Modular fixture and method for electrolytic polishing of internal cavities of semiconductor components

Abstract

The application discloses a semiconductor component inner cavity electrolytic polishing modular tool clamp and method, comprising a general anode base assembly, a cathode anti-inclination assembly, a side liquid discharge assembly and a local protection assembly. The general anode base assembly contains a general conductive bottom plate, and a workpiece can be directly placed as long as the bottom area is smaller than the bottom plate, without the need of customizing a positioning module, and only the side insulating block matched with the workpiece interface needs to be customized. The cathode anti-inclination assembly forms a two-point constraint structure by spot welding a cathode rod and a top insulating cover, and the head of the cathode rod is coated with a Teflon coating to realize insulation and short circuit prevention; the side liquid discharge assembly is provided with a diagonal radial liquid discharge hole, and gravity buoyancy is used to realize gas-liquid separation and liquid discharge; and the local protection assembly adopts a plastic plug to block the interface and protect the silver-plated thread. The core module of the application can be reused across specifications, and only the cathode rod insertion depth needs to be adjusted for changeover, and the power supply timing module can automatically control the polishing time length.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor component surface treatment technology, specifically relating to modular tooling fixtures and methods for electrolytic polishing of internal cavities of semiconductor components. Background Technology

[0002] In the manufacturing of semiconductor fluid control components (high-purity gas pressure reducing valves, multi-channel fittings, gas distribution manifolds, etc.), valve bodies often have 2-4 tubular branch interfaces. The weld seams on the inner walls of these interfaces need to be electropolished to achieve an ultra-high cleanliness level of Ra≤0.2μm. Electropolishing uses the workpiece as the anode and an auxiliary electrode as the cathode. A direct current is passed through the electrolyte, and polishing and passivation are achieved by selectively dissolving the workpiece surface.

[0003] The existing electropolishing process for deep-hole internal cavities of semiconductor valve bodies has several technical defects: 1. Traditional operations rely on manual assembly of simple tooling, which can only process a single cavity at a time. Multi-cavity valve bodies require repeated disassembly and assembly. Polishing time is controlled manually, resulting in large timing errors. The depth and position of the cathode insertion are adjusted manually based on experience, which can easily lead to uneven polishing. The cathode touching the hole wall can also cause a short circuit, resulting in the direct scrapping of the workpiece.

[0004] 2. Existing tooling is mostly an integrated non-standard structure deeply coupled with the parts. Core functional structures such as anti-skewing and drainage channels are bound to the part positioning and clamping structures. After the part interface specifications are changed, the core module often needs to be re-molded, resulting in long customization cycles, high repeated investment costs, and is not conducive to the production of multi-specification small-batch parts.

[0005] 3. The slender cathode is fixed by a single point of suspension, which is prone to skew and makes it difficult to ensure the concentricity between the cathode and the hole wall. The deeper the channel and the smaller the diameter, the higher the risk of skew, which will cause uneven polishing of the inner wall, short circuit and ablation of the workpiece, and make it difficult to guarantee the yield.

[0006] 4. The gas generated by the electrolytic reaction is prone to accumulate inside the deep hole, forming a gas blockage dead zone. The current density distribution inside the hole is unbalanced, resulting in local under-polishing or over-polishing. The polishing quality of the inner wall is inconsistent and cannot meet the stringent inner wall specifications of semiconductors.

[0007] 5. When the outer surface is plated by brush, the electrolyte can easily seep into the VCR thread gap, forming a galvanic cell with the silver plating layer and causing electrochemical corrosion, resulting in thread seizing, sealing failure, and direct scrapping of high-value parts.

[0008] In summary, the industry urgently needs a modular tooling fixture that can overcome all the above-mentioned defects, has cross-specification reuse capability, supports efficient parallel processing of multiple cavities, and has automatic timing control. Summary of the Invention

[0009] The purpose of this invention is to provide a modular tooling fixture for electropolishing of internal cavities of semiconductor components, in order to solve the technical defects of existing internal cavity electropolishing methods mentioned in the background, such as low efficiency of manual operation, large human timing deviation, poor operation stability, high cost of tooling customization, inability to reuse core functional modules, skewed cathodes in deep holes, difficulty in draining liquid inside holes, and easy corrosion of sensitive plating layers.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a modular tooling fixture for electrolytic polishing of the inner cavity of semiconductor components, comprising a general anode base assembly, a cathode anti-tilting assembly, a side drainage assembly, and a local protection assembly.

[0011] The universal anode base assembly includes a conductive base plate, which is used to electrically connect to the positive terminal of the power supply and serve as the mounting base for the tooling. The conductive base plate is a universal component, and the workpiece can be placed directly on the conductive base plate. As long as the bottom area of ​​the workpiece is smaller than the area of ​​the conductive base plate, it can be placed directly without the need to customize a positioning module according to the workpiece specifications; only a side insulating block that is threaded to the side interface of the workpiece needs to be customized. The cathode anti-skew assembly includes a cathode rod and a top insulating cover. The cathode rod is composed of a thin titanium rod and a titanium tube. One end of the thin titanium rod is inserted into the titanium tube, and the outer diameter of the titanium tube is equal to the inner diameter of the female cathode wire. The thin titanium rod and the titanium tube are fixed by spot welding. The thin titanium rod segment extends into the internal cavity of the workpiece and serves as the cathode within the thin cavity during electroplating. The titanium tube segment is used to connect to the cathode wire. The top insulating cover has a cathode rod insertion hole adapted to the thin titanium rod segment. The thin titanium rod segment passes through the cathode rod insertion hole and extends into the internal cavity of the workpiece to form a lower end limit. Fasteners are inserted and locked through radial fastener assembly holes to prevent the slender cathode from skewing. The titanium tube segment fixes the cathode wire to the negative terminal of the power supply using a clamp-type or female plug-in type. The head of the thin titanium rod segment is covered with a protective Teflon coating for insulation and short-circuit protection. The top insulating cover also has a water pipe insertion hole for connecting an electrolyte conduit, and the hole is locked with a fastening screw. The side drainage assembly includes a side insulating block that can be detachably installed at the side interface of the workpiece. The side insulating block has a through hole for the electrode to pass through and a radial drainage hole. The cathode rod extends through the through hole of the side insulating block into the side interface of the workpiece, forming an auxiliary cathode section. The side insulating block has an interface structure on its exterior for connecting the female end of the cathode wire. The cathode rod is electrically connected to the cathode wire through this interface structure, and the electrolyte is discharged from the lower side under the action of gravity. The side insulating block has two connection types: internal thread and external thread, which are adapted to workpiece interfaces with different thread specifications. The side insulating block is a customized replacement part according to the thread specifications of the workpiece interface. The local protection component includes a plastic plug that can be detachably installed at the side interface of the workpiece. The plastic plug has a similar structure to the side insulating block and is used to physically seal the workpiece interface when the outer surface of the workpiece is electroplated, thereby achieving the effect of protecting the silver-plated threads. The cathode anti-tilt assembly, side drainage assembly, and local protection assembly are universal standard modules independent of the workpiece. When changing workpieces of different specifications, as long as the workpiece interface diameter is the same, the universal standard module can be completely reused. Only the depth of the cathode rod inserted into the internal cavity of the workpiece needs to be adjusted by moving it up and down to adapt to cavities of different depths, without the need for redesign and manufacturing. The tooling fixture can simultaneously install cathode anti-skew components and side drainage components in multiple cavities of the workpiece, enabling simultaneous electrolytic polishing of multiple cavities; the power supply is equipped with a timing control module, which directly controls the polishing time, eliminating the need for manual timing.

[0012] Furthermore, the conductive base plate is a circular or rectangular titanium or stainless steel plate with a polished surface and pre-drilled standard mounting array holes; the area of ​​the conductive base plate is larger than the maximum bottom area of ​​the workpiece to be processed, and the workpiece is placed directly on the conductive base plate and fixed and positioned by the threaded connection of the side insulating block; when the conductive base plate is rectangular, it is suitable for bearing long strip-shaped or rectangular cross-section workpieces with multiple rows of side interfaces.

[0013] Furthermore, the cathode rod is formed by spot welding of a thin titanium rod and a titanium tube. The head of the titanium tube segment is fixed with a cathode wire by a clamp or a female plug-in type. The cathode wire is used to connect to the negative terminal of the power supply. The head of the thin titanium rod segment is covered with a protective Teflon coating, which has the function of insulation and short circuit prevention. The outer diameter of the titanium tube matches the inner diameter of the female cathode wire, realizing a plug-in quick connection.

[0014] Furthermore, the top insulating cover has a cathode rod insertion hole and a water pipe insertion hole adapted to the thin titanium section of the cathode rod. The cathode rod insertion hole allows the thin titanium section of the cathode rod to pass through and forms a lower end limit. The water pipe insertion hole is used to connect the electrolyte conduit. The hole is locked by a fastening screw. The top insulating cover has a radial fastener mounting hole. The fastener passes through the radial fastener mounting hole and abuts against the cathode rod to achieve anti-tilting locking.

[0015] Furthermore, the radial drain hole is inclined and forms an angle with the horizontal plane, so that the electrolyte is discharged from the lower end of the flow channel under the action of gravity, and the bubbles naturally overflow from the upper end of the flow channel under the action of buoyancy, forming a gas-liquid separation drain structure.

[0016] Furthermore, the cathode rod is an integral long strip structure formed by spot welding a thin titanium rod and a titanium tube, which passes sequentially through the top insulating cover, the internal cavity of the workpiece, and the side insulating block; the section of the cathode rod located in the side interface serves as an auxiliary cathode and is electrically connected to the section located in the internal cavity of the workpiece; the titanium tube section of the cathode rod extends to the outside of the side insulating block and is connected to the cathode wire through a female plug-in structure to achieve single-point multi-cavity power supply.

[0017] Furthermore, the side insulating block has two types: an internal thread connection structure and an external thread connection structure, which are adapted to the side interfaces of workpieces with different thread specifications respectively; the internal thread type side insulating block has an internal thread hole that is adapted to the external thread interface of the workpiece; the external thread type side insulating block has an external thread section that is adapted to the internal thread interface of the workpiece; the side insulating block is a customized replacement part according to the thread specification of the workpiece interface, and the conductive base plate and the cathode anti-skew assembly are general-purpose parts.

[0018] Furthermore, it also includes a special electric brush for cleaning the outer wall of a workpiece. The electric brush includes a conductive titanium rod and a metal tube integrally fixedly connected thereto. The metal tube is used to pass in electrolyte to achieve simultaneous operation of brushing and electrolyte supply.

[0019] Furthermore, the workpieces adapted to the tooling fixture are semiconductor valve bodies or cavities with two to four lateral interfaces, including two-way, three-way, four-way, and Y-type and cross-type multi-branch structures; when changing types, only the lateral insulating blocks that match the thread specifications of the workpiece interfaces need to be replaced, and the cathode anti-skew assembly and local protection assembly can be completely reused when the interface diameter is the same, and only the length of the cathode rod in the cavity needs to be adjusted; the conductive base plate is completely universal and does not need to be replaced.

[0020] Furthermore, the tooling fixture can simultaneously install multiple sets of cathode anti-skew components and side drainage components in multiple cavities of the workpiece. The cathode wires of the multiple sets of cathode anti-skew components are connected in parallel to the negative terminal of the power supply, realizing simultaneous electrolytic polishing of multiple cavities. The power supply is equipped with a timing control module, which directly controls the polishing time by timing, replacing manual timing operation.

[0021] This invention also discloses an electrolytic polishing method for the inner cavity of a semiconductor component, which uses the above-mentioned tooling fixture to complete the operation and includes the following steps: S1: Place the workpiece directly on the conductive base plate, which is electrically connected to the positive terminal of the power supply. The conductive base plate is a universal component; it can be placed directly on the workpiece as long as the bottom area of ​​the workpiece is smaller than the area of ​​the conductive base plate. S2: Install a top insulating cover on the top of the workpiece. Insert the thin titanium rod segment of the cathode rod through the cathode rod insertion hole of the top insulating cover into the internal cavity of the workpiece to form a lower end limit. Secure the cathode by inserting fasteners through the radial fastener assembly holes to prevent the cathode from tilting. The titanium tube segment of the cathode rod is fixed to the cathode wire and connected to the negative terminal of the power supply through a clamp or female plug type. The Teflon coating on the head of the thin titanium rod segment serves as insulation and short circuit prevention. Connect the electrolyte conduit through the water pipe insertion hole of the top insulating cover and lock it with fastening screws. S3: Install side insulating blocks that match the thread specifications of the interface at each side interface of the workpiece, so that the auxiliary cathode section extends into the inner cavity of the interface, and the radial drain hole of the side insulating block faces downwards; when electroplating the outer surface of the workpiece, install plastic plugs at the side interfaces that do not need electroplating to physically seal the workpiece interface to protect the silver-plated threads. S4: Electrolyte is injected through the water pipe socket of the top insulating cover, and the power is turned on for electrolytic polishing. The polishing time is directly controlled by the timing control module of the power supply. The power supply is automatically turned off after the set time is reached. During the polishing process, the electrolyte is discharged from the downward side through the radial drain hole of the side insulating block under the action of gravity, and the bubbles overflow from the top, realizing gas-liquid separation. S5: When the workpiece has multiple cavities, the cathode anti-skew assembly and the side drainage assembly are installed in the multiple cavities at the same time. Multiple sets of cathode wires are connected in parallel to the negative terminal of the power supply and controlled by the power supply to realize simultaneous electrolytic polishing of multiple cavities.

[0022] Compared with the prior art, the beneficial effects of the present invention are: (1) Simultaneous processing of multiple cavities significantly improves processing efficiency. The modular structure supports the simultaneous arrangement of cathode anti-tilt components and side drainage components in multiple cavities, and multiple sets of cathode wires are connected to the negative terminal of the power supply. For three-way and four-way multi-cavity valve bodies, all internal cavities are polished in one go, eliminating the traditional manual cavity-by-cavity processing mode, shortening the production cycle, and adapting to the needs of multi-variety, small-batch, and high-consistency production of semiconductor components.

[0023] (2) Automatic power supply timing control ensures high process stability and good batch consistency. The polishing time is controlled by the power supply's built-in timing module, with timing accuracy reaching the second or even millisecond level. The power is automatically cut off after processing, eliminating the need for manual timing estimation. This eliminates time deviations caused by human operation, ensures uniform polishing time for different cavities and different workpieces of the same workpiece, avoids over-polishing and under-polishing defects caused by timing deviations, and ensures batch stability of inner wall polishing quality.

[0024] (3) This invention decouples high-value functional modules such as anti-skew, drainage, and protection from threaded connectors that change with the product. Under the condition that the workpiece interface diameter is the same, all core modules can be reused, and only the depth of the cathode rod inserted into the cavity needs to be adjusted to adapt to workpieces with different cavity depths; expensive core modules do not need to be scrapped with workpiece specifications, maximizing the module reuse rate and reducing the investment in comprehensive tooling for multi-variety products.

[0025] (4) The cathode rod is a thin titanium rod that passes through the top insulating cover insertion hole and extends into the cavity to form a lower limit. It is locked with radial fasteners to form a two-point constraint of "lower limit + upper lock". This ensures that the slender cathode and the inner wall of the deep hole are concentric, improves the polishing uniformity, and prevents the cathode from short-circuiting due to contact with the hole wall, which would cause the workpiece to be scrapped. This overcomes the problem of poor concentricity of traditional single-point suspension fixation.

[0026] (5) Gas-liquid separation and drainage structure to eliminate the gas blockage dead zone in deep holes. The radial drainage holes are arranged at an angle on the side insulating blocks. The liquid is discharged downward and the bubbles overflow upward by using gravity and buoyancy. This eliminates the gas blockage dead zone in the hole, and the electrolyte flow field and current density are evenly distributed. This avoids local over-polishing and under-polishing and ensures that the inner wall roughness meets the ultra-high cleanliness requirements of semiconductor Ra≤0.2μm. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the universal conductive base plate of the present invention; Figure 2 This is a schematic diagram of the structure of the top insulating cover of the present invention; Figure 3 This is a schematic diagram of the structure of the cathode rod of the present invention; Figure 4 This is a schematic diagram of the side drainage assembly of the present invention; Figure 5 This is a cross-sectional view of the main components assembled according to Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the assembly of a multi-cavity workpiece with a rectangular bottom surface according to the present invention; In the diagram: 1. Positive power supply connection point (anode rod insertion hole); 2. Cathode rod insertion hole; 3. Water pipe insertion hole; 4. Radial fastener assembly hole; 5. Radial drain hole; 6. Conductive base plate; 7. Workpiece; 8. Side insulating block; 9. Cathode rod; 10. Internal cavity of the workpiece; 11. Top insulating cover; 12. Rectangular conductive base plate; 13. Rectangular cross-section workpiece. Detailed Implementation

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Electropolishing of a Three-Interface Four-Cavity Semiconductor Valve Body Combined with appendix Figures 1-5 This embodiment discloses an electrolytic polishing fixture for the inner wall of a three-interface, four-cavity semiconductor valve body. The valve body has one top interface and two symmetrical side interfaces; the top interface includes two cavities, forming a four-cavity structure (2 main cavities + 2 interface cavities). The fixture includes a universal anode base assembly, a cathode anti-tilt assembly, a side drainage assembly, and a local protection assembly.

[0031] Universal anode base assembly: The conductive base plate 6 is made of circular titanium plate with a polished surface, serving as the mounting base for the tooling and connecting to the positive terminal of the power supply; the base plate has pre-drilled standard array holes, and the positive terminal of the power supply is connected through the anode rod insertion hole 1. The conductive base plate 6 is a universal component, and the workpiece 7 can be placed directly on top of the base plate. As long as the bottom area of ​​the workpiece is smaller than the base plate, it can be directly supported without the need for a customized positioning module; the workpiece is positioned by the threaded connection of the side insulating block 8.

[0032] Cathode Anti-Tilting Component: The cathode rod 9 is assembled by spot welding of a thin titanium rod and a titanium tube. One end of the thin titanium rod is inserted into the titanium tube, and the outer diameter of the titanium tube matches the inner diameter of the female cathode wire connector. The thin titanium rod extends into the internal cavity 10 of the workpiece to act as the electrolytic cathode, and the titanium tube is used to connect the cathode wire. The top insulating cover 11 has a cathode rod insertion hole 2, through which the thin titanium rod passes and extends into the cavity to form a lower end limit. Fasteners are installed and locked through the radial fastener assembly hole 4 to constrain the cathode rod and prevent tilting. The titanium tube section is connected to the cathode wire through the female connector to connect to the negative terminal of the power supply. The head of the thin titanium rod is covered with a Teflon insulating coating to prevent short circuits. The top insulating cover 11 has a water pipe insertion hole 3, through which the electrolyte conduit is connected and locked with fastening screws.

[0033] Side drainage assembly: The side insulating block 8 is detachably threaded and mounted on the side interface of the workpiece 7. It comes in two specifications: internal and external threads, adaptable to different workpiece interface types. This is the only component in this fixture that requires customization to match the workpiece thread. The cathode rod 9 sequentially passes through the top insulating cover 11, the workpiece cavity 10, and the through hole of the side insulating block 8, extending into the side interface to form an auxiliary cathode section. The auxiliary cathode end is equipped with a PTFE protective layer for fixed-point protection. The titanium tube section extending outward from the cathode rod features a standard plug-in structure for quick connection to the cathode wire. The side insulating block 8 has inclined radial drainage holes 5; the electrolyte flows downwards under gravity, while bubbles overflow upwards due to buoyancy, completing gas-liquid separation.

[0034] Local protection components: The structure of the plastic plug is consistent with that of the side insulating block 8, and the thread specification matches the workpiece interface; when the outer surface of the workpiece is electroplated, the plug is screwed onto the interface that does not require treatment, physically isolating the electrolyte and protecting the internal silver-plated threads.

[0035] The working process of this embodiment is as follows: The three-port valve body workpiece 7 is placed on a circular conductive base plate 6, which is connected to the positive terminal of the power supply. A top insulating cover 11 is installed on top of the workpiece. A thin titanium cathode rod extends into the cavity through the insertion hole, and fasteners are tightened to prevent tilting. A cathode wire is inserted into the titanium tube end and connected to the negative terminal of the power supply. An electrolyte conduit is connected to the water pipe insertion hole 3. Side insulating blocks 8 are installed on both sides of the workpiece interface, and the cathode rod extends into the side interface. Multiple sets of cathode wires are connected in parallel to the negative terminal of the power supply to achieve simultaneous polishing of multiple cavities. Electrolyte is introduced through the water pipe insertion hole. When the power is turned on, the power timing module starts timing and automatically cuts off the power when the set time is reached. During the electrolysis process, the electrolyte and bubbles are discharged through the inclined radial drain hole 5 to achieve gas-liquid separation. When performing brush plating on the outer surface, interfaces that do not require treatment are replaced with plastic plugs.

[0036] Example 2: Application of dual-interface workpieces in type change When machining workpiece 7 with dual symmetrical side interfaces, the conductive base plate 6 can be reused without replacement; only the side insulating block 8 matching the workpiece thread specification needs to be replaced. The two side drainage assemblies are respectively assembled at the two side interfaces, with the top insulating cover 11 centrally located.

[0037] Under the condition that the workpiece interface diameter is consistent with that of Example 1, the cathode rod 9, the top insulating cover 11, and the plastic plug are all reused; loosen the internal fasteners of the radial fastener assembly hole 4, move the cathode rod 9 axially, adjust the depth of the thin titanium rod into the cavity, and after confirming the position, re-tighten the fasteners to adapt to different cavity depths. There is no need to re-mold and process the parts. Only the side insulating block 8 needs to be replaced to complete the product change.

[0038] Example 3: Application of multi-port valve body workpiece replacement Process valve body workpieces with three to four side interfaces, such as Y-type and cross-type. 6 The conductive base plate remains universal and does not need to be replaced; replace the side insulating blocks 8 with matching interface thread specifications, and simultaneously increase the number of side drainage components.

[0039] The workpiece interface diameter remains unchanged, and the cathode anti-skew component can be completely reused, with only the depth of the cathode rod inserted into the cavity being adjusted. Multiple cathode components are assembled simultaneously, and the cathode wires are connected in parallel to the negative terminal of the power supply. Multiple cavities are polished synchronously, and the power supply is timed uniformly to ensure that the polishing time of each cavity is consistent, achieving low-cost and rapid changeover.

[0040] Example 4: Application of Rectangular Bottom Multi-Cavity Workpiece in Model Change Reference Appendix Figure 6 The workpiece 13, a rectangular cross-section gas distribution manifold, is machined. The workpiece has a rectangular bottom surface and multiple lateral interfaces arranged along its length. A rectangular conductive base plate 12 is selected; this is a general-purpose component and does not require remanufacturing.

[0041] A rectangular cross-section workpiece 13 is placed directly on a rectangular conductive base plate 12, which is connected to the positive terminal of a power supply. Each side interface of the workpiece is fitted with a corresponding threaded insulating block 8 to assist the cathode in extending into each interface cavity. Multiple sets of cathode wires are connected in parallel to the negative terminal of the power supply, and multiple rows of cavities are polished simultaneously. With the interface diameter unchanged, the cathode rod 9 and the top insulating cover 11 are completely reused; only the depth of the cathode rod insertion is adjusted, and the replacement is completed by simply replacing the low-cost side insulating blocks 8.

[0042] Example 5: Electropolishing Process This embodiment discloses a process method for electrolytic polishing of the internal cavity of semiconductor components using the above-mentioned tooling, the steps of which are as follows: Step 1: Place the workpiece 7 directly on the conductive base plate 6, which is electrically connected to the positive terminal of the power supply. The conductive base plate 6 is a universal component; as long as the bottom area of ​​the workpiece is smaller than the area of ​​the conductive base plate 6, it can be placed directly without the need for a customized positioning module. Step 2: Install the top insulating cover 11 on the top of the workpiece 7. Insert the thin titanium rod segment of the cathode rod 9 through the cathode rod insertion hole 2 of the top insulating cover 11 into the internal cavity 10 of the workpiece to form a lower end limit. Secure the cathode by inserting fasteners through the radial fastener assembly hole 4 to prevent the cathode from tilting. The head of the titanium tube segment of the cathode rod 9 is fixed to the cathode wire and connected to the negative terminal of the power supply through a clamp or female plug type. The Teflon coating on the head of the thin titanium rod segment serves as insulation and short circuit prevention. Connect the electrolyte conduit to the water pipe insertion hole 3 of the top insulating cover 11 and lock it with fastening screws. Step 3: Install side insulating blocks 8 that are compatible with the thread specifications of the interface at each side interface of the workpiece 7, so that the auxiliary cathode section extends into the inner cavity of the interface, and the radial drain hole 5 of the side insulating block 8 faces downwards; when the outer surface of the workpiece is electroplated, install the plastic plug at the side interface that does not need to be electroplated to physically seal the workpiece interface to protect the silver-plated threads. Step 4: Electrolyte is injected through the water pipe insertion hole 3 of the top insulating cover 11, and the power is turned on for electrolytic polishing. The polishing time is directly controlled by the timing control module of the power supply. The power supply is automatically turned off after the set time is reached. During the polishing process, the electrolyte is discharged from the downward side through the radial drain hole 5 of the side insulating block 8 under the action of gravity, and the bubbles overflow from the top, realizing gas-liquid separation. Step 5: When workpiece 7 has multiple cavities, the cathode anti-tilt assembly and the side drainage assembly are installed in multiple cavities at the same time. Multiple sets of cathode wires are connected in parallel to the negative terminal of the power supply and controlled by the power supply to realize simultaneous electrolytic polishing of multiple cavities. Compared with the existing manual single-cavity processing method, the processing efficiency is greatly improved and the consistency and stability of polishing quality are significantly improved.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular tooling fixture for electrolytic polishing of the inner cavity of semiconductor components, comprising a general anode base assembly, a cathode anti-tilting assembly, a side drainage assembly, and a local protection assembly, characterized in that, The universal anode base assembly includes a conductive base plate, which is used to electrically connect to the positive terminal of the power supply and serve as the mounting base for the tooling. The cathode anti-skew assembly includes a cathode rod and a top insulating cover. The cathode rod is composed of a thin titanium rod and a titanium tube. One end of the thin titanium rod is inserted into the titanium tube, and the outer diameter of the titanium tube is equal to the inner diameter of the female cathode wire. The thin titanium rod and the titanium tube are fixed by spot welding. The thin titanium rod segment extends into the internal cavity of the workpiece and serves as the cathode within the thin cavity during electroplating. The titanium tube segment is used to connect to the cathode wire. The top insulating cover has a cathode rod insertion hole adapted to the thin titanium rod segment. The thin titanium rod segment passes through the cathode rod insertion hole and extends into the internal cavity of the workpiece to form a lower end limit. Fasteners are inserted and locked through radial fastener assembly holes to prevent the slender cathode from skewing. The titanium tube segment fixes the cathode wire to the negative terminal of the power supply using a clamp-type or female plug-in type. The head of the thin titanium rod segment is covered with a protective Teflon coating for insulation and short-circuit protection. The top insulating cover also has a water pipe insertion hole for connecting an electrolyte conduit, and the hole is locked with a fastening screw. The side drainage assembly includes a side insulating block that can be detachably installed at the side interface of the workpiece. The side insulating block has a through hole for the electrode to pass through and a radial drainage hole. The cathode rod extends through the through hole of the side insulating block into the side interface of the workpiece to form an auxiliary cathode section. The side insulating block has an interface structure for connecting the female end of the cathode wire. The cathode rod is electrically connected to the cathode wire through this interface structure, and the electrolyte is discharged from the lower side under the action of gravity. The local protection component includes a plastic plug that can be detachably installed at the side interface of the workpiece, which is used to physically seal the workpiece interface when the outer surface of the workpiece is electroplated, thereby achieving the effect of protecting the silver-plated threads. The cathode anti-tilt assembly, side drainage assembly, and local protection assembly are general standard modules independent of the workpiece.

2. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The conductive base plate is a circular or rectangular titanium or stainless steel plate with a polished surface and pre-drilled standard mounting array holes. The area of ​​the conductive base plate is larger than the maximum bottom area of ​​the workpiece to be processed. The workpiece is placed directly on the conductive base plate and fixed and positioned by the threaded connection of the side insulating blocks. When the conductive base plate is rectangular, it is suitable for supporting long strip-shaped or rectangular cross-section workpieces with multiple rows of side interfaces.

3. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The head of the thin titanium rod segment is coated with a protective Teflon coating, which has the function of insulation and short circuit prevention; the outer diameter of the titanium tube matches the inner diameter of the female cathode wire, realizing a plug-in quick connection; the head of the titanium tube segment fixes the cathode wire with a clamp or female plug-in type, and the cathode wire is used to connect to the negative terminal of the power supply.

4. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The top insulating cover has a cathode rod insertion hole and a water pipe insertion hole adapted to the thin titanium section of the cathode rod. The cathode rod insertion hole allows the thin titanium section of the cathode rod to pass through and forms a lower end limit. The water pipe insertion hole is used to connect the electrolyte conduit. The hole is locked by a fastening screw. The top insulating cover has a radial fastener mounting hole. The fastener passes through the radial fastener mounting hole and presses against the cathode rod to achieve anti-tilting locking.

5. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The radial drain hole is inclined and forms an angle with the horizontal plane, so that the electrolyte is discharged from the lower end of the flow channel under the action of gravity, and the bubbles naturally overflow from the upper end of the flow channel under the action of buoyancy, forming a gas-liquid separation drain structure.

6. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The cathode rod is an integral long strip structure formed by spot welding a thin titanium rod and a titanium tube, which passes through the top insulating cover, the internal cavity of the workpiece, and the side insulating block in sequence; the section of the cathode rod located in the side interface serves as an auxiliary cathode and is electrically connected to the section located in the internal cavity of the workpiece; the titanium tube section of the cathode rod extends to the outside of the side insulating block and is connected to the cathode wire through a female plug-in structure to realize single-point multi-cavity power supply.

7. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The side insulating block has two types: internal thread connection structure and external thread connection structure, which are adapted to the side interfaces of workpieces with different thread specifications. The internal thread type side insulating block has an internal thread hole that is adapted to the external thread interface of the workpiece. The external thread type side insulating block has an external thread section that is adapted to the internal thread interface of the workpiece. The side insulating block is a customized replacement part according to the thread specification of the workpiece interface. The conductive base plate and the cathode anti-skew assembly are general-purpose parts.

8. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The tooling fixture is adapted to workpieces that are semiconductor valve bodies or cavities with two to four side interfaces, including two-way, three-way, four-way, and Y-type and cross-type multi-branch structures. When changing models, only the side insulating blocks that match the thread specifications of the workpiece interfaces need to be replaced. When the interface diameter is the same, the cathode anti-skew component and the local protection component can be completely reused. Only the length of the cathode rod in the cavity needs to be adjusted. The conductive base plate is completely universal and does not need to be replaced.

9. The modular tooling fixture for electrolytic polishing of semiconductor component cavities according to claim 1, characterized in that, The tooling fixture can simultaneously install multiple sets of cathode anti-skew components and side drainage components in multiple cavities of the workpiece. The cathode wires of the multiple sets of cathode anti-skew components are connected in parallel to the negative terminal of the power supply, realizing simultaneous electrolytic polishing of multiple cavities. The power supply is equipped with a timing control module, which directly controls the polishing time by timing the power supply, replacing manual timing operation. It also includes a special brush for cleaning the outer wall of the workpiece. The brush includes a conductive titanium rod and a metal thin tube integrally fixedly connected to it. The metal thin tube is used to pass in the electrolyte, realizing the synchronous operation of brushing and supplying electrolyte at the same time.

10. A method for electrolytic polishing of the inner cavity of a semiconductor component using the tooling fixture described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Place the workpiece directly on the conductive base plate, which is electrically connected to the positive terminal of the power supply. The conductive base plate is a universal component; it can be placed directly on the workpiece as long as the bottom area of ​​the workpiece is smaller than the area of ​​the conductive base plate. S2: Install a top insulating cover on the top of the workpiece. Insert the thin titanium rod segment of the cathode rod through the cathode rod insertion hole of the top insulating cover into the internal cavity of the workpiece to form a lower end limit. Secure the cathode by inserting fasteners through the radial fastener assembly holes to prevent the cathode from tilting. The titanium tube segment of the cathode rod is fixed to the cathode wire and connected to the negative terminal of the power supply through a clamp or female plug type. The Teflon coating on the head of the thin titanium rod segment serves as insulation and short circuit prevention. Connect the electrolyte conduit through the water pipe insertion hole of the top insulating cover and lock it with fastening screws. S3: Install side insulating blocks that match the thread specifications of the interface at each side interface of the workpiece, so that the auxiliary cathode section extends into the inner cavity of the interface, and the radial drain hole of the side insulating block faces downwards; when electroplating the outer surface of the workpiece, install plastic plugs at the side interfaces that do not need electroplating to physically seal the workpiece interface to protect the silver-plated threads. S4: Electrolyte is injected through the water pipe socket of the top insulating cover, and the power is turned on for electrolytic polishing. The polishing time is directly controlled by the timing control module of the power supply. The power supply is automatically turned off after the set time is reached. During the polishing process, the electrolyte is discharged from the downward side through the radial drain hole of the side insulating block under the action of gravity, and the bubbles overflow from the top, realizing gas-liquid separation. S5: When the workpiece has multiple cavities, the cathode anti-skew assembly and the side drainage assembly are installed in the multiple cavities at the same time. Multiple sets of cathode wires are connected in parallel to the negative terminal of the power supply and controlled by the power supply to realize simultaneous electrolytic polishing of multiple cavities.

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