TW201721656A - Bump structure and manufacturing method thereof - Google Patents

Abstract

A bump structure including a bump body and a plurality of micro-particle fillers is provided. The micro-particle fillers are distributed in the bump body, wherein diameters of the micro-particle fillers are between 0.05 micrometer and 1 micrometer, and the ratio of the micro-particle fillers distributed in the bump body is between 25% and 50%. A manufacturing method of the bump structure including the following steps is also provided. A plurality of micro-particle fillers are doped into a plating solution. A bump body is formed on a workpiece through the plating solution, and the micro-particle fillers are mixed into the bump body, wherein diameters of the micro-particle fillers are between 0.05 micrometer and 1 micrometer, and the ratio of the micro-particle fillers distributed in the bump body is between 25% and 50%.

Description

Bump structure and manufacturing method thereof

The present invention relates to a bump structure and a method of fabricating the same.

In recent years, as the demand for electronic products has become more highly functional, the signal transmission has increased in speed, and the circuit components have become denser, the technology of the semiconductor-related industry has also evolved. Generally, after completing the fabrication of the integrated circuit, the semiconductor wafer needs to electrically connect the external contacts of the integrated circuit and other components (such as the substrate and the printed circuit board) through the conductive structures (such as bumps and wires). ), in order to transmit electrical signals.

Taking the plating bump structure as an example, its application is common in chip on film (COF) or chip on glass (COG). Generally, the bump structure is directly formed on the surface of the semiconductor wafer by an electroplating process, and then after the semiconductor wafer is separated into a single wafer, the wafer is electrically connected to the flexible substrate by a bump structure formed on the wafer. (ie, a film substrate) or a conductive pattern on a glass substrate (eg, a pin or a conductive contact). The bump structure and the conductive pattern may form a bond by direct pressing, or may be electrically connected by using a conductive paste (for example, an anisotropic conductive paste). When the hardness of the bump structure is insufficient, it is easy to be broken or collapsed due to the force during the press-bonding to the conductive pattern, thereby reducing the strength and the joint effect of the bump structure. In addition, if the entire bump structure is made of a noble metal material (such as gold) which is expensive, the production cost of the bump structure cannot be effectively reduced.

The invention provides a bump structure and a manufacturing method thereof, which are suitable for increasing the hardness of the bump structure, thereby improving the strength and the joint effect of the bump structure, and at the same time reducing the production cost.

The bump structure of the present invention comprises a bump body and a plurality of particulate fillers. The microparticle filler is distributed in the body of the bump, wherein the diameter of the microparticle filler is between 0.05 micrometers and 1 micrometer, and the proportion of the microparticle filler in the bulk of the bump is between 25% and 50%.

The method for fabricating the bump structure of the present invention comprises the steps of: doping a plurality of fine particle fillers in a plating solution. Forming a bump body on a plating member by a plating solution, and mixing the microparticle filler into the bump body, wherein the diameter of the microparticle filler is between 0.05 micrometers and 1 micrometer, and the microparticle filler is distributed in the bump body. The ratio is between 25% and 50%.

In an embodiment of the invention, the microparticle filler is formed in the bump body simultaneously with the plating solution by being mixed into a plating solution for forming the bump body.

In an embodiment of the invention, the particulate filler described above comprises a Silicon based material.

In an embodiment of the invention, the material of the bump body comprises gold, silver or copper.

In an embodiment of the invention, the proportion of the microparticle filler distributed in the body of the bump is between 30% and 45%.

In an embodiment of the invention, the plurality of ion stacks in the plating solution are deposited to form a bump body, and the microparticle filler is doped between the ions to be mixed into the bump body during ion stacking.

In an embodiment of the invention, the plating solution includes a material containing gold, silver or copper ions, and the ions include gold, silver or copper ions.

In an embodiment of the invention, the step of forming the bump body by the plating solution comprises uniformly stirring the plating solution to suspend the particulate filler in the plating solution.

Based on the above, the bump structure of the present invention and the manufacturing method thereof dope the plurality of fine particle fillers in the plating solution, and form the bump body by the plating solution to mix the fine particle filler into the bump body. As such, the bump structure includes a bump body and a particulate filler distributed therein, wherein the diameter of the particulate filler is between 0.05 micrometers and 1 micrometer, and the proportion of the particulate filler in the bump body is between 25% and 50%. between. Accordingly, the bump structure of the present invention and the manufacturing method thereof are suitable for increasing the hardness of the bump structure, thereby improving the strength and the joint effect of the bump structure, and at the same time reducing the production cost.

The above described features and advantages of the invention will be apparent from the following description.

1 is a schematic view of a bump structure in accordance with an embodiment of the present invention. Referring to FIG. 1 , in the embodiment, the bump structure 100 includes a bump body 110 and a plurality of fine particle fillers 120 . The microparticle filler 120 is distributed in the bump body 110, wherein the diameter d of the microparticle filler 120 is between 0.05 micrometers (μm) and 1 micrometer, and the proportion of the microparticle filler 120 distributed in the bump body 110 is 25%. Between 50%. In particular, the bump structure 100 can be fabricated on a semiconductor wafer or other suitable carrier 10 as an electrical connection between the carrier 10 and other electronic components, such as a circuit board or other suitable electronic component. Conductive structure. Among them, a common bump structure is formed by ion deposition deposition in a plating solution in an electroplating process. In contrast, the bump structure 100 of the present embodiment further includes the fine particle filler 120 on the bump body 110 during the manufacturing process to improve the hardness of the bump structure 100.

FIG. 2 is a schematic view showing the manufacturing process of the bump structure of FIG. 1. FIG. Referring to FIG. 1 and FIG. 2, in the embodiment, the manufacturing method of the bump structure 100 includes the following steps. First, a plating solution 22 is placed in a plating apparatus 20 (for example, a plating tank), and a plurality of fine particle fillers 120 are doped in the plating solution 22. Next, the bump body 110 is formed on the plating member 24 by the plating solution 22, and the fine particle filler 120 is mixed into the bump body 110. That is, the fine particle filler 120 is simultaneously formed in the bump body 110 with the plating solution 22 by being mixed into the plating solution 22 for forming the bump body 110.

In detail, in the present embodiment, the plating solution 22 includes a material containing gold, silver or copper ions, such as potassium gold cyanide (KAu(CN) ₂ ), potassium silver cyanide (KAg (CN) ₂ Or copper sulfate (CuSO ₄ ), and the ions include gold, silver or copper ions, but the invention is not limited thereto. Furthermore, the microparticle filler 120 comprises a Silicon based material such as cerium oxide (SiO ₂ ), or aluminum oxide (Al ₂ O ₃ ), barium titanate (BaTiO ₃ ), titanium dioxide (TiO). ₂ ), zirconium dioxide (ZrO ₂ ), magnesium oxide (MgO), lithium aluminate (LiAlO ₂ ), magnesium aluminate (MgAl ₂ O ₄ ) or other suitable oxide materials, the invention does not limit the particulate filler 120 Materials, which can be adjusted as needed. In addition, the plating member 24 is, for example, the aforementioned semiconductor wafer or other suitable carrier 10 (shown in FIG. 1), and the bump body 110 is formed on the plating member 24 (ie, the carrier 10) in the manufacturing method. Wherein, the bump body 110 may be formed on a specific region 24a of the semiconductor wafer as the plating member 24, and the specific region 24a may be formed by the barrier structure 24b (for example, patterned photoresist) on the plating member 24. The spacer body 110 is formed in a specific region 24a surrounded by the barrier structure 24b, but the invention is not limited thereto.

Further, the plating member 24 is usually fixed to a workpiece holder (not shown) and then immersed in a plating bath containing the plating solution 22. The power supply V is electrically connected to the workpiece holder of the fixed plating member 24, and provides a negative electrode output to the workpiece holder to constitute the cathode 26. An anode 28 is also provided in the electroplating apparatus 20, and the power supply V provides a positive output to the anode 28. During the electroplating process, the power supply V applies a voltage that causes charge to flow from the anode 28 to the plated member 24 (i.e., the cathode 26). The charge flow produces an electrochemical reaction (i.e., redox reaction) that causes a plurality of ions (i.e., the aforementioned gold, silver, or copper ions) in the plating solution 22 to be deposited on the plating member 24 to form the bump body 110. In other words, by the electroplating process, the plurality of ions in the plating solution 22 are moved through the redox reaction toward the plating member 24 located at the cathode 26, and stacked to form the bump body 110 while the microparticle filler 120 is interposed between the ions. To be mixed into the bump body 110 during ion stacking. The step of forming the bump body 110 by the plating solution 22 includes uniformly stirring the plating solution 22 so that the fine particle filler 120 is more uniformly suspended in the plating solution 22. This contributes to the uniform distribution of the particulate filler 120 in the bump body 110.

Referring to FIG. 1 , in the embodiment, the bump structure 100 is formed on the carrier 10 (ie, the plated member 24 ) by the above-mentioned manufacturing method, wherein the material of the bump body 110 includes gold, silver or copper, and the bump body 110 The height h is between about 12 microns and 15 microns, and the width w is between about 10 microns and 15 microns, although the invention is not limited thereto. Wherein, the diameter d of the microparticle filler 120 is between 0.05 micrometers and 1 micrometer, and the proportion of the microparticle filler 120 distributed in the bump body 110 is between 25% and 50%. Preferably, the proportion of the microparticle filler 120 distributed in the bump body 110 is between 30% and 45%. Adjusting the proportion of the fine particle filler 120 in the bump body 110 within the above range helps to improve the hardness of the bump structure 100, but does not affect the conductivity of the bump structure 100. However, the present invention is not limited to the above ratio, which can be adjusted as needed.

Therefore, in the embodiment, the microparticle filler 120 is mixed into the bump body 110 in the electroplating process, so that the bump structure 100 is matched with the bump body 110 of a metal material (for example, gold, silver or copper). The non-metallic material (for example, a bismuth-based material or other oxide material) is composed of the micro-particle filler 120, that is, the bump structure 100 is a composite material, so the bump structure 100 has higher hardness than the common bump structure. With the above design, when the semiconductor wafer as the carrier 10 is electrically connected to other electronic components (such as a circuit board) through the bump structure 100 as a conductive structure, the bump structure 100 can be pressed through a conductive paste or other suitable manner. A conductive pattern (such as a conductive contact or pin) that is attached to an electronic component. At this time, since the bump structure 100 has high hardness, it is not easily damaged or collapsed during the pressing process, and has a good electrical connection effect. Moreover, the bump structure 100 is formed of a metal bump body 110 and a non-metallic particulate filler 120, so that the metal in the bump structure 100 is compared to the entire bump structure made of gold or other precious metal material. The material ratio is reduced, which in turn reduces production costs. Accordingly, the bump structure 100 and its fabrication method are adapted to increase the hardness of the bump structure 100, thereby improving the strength and bonding effect of the bump structure while reducing production costs.

In summary, the bump structure of the present invention and the manufacturing method thereof comprise a plurality of microparticle fillers in the plating solution, and the bump body is formed by the plating solution, so that the microparticle filler is deposited on the ion stack of the plating solution to form the bump body. The process is mixed into the body of the bump. As such, the bump structure includes a bump body and a particulate filler distributed therein, wherein the diameter of the particulate filler is between 0.05 micrometers and 1 micrometer, and the proportion of the particulate filler in the bump body is between 25% and 50%. between. Accordingly, the bump structure of the present invention and the manufacturing method thereof are suitable for increasing the hardness of the bump structure, thereby improving the strength and the joint effect of the bump structure, and at the same time reducing the production cost.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧ Carrier
20‧‧‧Electroplating unit
22‧‧‧ plating solution
24‧‧‧ plating parts
24a‧‧‧Specific areas
24b‧‧‧ Barrier structure
26‧‧‧ cathode
28‧‧‧Anode
100‧‧‧bump structure
110‧‧‧Bump body
120‧‧‧Microparticle filler
D‧‧‧diameter
H‧‧‧height
V‧‧‧Power supply
w‧‧‧Width

1 is a schematic view of a bump structure in accordance with an embodiment of the present invention. FIG. 2 is a schematic view showing the manufacturing process of the bump structure of FIG. 1. FIG.

10‧‧‧ Carrier

100‧‧‧bump structure

110‧‧‧Bump body

120‧‧‧Microparticle filler

D‧‧‧diameter

H‧‧‧height

w‧‧‧Width

Claims (10)

A bump structure comprising: a bump body; and a plurality of microparticle fillers distributed in the bump body, wherein the microparticle fillers have a diameter of between 0.05 micrometers (μm) and 1 micrometer, and The proportion of the microparticle filler distributed in the body of the bump is between 25% and 50%. The bump structure of claim 1, wherein the microparticle filler is simultaneously formed in the bump body by being mixed into a plating solution for forming the bump body. The bump structure of claim 1, wherein the particulate filler comprises a Silicon based material. The bump structure of claim 1, wherein the material of the bump body comprises gold, silver or copper. The bump structure of claim 1, wherein the proportion of the microparticle fillers distributed in the bump body is between 30% and 45%. A method for fabricating a bump structure, comprising: mixing a plurality of microparticle fillers in a plating solution; and forming a bump body on a plating member by the plating solution, and mixing the microparticle fillers into the bump body The microparticle filler has a diameter of between 0.05 micrometers and 1 micrometer, and the proportion of the microparticle fillers distributed in the bump body is between 25% and 50%. The method of fabricating the bump structure of claim 6, wherein the particulate filler comprises a bismuth based material. The method for fabricating a bump structure according to claim 6, wherein the plurality of ion stack deposition in the plating solution constitutes the bump body, and the microparticle filler is mixed between the ions to be The bump body is mixed into the ion body. The method for fabricating a bump structure according to claim 8, wherein the plating solution comprises a material containing gold, silver or copper ions, and the ions comprise gold, silver or copper ions. The method for fabricating a bump structure according to claim 8, wherein the step of forming the bump body by the plating solution comprises uniformly stirring the plating solution to suspend the fine particle filler in the plating solution.