Method for implanting metal connecting piece into electronic substrate based on glass screen plate

Abstract

The invention relates to a method for implanting a metal connecting piece into an electronic substrate based on a glass screen plate. The method comprises the following steps: S101, fixing the electronic substrate on a carrying table; s102, printing a conductive medium pattern on the electronic substrate to form a conductive medium pattern array; s103, a plurality of metal connecting pieces are laid on the electronic base body through a mesh array of a glass mesh plate, the metal connecting pieces make up-down contact with the conducting medium patterns in a one-to-one correspondence mode, after completion, the relative position of the glass mesh plate and the carrying table is kept unchanged, and a plurality of meshes of the mesh array correspond to a plurality of conducting medium patterns in an up-down one-to-one correspondence mode; and S104, laser is emitted to the conductive medium pattern through the glass screen plate through a laser backflow mechanism, and welding of the metal connecting piece and the conductive medium pattern is completed. The production efficiency and the process stability are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor processing, and in particular relates to a method for implanting a metal connector into an electronic matrix based on a glass mesh. Background Art

[0002] As semiconductor technology develops towards high performance and high integration, chip interconnection technology faces higher requirements - high-performance computing (such as CPU, GPU), AI chips and other fields urgently need smaller interconnection spacing (to support high-speed data transmission), lower resistance (to ensure signal and power integrity) and higher reliability (to adapt to complex working conditions). The traditional process of implanting metal connectors into electronic substrates (such as substrate / wafer ball / column) mainly relies on the assistance of metal stencils: first, a conductive medium pattern (such as solder paste dots) is printed on the electronic substrate, and then the metal connectors are laid on the surface of the electronic substrate through the mesh array of the metal stencil. The metal stencil needs to be removed and then the whole is heated in a reflow oven to complete the welding. However, this process has the following significant defects: First, the step of removing the metal stencil increases the complexity of the process and reduces production efficiency; second, the overall heating efficiency of the reflow oven is low; third, the overall heating of the reflow oven can easily cause the carrier, substrate / wafer and equipment to expand and contract inconsistently due to differences in thermal expansion and contraction coefficients, affecting the interconnection accuracy. Summary of the Invention

[0003] Based on this, in order to solve the above technical problems, a method for implanting metal connectors into an electronic substrate based on a glass mesh is provided.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for implanting a metal connector into an electronic substrate based on a glass mesh, characterized by comprising:

[0006] S101, fixing the electronic substrate on the carrier;

[0007] S102, printing a conductive medium pattern on the electronic substrate to form a conductive medium pattern array;

[0008] S103, laying a plurality of metal connectors on the electronic substrate through a mesh array of a glass mesh plate, so that the metal connectors contact the conductive medium patterns one by one, and after completion, maintaining the relative positions of the glass mesh plate and the carrier unchanged, wherein the plurality of meshes of the mesh array correspond one by one to the plurality of conductive medium patterns;

[0009] S104 , using a laser reflow mechanism to project laser light through the glass mesh toward the conductive medium pattern, thereby completing welding of the metal connector and the conductive medium pattern.

[0010] The beneficial effects of the present invention are as follows:

[0011] 1. The process steps are simplified and the production efficiency is significantly improved:

[0012] The traditional process requires an additional step of "removing the metal mesh" after laying the balls / pillars. This application keeps the relative positions of the glass mesh and the carrier unchanged after laying the metal connectors on the electronic substrate, that is, the glass mesh is not removed, thus eliminating the mesh removal step and directly entering the laser reflow process, greatly improving production efficiency.

[0013] 2. Laser heating is highly efficient and shortens process time:

[0014] Compared with the reflow oven heating method, the laser energy is concentrated and the heating speed is fast. With the synergistic effect of eliminating the stencil removal process, the process efficiency is doubled.

[0015] 3. The impact of thermal stress is minimized and process stability is improved:

[0016] Laser reflow heating is used to replace the overall heating of traditional reflow ovens, and only localized heating of the conductive medium pattern is precisely performed. This avoids the problem of inconsistent thermal expansion and contraction caused by the overall heating of the carrier, substrate / wafer and equipment, effectively reduces the risk of interconnect position offset, and improves the accuracy of ball / pillar planting. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a method for implanting a metal connector into an electronic substrate based on a glass mesh provided in an embodiment of the present application;

[0018] Figure 2 (a) is a schematic diagram of S101 of an embodiment of the present application, (b) is a schematic diagram of S102 of an embodiment of the present application, (c) is a schematic diagram of S103 of an embodiment of the present application, and (d) is a schematic diagram of S104 of an embodiment of the present application;

[0019] Figure 3 This is a structural diagram of the glass mesh panel according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] The following will illustrate the implementation of the present invention in conjunction with the drawings in the specification. It should be noted that the implementation methods involved in this specification are not exhaustive and do not represent the only implementation methods of the present invention. The following corresponding embodiments are only for the purpose of clearly illustrating the invention content of the patent of this invention and are not intended to limit its implementation methods. For ordinary technicians in this field, different forms of changes and modifications can be made based on the description of this embodiment. Any obvious changes or modifications that belong to the technical concept and invention content of the present invention are also within the scope of protection of the present invention.

[0021] like Figure 1As shown, the embodiment of the present application provides a method for implanting a metal connector into an electronic substrate based on a glass mesh, comprising:

[0022] S101、 Figure 2 As shown in (a), the electronic substrate 1 is fixed on the stage 2.

[0023] The electronic substrate 1 refers to a substrate or a wafer.

[0024] In this embodiment, the carrier 2 is a vacuum table having a plurality of vacuum air holes 21 thereon, and the upper surface has a positioning structure for positioning the electronic substrate, such as a positioning pin or a positioning groove. After the electronic substrate 1 is positioned on the carrier 2, the electronic substrate 1 is fixed on the carrier 2 by vacuum adsorption.

[0025] S102, such as Figure 2 As shown in (b), a conductive medium pattern 4 is printed on the electronic substrate 1 by a printing mechanism 3 to form a conductive medium pattern array.

[0026] Specifically, the conductive medium is flux, solder paste, copper paste or silver paste, etc. Taking solder paste as an example, the conductive medium pattern can be solder paste dots, and the conductive medium pattern array is generally a matrix array.

[0027] Among them, the printing method can be steel screen printing, dispensing or piezoelectric inkjet printing, etc. It can be understood that different printing methods need to be implemented using corresponding printing mechanisms. During specific implementation, the corresponding printing method is selected according to the different conductive media.

[0028] Taking stencil printing as an example, the carrier 2 needs to be moved under the stencil so that the pads on the electronic substrate 1 correspond one to one with the mesh holes of the stencil, thereby printing the conductive medium pattern one to one on the pads.

[0029] S103, such as Figure 2 As shown in FIG. 5 , multiple metal connectors are laid on the electronic substrate 1 through the mesh array of the glass mesh 5 so that the metal connectors are in contact with the conductive medium pattern 4 one by one. After completion, the relative positions of the glass mesh 5 and the carrier 2 remain unchanged. The specific process is as follows:

[0030] S31 , moving the carrier 2 carrying the electronic substrate 1 printed with the conductive medium pattern array to below the glass screen 5 .

[0031] S32 , a feeding mechanism pours a plurality of metal connectors onto the glass mesh plate 5 , wherein the number of the metal connectors is greater than the number of meshes on the glass mesh plate 5 .

[0032] S33, sweep the metal connector 6 into the mesh with a brush so that it contacts the corresponding conductive medium pattern 4 from top to bottom. Figure 2 (d).

[0033] S34. Remove the remaining excess metal connectors from the glass mesh.

[0034] The meshes of the mesh array correspond to the conductive medium patterns one by one. The metal connector is a metal ball 61 or a metal column 62, such as a tin ball or a copper column.

[0035] It should be pointed out that when the metal connector is a metal column, after it contacts the conductive medium pattern from top to bottom, it is supported by the mesh of the glass mesh to prevent tilting.

[0036] S104, such as Figure 2 As shown in (d), the laser reflow mechanism 7 is used to irradiate the laser through the glass mesh 5 to the conductive medium pattern 4, thereby completing the welding between the metal connector and the conductive medium pattern 4.

[0037] Among them, Figure 3 As described, the glass mesh plate 5 includes a rectangular glass plate 51 and an outer frame 52. The above-mentioned mesh array is formed on the glass plate 51, and quartz glass can be used. The outer frame 52 is rectangular and concentrically located on the outside of the glass plate 51. The two are connected by an elastic bandage 53. During operation, the rigidity of the glass plate 51 can be released to prevent it from breaking. The elastic bandage 53 is made of elastic fiber material, which is bonded and fixed to the glass plate 51 and the outer frame 52. The glue used for bonding and fixing can be epoxy resin glue or special adhesive (such as 3M glue).

[0038] The beneficial effects of the method for implanting a metal connector into an electronic substrate based on a glass mesh provided in the embodiment of the present application are as follows:

[0039] 1. The process steps are simplified and the production efficiency is significantly improved:

[0040] The traditional process requires an additional step of "removing the metal mesh" after laying the balls / pillars. This application keeps the relative positions of the glass mesh and the carrier unchanged after laying the metal connectors on the electronic substrate, that is, the glass mesh is not removed, thus eliminating the mesh removal step and directly entering the laser reflow process, greatly improving production efficiency.

[0041] 2. Laser heating is highly efficient and shortens process time:

[0042] Compared with the reflow oven heating method, the laser energy is concentrated and the heating speed is fast. With the synergistic effect of eliminating the stencil removal process, the process efficiency is doubled.

[0043] 3. The impact of thermal stress is minimized and process stability is improved:

[0044] Laser reflow heating is used to replace the overall heating of traditional reflow ovens, and only localized heating of the conductive medium pattern is precisely performed. This avoids the problem of inconsistent thermal expansion and contraction caused by the overall heating of the carrier, substrate / wafer and equipment, effectively reduces the risk of interconnect position offset, and improves the accuracy of ball / pillar planting.

[0045] In addition, for the column planting process, during the laser reflow process, the glass mesh supports the column to prevent tilting and ensure the accuracy of column planting.

[0046] Obviously, those skilled in the art should realize that the above embodiments are only used to illustrate the present invention and are not used to limit the present invention. As long as they are within the scope of the spirit of the present invention, any changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for implanting a metal connector into an electronic substrate based on a glass mesh, characterized in that: include: S101, fixing the electronic substrate on the carrier; S102, printing a conductive medium pattern on the electronic substrate to form a conductive medium pattern array; S103, laying a plurality of metal connectors on the electronic substrate through a mesh array of a glass mesh plate, so that the metal connectors contact the conductive medium patterns one by one, and after completion, maintaining the relative positions of the glass mesh plate and the carrier unchanged, wherein the plurality of meshes of the mesh array correspond one by one to the plurality of conductive medium patterns; S104 , using a laser reflow mechanism to project laser light through the glass mesh toward the conductive medium pattern, thereby completing welding of the metal connector and the conductive medium pattern.

2. The method for implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: The carrier is a vacuum stage, and S101 further includes: The electronic matrix is ​​fixed on the carrier by vacuum adsorption.

3. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 2, characterized in that: The upper surface of the vacuum table has a positioning structure for positioning the electronic substrate.

4. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: The electronic matrix is ​​a substrate or a wafer, and the conductive medium is flux, solder paste, copper paste or silver paste.

5. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 4, characterized in that: The printing is performed by steel screen printing, dispensing or piezoelectric inkjet printing.

6. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: The metal connecting piece is a metal ball or a metal column.

7. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: When the metal connecting piece is a metal column, it is supported by the mesh of the glass mesh after it contacts the conductive medium pattern from top to bottom.

8. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: The S103 further includes: Moving the carrier with the electronic substrate printed with the conductive medium pattern array to below the glass stencil; A feeding mechanism pours a plurality of metal connectors onto the glass mesh plate, wherein the number of the metal connectors is greater than the number of meshes on the glass mesh plate; Use a brush to sweep the metal connector into the mesh and make contact with the corresponding conductive medium pattern; removing excess metal connectors from the glass mesh; After completion, the relative positions of the glass screen and the carrier are kept unchanged.

9. The method of implanting a metal connector into an electronic substrate based on a glass mesh according to claim 1, characterized in that: The glass mesh plate comprises a rectangular glass plate and an outer frame. The mesh array is formed on the glass plate. The outer frame is concentrically located on the outside of the glass plate, and the two are connected by an elastic bandage.

10. The method for implanting a metal connector into an electronic substrate based on a glass mesh according to claim 9, characterized in that: The elastic bandage is bonded and fixed to the glass plate and the outer frame.

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