A positioning tool for semi-automatic point sealing and an assembling method thereof

Abstract

The application belongs to the technical field of semiconductors, and discloses a positioning tool for semi-automatic point sealing and an assembling method thereof. The positioning tool comprises a limiting plate and a clamping seat. The limiting plate is provided with through holes for mounting surface-mounted devices. The clamping seat is provided with grooves matched with the through holes. The clamping seat is fixedly installed at the upper end of the limiting plate. The surface-mounted device comprises a tube shell and a cover plate. The tube shell is installed in reverse on the upper end of the cover plate. A plurality of through holes on the same horizontal line are communicated with each other. A plurality of surface-mounted devices in the same row are positioned. Multiple workpieces are continuously point sealed in a single clamping operation. The time length of repeated clamping is reduced. The operation efficiency of semi-automatic point sealing is improved. The tube shell is installed in reverse on the upper end of the cover plate and is fixed. The circuit cavity is protected. Excess substances are avoided. The limiting plate through hole provides space for the point sealing roller to press down. The normal operation of the point sealing operation is ensured.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology and relates to a positioning fixture for semi-automatic spot sealing and its assembly method. Background Technology

[0002] Semiconductor integrated circuit sealing methods include parallel seam welding, energy storage welding, and fusion sealing. Parallel seam welding includes spot sealing and flat sealing, which has low operating costs and good hermeticity. Spot sealing is an operation of placing and pre-soldering the cover plate before integrated circuit sealing, aligning the cover plate and temporarily fixing it. Semi-automatic spot sealing is the final process before circuit sealing. In existing semi-automatic cover sealing, the circuit cavity is always in an open upward state, providing a direct channel for the introduction of foreign matter. Once environmental dust, operational debris, welding spatter, and other foreign matter enter the circuit cavity, they directly affect the electrical performance and long-term reliability of the chip.

[0003] like Figure 1 a and such Figure 1 As shown in b, during the process of placing the circuit into the card slot, excess material can easily fall directly into the open circuit cavity; such as Figure 1 c and such Figure 1 As shown in d, when the cover plate is stored in the magazine compartment, environmental dust and particulate matter generated by magazine wear easily adhere to its surface, and these particles enter the circuitry during the cover plate assembly; for example... Figure 1 e and such Figure 1 As shown in f, during the spot sealing welding process between the cover plate and the tube shell, metal spatter and debris generated during welding can easily fall into the circuit cavity, creating internal foreign matter problems. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a positioning fixture for semi-automatic spot sealing and its assembly method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a positioning fixture and its assembly method for semi-automatic spot sealing, including a limiting plate and a mounting base. The limiting plate is provided with through holes for mounting surface mount devices. Several through holes on the same horizontal line are interconnected. The mounting base is provided with grooves that match the through holes. The mounting base is fixedly installed on the upper end of the limiting plate. The surface mount device includes a tube shell and a cover plate.

[0006] Furthermore, the tube shell is installed on the upper end of the cover plate, and the side of the tube shell with the circuit cavity is fixedly connected to the cover plate.

[0007] Furthermore, both the limiting plate and the card holder are made of graphite material.

[0008] Furthermore, the casing is a surface-mount device ceramic casing with a Kovar sealing ring.

[0009] Furthermore, the cover plate is made of gold-plated Kovar alloy.

[0010] Furthermore, the cover plate is 0.1 mm smaller than the single-side length of the tube shell.

[0011] This invention discloses an assembly method for a positioning fixture used in semi-automatic spot sealing. Based on the aforementioned positioning fixture for semi-automatic spot sealing, the method includes the following steps: Step 1: Place the limiting plate stably on a table; Step 2: Place one side of the cover plate into the through hole; Step 3: Install the tube shell cavity upside down on the upper end of the cover plate; Step 4: Repeat Step 2 and Step 3 to fix the holder to the limiting plate containing the tube shell and cover plate; Step 5: Weld the tube shell and cover plate using a spot sealing device.

[0012] Furthermore, both the tube shell and the cover plate are placed using a vacuum suction pen.

[0013] Furthermore, the through hole includes a first through hole and a second through hole disposed around the first through hole, wherein the first through hole is disposed in a horizontal direction and the second through hole is disposed in a vertical direction.

[0014] Furthermore, the four corners of the cover plate abut against the inner wall of the first through hole.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a positioning fixture for semi-automatic spot sealing. Through holes on the limiting plate circumferentially limit the cover plate and housing of surface mount devices, effectively suppressing horizontal movement during spot sealing operations. This eliminates positional offsets caused by equipment identification alignment errors and spot sealing vibrations, ensuring the consistency of the cover plate and housing positions, and improving the packaging accuracy and finished product yield of surface mount devices. Several interconnected through holes on the same horizontal line can position multiple surface mount devices in the same row, completing continuous spot sealing of multiple workpieces in a single clamping operation, reducing the time spent on repeated clamping, and improving the efficiency of semi-automatic spot sealing. A groove adapted to a second through hole is provided on the clamping base. The clamping base is installed on the upper end of the limiting plate, ensuring a flat and fitted fit between the housing and cover plate during spot sealing, avoiding warping and misalignment. Furthermore, assembling the limiting plate and clamping base improves clamping stability and ensures the packaging quality of batch spot sealing operations.

[0016] The tube shell is inverted and installed on the upper part of the cover plate, and one side of the cavity is fixedly connected to the cover plate, forming physical protection for the circuit area and preventing environmental particles and solder residue from falling into the cavity during the sealing process, causing pollution or short circuits. At the same time, it improves the connection strength and flatness of the tube shell and the cover plate, preventing the cover plate from loosening or shifting due to the stress and deformation of the sealing process, thus enhancing the overall structural stability and sealing reliability. The hollow structure of the limiting plate provides an unobstructed operating surface for the sealing operation. Precise positioning is achieved through the through holes on the limiting plate and the grooves on the card holder, which facilitates continuous sealing operations by the sealing equipment, ensuring the consistency and accuracy of the sealing trajectory. It also avoids friction and collision with the tooling parts during the clamping and handling of the cover plate, reducing the risk of appearance damage during the clamping process.

[0017] The cover plate is 0.1 mm shorter than the single side length of the tube shell. A stepped structure is formed at the assembly edge of the tube shell and the cover plate. The first through hole is used to circumferentially limit the cover plate. When the cover plate is housed in the first through hole, the inner wall of the first through hole abuts against the side edges at the four corners of the cover plate, thus constraining the horizontal displacement of the cover plate.

[0018] Both the limiting plate and the mounting base are made of high-purity graphite, which can withstand the localized high temperatures during spot welding and has a low coefficient of thermal expansion, ensuring long-term stability of positioning accuracy. It is easy to perform high-precision machining to meet alignment requirements; it does not produce metal shavings and has minimal wear, reducing the risk of foreign matter buildup from wear; it does not wet or adhere to molten solder, preventing solder spatter from adhering to the tooling surface during spot welding. The high-purity graphite has a purity of 99.9%, overcoming the shortcomings of traditional metal materials such as slow thermal conductivity, low hardness, and easy introduction of metal foreign matter.

[0019] An assembly method for a positioning fixture used in semi-automatic spot sealing involves first laying a limiting plate flat, then sequentially installing a cover plate and a tube shell, and finally installing a mounting bracket. This method facilitates quick mastery by operators and reduces assembly error rates. During assembly, the cover plate is first placed into the through hole of the limiting plate, and then one side of the tube shell cavity is inverted and fastened to the upper end of the cover plate. This provides a foundation for spot welding operations and protects the circuit cavity from splashing of foreign matter or molten solder during welding. Multiple sets of surface mount devices are installed in a single limiting plate, and then the mounting bracket is fixedly connected to the entire plate and clamped in one go for locking, improving the production efficiency of batch spot sealing. After assembly, the limiting plate and the mounting bracket provide rigid constraints from the top and bottom sides, suppressing horizontal movement and vertical warping of the electrode wheel during welding, and reducing the incidence of problems such as incomplete welding, off-center welding, and overflow welding.

[0020] Each through-hole includes a first through-hole and a second through-hole. The second through-hole is located above the first through-hole. The first through-hole extends horizontally, and the second through-hole extends vertically. The first and second through-holes are connected to form an elongated through-hole profile with an expansion groove. The internal profile of the first through-hole is adapted to the profile of the cover plate to accommodate the cover plate and provide it with accommodating space. When the cover plate is placed in the through-hole, its four corners abut against the inner wall of the first through-hole, and the four corners act as limiting points, restricting the cover plate in the X and Y directions in the horizontal plane to prevent horizontal displacement and rotation. The internal profile of the second through-hole is adapted to the profile of the tube shell to accommodate the tube shell and provide it with accommodating space. When the tube shell is placed in the second through-hole, its four corners abut against the inner wall of the second through-hole, and the four corners act as limiting points, restricting the tube shell in the X and Y directions in the horizontal plane to prevent horizontal displacement and rotation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the technical problems of the existing semi-automatic cover plate in point sealing according to the present invention; Figure 2 This is a schematic diagram of the structure of the shell and cover plate in an embodiment of the present invention; Figure 3 a is a schematic diagram of the limiting plate in an embodiment of the present invention, and b is a partial enlarged view of point A; Figure 4 This is a schematic diagram of the card holder structure in an embodiment of the present invention; Figure 5 This is a flowchart of an assembly method for a positioning fixture used in semi-automatic spot sealing according to the present invention.

[0022] Figure label: 1-Limiting plate; 2-Card holder; 3-Tube shell; 4-Cover plate. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0025] Example 1 The present invention provides a positioning fixture for semi-automatic spot sealing, comprising a limiting plate 1 and a mounting base 2. The limiting plate 1 is provided with through holes for mounting surface mount devices. Several through holes on the same horizontal line are interconnected. The mounting base 2 is provided with grooves that are adapted to the through holes. The mounting base 2 is fixedly installed on the upper end of the limiting plate 1. The surface mount device includes a tube shell 3 and a cover plate 4.

[0026] like Figure 3 a and such Figure 4 As shown, the positioning fixture includes a limiting plate 1 and a mounting base 2. The limiting plate 1 is a rectangular flat plate that limits the cover plate 4 and the tube shell 3. The plate body of the limiting plate 1 is provided with multiple sets of through holes. Each set of through holes corresponds to an independent surface mount device mounting station, which is used to accommodate and position the cover plate 4 and the tube shell 3 of the surface mount device. The multiple sets of through holes are evenly arranged in a row and column matrix. Several through holes on the same horizontal line are interconnected to form a continuous long strip channel, while the through holes in the same vertical column remain independently separated.

[0027] By connecting the through holes on the same horizontal line, the processing flow of the limiting plate 1 is simplified, the processing steps and tool wear are reduced, and the manufacturing cost is lowered. In addition, there are no dead corner areas with independent hole positions, which facilitates centralized blowing before and after operation, avoids the accumulation of foreign matter in dead corners, and reduces the risk of foreign matter contamination caused by the tooling itself.

[0028] Each through hole includes a first through hole and a second through hole. The second through hole is located at the upper end of the first through hole. The first through hole extends horizontally, and the second through hole extends vertically. The first through hole and the second through hole are connected to form an elongated through hole profile with expansion grooves at both ends. The inner contour of the first through hole is adapted to the main contour of the cover plate 4 to accommodate the cover plate 4 and provide accommodating space for the cover plate 4. When the cover plate 4 is placed in the through hole, the four corners of the cover plate 4 abut against the inner wall of the first through hole. The cover plate 4 is limited in the X and Y directions in the horizontal plane by the abutting and limiting of the four corners, so as to prevent the cover plate 4 from horizontally shifting or rotating. The inner contour of the second through hole is adapted to the main contour of the tube shell 3 to accommodate the tube shell 3 and provide accommodating space for the tube shell 3. When the tube shell 3 is placed in the through hole, the four corners of the tube shell 3 abut against the inner wall of the second through hole. The tube shell 3 is limited in the X and Y directions in the horizontal plane by the abutting and limiting of the four corners, so as to prevent the tube shell 3 from horizontally shifting or rotating.

[0029] Compared to the full-circle hole wall positioning, this design reduces the contact area between the side wall of the cover plate 4 and the hole wall, making it easier for the vacuum suction pen nozzle to pick up and place the cover plate 4. This reduces the risk of scratches during handling and avoids the introduction of debris or other contaminants caused by scratches. Simultaneously, it provides working space for the spot-sealing rollers, allowing them to perform spot-sealing operations on the cover plate surface.

[0030] like Figure 4 As shown, the outer dimensions of the mounting bracket 2 match those of the limiting plate 1, facilitating assembly. The upper surface of the mounting bracket 2 has grooves that match the through holes on the limiting plate 1; the arrangement and number of the grooves correspond one-to-one with the arrangement and number of the through holes. When the limiting plate 1 is connected to the mounting bracket 2, the through holes and grooves are aligned coaxially, forming a mounting cavity for the surface mount device. The inner contour of the groove matches the bottom contour of the housing 3, supporting the bottom structure of the housing 3 and providing vertical support and horizontal constraint to the lower end of the housing 3, ensuring stability during spot sealing welding and preventing displacement or shaking.

[0031] like Figure 2As shown, the surface mount device includes a housing 3 and a cover plate 4. The housing 3 is mounted on the upper end of the cover plate 4, and one side of the housing 3 cavity is inverted and fixedly connected to the cover plate 4. The housing 3 is a ceramic shell with a Kovar sealing ring for surface mount devices. The main body is a ceramic cavity structure, which has insulation, hermeticity, and thermal stability. The cavity is used to place semiconductor chips and related interconnect circuit structures. A Kovar sealing ring is provided at the upper opening of the housing 3. The sealing ring is sintered with the ceramic cavity and is used to weld with the cover plate 4 to form a hermetic packaging structure. The cover plate 4 is made of gold-plated Kovar alloy. The base material is Kovar alloy, which has a similar coefficient of thermal expansion to the ceramic housing, which can reduce the thermal stress after welding. The surface of the cover plate 4 is plated with a gold layer to improve welding performance and resistance to oxidation and corrosion.

[0032] The cover plate 4 is 0.1 mm shorter on one side than the shell 3. The first through hole limits the cover plate 4. When the cover plate 4 is installed in the first through hole, the inner wall of the first through hole abuts against the sides of the four corners of the cover plate 4. The second through hole limits the shell 3. When the shell 3 is installed in the second through hole, the inner wall of the second through hole abuts against the sides of the four corners of the shell 3. After the cover plate 4 and the shell 3 are installed, a uniformly wide annular step is formed on their outer edges. Figure 3 As shown in b.

[0033] In this embodiment, both the limiting plate 1 and the card holder 2 are made of high-purity graphite material, which can withstand the local high temperature during the spot sealing welding process and has a low coefficient of thermal expansion, ensuring the long-term stability of positioning accuracy; it is easy to achieve high-precision machining to meet the alignment requirements; it will not produce metal shavings and has little wear, reducing the risk of excess material caused by its own wear; it does not wet and adhere to the solder, and the solder splashed during the welding process will not adhere to the tooling surface.

[0034] First, cover plate 4 is installed in the through hole, and the four corners of cover plate 4 are positioned through the first through hole. Then, tube shell 3 is placed upside down on top of cover plate 4, so that the sealing ring of tube shell 3 is aligned vertically with cover plate 4. Then, the groove of card holder 2 is inserted into the bottom of tube shell 3. Throughout this process, the tube shell cavity faces downward, preventing environmental dust, operational debris, welding spatter, and other waste from falling directly into the circuit cavity. After installation, the whole unit is flipped over so that the limiting plate 1 is located on the upper surface of card holder 2.

[0035] Example 2 The present invention discloses an assembly method for a positioning fixture for semi-automatic spot sealing, comprising the following steps: Figure 5 As shown, Step 1: Place the limiting plate 1 stably on the table; Step 2: Place the cover plate 4 into the through hole; Step 3: Install the tube shell 3 upside down on the upper end of the cover plate 4; Step 4: Repeat Step 2 and Step 3 to fix the card seat 2 to the limiting plate 1 containing the tube shell 3 and the cover plate 4; Step 5: Spot weld the tube shell 3 and the cover plate 4 using the equipment electrode wheel.

[0036] First, clean the work surface to remove any residual dust, debris, and stains. Place the limit plate 1 horizontally on the cleaned work surface. Before cleaning the work surface, blow out the inner walls of the through holes in the limit plate 1 to remove ambient dust.

[0037] A vacuum suction pen is used to pick up and place the cover plate 4. The nozzle of the vacuum suction pen is cleaned before use. When picking up the cover plate 4, the nozzle of the vacuum suction pen is aligned with the center area of ​​the cover plate 4 for vacuum adsorption. The cover plate 4 is picked up in a horizontal position to avoid tilting or falling off. After picking up the cover plate 4, it is moved directly above the corresponding through hole of the limiting plate 1. The angle and horizontal position of the cover plate 4 are adjusted so that the four corners of the cover plate 4 are aligned with the first through hole. Then, the cover plate 4 is lowered so that the four corners of the cover plate 4 abut against the inner wall of the first through hole.

[0038] Using a vacuum suction pen to pick up and place the cover plate 4 avoids direct human contact with the device, reducing contaminants and excess materials such as sebum, dust, and fibers from human hands. Simultaneously, vacuum suction ensures the stability of the cover plate 4 during handling, preventing structural damage caused by bumps or drops. This eliminates the need for repeated manual adjustments, improving efficiency.

[0039] Using a vacuum suction pen, pick up the tube shell 3. Align the nozzle of the vacuum suction pen with the center area of ​​the bottom of the tube shell 3. After picking up the tube shell 3, move it directly above the cover plate 4. Adjust the horizontal position and angle of the tube shell 3 so that the sealing ring at the top of the tube shell 3 is coaxially aligned with the cover plate 4. Then, invert one side of the tube shell 3 and attach it to the top of the cover plate 4. Using a vacuum suction pen to pick up and place the tube shell 3 can protect the inside of the tube shell 3 from introducing foreign objects and avoid scratches and other cosmetic problems.

[0040] Install all the tube shells 3 and cover plates 4 using the same operating method. Snap the bracket 2 onto the upper end of the limiting plate 1, so that the grooves on the bracket 2 fit into the bottom of the tube shell 3 one by one.

[0041] After assembly, the positioning fixture is flipped over and transferred to the semi-automatic pre-welding machine. The position of the electrode wheel and the welding parameters of the machine are adjusted, with the electrode wheel aligned with the middle area of ​​the edge of the cover plate 4. The welding parameters are set according to the circuit characteristics. The electrode wheel uses resistance heat generated by the current to melt the plating on the surface of the cover plate 4 and the sealing ring of the tube shell 3, and they combine to form a welding interface. After cooling, a weld point is formed, which temporarily fixes the tube shell 3 and the cover plate 4.

[0042] During spot welding, the limiting plate 1 and the holder 2 are fixed, providing positioning and constraint for the tube shell 3 and the cover plate 4. This prevents displacement due to electrode wheel pressure during welding, ensuring accurate welding position. Furthermore, since the cover plate 4 is fixed to the tube shell 3, it prevents metal spatter from being introduced into the circuit cavity, thus avoiding the formation of excess metal. After spot welding, the limiting plate 1 and the holder 2 are separated, and the spot-sealed component is removed.

[0043] Using electrode wheels for spot welding, the limiting plate 1 and the card holder 2 provide positioning support and physical protection for the device during the welding process, improving the consistency of the solder joints and the welding quality, preventing spot welding spatter from entering the circuit cavity, directly reducing the risk of introducing foreign matter from the welding process, and improving the reliability of the package.

[0044] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and the disclosed concept of the present invention, should be covered within the scope of protection of the present invention.

[0045] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

Claims

1. A positioning fixture for semi-automatic spot sealing, characterized in that: It includes a limiting plate (1) and a card holder (2). The limiting plate (1) is provided with through holes for mounting surface mount devices. Several through holes on the same horizontal line are interconnected. The card holder (2) is provided with grooves that match the through holes. The limiting plate (1) is fixedly installed on the upper end of the card holder (2). The surface mount device includes a housing (3) and a cover plate (4).

2. The positioning fixture for semi-automatic spot sealing according to claim 1, characterized in that: The casing (3) is installed on the upper end of the cover plate (4), and the side of the casing (3) with the circuit cavity is fixedly connected to the cover plate (4).

3. The positioning fixture for semi-automatic spot sealing according to claim 2, characterized in that: Both the limiting plate (1) and the card holder (2) are made of graphite material.

4. The positioning fixture for semi-automatic spot sealing according to claim 3, characterized in that: The casing (3) is a ceramic shell with Kovar sealing ring for surface mount devices.

5. The positioning fixture for semi-automatic spot sealing according to claim 4, characterized in that: The cover plate (4) is made of gold-plated Kovar alloy.

6. The positioning fixture for semi-automatic spot sealing according to claim 5, characterized in that: The cover plate (4) is 0.1 mm shorter on one side than the shell (3).

7. An assembly method for a positioning fixture used in semi-automatic spot sealing, characterized in that, The positioning fixture for semi-automatic spot sealing according to any one of claims 1-6 includes the following steps: Step 1: Place the limiting plate (1) stably on the table; Step 2: Place the flat side of the cover plate (4) (with the side with the boss facing upwards) into the through hole; Step 3: Install the tube shell (3) cavity upside down on the upper end of the cover plate (4); Step 4: Repeat steps 2 and 3 to fix the card holder (2) to the limiting plate (1) containing the tube shell (3) and the cover plate (4); Step 5: Weld the pipe shell (3) and the cover plate (4) using a spot sealing device.

8. The assembly method of the positioning fixture for semi-automatic spot sealing according to claim 7, characterized in that: When placing the tube shell (3) and the cover plate (4), a vacuum suction pen is used.

9. The assembly method of the positioning fixture for semi-automatic spot sealing according to claim 8, characterized in that: The through hole includes a first through hole and a second through hole disposed around the first through hole. The first through hole is disposed in a horizontal direction, and the second through hole is disposed in a vertical direction.

10. The assembly method of the positioning fixture for semi-automatic spot sealing according to claim 9, characterized in that: The corner of the cover plate (4) abuts against the inner wall of the first through hole.

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