CN-121985856-A - Bump mass transfer method for integrated circuit

Abstract

The invention discloses a mass transfer method of integrated circuit bumps, which belongs to the field of integrated circuit manufacturing and comprises a first substrate, a second substrate, a third solder, a fourth solder, a fifth solder and a fifth solder. The invention solves the problem of copper needle mass transfer secondary reflow soldering by means of epoxy resin fixation, and improves the reliability of products to a great extent. The invention may also be applied to similar reflow soldering processes with secondary or multiple reflow processes.

Inventors

• ZHANG SHENG

Assignees

• 日月新半导体(苏州)有限公司

Dates

Publication Date

20260505

Application Date

20260206

Claims (9)

1. 1. The integrated circuit bump bulk transfer method is characterized by comprising the following steps: The first step is a substrate (1); Step two, printing a welding agent (2) on the surface of the substrate (1); Step three, attaching a copper column (3) on the welding agent (2) and performing reflow soldering operation; Filling glue (4) on the bottom of the copper column (3); And fifthly, bonding the flip chip (6) onto the substrate (1) and performing reflow soldering operation.
2. 2. The method of claim 1, wherein the integrated circuit bump bulk transfer is characterized by: and step four, filling glue (4) on the bottom of the copper column (3) through a jet pump (5).
3. 3. The method of claim 2, wherein the integrated circuit bump bulk transfer is characterized by: the jet pump (5) performs dispensing operation under the condition that the bottom of the copper column (3) adopts a non-contact suspension mode.
4. 4. The method of claim 2, wherein the integrated circuit bump bulk transfer is characterized by: The bottom of the jet pump (5) is connected with a dispensing needle.
5. 5. The method of claim 1, wherein the integrated circuit bump bulk transfer is characterized by: In the fourth step, the main component of the filling glue (4) is epoxy resin.
6. 6. The method of claim 4, wherein the bulk transfer of the integrated circuit bumps is: the curing temperature of the filling glue (4) is in the range of 170-200 ℃.
7. 7. The method of claim 1, wherein the integrated circuit bump bulk transfer is characterized by: the outside of the jet pump (5) is connected with a piezoelectric valve.
8. 8. The method of claim 1, wherein the integrated circuit bump bulk transfer is characterized by: The solder (2) comprises solder paste.
9. 9. An integrated circuit bump structure according to any one of claims 1 to 8 wherein: The substrate (1) is provided with copper columns (3) through a welding agent (2) arranged above, filling glue (4) is arranged between the bottoms of the copper columns (3) and the substrate (1), and a chip (6) is arranged above the substrate (1).

Description

Bump mass transfer method for integrated circuit Technical Field The invention belongs to the technical field of integrated circuit manufacturing, and particularly relates to a bump mass transfer method of an integrated circuit. Background In the technical field of integrated circuit manufacturing, a bump interconnection technology is a core process for realizing electrical connection and mechanical fixation of a chip and a substrate, wherein copper pillar bumps are widely applied to a high-performance chip packaging scene due to the advantages of high density, low impedance, excellent electromigration resistance, excellent heat conduction performance and the like. The current mainstream copper pillar bump welding process needs to be subjected to multiple thermal processing and bonding steps, and the connection and fixation of the copper pillar and the substrate and the chip and the copper pillar are realized through step-by-step welding, so that the method is a relatively mature technical scheme in the existing packaging production line. However, the conventional process has a significant technical bottleneck in the actual mass production process, and particularly, the problems of serious influence on product quality, such as copper pillar inclination, inconsistent welding height (BLT) and the like, are very easy to occur after multiple times of hot working. On one hand, the printing mode of hard brush tin paste is difficult to ensure the uniformity of the coating amount of the tin paste, so that the solder at the bottom of a copper column is unevenly distributed, the wetting force after the solder is melted is unbalanced in a high-temperature environment of hot working, and uneven lateral tension is generated, so that the copper column is inclined, on the other hand, in the process of multiple hot working, the thermal stress generated by unmatched thermal expansion Coefficients (CTE) of different materials such as a substrate, the copper column and a chip is continuously accumulated, and the position deviation and the height deviation of the copper column are further aggravated. In addition, the deviation of the precision of the pre-implant board mounting can be amplified in the subsequent hot working, and the perpendicularity and the welding height consistency of the copper columns are also adversely affected. The problems of copper pillar inclination, BLT inconsistency and the like can directly lead to a series of hidden dangers, namely, the problems of firstly destroying the stability of electrical connection between a chip and a substrate, increasing signal transmission delay and loss and even causing short circuit or open circuit faults, secondly, reducing the mechanical reliability of a packaging structure, enabling a product to be more likely to fail due to environmental factors such as vibration, temperature circulation and the like in the subsequent use process, thirdly, obviously reducing the production yield, increasing the reworking cost and severely restricting the mass production efficiency of high-integration and high-precision integrated circuit products. Disclosure of Invention Aiming at the situation, in order to overcome the defects of the prior art, the invention provides a mass transfer method for integrated circuit bumps, which effectively solves the problems that the copper pillars are subjected to secondary or multiple reflow soldering in the current market, and the conventional solder is subjected to secondary melting, so that the copper pillars are inclined, poor in BLT, and cold joint. The invention provides a method for transferring a huge amount of integrated circuit bumps, which comprises the following steps of a substrate; Step two, printing a welding agent on the surface of the substrate; step three, attaching copper columns on the welding agent and performing reflow soldering operation; filling glue on the bottom of the copper column; And fifthly, bonding the flip chip onto the substrate and performing reflow soldering operation. And step four, filling glue into the bottom of the copper column through a jet pump. Preferably, the jet pump performs dispensing operation under the condition that a non-contact suspension mode is adopted at the bottom of the copper column. Preferably, the bottom of the jet pump is connected with a dispensing needle. Preferably, in the fourth step, the main component of the filling glue is epoxy resin. Preferably, the curing temperature of the filler is in the range of 170-200 ℃. Preferably, a piezoelectric valve is connected to the outside of the jet pump. Preferably, the solder comprises solder paste. Further, the substrate is attached with copper columns through a welding agent arranged above, filling glue is arranged between the bottoms of the copper columns and the substrate, and a chip is arranged above the substrate. The invention has the beneficial effects that the scheme provides a method for transferring the bump of the integrated circu