A hanger for improving electroplating uniformity

Abstract

The utility model discloses a hanger for improving the uniformity of electroplating, comprising a hanger assembly and a back plate assembly matched with the hanger assembly; the hanger assembly comprises a hanger, a circular groove matched with the back plate assembly, a conductive ring arranged in the circular groove, a power connection sheet arranged on the hanger, a first wire groove arranged on the hanger and a conductive rib arranged at the tail end of the first wire groove; the back plate assembly comprises a back plate, a node channel arranged at the center of the back plate, a conductive contact arranged on the back plate, a second wire groove arranged on the back plate and a wiring groove arranged on the back plate. The hanger assembly composed of the hanger, the circular groove, the conductive ring, the power connection sheet, the first wire groove and the conductive ribs is used in conjunction with the back plate assembly composed of the back plate, the node channel, the conductive contact and the wiring groove, so as to achieve the purpose of uniform distribution of current density and improve the quality of wafer electroplating.

Description

Technical Field

[0001] The utility model relates to the field of semiconductors, in particular to a hanger for improving electroplating uniformity. Background Art

[0002] In the existing technology, whether it is nano-level interconnection process or micron-level copper pillar, bump, rewiring and other advanced packaging processes, wafer electroplating process is an important metallization technology to achieve electronic interconnection and plays an indispensable role. Wafer electroplating technology can produce metal bumps of different sizes, pitches and geometric shapes, also called plating, and has very high requirements for the uniformity of bump thickness. Uneven surface after electroplating will lead to poor contact of chip pins, and peeling and falling off are prone to occur in the back-end welding joint, which may fail the reliability test of the packaged product.

[0003] In traditional processes, wafer electroplating usually uses an annular conductive component to supply power from the periphery of the wafer to the surface of the wafer. Common factors that affect the uniformity of the coating are: the annular conductive component in contact with the surface of the wafer receives an uneven distribution of current density. Specifically, when powered by an external power supply, the current flows from the wires on the hanger into the annular conductive component, thereby powering the wafer. Since the lengths of the paths taken by the wires are different, the impedance of each circuit is different, and the current density distribution is uneven; the wire contact points are arranged at the edge of the wafer, and the distance from the edge to the center is not equal, resulting in different voltage differences from different edge contact points to the center of the wafer, which also causes uneven current density distribution.

[0004] How to effectively solve the problem of uneven current density distribution is a technical problem that urgently needs to be solved in this technical field.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Utility Model Content

[0006] In order to solve the above technical problems, the utility model proposes a hanger for improving the uniformity of electroplating, so as to achieve the purpose of achieving uniform distribution of current density and improving the quality of wafer electroplating.

[0007] In order to achieve the above object, the technical solution of the utility model is as follows:

[0008] A hanger for improving electroplating uniformity, comprising a hanger assembly and a back plate assembly matched with the hanger assembly;

[0009] The rack assembly comprises a rack, a circular groove arranged to match the back plate assembly, a conductive ring arranged in the circular groove, a power connection plate arranged on the rack, a first wire groove arranged on the rack, and a conductive rib arranged at the tail end of the first wire groove; the power connection plate is arranged at the head end of the first wire groove;

[0010] The backplane assembly includes a backplane, a node channel arranged in the center of the backplane, conductive contacts arranged on the backplane and distributed around the backplane, a second wire groove arranged on the backplane to realize the connection between the node channel and the conductive contact, and a wiring groove arranged on the backplane; one end of the wiring groove is connected to the node channel, and the conductive contact is used in conjunction with the conductive ribs.

[0011] The utility model achieves the purpose of uniform distribution of current density and improving wafer electroplating quality by using a hanger assembly consisting of a hanger, a circular groove, a conductive ring, a power connection sheet, a first wire groove, and conductive ribs in conjunction with a backplane assembly consisting of a backplane, a node channel, a conductive contact, and a wiring groove.

[0012] It is worth noting that the conductive ring includes four electrodes distributed around the circular groove;

[0013] The back plate is provided with four conductive contacts, which are used in pairs with the electrodes.

[0014] It is worth noting that the second wire groove and the wiring groove are staggered, and the wiring groove is connected to the first wire groove through the conductive ribs.

[0015] It is worth noting that the side surface of the back plate is a frustum structure.

[0016] It is worth noting that a plurality of fixing holes are provided on the back plate and the bracket, and the back plate is connected to the bracket via the fixing holes and screws matching the fixing holes.

[0017] The utility model has the following advantages:

[0018] 1. The utility model achieves the purpose of uniform distribution of current density and improving the quality of wafer electroplating by using a hanger assembly consisting of a hanger, a circular groove, a conductive ring, a power connection sheet, a first wire groove, and a conductive rib in conjunction with a backplane assembly consisting of a backplane, a node channel, a conductive contact, and a wiring groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0020] Figure 1 A schematic diagram of the structure of a hanger for improving electroplating uniformity disclosed in an embodiment of the utility model;

[0021] Figure 2 A schematic diagram of the structure of a rack assembly in a rack for improving electroplating uniformity disclosed in an embodiment of the utility model;

[0022] Figure 3 A schematic diagram of the structure of a back plate assembly in a hanger for improving electroplating uniformity disclosed in an embodiment of the utility model;

[0023] The numbers and letters in the figure represent the corresponding component names:

[0024] 11. Hanger 13. Electrode 12. Circular groove 14. Electrical connection plate 15. First wire groove 16. Conductive rib

[0025] 21. Back plate 22. Node channel 23. Conductive contact 24. Second wire groove 25. Wiring groove 3. Fixing hole. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] The utility model provides a hanger for improving electroplating uniformity. Its working principle is to achieve the purpose of uniform distribution of current density and improving wafer electroplating quality through the use of a hanger assembly composed of a hanger, a circular groove, a conductive ring, a power connection sheet, a first wire groove, and a conductive rib in combination with a back plate assembly composed of a back plate, a node channel, a conductive contact, and a wiring groove.

[0028] The present invention is further described in detail below in conjunction with embodiments and specific implementation methods.

[0029] like Figure 1-Figure 3 As shown, a hanger for improving electroplating uniformity includes a hanger assembly and a back plate assembly matched with the hanger assembly;

[0030] The hanger assembly includes a hanger 11, a circular groove 12 arranged to match the backplane assembly, a conductive ring arranged in the circular groove, a power connection plate 14 arranged on the hanger [the power connection plate 14 contacts with the external wire for electrical conduction], a first wire groove 15 arranged on the hanger and a conductive rib 16 arranged at the tail end of the first wire groove; the power connection plate is arranged at the head end of the first wire groove; the conductive ring includes four electrodes 13 distributed around the circular groove.

[0031] The backplane assembly includes a backplane 21, a node channel 22 arranged at the center of the backplane, four conductive contacts 23 arranged on the backplane and distributed around the backplane, a second wire groove 24 arranged on the backplane to realize the node channel and the conductive contact [adjacent second wire grooves are arranged vertically] and a wiring groove 25 arranged on the backplane [the second guide groove, wiring groove and node channel are all laid with wires to form a connection circuit, and the wiring groove is flush with the contact surface of the backplane hanger and does not intersect with the second wire groove. The current is only shunted through the node channel to ensure the conduction direction of the current; the current is led to the electrode 13 on the hanger through the conductive contact 23 connected to each second wire groove]; one end of the wiring groove is connected to the node channel, and the conductive contact is used in conjunction with the conductive rib. The conductive contact is used in pairs with the electrode. The second wire groove and the wiring groove are staggered, and the wiring groove is connected to the first wire groove through the conductive rib.

[0032] The back plate and the bracket are both provided with a plurality of fixing holes 3, and the back plate is connected to the bracket via the fixing holes and screws matched with the fixing holes.

[0033] The specific use steps of the utility model are as follows: Figure 1-Figure 3 As shown, the wafer is placed on the electrode 13 of the circular groove 12, the front side of the wafer, i.e., the side containing the integrated circuit, contacts the electrode 13, and the back side without the integrated circuit contacts the wafer contact surface of the back plate. When the fixing holes of the back plate and the rack are tightened by bolts, the back plate will press the wafer against the conductive ring, and the conductive contact will be completely in contact with the edge of the wafer. At this time, the electrode 13 and the conductive contact 23 contact to form a path. The conductive rib 16 will be inserted into the wiring groove 25 to complete the mechanical bonding. During electroplating, the current will flow into the node channel of the back plate along the upper part of the rack, and then flow evenly to the electrode (13) along the four second wire grooves 24. Since the length of the wire grooves is equal to the radius of the back plate, the wire impedance is equal, and the current density of each wire groove at this time is theoretically consistent, so that the problem of uniformity of wafer bumps after electroplating can be effectively improved. Moreover, the more wire grooves are provided, the better the electroplating uniformity will be under the condition that the angles are equal to each other.

[0034] In actual use, only the power connection sheet 14 and the conductive fins 16 are exposed to the air, and the first wire groove 15 is sealed by resin, and the circuit therein is prohibited from contacting the electroplating solution.

[0035] Through the above method, the utility model provides a hanger for improving the uniformity of electroplating. The hanger assembly composed of a hanger, a circular groove, a conductive ring, a power connection plate, a first wire groove, and a conductive rib is used in conjunction with a backplane assembly composed of a backplane, a node channel, a conductive contact, and a wiring groove. The problem of uneven current density during electroplating is effectively solved through structural innovation. The method is simple and effective. The hanger can be adapted to a variety of 12-inch wafer electroplating equipment, achieving the purpose of achieving uniform distribution of current density and improving wafer electroplating quality.

[0036] The above is only a preferred embodiment of a hanger for improving electroplating uniformity disclosed in the present utility model. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept of the present utility model, which all fall within the protection scope of the present utility model.

Claims

1. A hanger for improving electroplating uniformity, characterized in that: It comprises a hanger assembly and a back plate assembly matched with the hanger assembly; The rack assembly includes a rack, a circular groove matched with the back plate assembly, a conductive ring arranged in the circular groove, a power connection plate arranged on the rack, a first wire groove arranged on the rack, and a conductive rib arranged at the tail end of the first wire groove; The power connection plate is arranged at the head end of the first wire groove; The backplane assembly includes a backplane, a node channel arranged in the center of the backplane, conductive contacts arranged on the backplane and distributed around the backplane, a second wire groove arranged on the backplane to realize the connection between the node channel and the conductive contact, and a wiring groove arranged on the backplane; one end of the wiring groove is connected to the node channel, and the conductive contact is used in conjunction with the conductive ribs.

2. A hanger for improving electroplating uniformity according to claim 1, characterized in that: The conductive ring includes four electrodes distributed around the circular groove; The back plate is provided with four conductive contacts, which are used in pairs with the electrodes.

3. A hanger for improving electroplating uniformity according to claim 1, characterized in that: The second wire groove and the wiring groove are staggered, the wiring groove is connected to the first wire groove through the conductive rib, and the wiring groove is bonded to the conductive rib.

4. A hanger for improving electroplating uniformity according to claim 1, characterized in that: The side surface of the back plate is in a frustum structure.

5. The hanger for improving electroplating uniformity according to claim 1, characterized in that: The back plate and the rack are both provided with a plurality of fixing holes, and the back plate is connected to the rack via the fixing holes and screws matched with the fixing holes.

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