A method for manufacturing a glass adapter plate that improves the reliability of electrical interconnections

Abstract

The application discloses a preparation method of a glass adapter plate capable of improving electrical interconnection reliability, and belongs to the field of semiconductor packaging manufacturing. S1, picosecond laser drilling is performed at a through hole position of a glass substrate to form a laser through hole; the front surface of the glass substrate is marked as an A surface, the back surface is marked as a B surface, the picosecond laser enters from the A surface, and the aperture of the laser through hole on the A surface is 0.3-0.6 of a target aperture; S2, the glass substrate is etched in an etching solution, and the glass substrate is taken out when the aperture on the A surface is etched to the target aperture; S4, bottom metal is formed on the A surface, the B surface and the hole wall of the laser through hole of the glass substrate through magnetron sputtering; S5, photoresist is spin-coated, dried, exposed, developed and electroplated with metal to form a metal patterned glass substrate; S6, dry etching is performed to remove the bottom metal on the metal patterned glass substrate which is not covered by the electroplated metal, and a glass adapter plate with high electrical interconnection reliability is obtained. The application improves the electrical interconnection reliability of the glass adapter plate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging manufacturing, and more specifically, to a method for preparing a glass adapter plate that can improve the reliability of electrical interconnects. Background Technology

[0002] Glass adapters are a key technology for breaking through the bottleneck of chip computing power. Glass adapters utilize glass vias and redistribution layers to build a high-density electrical interconnection "bridge" between the chip and the substrate. Compared with traditional silicon adapters, the superior dielectric properties of glass adapters ensure the integrity of high-frequency signals, and the adjustable expansion coefficient can effectively suppress warping. They are the core carrier for realizing 2.5D / 3D advanced packaging and meeting the computing power requirements of AI.

[0003] Although laser drilling is fast in glass transition plate manufacturing, the holes formed are prone to burrs, cracks, and rough sidewalls, which affect the quality of subsequent metallization filling, thereby reducing the stability of high-frequency signal transmission and causing a decrease in structural strength. Therefore, the existing through-hole manufacturing process adopts the method of laser scanning + wet etching. The specific process is as follows: laser scanning is used to form ablation points at the through-hole positions on the front and back of the glass substrate. Then, the glass substrate is placed in an etching solution (such as HF acid). Since the etching rate at the ablation point is extremely high (higher than the etching rate at other parts of the glass substrate), etching is performed on the glass substrate with the ablation point as the center. When the diameter of the hole formed by the etching on the front (or back) of the glass substrate reaches the designed through-hole diameter, the glass substrate is removed from the etching solution, and the through-hole manufacturing process is completed.

[0004] Existing through-hole manufacturing processes have the following defects: the formed through-holes are incomplete in shape, and the corrosion of through-holes varies in size, which affects the quality of subsequent metallization filling, reduces the stability of high-frequency signal transmission, and leads to a decrease in structural strength. More seriously, for thicker glass substrates (e.g., thickness > 0.5 mm), blind holes are also prone to occur, which can cause voids or thin plating layers at the bottom of the holes due to electroplating solution residue or trapped air bubbles during subsequent metallization, resulting in product scrap. (If the product is not detected during product testing and is used to carry the chip, when the chip heats up, the residue in the hole will expand due to heat and generate stress, which may cause local signal open circuits or even glass shattering, ultimately causing the entire packaged device to fail.) Summary of the Invention

[0005] To address the above problems, this invention provides a method for preparing a glass adapter plate that improves the reliability of electrical interconnection, thereby enhancing the electrical interconnection reliability of the glass adapter plate.

[0006] A method for preparing a glass adapter plate that can improve the reliability of electrical interconnection includes the following steps: S1. Picosecond laser drilling is performed at the through-hole position of the glass substrate to form a laser through-hole. The front side of the glass substrate is denoted as surface A and the back side is denoted as surface B. The picosecond laser enters from surface A. The diameter of the laser through-hole on surface A is 0.3~0.6 times the target diameter. The target diameter is 200μm~300μm. The laser drilling parameters are: cutting head 20W~50W, frequency 700Hz~1200Hz, speed 1200mm / s~1500mm / s, ultraviolet wavelength 355nm. S2, the glass substrate is etched in the etching solution. When the aperture of the A side is etched to the target aperture, the glass substrate is removed. S3, both sides A and B are polished; S4, a base metal is formed on the A and B sides of the glass substrate and the wall of the laser-through hole by magnetron sputtering; S5, spin-coating photoresist, drying, exposure, development, and electroplating metal to form a metal patterned glass substrate; S6, dry etching, removes the base gold not covered by electroplated metal on the patterned glass substrate to obtain a glass adapter board with high electrical interconnect reliability.

[0007] Optionally, in S1, after forming the laser-through hole, plasma cleaning is used to remove residual glass debris, microcracks, and slag within the laser-through hole of the glass substrate.

[0008] Optionally, in S2, after the glass substrate is removed, the residual etching solution on the glass substrate is removed.

[0009] Optionally, in S2, the residual etching solution on the glass substrate is removed by sequentially cleaning with deionized water, neutralizing, ultrasonic cleaning, and rinsing with deionized water; after removing the residual etching solution on the glass substrate, the glass substrate is dried.

[0010] Optionally, in S2, the glass substrate is vertically positioned in the etching solution during etching.

[0011] Optionally, in S1, the thickness of the glass substrate is >0.5mm.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention improves the roundness of holes in thick glass substrates (roundness above 90%) by first controlling the diameter of the laser-entered vias within a specific range of the target diameter, and then wet etching to the target diameter, ensuring a 100% through-hole rate and improving the electrical interconnect reliability of glass adapter boards.

[0013] The present invention also controls the microcracks in laser drilling by using the parameters of the laser drilling of the skin laser. When the diameter of the laser through hole on surface A is a target diameter of a specific ratio (target diameter is 200μm~300μm), no microcracks are seen under a 30X microscope, so that the diameter of surface A and surface B are basically the same after S2.

[0014] This invention also improves the characteristics of the hole by double-sided polishing after etching, eliminates the adverse effects of the oxide layer caused by the laser thermal effect around the hole, and improves the subsequent lifespan of the product. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a 100X image of the laser-cut through-hole in the product photograph of Embodiment 3 of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0019] In the following embodiments and comparative examples, the glass substrate size is 510mm×515mm×0.6mm, and the target aperture is 0.3mm.

[0020] Example 1 A method for preparing a glass adapter plate that can improve the reliability of electrical interconnection includes the following steps: S1, Picosecond laser is used to drill holes in the vias of the glass substrate to form laser vias, and then plasma cleaning is used to remove the glass debris and slag remaining in the laser vias of the glass substrate.

[0021] During drilling, the picosecond laser enters from the front side of the glass substrate, which is designated as side A and the back side as side B. After laser drilling, the diameter of the laser-drilled hole on side A is 0.5 times the target hole diameter.

[0022] The parameters for laser drilling are: 30W cutting head, 1000 Hz frequency, 1400 mm / s speed, and 355 nm ultraviolet wavelength.

[0023] S2, the glass substrate is placed in the etching solution for chemical etching. When the aperture of the A side is etched to the target aperture, the glass substrate is removed and the residual etching solution on the glass substrate is removed.

[0024] The corrosive solution was HF acid purchased from the market.

[0025] During chemical etching, the glass substrate is placed vertically.

[0026] During the process of removing residual etching solution from the glass substrate, the process involves sequential immersion in a deionized water bath for cleaning, neutralization, ultrasonic cleaning, rinsing with deionized water, and drying.

[0027] S4 uses magnetron sputtering to form a base gold layer on the A-side, B-side, and the walls of the laser-through holes of the glass substrate.

[0028] The magnetron sputtering coating machine was set to a sputtering power of 500W, an argon flow rate of 1600sccm, and a base gold sputtering sequence of Ti, Pt, Au, with a target thickness of 2000 angstroms per film layer.

[0029] S5 involves spin-coating photoresist, drying, exposure, development, and electroplating metal to form a patterned metal glass substrate.

[0030] S6, dry etching, removes the base gold not covered by electroplated metal on the patterned glass substrate to obtain a glass adapter board with high electrical interconnect reliability.

[0031] Dry etching is performed in a plasma etching machine, where the base gold that is not covered by electroplated metal is etched away.

[0032] Example 2 The difference compared to Example 1 is as follows: In this embodiment, in S1, the diameter of the laser-guided hole on surface A is 0.6 times the target diameter.

[0033] Example 3 The difference compared to Example 1 is as follows: After S2 and before S4, it also includes S3, double-sided polishing, to remove unevenness and increased roughness caused by etching.

[0034] The 100X image of the laser-guided hole in the product photograph of this embodiment is shown below. Figure 1 .

[0035] Comparative Example 1 The difference compared to Example 1 is as follows: In this comparative example, in S1, the diameter of the laser-guided hole on surface A is 0.9 times the target diameter.

[0036] Comparative Example 2 The difference compared to Example 1 is as follows: In this comparative example, in S1, the laser drilling forms a laser blind hole (non-through hole, not drilled).

[0037] In this comparative example, the aperture of the laser blind hole on surface A is also 0.5 times the target aperture.

[0038] Comparative Example 3 The difference compared to Example 1 is as follows: In this comparative example, S1 is: using a laser to scan the A side and the corresponding B side at the through-hole position of the glass substrate to form ablation points, and then plasma cleaning to remove the residual glass debris and slag on the glass substrate.

[0039] The laser scanning parameters are: 30W cutting head, 1000 Hz frequency, 1000 mm / s speed, and 2 to 3 scans.

[0040] Comparative Example 4 The difference compared to Example 1 is as follows: In this comparative example, in S1, the diameter of the laser-drilled through-hole on surface A is the target diameter; in S2, chemical etching stops when the hole wall is smooth, that is, it only eliminates defects such as burrs, cracks and rough sidewalls caused by laser drilling.

[0041] Comparative Example 5 Compared to Comparative Example 4, the difference is: In this comparative example, after S1, S2 is skipped and the process proceeds directly to S4.

[0042] Before S3, the roundness and porosity of Examples 1-3 and Comparative Examples 1-5 were tested respectively, and the results are shown in Table 1 below.

[0043] Table 1 Roundness, Porosity and Appearance As shown in Table 1, Examples 1, 2, and 3, compared to Comparative Examples 1 to 5, improved the roundness of the holes, the permeability, and the oxide layer around the holes, thereby reducing signal loss caused by roundness, open circuit problems caused by permeability, and open circuit problems caused by metal adhesion caused by the oxide layer around the holes during application, thus improving the reliability of electrical interconnection. Examples 1, 2, and 3, compared to Comparative Examples 1 to 5, reduced microcracks and edge chipping, thereby reducing the fragmentation problem caused by the reduction of mechanical stress caused by microcracks and edge chipping, which is due to the stress of the film system and the thermal stress of the material itself.

[0044] The electrical interconnection reliability of the glass adapter boards in Examples 1-3 and Comparative Examples 1-5 was tested respectively, and the results are shown in Table 2 below.

[0045] Table 2 Electrical Interconnection Reliability As shown in Table 2, Examples 1, 2, and 3, compared to Comparative Examples 1 to 5, improved the roundness of the holes, the permeability, and the oxide layer around the holes, thereby improving the signal loss caused by roundness, the open circuit problem caused by permeability, and the open circuit problem caused by metal adhesion caused by the oxide layer around the holes during application, thus improving the reliability of electrical interconnection. Examples 1, 2, and 3, compared to Comparative Examples 1 to 5, reduced microcracks and edge chipping, thereby reducing the fragmentation problem caused by the reduction of mechanical stress caused by microcracks and edge chipping, which is due to the stress of the film system and the thermal stress of the material itself.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a glass adapter plate that can improve the reliability of electrical interconnection, characterized in that, Includes the following steps: S1. Picosecond laser drilling is performed at the through-hole position of the glass substrate to form a laser through-hole. The front side of the glass substrate is denoted as surface A and the back side is denoted as surface B. The picosecond laser enters from surface A. The diameter of the laser through-hole on surface A is 0.3~0.6 times the target diameter. The target diameter is 200μm~300μm. The laser drilling parameters are: cutting head 20W~50W, frequency 700Hz~1200Hz, speed 1200mm / s~1500mm / s. S2, the glass substrate is etched in the etching solution. When the aperture of the A side is etched to the target aperture, the glass substrate is removed. S3, both sides A and B are polished; S4, a base metal is formed on the A and B sides of the glass substrate and the wall of the laser-through hole by magnetron sputtering; S5, spin-coating photoresist, drying, exposure, development, and electroplating metal to form a metal patterned glass substrate; S6, dry etching, removes the base gold not covered by electroplated metal on the patterned glass substrate to obtain a glass adapter board with high electrical interconnect reliability.

2. The method for preparing the glass adapter plate that improves electrical interconnect reliability according to claim 1, characterized in that, In S1, after the laser-guided hole is formed, plasma cleaning is used to remove residual glass debris, microcracks, and slag inside the laser-guided hole of the glass substrate.

3. The method for preparing the glass adapter plate that improves electrical interconnect reliability according to claim 1, characterized in that, In step S2, after the glass substrate is removed, the residual etching solution on the glass substrate is removed.

4. The method for preparing the glass adapter plate that improves electrical interconnect reliability according to claim 2, characterized in that, In step S2, the residual etching solution on the glass substrate is removed by sequentially cleaning with deionized water, neutralizing, ultrasonic cleaning, and rinsing with deionized water; after removing the residual etching solution on the glass substrate, the glass substrate is dried.

5. The method for preparing the glass adapter plate that improves electrical interconnect reliability according to claim 2, characterized in that, In S2, the glass substrate is vertically positioned in the etching solution during etching.

6. The method for preparing the glass transition plate that improves electrical interconnect reliability according to any one of claims 1-5, characterized in that, In S1, the thickness of the glass substrate is >0.5mm.

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