Cover plate pre-welding method for gold-tin fusion-sealed product and gold-tin fusion-sealed product

Abstract

The invention belongs to the technical field of semiconductor integrated circuit packaging, and discloses a cover plate pre-welding method for a gold-tin fusion-sealed product and the gold-tin fusion-sealed product. According to the method, a plurality of tube shells are sequentially fixed in an arrayed groove; determining the fixed position of the cover plate relative to the tube shell based on an image recognition system according to the size parameters, the gray level parameters and the contrast ratio parameters of the cover plate and the tube shell; a plurality of cover plates are placed on the corresponding tube shells according to the fixing positions, and local welding is conducted on the cover plates, so that pre-welding operation of the cover plates of the gold-tin fusion sealing product is achieved; by adopting the method, automatic and high-precision cover plate placement and pre-welding operation are realized, and the risks of generation of redundancy, accidental touch of a bonding wire, deviation of the cover plate from a tube shell and the like are avoided; and after spot welding is carried out through the method, a clamp can be directly used for carrying out heat sealing pressure applying operation, the defects that due to heat sealing in a mold heat conduction mode, a circuit is heated unevenly, and heating and cooling are difficult to control are overcome, and the overall quality of the sealing cap can be improved.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor integrated circuit packaging and testing, and in particular relates to a cover plate pre-welding method for a gold-tin melting-sealing product and a gold-tin melting-sealing product. Background Art

[0002] With the development of the aerospace field, fusion-sealed products are widely used in high-reliability semiconductor integrated circuits due to their advantages of high airtightness, strong corrosion resistance, and few PIND problems. The packaging process of fusion-sealed products uses gold-tin (AuSn20) solder rings as soldering brazing materials. Under high temperatures above 300°C, a certain welding pressure is used to cause melting and eutectic processes, achieving close contact between the ceramic tube shell and the metal cover plate and completing airtight packaging. It is also an important packaging method for high-reliability semiconductor integrated circuits.

[0003] The sealing products mainly use ceramic tube shells such as LCC, CSOP, and FCP, and the cover plate is gold-plated Kovar alloy. The packaging process mainly uses two methods for assembly: clamping with a fixture or inverted tooling. However, the method of using a fixture is to manually place and align the cover plate. This process has problems such as different operators' different techniques, visual identification of the cover plate's position, and manual positioning of the needle. It is easy to cause risks such as excess objects, accidental contact with bonding wires, and the cover plate deviating from the tube shell, resulting in low circuit packaging yield and production efficiency; the inverted tooling is to seal the package by mold limitation and mold heat transfer. The position of the cover plate and the tube shell can be fixed, but the existence of the mold will hinder the overflow of the solder, which is easy to cause poor overflow of gold-tin solder, breakpoints and gaps; at the same time, packaging by mold heat conduction will also cause uneven heating of the circuit, and it is difficult to control the temperature rise and fall, which will ultimately affect the quality of the cap.

[0004] It can be seen that the existing gold-tin sealing packaging methods all have hard problems that cannot be improved by the process, and they are all manually operated, resulting in the gold-tin sealing process having poor performance in terms of yield and production efficiency compared to other packaging processes. Summary of the invention

[0005] The purpose of the present invention is to provide a cover pre-soldering method for gold-tin sealing products and a gold-tin sealing product, so as to solve the technical problems that the existing gold-tin sealing packaging methods all have hard problems that cannot be improved by the process, and all are manual operations, resulting in the gold-tin sealing process having poor performance in yield and production efficiency compared with other packaging processes.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A cover plate pre-welding method for a gold-tin sealing product comprises the following steps: Fixing a plurality of tube shells in the array grooves in sequence; Determine the fixed position of the cover plate relative to the tube shell based on the image recognition system and according to the size parameters of the cover plate and the tube shell, as well as the contrast parameters and the grayscale parameters; Multiple cover plates are placed on the corresponding tube shells according to fixed positions, and the cover plates are partially welded to realize the pre-welding operation of the cover plates of the gold-tin sealing product.

[0007] Furthermore, the image recognition system can adjust the grayscale and contrast parameters based on the size parameters of the tube shell to highlight the shape of the tube shell, search and match the set size through the device camera until the match is successful, and output the grayscale and contrast parameters of the tube shell corresponding to the successful match; Based on preset size parameters of the tube shell, size parameters of the cover plate, contrast and grayscale parameters of the tube shell, and arrayed groove spacing parameters, a fixed position is obtained and output.

[0008] Furthermore, the specific steps of placing the cover plate on the tube shell according to the fixed position include: Use a negative pressure suction nozzle to suck each cover plate in turn; According to the fixed position of the output, each cover plate is placed on the corresponding tube shell in turn.

[0009] Furthermore, before the negative pressure suction nozzle adsorbs each cover plate, all the cover plates are stored in the magazine compartment.

[0010] Furthermore, the cover plates on the tube shells in the arrayed grooves are locally welded in sequence in an S-shaped movement manner.

[0011] Furthermore, during the welding process of the cover plate, a tungsten-copper alloy electrode wheel is used to perform surface welding treatment on the cover plate.

[0012] Furthermore, during the cover plate welding process, two tungsten-copper alloy electrode wheels are used; the pulse current passes through the cover plate, solder and tube shell from one tungsten-copper alloy electrode wheel, and then returns to the power supply from the other tungsten-copper alloy electrode wheel to form a loop.

[0013] Furthermore, the tube shell is a flat ceramic tube shell.

[0014] Furthermore, the cover plate is made of gold-plated Kovar alloy.

[0015] A gold-tin sealing product is manufactured based on the cover plate pre-welding method for the gold-tin sealing product.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a cover plate pre-welding method for a gold-tin sealing product, the pre-welding method is performed by fixing a plurality of tube shells in an arrayed groove in sequence; determining the fixed position of the cover plate relative to the tube shell based on an image recognition system and according to the size parameters of the cover plate and the tube shell, as well as the grayscale parameters and the contrast parameters; placing a plurality of cover plates on the corresponding tube shells according to the fixed positions, and locally welding the cover plates to realize the pre-welding operation of the cover plates of the gold-tin sealing product; the method is adopted to realize automated and high-precision cover plate placement and pre-welding operations, avoiding the risks of redundant materials, accidental contact with bonding wires and cover plates deviating from the tube shell, etc.; and after spot welding by the method, a clamp can be directly used to apply pressure for sealing, avoiding the defects of uneven heating of the circuit and difficulty in controlling temperature rise and fall caused by sealing by heat conduction of a mold, which helps to improve the overall quality of the cap.

[0017] Preferably, in the present invention, the image recognition system not only recognizes the size parameters of the tube shell, but also takes into account the contrast and grayscale parameters, which improves the accuracy of determining the position of the cover plate, further reduces the error of manual operation, and improves the reliability and consistency of packaging.

[0018] Preferably, in the present invention, a negative pressure suction nozzle is used to absorb and place the cover plate, thereby achieving accurate grasping and positioning of the cover plate, avoiding errors and damages that may be caused by manual operation using tweezers or a suction pen, and improving production efficiency and packaging quality.

[0019] Preferably, in the present invention, the cover plate is stored in a magazine compartment, which is convenient for management and automated operation, improves the cleanliness and efficiency of the production line, and also helps to reduce damage to the cover plate during transportation and storage.

[0020] Preferably, in the present invention, the S-shaped movement method is used for local welding, which can more effectively utilize the welding equipment and improve the welding efficiency. It also helps to reduce the heat accumulation during the welding process and protect the circuit from overheating.

[0021] Preferably, in the present invention, a tungsten-copper alloy electrode wheel is used for surface welding treatment, which improves the stability and reliability of welding, and also helps to reduce spatter and pollution during welding, thereby improving the packaging quality.

[0022] Further preferably, in the present invention, two tungsten-copper alloy electrode wheels are used to form a welding circuit, which can transfer heat more evenly, improve welding quality, and also help reduce energy consumption and costs during the welding process.

[0023] Preferably, in the present invention, a flat ceramic tube shell is used as the tube shell material, which has excellent insulation performance and mechanical strength, and helps to improve the reliability and durability of the gold-tin sealing product.

[0024] Preferably, in the present invention, the cover plate is made of gold-plated Kovar alloy, which has good conductivity and corrosion resistance, helps to protect the circuit from the influence of the external environment, and improves the service life and performance of the gold-tin sealing product.

[0025] The present invention also provides a gold-tin sealing product, which is prepared by the cover plate pre-soldering method for the gold-tin sealing product, thereby effectively avoiding many disadvantages of manual operation in the traditional gold-tin sealing packaging method, such as excess objects, accidental contact with bonding wires, cover plate deviation from the tube shell caused by differences in operator techniques, errors in naked eye recognition, inaccurate positioning, etc., as well as process hard problems such as poor solder overflow, breakpoint gaps, uneven circuit heating and difficult temperature control caused by the mold limiting heat transfer method; this product significantly improves the yield and production efficiency of gold-tin sealing products by adopting an innovative pre-soldering method, making the gold-tin sealing process more competitive in terms of packaging quality, production efficiency and cost control. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a tube shell provided by an embodiment of the present invention; Figure 2 A schematic diagram of a cover plate structure provided by an embodiment of the present invention; Figure 3 A schematic diagram of the structure of the arrayed grooves provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a magazine provided by an embodiment of the present invention; Figure 5 A schematic diagram of identification and positioning provided by an embodiment of the present invention; Figure 6 A schematic diagram of a negative pressure nozzle and a tungsten-copper alloy electrode wheel provided in an embodiment of the present invention; Figure 7 A schematic diagram of welding using an S-shaped movement method provided in an embodiment of the present invention.

[0027] Reference numerals: 1. Tube shell; 2. Cover plate; 3. Arrayed grooves; 4. Magazine compartment; 5. Tungsten-copper alloy electrode wheel; 6. Negative pressure nozzle. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0030] Example 1 As mentioned in the background technology, the existing sealing process uses a fixture to manually place and align the cover plate. This process has problems such as different operators' different techniques, visual identification of the cover plate position, and manual positioning. It is easy to cause risks such as excess objects, accidental contact with bonding wires, and the cover plate deviating from the shell, resulting in low circuit packaging yield and production efficiency; the inverted tooling is sealed by the mold limit and mold heat transfer method. The position of the cover plate and the shell can be fixed, but the existence of the mold will hinder the overflow of the solder, which is easy to cause poor overflow of gold-tin solder, breakpoints and gaps; at the same time, the mold is packaged in a heat conduction manner, which will also cause uneven heating of the circuit, and it is difficult to control the temperature rise and fall, which will eventually affect the quality of the cap. With the development of science and technology and the increase in the number of tasks, the demand for semiconductor integrated circuits has also increased. In addition, the current industrial model has gradually transformed into an automated production model. In order to improve the quality and production efficiency of product packaging, new automated production sealing process technologies must be developed.

[0031] In order to solve the above problems, the present embodiment provides a cover plate pre-welding method for gold-tin sealing products. The method adopts the visual system of the fully automatic spot sealing equipment to ensure the high-precision alignment of the gold-tin cover plate and the ceramic tube shell, and locally pre-welds the surface of the cover plate through electric current, and preliminarily fixes the cover plate with the sealing circuit, thereby achieving the purpose of positioning the cover plate, replacing the manual picking, placing, and aligning of the cover plate, and transforming the manual operation mode into a fully automatic production mode, which not only ensures the quality of sealing, but also simplifies the manual assembly method and improves production efficiency.

[0032] In this embodiment, the specific inventive principle is conceived as follows: First, the cover plate and the circuit are positioned and assembled through the image recognition system (visual system) and negative pressure nozzle of the equipment, and then the electrode wheel discharges on both sides of the cover plate. The pulse current passes through the cover plate, solder and tube shell from one electrode, and then returns to the power supply from another electrode to form a loop. During this period, Joule heat is generated and the temperature rises, causing the solder in a small area to melt and partially melt with the gold-plated layer on the surface of the cover plate and the tube shell. After the molten coating cools down, the cover plate, solder and tube shell are combined together to achieve the purpose of temporary fixation.

[0033] Second, the equipment is equipped with negative pressure nozzles of different sizes to meet the pre-welding needs of covers of different sizes. The greater suction force avoids the risk of the cover falling off during the picking and transferring process.

[0034] Third, the image recognition system accurately identifies the position of the cover plate and the tube shell based on the image contrast and grayscale and makes appropriate adjustments to ensure accurate positioning between the cover plate and the tube shell to avoid offset.

[0035] Fourth, the electrode material is made of WCu alloy (tungsten-copper alloy) with high hardness, high density and good conductivity. Compared with traditional copper electrodes, it ensures good contact between the electrode and the cover surface without brown stains and other appearance problems.

[0036] Fifth, through appropriate equipment power, pre-welding time and discharge times, the pre-welding temperature can be greater than the melting point of the solder and less than the melting points of the cover plate and tube shell coating, ensuring that only local solder melts.

[0037] It can be seen that based on the above principles, the cover plate pre-welding method for gold-tin sealing products provided by the present invention solves the problem that the sealing process has long required manual operation to assemble the cover plate, and transforms the manual mode into a fully automatic production mode, thereby greatly improving production efficiency; at the same time, it solves the problems of poor consistency in manual operation, cover plate position offset, and accidental contact with the bonding wire in the cavity, thereby improving the packaging yield rate, achieving the purpose of reducing costs and increasing efficiency, and creating more economic benefits for the enterprise.

[0038] The present invention can be widely used in the field of semiconductor integrated circuit gold-tin sealing packaging. The tube shell (1) used in this example is a QF0606-10 flat ceramic tube shell (package form FCP10), and the cover plate (2) is a matching MA06090609A gold-plated Kovar alloy.

[0039] This embodiment provides a cover plate pre-welding method for a gold-tin sealing product, comprising: Fixing a plurality of tube shells (1) in sequence in the arrayed grooves (3); Determining a fixed position of the cover plate (2) relative to the tube shell (1) based on an image recognition system and according to size parameters of the cover plate (2) and the tube shell (1) as well as grayscale and contrast parameters; A plurality of cover plates (2) are placed on the corresponding tube shell (1) according to fixed positions, and the cover plates (2) are locally welded to achieve pre-welding of the cover plates of the gold-tin sealing product.

[0040] The more detailed steps are as follows: like Figure 1 As shown, taking QF0606-10 flat tube shell and MA06090609A matching cover as an example, the steps include: like Figure 3As shown, step 1: place the QF0606-10 tube shell (1) into the array groove (3) of the base and fix it; like Figure 2 and Figure 4 As shown, step 2: place the MA06090609A cover plate (2) into the matching magazine compartment; Step 3: inputting measurable data such as the size of the tube shell (1), the cover plate (2), the base, and the spacing of the arrayed grooves (3) into the point sealing device. In this step, measurements can also be performed in advance to obtain preset related parameters; like Figure 5 As shown, step 4: Based on the recognition results of the image recognition system, adjust the contrast and grayscale parameters of the image display of the point sealing equipment to ensure the accuracy of recognition. After the parameter debugging is completed, it can be saved as a fixed program and can be directly called when it is packaged again later; combined with Figure 6 , using a negative pressure suction nozzle (6) to absorb each cover plate (2) and place it on the tube shell (1) according to a fixed position; like Figure 7 As shown, step five: after the point sealing device is reset, the cover plate (2) is pre-welded to the tube shell (1) in the base of the arrayed groove (3) in an S-shaped manner; Figure 6 As shown, in this step, two tungsten-copper alloy electrode wheels (5) are used for local welding; the pulse current passes from one tungsten-copper alloy electrode wheel (5) through the cover plate (2), the solder and the tube shell (1), and then returns to the power supply from the other tungsten-copper alloy electrode wheel (5) to form a circuit; Step 6: After all the tube shells in the base are pre-welded, the equipment stops automatically, and then repeat steps 1 to 5; thus, the cover pre-welding operation of the gold-tin sealing product is realized.

[0041] It can be seen that the present invention provides a cover plate pre-welding method for a gold-tin sealing product and a gold-tin sealing product. The present invention adopts the method for fully automatic cover plate assembly of a circuit tube shell, and transforms the gold-tin sealing packaging process from a manual operation mode to a machine fully automatic production mode, thereby solving the problem of poor consistency of manual operation and avoiding the problem of manual operation cover plate deviation and accidental contact with the bonding wire in the cavity. Compared with the existing process, it has the following advantages: First, the use of negative pressure nozzles of different sizes can meet the pre-welding needs of covers of different sizes. The greater suction force and automatic alarm when the suction force is insufficient avoid the risk of the cover falling off during the transfer process.

[0042] Second, the image recognition system of the spot sealing equipment adjusts the grayscale and contrast parameters based on the preset input tube shell size, identifies the tube shell size corresponding to the preset value in the base through the equipment camera and adjusts the position, and finally transports and spot welds the cover plate; this method eliminates the need for manual alignment of the cover plate and the tube shell, improves the assembly speed, thereby improving production efficiency, and eliminates the problem of cover plate offset.

[0043] Third, it replaces the manual assembly process of using tweezers and suction pens, reduces the problem of cover plate scratches caused by tools, and eliminates the risk of tweezers accidentally touching the bonding wire in the cavity.

[0044] Fourth, the use of WCu alloy electrodes with excellent physical properties ensures good contact between the electrode and the cover surface, without brown stains and other appearance problems, compared with traditional Cu electrodes.

[0045] Fifth, by developing appropriate point sealing equipment parameters, the pre-soldering temperature is greater than the melting point of the solder and less than the melting points of the cover and shell coatings, ensuring that only local solder melts, without damaging the gold-plated layer on the surface of the cover and affecting the subsequent sealing process.

[0046] Sixth, transform the gold-tin sealing packaging process from manual operation mode to fully automatic machine production mode.

[0047] In summary, the method adopts the visual system of the fully automatic spot sealing equipment to ensure the high-precision alignment of the gold-tin cover plate and the ceramic tube shell, performs local spot welding on the surface of the cover plate through electric current, and preliminarily pre-welds the cover plate with the sealing circuit, thereby achieving the purpose of fixing the cover plate and replacing the manual picking, placing, and aligning of the cover plate; the negative pressure suction nozzle of the spot sealing equipment can meet the pre-welding of covers of different sizes, and the large suction force and automatic alarm when the suction force is insufficient also avoid the risk of the cover plate falling off during the transfer process; the image recognition system replaces the manual cover plate alignment operation, improves the assembly rate and production efficiency, and eliminates the problems of cover plate scratches, cover plate offset and tweezers accidentally touching the bonding wire in the cavity caused by tools; WCu alloy electrodes are used to replace traditional Cu electrodes to ensure good contact between the electrode and the cover plate surface, without appearance problems such as brown stains; through appropriate spot sealing equipment parameters, it is ensured that only local solder is melted, the coating on the surface of the cover plate is not damaged, and the subsequent sealing packaging process is not affected.

[0048] Through the present invention, the gold-tin melt-sealing packaging process is transformed from a manual operation mode to a fully automatic machine production mode, replacing the process of manually using tweezers and suction pens to assemble the cover plate, greatly improving the packaging quality and production efficiency of the melt-sealed products, achieving the purpose of reducing costs and increasing efficiency, and creating more economic benefits for the enterprise.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0050] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and the disclosed concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0051] The further detailed description made in the disclosure cannot be used to determine that the specific implementation modes of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A cover plate pre-welding method for gold-tin sealing products, characterized in that: The steps include: Fixing a plurality of tube shells (1) in sequence in the arrayed grooves (3); Determining a fixed position of the cover plate (2) relative to the tube shell (1) based on an image recognition system and according to size parameters, contrast parameters, and grayscale parameters of the cover plate (2) and the tube shell (1); A plurality of cover plates (2) are placed on the corresponding tube shell (1) according to fixed positions, and the cover plates (2) are locally welded to achieve pre-welding of the cover plates of the gold-tin sealing product.

2. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: The image recognition system can adjust the grayscale and contrast parameters based on the size parameters of the tube shell (1) to highlight the shape of the tube shell (1), search and match the set size through the device camera until the match is successful, and output the grayscale and contrast parameters of the tube shell (1) corresponding to the successful match; Based on the preset size parameters of the tube shell (1), the size parameters of the cover plate (2), the contrast and grayscale parameters of the tube shell (1), and the arrayed groove spacing parameters, a fixed position is obtained and output.

3. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: The specific steps of placing the cover plate (2) on the tube shell (1) according to the fixed position include: Adopting a negative pressure suction nozzle (6) to suck each cover plate (2) in turn; According to the output fixed position, each cover plate (2) is placed on the corresponding tube shell (1) in sequence.

4. The cover plate pre-welding method for gold-tin sealing products according to claim 3, characterized in that: Before the negative pressure suction nozzle (6) sucks each cover plate (2), all the cover plates (2) are stored in the magazine compartment (4).

5. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: The cover plate (2) on the tube shell (1) in the arrayed groove (3) is locally welded in sequence using an S-shaped movement method.

6. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: During the welding process of the cover plate (2), a tungsten-copper alloy electrode wheel (5) is used to perform surface welding treatment on the cover plate (2).

7. The cover plate pre-welding method for gold-tin sealing products according to claim 6, characterized in that: During the welding process of the cover plate (2), two tungsten-copper alloy electrode wheels (5) are used; a pulse current is passed from one tungsten-copper alloy electrode wheel (5) through the cover plate (2), solder and tube shell (1), and then returns to the power supply from the other tungsten-copper alloy electrode wheel (5) to form a circuit.

8. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: The tube shell (1) is a flat ceramic tube shell.

9. The cover plate pre-welding method for gold-tin sealing products according to claim 1, characterized in that: The cover plate (2) is made of gold-plated Kovar alloy.

10. A gold-tin sealing product, characterized in that: The product is manufactured based on the cover plate pre-welding method for gold-tin sealing products described in any one of claims 1-9.

Images