of the support 2 and optimize the elastic deformation performance of the support 2. After etching, a second oxide layer (2nd oxide layer) is deposited on the substrate surface. The thickness of the second oxide layer corresponds to the height of the upper bending section of the support 2 and is used to form the upper Z-shaped structure of the support 2.

[0070] S7, Exposure, Etching - Targeting the Second Oxide Layer In this step, photolithography and etching processes are performed on the second oxide layer. Based on the geometric parameters of the multi-bend structure of the support 2, the stepped cavity of the upper bend section of the support 2 is etched out, forming a continuous Z-shaped mold with the bottom support 2 structure.

[0071] S8, Deposition of support pillar material - performed in the mold cavity of the second oxide layer. In this step, the mold cavity of the second oxide layer is filled again with elastic conductive metal support column material to form the upper bending section of the support body 2, which is integrally connected with the bottom support body 2 structure, thus completing the mold filling and forming of the Z-shaped multi-bend elastic deformation structure of the support body 2, ensuring that the structure of each section of the support body 2 is continuous and elastic.

[0072] Step S200: Based on the geometric parameters of the multi-bend elastic deformation structure of the support 2, photolithography and etching are performed stepwise in the sacrificial layer to define the bending morphology mold of the bending segment of the support 2.

[0073] This step corresponds to Figure 11In step S9, specifically, after the multi-layer oxide layer mold of the support body 2 is formed, the process continues with photoresist coating, exposure, and development, i.e., final etching of the multi-layer oxide layer. This corrects the angle, height, and width of each bent section of the support body 2, ensuring that the mold cavity of the support body 2 perfectly matches the designed multi-bend elastic deformation structure, giving the support body 2 stable axial elastic deformation capability and stroke compensation performance. After this step is completed, the complete Z-shaped mold cavity of the support body 2 is formed, thus providing a foundation for the processing of the probe head 3 structure.

[0074] Step S300: Based on the front-narrow-back-wide convergent profile of the probe head 3 and the distribution range of the micro-protrusion structure 6 in the clamping working area, photolithography and etching are performed in the sacrificial layer to define the clamping cavity of the probe head 3 and its inner wall microstructure mold.

[0075] This step is used to form the core structure mold of the probe head 3. Specifically, after the support body 2 mold is formed, a third oxide layer (3rd oxide layer) is deposited on top of the multi-layer oxide layer. The thickness of the third oxide layer corresponds to the side view height of the probe head 3, providing space for the forming of the probe head 3.

[0076] Specifically, it corresponds to Figure 11 In step S10, the structure of the probe head 3 is exposed and etched. Specifically, based on parameters such as the converging clamping profile of the probe head 3 (narrower at the front and wider at the back), the clamping opening size, and the effective clamping area, photoresist is applied and exposed and developed using a high-precision mask to transfer the clamp-like structure pattern of the probe head 3 to the photoresist layer. Subsequently, the third oxide layer is patterned by dry etching to form the clamping cavity of the probe head 3, ensuring that the clamping opening size is 60%-95% of the diameter of the conductive pillar 4 of the micro-bump to be measured, thus meeting the interference fit requirements.

[0077] Meanwhile, on the inner wall of the probe head 3 cavity, extending inward from the edge of the clamping opening (e.g., an effective working area of ​​1 / 3-1 / 2 clamping length; it should be noted that 1 / 3-1 / 2 is only an example, and can be set according to the specific situation), a micro-rough structure mold with spike-like, thread-like, sawtooth-like, ridge-like, frosted, or corrugated shape is simultaneously formed by high-precision etching. This is used to form a self-cleaning micro-protrusion structure 6 on the inner wall of the probe, ensuring that the oxide layer and dirt can be effectively removed when the probe head 3 comes into contact with the conductive pillar 4.

[0078] In step S400, an elastic conductive metal is filled into the etched mold to form the support 2 and the probe head 3 as a single unit.

[0079] The complete mold includes a bending morphology mold and a probe head 3 clamping cavity and its inner wall microstructure mold.

[0080] This step corresponds to Figure 11In S11, the probe head 3 and the support 2 are grown. In the complete continuous mold cavity (including the Z-shaped bending section cavity of the support 2, the clamping cavity of the probe head 3 and the inner wall microstructure mold) formed by etching in the above steps, elastic conductive metal materials such as nickel-cobalt alloy, nickel-tungsten alloy, nickel-iron alloy, pure nickel or nickel-palladium alloy can be filled in one go by electroplating or chemical deposition.

[0081] During the metal filling process, the cavities of the support body 2 and the probe head 3 are continuously connected, achieving integrated molding of the support body 2 and the probe head 3 without any splicing interface. This ensures both the mechanical strength and elasticity consistency of the overall structure and enables low-resistance continuous transmission of electrical signals. After filling, chemical mechanical polishing is performed to remove excess metal, making the probe structure surface smooth and ensuring that the probe dimensional accuracy meets the requirements of micro-bump testing.

[0082] Step S500: Remove all sacrificial layers to release the micro-bump test probe 1, which has axial elastic deformation capability, clamping opening size constraint, and micro-bump structure 6.

[0083] This step corresponds to Figure 11 In step S12, the oxide layer is removed. Specifically, wet etching (such as BOE buffered oxide etchant) or dry etching process can be used to completely remove the first, second, and third oxide layers (all sacrificial layers) on the substrate, so that the formed probe structure is separated from the substrate, and an independent microbump test probe 1 is obtained.

[0084] The test probe of this application limits the axial height of the support 2 to a value greater than or equal to the sum of the side view height of the probe tip 3 and the thickness of the solder layer on top of the microbump. This structurally ensures that the probe tip 3 only contacts the conductive pillar 4, completely avoiding the top solder layer. Simultaneously, the elastic clamping method avoids the squeezing, scratching, and puncturing of the solder layer caused by traditional needle-point contact, eliminating reliability issues such as poor bonding, cold solder joints, and short circuits caused by solder layer damage during subsequent chip integration, thus improving the yield of advanced chip packaging. Furthermore, the continuous circumferential surface contact between the probe tip 3 and the conductive pillar 4 increases the effective contact area compared to traditional needle-point contact. Simultaneously, the micro-protrusion structure 6 in the working area held by the probe tip 3 removes the oxide layer and dirt from the surface of the conductive pillar 4, enabling direct contact between the probe tip 3 and the clean surface of the conductive pillar 4. This dual effect significantly reduces contact resistance, minimizes signal attenuation and interference during testing, and allows the external testing system 5 to accurately acquire the electrical signal of the microbump, thereby improving the accuracy and precision of the test. In addition, this embodiment sets the support body 2 as a multi-bend axial elastic deformation structure, so that the support body 2 has adaptive floating and buffer space in the vertical direction. This allows it to respond in real time to chip warping, deformation and surface unevenness during the test. By compensating for the stroke through axial elastic deformation, it always maintains stable clamping and low-resistance electrical connection between the probe head 3 and the conductive pillar 4. This effectively avoids problems such as poor contact, signal fluctuation and contact failure caused by poor chip coplanarity, improves the stability and consistency of the test process, and improves the yield of microbump batch testing.

[0085] In addition, the manufacturing process provided in this application embodiment is compatible with existing semiconductor photolithography, etching and electroplating processes, and can realize the integrated molding of the support body 2 and the probe head 3. The prepared probe structure has high precision, good consistency, excellent mechanical strength and conductivity. At the same time, this process can realize mass production, with high production efficiency and low cost, and can meet the industrial large-scale demand for micro-bump test probes 1 in the field of advanced semiconductor packaging and testing.

[0086] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A micro-bump test probe, characterized in that, include: Support body and probe tip; The probe head is an elastic clamping structure with a first clamping arm and a second clamping arm arranged opposite to each other. The first clamping arm and the second clamping arm form a clamping opening in the free state, and the clamping opening has a convergent smooth curved surface profile that is narrow at the front and wide at the back along the clamping direction. The size of the clamping opening is less than or equal to the diameter of the conductive column of the micro-bump to be measured. The support is connected to the end of the probe head away from the clamping opening. The support is an axially elastic deformation structure, and the axial height of the support is greater than or equal to the sum of the side view height of the probe head and the thickness of the top solder layer of the micro-bump to be tested.

2. The micro-bump test probe according to claim 1, characterized in that, The clamping working area of ​​the probe head is provided with a micro-protrusion structure; The micro-protrusion structure includes at least one of the following: spike-like, thread-like, serrated, pyramidal, prismatic, or roughened surface.

3. The micro-bump test probe according to claim 2, characterized in that, The micro-protrusion structures are distributed on the inner sidewalls of the first clamping arm and the second clamping arm.

4. The microbump test probe according to claim 1, characterized in that, The support is a multi-bend elastic deformation structure; the support includes at least two reverse bending segments, forming a Z-shape or a zigzag shape.

5. The microbump test probe according to claim 1, characterized in that, The probe head is made of an elastic conductive material.

6. The microbump test probe according to claim 1, characterized in that, Once the conductive column is fully inserted into the probe head, the first clamping arm and the second clamping arm form an enveloping contact along the circumference of the conductive column, so that the side surface of the conductive column is in continuous circumferential contact with the inner wall of the probe head.

7. A micro-bump testing device, characterized in that, The test probe includes the micro-bump test probe according to any one of claims 1-6; the test probe is electrically connected to an external test system, and the test probe establishes an electrical connection with the conductive column of the micro-bump to be tested through the probe head.

8. A method for testing micro-bumps, characterized in that, include: The probe head of the micro-bump test probe according to any one of claims 1-6 is translated along the direction toward the conductive column of the micro-bump to be tested, so that the probe head wraps around and elastically clamps the conductive column. A low-resistance electrical connection is established through circumferential continuous surface contact between the probe head and the conductive pillar, and the electrical signal test of the micro-bump to be tested is completed.

9. The micro-bump testing method according to claim 8, characterized in that, During testing, when the chip warps, deforms, or becomes uneven, the axial elastic deformation structure of the test probe support compensates for this by vertical elastic deformation, thus maintaining stable clamping and electrical connection between the probe head and the conductive pillar.

10. A manufacturing process for a micro-bump test probe, characterized in that, The manufacturing process for producing the microbump test probe according to any one of claims 1-6 includes: A substrate is provided, and a sacrificial layer is formed on the substrate; Based on the geometric parameters of the multi-bend elastic deformation structure of the support, photolithography and etching are performed stepwise in the sacrificial layer to define the bending morphology mold of the bending segment of the support. Based on the narrow front and wide rear convergent profile of the probe head and the distribution range of the micro-protrusion structure in the clamping working area, photolithography and etching are performed in the sacrificial layer to define the probe head clamping cavity and its inner wall microstructure mold. An elastic conductive metal is filled into the complete mold formed by etching, so that the support body and the probe head are integrally formed; the complete mold includes the bending morphology mold and the probe head clamping cavity and its inner wall microstructure mold. Remove all of the sacrificial layers to release a microbump test probe with axial elastic deformation capability, clamping opening size constraint, and micro-bump structure.

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