Wafer-level eutectic jig and forming method of packaging structure

Abstract

The invention relates to a wafer-level eutectic jig and a forming method of a packaging structure, and the wafer-level eutectic jig comprises a pedestal, the upper surface of the pedestal is used for placing a wafer, and the upper surface of the wafer is provided with a plurality of mounting areas which are arranged in rows and columns; the steel mesh is installed on the upper surface of the base, the steel mesh is provided with a plurality of mesh holes, each mesh hole is exposed out of the corresponding surface mounting area on the wafer, and a glass light window to be subjected to eutectic welding with the corresponding surface mounting area on the wafer is placed in each mesh hole; the weight component comprises a plurality of weight heads, and each weight head is arranged on the upper surface of the corresponding glass light window and used for applying downward pressing gravity when the glass light window is welded to the corresponding mounting area on the wafer in an eutectic mode. According to the wafer-level eutectic jig, the eutectic welding efficiency is improved, and the productivity is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor packaging, and in particular to a method for forming a wafer-level eutectic fixture and a packaging structure. Background Art

[0002] The existing MEMS device packaging adopts a glue-binding solution, which can only achieve ordinary IP-level waterproofness but cannot achieve a high degree of airtightness, thus affecting the life of the MEMS device.

[0003] In order to improve the airtightness of MEMS devices and increase the service life of MEMS devices, more advanced processes are needed to hermetically seal MEMS devices. In this context, the eutectic welding process came into being. The eutectic welding process can greatly improve the airtightness of MEMS devices. At present, the mainstream implementation method of the eutectic welding process is: the eutectic welding process uses Au80Sn20 eutectic solder, which is heated and pressed by a hot welding head. The Au80Sn20 eutectic solder directly diffuses the eutectic at about 300℃~320℃. The existing hot welding head can only perform eutectic welding and sealing on a single MEMS device at a time, which has low production efficiency and is not conducive to the improvement of production capacity. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a method for forming a wafer-level eutectic fixture and a packaging structure, so as to improve the efficiency of eutectic welding and increase production capacity.

[0005] In order to solve the above problems, the present application provides a wafer-level eutectic fixture, including:

[0006] A base, the upper surface of which is used to place a wafer, and the upper surface of which has a plurality of mounting areas arranged in rows and columns;

[0007] A steel mesh, the steel mesh is mounted on the upper surface of the base, the steel mesh has a plurality of mesh holes, each of the mesh holes exposes a corresponding mounting area on the wafer, and each of the mesh holes is used to place eutectic solder and a glass window to be eutectically welded with the corresponding mounting area on the wafer;

[0008] The weight component includes a plurality of weight terminals, each of which is placed on the upper surface of the corresponding glass window and is used to apply downward pressure when the glass window is eutectically soldered to the corresponding mounting area on the wafer through the eutectic solder.

[0009] In some embodiments, the weight component also includes a weight tray, a weight limiting plate, a weight rod and a counterweight block, wherein the weight tray is placed on the upper surface of the steel mesh, the weight limiting plate is suspended and fixed above the weight tray by a support, the weight limiting plate has a plurality of positioning holes, the weight limiting plate has limiting holes corresponding to the positioning holes, the weight rod includes an upper part and a lower part connected to each other, the upper part of the weight rod is inserted into the limiting hole, the lower part of the weight rod is inserted into the corresponding positioning hole, the counterweight block is fixed on the upper surface of the weight rod, and the weight terminal is fixed on the bottom surface of the lower part of the weight rod.

[0010] In some embodiments, the weight component further includes a limiting block fixed between the weight rod and the weight terminal.

[0011] In some embodiments, the limit block includes a first part and a second part connected to each other, the size of the first part is larger than the size of the second part, and the size of the first part is larger than the size of the positioning hole, the size of the second part is smaller than or equal to the size of the positioning hole, the first part of the limit block is limited to the upper surface or above the upper surface of the weight tray, and the second part of the limit block is limited in the positioning hole.

[0012] In some embodiments, outer sides of first portions of adjacent limiting blocks corresponding to adjacent positioning holes abut against each other.

[0013] In some embodiments, the top end of the upper portion of the weight rod is higher than the upper surface of the weight limiting plate, and the counterweight block is fixed to the side wall surface of the upper portion higher than the upper surface of the weight limiting plate.

[0014] In some embodiments, the weight tray and the weight limiting plate are made of quartz glass; the weight terminal is made of high temperature resistant plastic.

[0015] In some embodiments, the weight member has only a few weight heads.

[0016] In some embodiments, when the weight terminal is placed on the upper surface of the corresponding glass light window, the bottom surface of the weight terminal contacts the upper surface of the glass light window at a single point or multiple points.

[0017] In some embodiments, the weight terminal includes a central portion and a plurality of raised portions located on the side walls surrounding the central portion; when the weight terminal is placed on the upper surface of the corresponding glass light window, the central portion and the bottom end surfaces of the raised portions contact the upper surface of the glass light window, and the side surfaces of the plurality of raised portions contact the inner walls of the mesh holes in the steel mesh.

[0018] In some embodiments, the material of the weight dock is metal, and the volumes and weights of the weight docks are different. By adjusting the volume of the weight dock, the weight of the weight dock is adjusted, and then the size of the downward pressure applied is adjusted.

[0019] In some embodiments, the lower surface of the base has a magnet, and the magnet is used to adsorb the steel mesh on the upper surface of the base.

[0020] In some embodiments, the upper surface of the base further has a steel mesh position regulator, and the steel mesh position regulator is used to adjust the position of the steel mesh.

[0021] In some embodiments, the wafer is fixed to the upper surface of the base by a pressure spring.

[0022] On the other hand, the present application also provides a method for forming a packaging structure, including:

[0023] Providing the aforementioned wafer-level eutectic fixture;

[0024] Providing a wafer, fixing the wafer on the upper surface of the base, wherein the upper surface of the wafer has a plurality of mounting areas arranged in rows and columns;

[0025] forming eutectic solder on the surface of the mounting area of ​​the wafer;

[0026] A steel mesh is installed on the upper surface of the base, wherein each mesh hole in the steel mesh exposes a corresponding mounting area on the wafer;

[0027] Placing a glass light window in each of the meshes;

[0028] A weight component is installed on the steel net, and the weight component includes a plurality of weight terminals, each of which is placed on the upper surface of the corresponding glass window. The weight terminals apply downward gravity to the glass window, and the glass window is eutectically welded to the corresponding mounting area on the wafer through the eutectic solder.

[0029] In some embodiments, when installing the steel mesh, the steel mesh is aligned with the wafer.

[0030] In some embodiments, the material of the eutectic solder is Au80Sn20 eutectic solder.

[0031] In some embodiments, the gas atmosphere of the furnace chamber during the eutectic welding is an inert gas.

[0032] In some embodiments, the pressure of the furnace chamber during the eutectic welding is normal pressure, negative pressure or positive pressure.

[0033] The wafer-level eutectic fixture and packaging structure formation method mentioned above in the present application, in some embodiments, the wafer-level eutectic fixture includes: a base, the upper surface of the base is used to place the wafer, the upper surface of the wafer has a plurality of mounting areas arranged in rows and columns; a steel mesh, the steel mesh is installed on the upper surface of the base, the steel mesh has a plurality of mesh holes, each of the mesh holes exposes a corresponding mounting area on the wafer, each of the mesh holes is used to place eutectic solder and glass window to be eutectically welded with the corresponding mounting area on the wafer; a weight component, the weight component includes a plurality of weight terminals, each of the weight terminals is placed on the upper surface of the corresponding glass window, and is used to apply downward gravity when the glass window is eutectically welded to the corresponding mounting area on the wafer through the eutectic solder. That is, the wafer-level eutectic fixture in the present application, through the cooperation of the steel mesh and weight components of the aforementioned specific structure, can simultaneously and accurately eutectically weld several glass windows on the surface of several corresponding mounting areas on a wafer, thereby improving the efficiency of eutectic welding and increasing production capacity. In addition, when the wafer-level eutectic fixture of the present application is used for the eutectic welding, the pressure of the furnace chamber is normal pressure, negative pressure or positive pressure, realizing multiple choices of the air pressure in the space sealed by the glass window, and easily achieving high air tightness in the space sealed by the glass window. In addition, when the wafer-level eutectic fixture of the present application is used for the eutectic welding, the gas atmosphere of the furnace chamber can be an inert gas, which improves the drying performance in the space sealed by the glass window. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1-Figure 2 This is a schematic diagram of the structure of a wafer-level eutectic fixture in one embodiment of the present application;

[0035] Figure 3 This is a schematic structural diagram of a wafer-level eutectic fixture in another embodiment of the present application;

[0036] Figure 4-Figure 12 It is a structural schematic diagram of the formation process of the packaging structure in one embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. When describing the embodiments of the present application in detail, for the convenience of explanation, the schematic diagram will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present application. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0038] An embodiment of the present application provides a wafer-level eutectic fixture, referring to Figure 1 and Figure 2 , Figure 2 for Figure 1The structural schematic diagram of the weight component, the wafer-level eutectic fixture comprises:

[0039] The base 100 has an upper surface for placing a wafer 200, and the upper surface of the wafer 200 has a plurality of mounting areas 20 arranged in rows and columns (see Figure 4 );

[0040] A steel mesh 101, the steel mesh 101 is mounted on the upper surface of the base 100, the steel mesh 101 has a plurality of mesh holes 102, each of the mesh holes 102 exposes a corresponding mounting area 20 on the wafer 200, and each of the mesh holes 102 is used to place a eutectic solder (not shown in the figure) and a glass window 201 to be eutectically welded with the corresponding mounting area 20 on the wafer 200;

[0041] The weight component includes a plurality of weight terminals 103 , each of which is placed on the upper surface of the corresponding glass window 201 , and is used to apply downward pressure when the glass window 201 is eutectically soldered to the corresponding mounting area 20 on the wafer 200 through the eutectic solder.

[0042] The base 100 includes an upper surface and a lower surface opposite to each other, and the upper surface of the base is used to place and fix the wafer 200. In some embodiments, the wafer 200 is fixed to the upper surface of the base 100 by a compression spring, and specifically, the compression spring can be fixed to the non-mounting area of ​​the wafer 200.

[0043] The upper surface of the base 100 is a flat surface to avoid scratching the wafer 200. In some embodiments, the roughness of the upper surface of the base 100 is Ra<0.05.

[0044] The base 100 is made of a material with good thermal conductivity, small thermal deformation, and fast heat dissipation. In some embodiments, the base 100 is made of 6061 aluminum, aluminum nitride, or other suitable metal or alloy materials. In some embodiments, the base 100 is at least 5 mm thick to prevent deformation of the base.

[0045] In some embodiments, the base 100 may be fixed on a heating platform, and specifically, the four corners of the base are fixed on the heating platform by screws. The heating platform is used to heat the eutectic solder during the eutectic welding process.

[0046] The wafer 200 includes a plurality of mounting areas 20 arranged in rows and columns (see Figure 4), each mounting area 20 of the wafer is formed with a MEMS (MEMS, Micro-Electro-Mechanical System) device, the MEMS device includes a MEMS sensor, and the MEMS sensor includes a MEMS optical sensor. Through the wafer-level eutectic fixture of the present application, a glass light window 201 can be mounted on each mounting area 20 through a eutectic welding process, and the corresponding mounting area 20 is sealed through the glass light window 201, that is, the MEMS device formed in the corresponding mounting area 20 is sealed. After the glass light window 201 is mounted, the wafer 200 can be divided to form a number of discrete MEMS structures with glass light windows 201.

[0047] In some embodiments, the material of the wafer 200 is silicon (Si), germanium (Ge), or silicon germanium (GeSi), silicon carbide (SiC); it can also be silicon on insulator (SOI), germanium on insulator (GOI); or it can also be other materials, such as III-V group compounds such as gallium arsenide. In other embodiments, the material of the wafer 200 can also be glass. In some embodiments, the size of the wafer 200 is 6 to 12 inches.

[0048] The steel mesh 101 is used to define the placement position of the glass light window 201, ensure that the glass light window 201 is placed on the surface of the corresponding mounting area 20 of the wafer 200, and prevent the glass light window 201 from being offset during the eutectic welding process, so as to improve the position accuracy of the glass light window 201 during eutectic welding and the effect of eutectic welding (such as improving the uniformity of eutectic welding and preventing cold welding), thereby helping to improve air tightness. The steel mesh 101 is installed on the upper surface of the base 100, and the steel mesh 101 has a plurality of mesh holes 102, which are arranged in rows and columns, and each of the mesh holes 102 exposes a corresponding mounting area 20 on the wafer 200, and each of the mesh holes 102 is used to place the glass light window 201 to be eutectically welded with the corresponding mounting area 20 on the wafer 200.

[0049] The steel mesh 101 includes an upper surface and a lower surface relative to each other, and the mesh 102 runs through the upper surface and the lower surface of the steel mesh. The shape of the mesh 102 in the steel mesh 101 is the same as the shape of the mounting area 20 of the wafer 200. The size of the mesh 102 in the steel mesh 101 is slightly larger than the size of the area 20 to be mounted on the wafer 200, or is the same as the size of the area 20 to be mounted on the wafer 200. In some embodiments, the shape of the mesh 102 in the steel mesh 101 and the shape of the mounting area 20 of the wafer 200 are both square.

[0050] In some embodiments, the material of the steel mesh 101 is stainless steel. In a specific embodiment, the material of the steel mesh 101 can be stainless steel containing Mn, so that the steel mesh 101 is mounted on the upper surface of the base 100 by magnetic adsorption. In other embodiments, the material of the steel mesh 101 can also be 6061 aluminum.

[0051] In some embodiments, the steel mesh 101 is mounted on the base 100 by screw fixation, snap fixation, or buckle fixation.

[0052] In some embodiments, the upper surface of the base 100 also has a steel mesh position regulator (not shown in the figure), which is used to adjust the position of the steel mesh 101 to further improve the accuracy of the position installation of the steel mesh 101. In a specific embodiment, the number of the steel mesh position regulators is four, and the position of the steel mesh 101 is adjusted from the four corners of the steel mesh 101 respectively, and the steel mesh position regulator includes a top screw adjustment. In a specific embodiment, when the number of the steel mesh position regulators is four, the position of one of the steel mesh position regulators is fixed, and the other three steel mesh position regulators can adjust the position of the steel mesh 101 in at least one direction. In a specific embodiment, when the number of the steel mesh position regulators is four, the position of one of the steel mesh position regulators is fixed, and the two steel mesh position regulators adjacent to the fixed steel mesh position regulator can adjust the position of the steel mesh 101 in the row direction and the column direction respectively, and the last steel mesh position regulator away from the fixed steel mesh position regulator can adjust the position of the steel mesh 101 in the row direction and the column direction.

[0053] The glass light window 201 is placed in the mesh 102 of the steel mesh 101, and each of the glass light windows 201 is located on the corresponding mounting area 20 of the wafer 200. In some embodiments, the glass light window 201 can be placed manually. In other embodiments, the glass light window 201 can also be placed automatically by equipment. In some embodiments, the outer wall of the glass light window 201 can fit tightly against the inner wall of the mesh 102 of the steel mesh 101. In other embodiments, there is a certain gap between the outer wall of the glass light window 201 and the inner wall of the mesh 102 of the steel mesh 101.

[0054] In some embodiments, the glass light window 201 is in the shape of a cover, and the glass light window 201 includes a cover top and a cover edge located around the edges of the lower surface of the cover top. When the glass light window 201 is eutectic welded on the mounting area 20 of the wafer 200, the bottom surface of the cover edge of the glass light window 201 is eutectic welded to the surface of the mounting area 20 of the wafer 200 through eutectic solder, and a sealed space is formed between the lower surface of the cover top of the glass light window 201, the inner wall of the cover edge of the glass light window 201, and the mounting area 20.

[0055] In some embodiments, the glass window 201 is made of translucent glass. In addition to being able to transmit light, the translucent glass has a certain strength and can achieve good sealing performance.

[0056] The weight component includes a plurality of weight terminals 103, each of which is placed on the upper surface of the corresponding glass window 201. The weight terminals 103 apply downward gravity when the glass window 201 is eutectically welded to the corresponding mounting area 20 on the wafer 200, so that the glass window 201 can be eutectically welded with the corresponding mounting area 20 on the wafer 200 faster and better to improve air tightness. Therefore, the wafer-level eutectic fixture of the present application, through the cooperation of the steel mesh and the weight component of the aforementioned specific structure, can simultaneously and accurately eutectically weld a plurality of glass windows 201 to the corresponding surfaces of the mounting areas 20 on a wafer, thereby improving the efficiency of eutectic welding and increasing production capacity. In addition, when the wafer-level eutectic fixture of the present application is used for the eutectic welding, the pressure of the furnace chamber is normal pressure, negative pressure or positive pressure, so that multiple choices of air pressure in the space sealed by the glass window 201 are realized, and high air tightness in the space sealed by the glass window 201 is easily achieved. Furthermore, when the wafer-level eutectic fixture of the present application is used for the eutectic welding, the gas atmosphere of the furnace chamber can be an inert gas, thereby improving the drying performance in the space sealed by the glass light window 201 .

[0057] In some embodiments, the weight component also includes a weight tray 104, a weight limiting plate 106, a weight rod 109 and a counterweight 110, wherein the weight tray 104 is placed on the upper surface of the steel mesh 101, the weight limiting plate 106 is suspended and fixed above the weight tray 104 by a pillar 108, the weight tray 104 has a plurality of positioning holes 105, the weight limiting plate 106 has a limiting hole 107 corresponding to the positioning hole 105, the weight rod 109 includes an upper part and a lower part connected to each other, the upper part of the weight rod 109 is inserted into the limiting hole 107, the lower part of the weight rod 109 is inserted into the corresponding positioning hole 105, the counterweight 110 is fixed on the upper surface of the weight rod 109, and the weight terminal 103 is fixed on the bottom surface of the lower part of the weight rod 109.

[0058] The weight tray 104 serves as the main supporting structure of the weight component, and the weight limiting plate 106 is used to prevent the weight terminal 103 from lateral displacement or tilting, especially when the glass window 201 is tilted, thereby better ensuring the effect of eutectic welding and air tightness.

[0059] In some embodiments, the weight component further includes a limit block 113 fixed between the weight rod 109 and the weight terminal 103 , and the limit block 113 limits the upward and downward movement position and the left and right movement position of the weight terminal 103 .

[0060] In some embodiments, the stopper 113 includes a first portion and a second portion connected to each other, the size of the first portion is larger than the size of the second portion, and the size of the first portion is larger than the size of the positioning hole 105, the size of the second portion is smaller than or equal to the size of the positioning hole 105, the first portion of the stopper 113 is limited to the upper surface or above the upper surface of the weight tray 104, and the second portion of the stopper 113 is limited to the positioning hole 105. In some embodiments, the outer sides of the first portions of adjacent stopper blocks 113 corresponding to adjacent positioning holes 105 abut against each other.

[0061] In some embodiments, the top of the weight terminal 103 has a bolt, and the limiting block 113 and the lower part of the weight limiting plate 106 have threaded holes, and the bolts on the top of the weight terminal 103 are fixed in the threaded holes.

[0062] In some embodiments, the top of the upper portion of the weight rod 109 is higher than the upper surface of the weight limiting plate 106, and the counterweight block 110 is fixed to the side wall surface of the upper portion higher than the upper surface of the weight limiting plate 106. By increasing or decreasing the weight of the counterweight block 110, the magnitude of the gravity pressing down on the corresponding weight terminal 103 can be adjusted to meet the eutectic welding requirements of different products or processes.

[0063] In some embodiments, the weight tray 104 and the weight limit plate 106 are made of quartz glass, which enhances the thermal radiation permeability, reduces the heat absorption of the weight tray 104 and the weight limit plate 106, and maintains the temperature uniformity of the entire wafer-level eutectic fixture during eutectic formation, thereby further improving the effect of eutectic welding (such as improving the uniformity of eutectic welding and preventing cold solder joints).

[0064] In some embodiments, in order to prevent the weight tray 104 and the steel mesh 101 from sliding relative to each other, the weight tray 104 and the steel mesh 101 are fixed by screws.

[0065] In some embodiments, when the weight terminal 103 is placed on the upper surface of the corresponding glass window 201, the bottom surface of the weight terminal 103 contacts the upper surface of the glass window 201 at a single point or multiple points, so as to reduce the contact area between the weight terminal 103 and the glass window 201, reduce the heat absorption of the eutectic solder (or annular eutectic solder) under the glass window 201 by the weight terminal 103, and further improve the effect of eutectic welding.

[0066] In some embodiments, the material of the weight terminal 103 is a high temperature resistant plastic that can withstand temperatures up to 350° C., specifically, it can be a PEEK material to protect the upper surface of the glass window 201 from scratches.

[0067] Another embodiment of the present application further provides a wafer-level eutectic fixture. The main difference between this embodiment and the previous embodiment is that the specific structure of the weight component of this embodiment is different from the specific structure of the weight component of the previous embodiment. For details, please refer to Figure 3 The weight component only has a number of weight terminals 103, and does not have structures such as a weight tray, a weight limiting plate, a weight rod and a counterweight block. In addition to the advantages of the aforementioned embodiments, this embodiment does not have a weight tray and a weight limiting plate, thereby reducing the absorption of heat by the two, further maintaining the temperature uniformity of the entire wafer-level eutectic fixture during eutectic, thereby further improving the effect of eutectic welding, preventing the risk of cold welding, and better ensuring airtightness.

[0068] In some embodiments, when the weight terminal 103 is placed on the upper surface of the corresponding glass window 201, the bottom surface of the weight terminal 103 contacts the upper surface of the glass window 201 at a single point or multiple points, so as to reduce the contact area between the weight terminal 103 and the glass window 201, reduce the heat absorption of the eutectic solder (or annular eutectic solder) under the glass window 201 by the weight terminal 103, and further improve the effect of eutectic welding.

[0069] In some embodiments, the weight dock 103 includes a central portion and a plurality of raised portions located on the side walls around the central portion; when the weight dock 103 is placed on the upper surface of the corresponding glass window 201, the central portion and the bottom end surfaces of the raised portions are in contact with the upper surface of the glass window, and the side surfaces of the plurality of raised portions are in contact with the inner walls of the mesh 102 in the steel mesh 101, thereby preventing the weight dock 103 from slipping in the mesh 102, improving the uniformity of gravity applied by the weight dock 103, and thus improving the effect of eutectic welding (such as improving the uniformity of eutectic welding and preventing cold solder joints).

[0070] In some embodiments, the material of the weight terminal 103 is metal, such as tungsten copper, which has the advantages of fast thermal conductivity, high density, and higher weight per certain volume. The volumes and weights of the weight terminals 103 are different to meet the eutectic welding requirements of different products or processes. By adjusting the volume of the weight terminal 103, the weight of the weight terminal 103 is adjusted, and then the magnitude of the downward pressure applied is adjusted.

[0071] In some embodiments, the lower surface of the base 100 has a magnet (not shown in the figure), and the magnet is used to adsorb the steel mesh on the upper surface of the base 100.

[0072] In some embodiments, the upper surface of the base 100 further has a steel mesh position regulator (112a-112d), which is used to adjust the position of the steel mesh 101 to further improve the accuracy of the position installation of the steel mesh 101. In a specific embodiment, the number of the steel mesh position regulators is four, and the position of the steel mesh 101 is adjusted from the four corners of the steel mesh 101 respectively, and the steel mesh position regulator includes a top screw adjustment. In a specific embodiment, when the number of the steel mesh position regulators is four, the position of one of the steel mesh position regulators is fixed, and the other three steel mesh position regulators can adjust the position of the steel mesh 101 in at least one direction. In a specific embodiment, when there are four steel mesh position regulators, the position of one steel mesh position regulator 112a is fixed, and the two steel mesh position regulators 112b and 112c adjacent to the fixed steel mesh position regulator 112a can respectively adjust the position of the steel mesh 101 in the row direction and the column direction, and the last steel mesh position regulator 112d away from the fixed steel mesh position regulator 112a can adjust the position of the steel mesh 101 in the row direction and the column direction. It should be noted that the row direction and the column direction correspond to the row and column arrangement direction of the plurality of mounting areas on the wafer 200.

[0073] In some embodiments, the steel mesh position regulator adjusts the position of the steel mesh by adjusting the top screw of the bolt 115 .

[0074] Another embodiment of the present application further provides a method for forming a packaging structure using the aforementioned wafer-level eutectic fixture. The formation direction is described in detail below in conjunction with the accompanying drawings.

[0075] refer to Figure 4 and Figure 5 ,in Figure 5 for Figure 4 The schematic cross-sectional structure diagram along the cutting line AB direction shows a wafer 200 , which is fixed on the upper surface of the base 100 . The upper surface of the wafer 200 has a plurality of mounting areas 20 arranged in rows and columns.

[0076] In some embodiments, a portion of the non-mounting area of ​​the wafer 200 is fixed to the upper surface of the base 100 via a pressure spring.

[0077] refer to Figure 6 , forming a eutectic solder 111 on the surface of the mounting area 20 of the wafer 200; referring to Figure 7 and Figure 8 ,in Figure 8 for Figure 7The schematic cross-sectional structure diagram along the cutting line AB shows that a steel mesh 101 is installed on the upper surface of the base 100 , and each mesh hole 102 in the steel mesh 101 exposes a corresponding mounting area 20 on the wafer 200 .

[0078] The eutectic solder 111 is formed on the surface of each mounting area 20 of the wafer. In some embodiments, the shape of the eutectic solder 111 corresponds to the shape of the bottom end of the cover edge of the glass window to be mounted. In a specific embodiment, the shape of the eutectic solder 111 can be ring-shaped.

[0079] In some embodiments, the material of the eutectic solder 111 is AuSn eutectic solder (gold-tin eutectic solder). In a specific embodiment, the AuSn eutectic solder is Au80Sn20 eutectic solder, that is, the AuSn eutectic solder contains 80% by mass of Au and 20% by mass of Sn.

[0080] In some embodiments, when installing the steel mesh 101 , the steel mesh 101 is aligned with the wafer 200 , so that each mesh hole 102 in the steel mesh 101 corresponds to a corresponding mounting area 20 on the wafer 200 .

[0081] refer to Fig. 9 and Fig.10 ,in Fig.10 for Fig. 9 A schematic diagram of the cross-sectional structure along the cutting line AB shows that a glass light window 201 is placed in each of the mesh holes 102 .

[0082] refer to Fig.11 or Fig.12 ,in Fig.12 for Fig.11 Schematic diagram of the cross-sectional structure along the cutting line AB, a weight component is installed on the steel mesh 101, and the weight component includes a plurality of weight terminals 103, each of the weight terminals 103 is placed on the upper surface of the corresponding glass light window 201, and the weight terminals 103 apply downward gravity to the glass light window 201, and the glass light window 201 is eutectically welded to the corresponding mounting area 20 on the wafer 200 through eutectic solder.

[0083] In some embodiments, the gas atmosphere of the furnace chamber during the eutectic welding is an inert gas, and the inert gas includes helium.

[0084] In some embodiments, the pressure of the furnace chamber during the eutectic welding is normal pressure, negative pressure or positive pressure. In a specific embodiment, the normal pressure is one standard atmospheric pressure; the negative pressure is formed by evacuating the furnace chamber, the pressure of the negative pressure is less than one standard atmospheric pressure, and the minimum pressure can be -101 kpa; the positive pressure is formed by inflating the furnace chamber, the pressure of the positive pressure is greater than one standard atmospheric pressure, and the maximum pressure can reach 0.4 Mpa.

[0085] It should be noted that the terms "including" and "having" and their variations involved in this application are intended to cover non-exclusive inclusions. The terms "first", "second", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, unless the context clearly indicates otherwise. It should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the embodiments in this application and the features in the embodiments can be combined with each other unless there is a conflict. In addition, in the above description, the description of well-known components and technologies has been omitted to avoid unnecessary confusion of the concepts of this application. In the above-mentioned embodiments, each embodiment focuses on the differences from other embodiments, and the same / similar parts between the embodiments can be referred to (or referenced) with each other.

[0086] Although the present application has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present application. Any technical personnel in this field can use the methods and technical contents disclosed above to make possible changes and modifications to the technical solution of the present application without departing from the spirit and scope of the present application. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are within the protection scope of the technical solution of the present application.

Claims

1. A wafer-level eutectic fixture, characterized in that: include: A base, the upper surface of which is used to place a wafer, and the upper surface of which has a plurality of mounting areas arranged in rows and columns; A steel mesh, the steel mesh is mounted on the upper surface of the base, the steel mesh has a plurality of mesh holes, each of the mesh holes exposes a corresponding mounting area on the wafer, and each of the mesh holes is used to place eutectic solder and a glass window to be eutectically welded with the corresponding mounting area on the wafer; The weight component includes a plurality of weight terminals, each of which is placed on the upper surface of the corresponding glass window and is used to apply downward pressure when the glass window is eutectically soldered to the corresponding mounting area on the wafer through the eutectic solder.

2. The wafer-level eutectic fixture according to claim 1, characterized in that: The weight component also includes a weight tray, a weight limiting plate, a weight rod and a counterweight block, wherein the weight tray is placed on the upper surface of the steel mesh, the weight limiting plate is suspended and fixed above the weight tray by a support, the weight limiting plate has a plurality of positioning holes, the weight limiting plate has limiting holes corresponding to the positioning holes, the weight rod includes an upper part and a lower part connected to each other, the upper part of the weight rod is inserted into the limiting hole, the lower part of the weight rod is inserted into the corresponding positioning hole, the counterweight block is fixed on the upper surface of the weight rod, and the weight terminal is fixed on the bottom surface of the lower part of the weight rod.

3. The wafer-level eutectic fixture according to claim 2, characterized in that: The weight component also includes a limiting block fixed between the weight rod and the weight terminal.

4. The wafer-level eutectic fixture according to claim 3, characterized in that: The limit block includes a first part and a second part connected to each other, the size of the first part is larger than the size of the second part, and the size of the first part is larger than the size of the positioning hole, the size of the second part is smaller than or equal to the size of the positioning hole, the first part of the limit block is limited to the upper surface of the weight tray or above the upper surface, and the second part of the limit block is limited in the positioning hole.

5. The wafer-level eutectic fixture according to claim 4, characterized in that: The outer sides of the first parts of adjacent limiting blocks corresponding to adjacent positioning holes abut against each other.

6. The wafer-level eutectic fixture according to claim 2, characterized in that: The top end of the upper part of the weight rod is higher than the upper surface of the weight limiting plate, and the counterweight block is fixed on the side wall surface of the upper part which is higher than the upper surface of the weight limiting plate.

7. The wafer-level eutectic fixture according to claim 2, characterized in that: The weight tray and the weight limiting plate are made of quartz glass; the weight terminal is made of high temperature resistant plastic.

8. The wafer-level eutectic fixture according to claim 1, characterized in that: The weight member has only a few weight terminals.

9. The wafer-level eutectic fixture according to claim 2 or 8, characterized in that: When the weight terminal is placed on the upper surface of the corresponding glass window, the bottom surface of the weight terminal contacts the upper surface of the glass window at a single point or multiple points.

10. The wafer-level eutectic fixture according to claim 8, characterized in that: The weight terminal includes a central portion and a plurality of raised portions located on the side walls around the central portion; when the weight terminal is placed on the upper surface of the corresponding glass light window, the central portion and the bottom end surfaces of the raised portions contact the upper surface of the glass light window, and the side surfaces of the plurality of raised portions contact the inner walls of the mesh holes in the steel mesh.

11. The wafer-level eutectic fixture according to claim 8, characterized in that: The material of the weight dock is metal, and the volumes and weights of the weight docks are different. The weight of the weight dock is adjusted by adjusting the volume of the weight dock, thereby adjusting the size of the downward pressure applied.

12. The wafer-level eutectic fixture according to claim 2 or 8, characterized in that: The lower surface of the base is provided with a magnet, and the magnet is used for adsorbing the steel mesh on the upper surface of the base.

13. The wafer-level eutectic fixture according to claim 12, characterized in that: The upper surface of the base is also provided with a steel mesh position regulator, and the steel mesh position regulator is used to adjust the position of the steel mesh.

14. The wafer-level eutectic fixture according to claim 2 or 8, characterized in that: The wafer is fixed on the upper surface of the base by a pressure spring.

15. A method for forming a packaging structure, characterized in that: include: Providing a wafer-level eutectic fixture as described in any one of claims 1 to 14; Providing a wafer, fixing the wafer on the upper surface of the base, wherein the upper surface of the wafer has a plurality of mounting areas arranged in rows and columns; Mounting eutectic solder on the mounting area surface of the wafer; A steel mesh is installed on the upper surface of the base, wherein each mesh hole in the steel mesh exposes a corresponding mounting area on the wafer; Placing a glass light window in each of the meshes; A weight component is installed on the steel net, and the weight component includes a plurality of weight terminals, each of which is placed on the upper surface of the corresponding glass window. The weight terminals apply downward gravity to the glass window, and the glass window is eutectically welded to the corresponding mounting area on the wafer through the eutectic solder.

16. The method for forming a package structure according to claim 15, wherein: When installing the steel mesh, align the steel mesh with the wafer.

17. The method for forming a package structure according to claim 15, wherein: The material of the eutectic solder is AuSn eutectic solder.

18. The method for forming a package structure according to claim 15, wherein: The gas atmosphere of the furnace chamber during the eutectic welding is an inert gas.

19. The method for forming a package structure according to claim 18, wherein: The pressure of the furnace chamber during the eutectic welding is normal pressure, negative pressure or positive pressure.

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