CN212303631U

CN212303631U - Bonding structure for reducing bubble formation in temporary bonding process

Info

Publication number: CN212303631U
Application number: CN202022203803.0U
Authority: CN
Inventors: 潘远杰; 周祖源; 薛兴涛
Original assignee: SJ Semiconductor Jiangyin Corp
Current assignee: SJ Semiconductor Jiangyin Corp
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2021-01-05
Anticipated expiration: 2030-09-30

Abstract

The utility model provides a reduce bonding structure that interim bonding process bubble formed, the structure includes at least: the bonding pad structure comprises a substrate, a TSV deep hole filled with metal and positioned in the substrate, a rewiring dielectric layer positioned on the surface of the substrate and a metal electrode positioned on the rewiring dielectric layer, wherein the surface of the rewiring dielectric layer is subjected to plasma treatment to form a coarsening structure; the adhesive layer is formed on the rewiring dielectric layer; the substrate is attached to the glue layer. By adding the plasma treatment process, the surface of the rewiring dielectric layer is roughened, so that the rewiring dielectric layer has good hydrophilicity, the fluidity of the temporary bonding adhesive is facilitated, the temporary bonding adhesive is in close contact with the rewiring dielectric layer, bubbles generated in the subsequent high-temperature CVD process are reduced, the risk of edge breakage is reduced, the yield of products can be improved, and the yield can be increased.

Description

Bonding structure for reducing bubble formation in temporary bonding process

Technical Field

The utility model belongs to advanced encapsulation field especially relates to a reduce bonding structure of interim bonding process bubble formation.

Background

With the rapid development of integrated circuit technology and the continuous improvement of chip performance, people also put higher and higher demands on the corresponding packaging technology. Since 2010, the emergence of intermediate packaging technologies such as Wafer Level Packaging (WLP), Through Silicon Vias (TSV), 2.5D interposer, 3DIC, fan-out, etc., has greatly improved the level of advanced packaging technologies. Currently, with the slow down of moore's law, the packaging technology has become an important means for miniaturization, multifunction, power consumption reduction and bandwidth improvement of electronic products. Advanced packaging technologies are moving towards system integration, high speed, high frequency and 3D.

In a 2.5D interposer processing platform, the glass substrate and the thinned silicon wafer need to be bonded together. However, during this bonding process, bubbles will appear in the subsequent high temperature CVD. Bubbles can damage the precision of the Chemical Mechanical Polishing (CMP) process. The stability of the process is affected and the yield of the product is reduced. Therefore, reducing the bubbles generated during the subsequent high temperature CVD process of temporary bonding is a technical difficulty faced by the field and is also a key to improve the competitiveness of the quality of the packaged product.

SUMMERY OF THE UTILITY MODEL

In the 2.5D interposer packaging technology, the substrate and the thinned silicon wafer need to be temporarily bonded together, but in the subsequent high-temperature CVD process, bubbles are easily generated at the bonding interface, which affects the accuracy of the subsequent CMP process and reduces the process stability and the product yield.

In view of the above-mentioned shortcomings of the prior art, the present invention provides a bonding method for reducing the formation of bubbles in the temporary bonding process, which is used to solve the problem of bubbles generated in the temporary bonding process in the prior art.

To achieve the above and other related objects, the present invention provides a bonding method for reducing bubble formation during temporary bonding, comprising the steps of: 1) providing a pad structure, wherein the pad structure comprises a substrate, a TSV deep hole filled with metal in the substrate, a rewiring dielectric layer on the surface of the substrate, and a metal electrode on the rewiring dielectric layer; 2) cutting off the corners of the substrate; 3) processing the rewiring medium layer by adopting plasma to enable the surface of the rewiring medium layer to have a coarsening structure, so that the hydrophilicity of the rewiring medium layer is improved; 4) and providing a substrate, and bonding the pad structure and the substrate by using an adhesive layer.

Optionally, the redistribution dielectric layer is made of one or a combination of two or more of PI, epoxy resin, silica gel, BPO, BCB, silicon oxide, phosphosilicate glass, and fluorine-containing glass.

Optionally, the metal filling comprises one of copper, gold and silver filling; the metal electrode is a copper-nickel-gold three-layer metal electrode.

Optionally, the method of cutting off the substrate corner comprises one of blade cutting and grinding wheel cutting.

Optionally, the plasma comprises exciting O with a magnetic field₂The obtained plasma has magnetic field power in the range of 400-2000W, and O₂The flow rate ranges from 400 to 1600sccm, the gas pressure ranges from 400 to 1600mtorr, and the processing time ranges from 20 to 120 seconds.

Optionally, the adhesive layer includes one of PI adhesive, PVB adhesive, and EVA adhesive, the bonding method includes one of compression molding, transfer molding, liquid sealing, plastic sealing, and vacuum lamination, and the substrate includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate.

The utility model also provides a bonded structure, the structure includes at least: the bonding pad structure comprises a substrate, a TSV deep hole filled with metal and positioned in the substrate, a rewiring dielectric layer positioned on the surface of the substrate and a metal electrode positioned on the rewiring dielectric layer, wherein the surface of the rewiring dielectric layer is subjected to plasma treatment to form a coarsening structure; the adhesive layer is formed on the rewiring dielectric layer; the substrate is attached to the glue layer.

Optionally, the substrate is a cut-away substrate.

Optionally, the metal filling comprises one of copper, gold and silver filling; the metal electrode is a copper-nickel-gold three-layer metal electrode, and the rewiring dielectric layer is made of one of PI, epoxy resin, silica gel, BPO, BCB, silicon oxide, phosphorosilicate glass and fluorine-containing glass.

Optionally, the adhesive layer includes one of PI adhesive, PVB adhesive, and EVA adhesive, and the substrate includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate.

As described above, the utility model provides a reduce bonding method and bonding structure that interim bonding process bubble formed has following beneficial effect: the utility model discloses an add plasma processing technology for the surface of rewiring dielectric layer becomes coarse, makes it have good hydrophilicity, thereby is favorable to the mobility of temporary bonding adhesive, realizes that temporary bonding glues and rewiring dielectric layer's in close contact with, reduces the production of bubble, thereby reduces the cracked risk in edge, can improve the output of product and can increase the productivity.

Drawings

Fig. 1 is a flow chart of a bonding method for reducing bubble formation during temporary bonding according to the present invention.

Fig. 2-5 show the utility model discloses a reduce bonding method schematic diagram of interim bonding process bubble formation, wherein, fig. 5 shows that the utility model discloses a bonding structure schematic diagram.

Description of the element reference numerals

100U type welding disk

101 silicon wafer

102 TSV deep hole

103 rewiring dielectric layer

104 copper layer

105 nickel layer

106 gold layer

200 cutter

300 plasma

400 glue layer

500 base plate

S1-S4

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structure are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.

For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.

Referring to fig. 1 to 5, it should be noted that the drawings provided in the present embodiment are only schematic illustrations for explaining the basic concept of the present invention, and only the components related to the present invention are shown in the drawings rather than being drawn according to the number, shape and size of the components in actual implementation, and the form, number and ratio of the components in actual implementation may be changed at will, and the layout of the components may be more complicated.

In order to realize high-density packaging, in the 2.5D adapter plate packaging scheme, the substrate and the thinned silicon wafer are temporarily bonded together through an adhesive layer, but bubbles are easily generated on a bonding interface in the subsequent high-temperature CVD process, so that the precision of the subsequent chemical mechanical polishing process is influenced. As shown in fig. 1, the present invention provides a bonding method for reducing bubble formation in a temporary bonding process, comprising the steps of: 1) providing a U-shaped bonding pad; 2) cutting off the edge corner of the substrate; 3) removing the basement membrane by acting plasma on the dielectric layer; 4) and temporarily bonding the U-shaped welding disk and the substrate by using the glue layer.

As shown in fig. 2, step 1) S1 is performed first, providing a pad structure, for example, providing a U-shaped pad 100, where the U-shaped pad 100 includes a silicon wafer 101, the silicon wafer 101 is thinned to a target thickness by a grinding or etching process, a metal-filled TSV deep hole 102 on the silicon wafer 101, a redistribution dielectric layer 103 on the surface of the silicon wafer, and a metal electrode on the redistribution dielectric layer 103; the rewiring dielectric layer can be made of one or a combination of more than two of PI, epoxy resin, silica gel, BPO, BCB, silicon oxide, phosphorosilicate glass and fluorine-containing glass. The metal filling of the TSV deep hole comprises one of copper filling, gold filling and silver filling. The metal electrode is a three-layer metal electrode comprising a copper layer 104, a nickel layer 105 and a gold layer 106, and the manufacturing method of the metal electrode can be one or a combination of a sputtering method, an electroless plating method and an electroplating method.

As shown in fig. 3, step 2) S2 is performed, and the blade 200 is used to cut off the corners of the silicon wafer 101 to reduce the possible offset of the subsequent temporary bonding process, and the grinding wheel may be used to cut off the corners of the silicon wafer 101.

As shown in FIG. 4, step 3) S3 is then performed to excite O with a magnetic field₂The plasma 300 is obtained by performing plasma treatment on the redistribution layer to make the surface of the redistribution layer have a roughened structure, so as to improve the hydrophilicity of the redistribution layer₂The magnetic field power of the obtained plasma can be between 400 and 2000W, and O₂The flow rate can be 400-1600 sccmThe air pressure can be 400-1600 mtorr, and the processing time can be 20-120 seconds. In one particular implementation, O is excited₂The magnetic field power of the obtained plasma can be 1000W, O₂The flow rate may be 800sccm, the gas pressure may be 800mtorr, and the processing time may be 60 seconds.

As shown in fig. 5, step 4) S4 is performed next, a substrate 500 is provided, the U-shaped bonding pad 100 is temporarily bonded to the substrate 500 by using a glue layer 400, the glue layer 400 may be one of PI glue, PVB glue and EVA glue, the initial form of the glue layer is liquid, and may be formed on the rewiring dielectric layer through a coating process or a dispensing process. Next, the glass substrate is contacted with the glue layer and the glue layer is cured, so that the U-shaped bonding pad 100 and the substrate 500 are temporarily bonded. The temporary bonding method comprises one of compression molding, transfer molding, liquid seal molding, plastic package process and vacuum lamination process. The substrate 500 includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate.

As shown in fig. 5, this embodiment further provides a bonding structure, where the bonding structure at least includes: a U-shaped pad 100, a glue layer 300 and a substrate 400.

The U-shaped welding disk 100 comprises a silicon chip 101, a TSV deep hole 102 filled with metal on the silicon chip, a rewiring dielectric layer 103 on the surface of the silicon chip and a metal electrode on the rewiring dielectric layer 103; the surface of the rewiring dielectric layer 103 is roughened by plasma treatment, so that the hydrophilicity of the rewiring dielectric layer is improved. For example, the silicon wafer 101 may be a silicon wafer with corners cut off. The metal filling comprises one of copper, gold and silver filling; the metal electrode is a copper-nickel-gold three-layer metal electrode, and the rewiring dielectric layer is made of one of PI, epoxy resin, silica gel, BPO, BCB, silicon oxide, phosphorosilicate glass and fluorine-containing glass.

The glue layer 400 is formed on the redistribution layer. The glue layer comprises one of PI glue, PVB glue and EVA glue.

The substrate 400 is attached to the glue layer. The substrate includes one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate, and a ceramic substrate.

To sum up, the utility model discloses an it removes basement membrane technology to add plasma, and the surface of rewiring dielectric layer becomes coarse, makes it have good hydrophilicity to be favorable to interim bonding adhesive mobility, realize the in close contact with of interim bonding glue and rewiring dielectric layer, reduce the production of bubble, thereby reduce the cracked risk in edge, can improve the output of product, and can increase the yield. Therefore, the utility model effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A bonding structure characterized by: the structure at least comprises:

the bonding pad structure comprises a substrate, a TSV deep hole filled with metal and positioned in the substrate, a rewiring dielectric layer positioned on the surface of the substrate and a metal electrode positioned on the rewiring dielectric layer, wherein the surface of the rewiring dielectric layer is subjected to plasma treatment to form a coarsening structure;

the adhesive layer is formed on the rewiring dielectric layer;

the substrate is attached to the glue layer.

2. The bonding structure of claim 1, wherein: the substrate is a substrate with cut corners.

3. The bonding structure of claim 1, wherein: the metal filling comprises one of copper, gold and silver filling; the metal electrode is a copper-nickel-gold three-layer metal electrode, and the rewiring dielectric layer is made of one of PI, epoxy resin, silica gel, BPO, BCB, silicon oxide, phosphorosilicate glass and fluorine-containing glass.

4. The bonding structure of claim 1, wherein: the glue film comprises PI glue, PVB glue and EVA glue, and the substrate comprises one of a glass substrate, a metal substrate, a semiconductor substrate, a polymer substrate and a ceramic substrate.