CN-118908437-B - Copper sulfate electroplating solution preparation device and method for chip packaging

CN118908437BCN 118908437 BCN118908437 BCN 118908437BCN-118908437-B

Abstract

The invention discloses a copper sulfate plating solution preparation device and method for chip packaging, and relates to the technical field of chip packaging, wherein the technical scheme is characterized by comprising a copper sulfate pentahydrate storage tank, a negative pressure feeder, a feeding volume bin, an electronic scale, a copper sulfate solution preparation tank, a preparation pump I, a microporous filter I, a resin barrel, a plating solution preparation tank, a spiral spray head, a preparation pump II, a heat exchanger and a microporous filter II; the copper sulfate pentahydrate storage tank is connected with a copper sulfate solution preparation tank through a negative pressure feeder, a feeding volume bin and an electronic scale, the copper sulfate solution preparation tank is communicated with an electroplating solution preparation tank through a microporous filter I and a resin barrel, the copper sulfate solution is added into the electroplating solution preparation tank through a preparation pump I after being prepared in the copper sulfate solution preparation tank, the electroplating solution preparation tank, the preparation pump II and a heat exchanger form a circulating system, and the electroplating solution is filled through the microporous filter II. The whole preparation device adopts an automatic instrument and logic control, and the whole process can realize automatic and intelligent operation.

Inventors

GUO LANFENG
LIU RENLONG
FU YANMEI
Tan tong
QIN XIANG
HE ZHAOBO
QIU FACHENG

Assignees

重庆大学

Dates

Publication Date: 20260508
Application Date: 20240403

Claims (9)

1. A copper sulfate plating solution preparation device for chip packaging is characterized by comprising a copper sulfate pentahydrate storage tank (1), a negative pressure feeder (2), a feeding volume bin (3), an electronic scale (4), a copper sulfate solution preparation tank (5), a preparation pump I (6), a microporous filter I (7), a resin barrel (8), a plating solution preparation tank (9), a spiral spray head (10), a preparation pump II (11), a heat exchanger (12) and a microporous filter II (13), wherein the copper sulfate pentahydrate storage tank (1) is connected with the copper sulfate solution preparation tank (5) through the negative pressure feeder (2), the feeding volume bin (3) and the electronic scale (4), the copper sulfate solution preparation tank (5) is communicated with the plating solution preparation tank (9) through the microporous filter I (7) and the resin barrel (8), the copper sulfate solution is added into the plating solution preparation tank (9) through the preparation pump I (6) after being prepared in the copper sulfate solution preparation tank (5), and the plating solution preparation tank (9) forms a circulation system with the preparation pump II (11) and the heat exchanger (12) and is filled with plating solution through the microporous filter II (13); The top of the copper sulfate solution preparation tank (5) is provided with a copper sulfate pentahydrate feeding pipeline (14) and an ultrapure water feeding pipeline (15), the ultrapure water feeding pipeline (15) is provided with a mass flowmeter (16) and a pneumatic valve (17), and the copper sulfate pentahydrate feeding pipeline is provided with a feeding volume bin (3) and a pneumatic valve (17); The electroplating solution preparation tank (9) is provided with an electronic grade sulfuric acid feeding pipeline (18), an electronic grade hydrochloric acid feeding pipeline (19), an ultrapure water feeding pipeline (15) and an organic additive feeding pipeline (20), and the electronic grade sulfuric acid feeding pipeline (18), the electronic grade hydrochloric acid feeding pipeline (19), the ultrapure water feeding pipeline (15) and the organic additive feeding pipeline (20) are respectively provided with a mass flowmeter (16) and a pneumatic valve (17), and the mass flowmeter (16) and the pneumatic valve (17) are connected into a DCS control system by electric signals.
2. The copper sulfate plating solution preparation device for chip packaging according to claim 1, wherein the copper sulfate pentahydrate feeding pipeline (14), the ultrapure water feeding pipeline (15), the plating solution preparation tank (9), the first preparation pump (6), the second preparation pump (11), the heat exchanger (12), the electronic grade sulfuric acid feeding pipeline (18), the electronic grade hydrochloric acid feeding pipeline (19), the ultrapure water feeding pipeline (15) and the organic additive feeding pipeline (20) are made of stainless steel 304 or 316L lined PFA, and PFA is modified high-smoothness PFA.
3. The copper sulfate plating solution preparation device for chip packaging according to claim 1, wherein the inside of the plating solution preparation tank (9) is provided with an ultrapure water feeding spiral nozzle (10).
4. The copper sulfate plating solution preparation device for chip packaging according to claim 1 is characterized in that a first microporous filter (7) is provided with a fin type folding microporous filter element with the filter element precision of 0.1 micrometer, a second microporous filter (13) is provided with a fin type folding microporous filter element with the filter element precision of 0.05 micrometer, a microporous filter element framework is made of PFA, a filter membrane is made of PTFE, hydrophilic modification is carried out on the filter membrane, and the surface tension after modification is 35-40mN/m.
5. The device for preparing copper sulfate plating solution for chip packaging according to claim 1, wherein the resin barrel (8) is made of aminophosphonic acid type chelate resin.
6. A preparation method of a copper sulfate plating solution for chip packaging is characterized by selecting the copper sulfate plating solution preparation device for chip packaging according to any one of claims 1-5 for preparation, and comprises the following steps: Firstly, adding quantitative ultrapure water into a copper sulfate solution preparation tank (5), starting a self-circulation system of the preparation tank, sucking superior copper sulfate pentahydrate into a feeding volume bin (3) through a negative pressure feeder (2), placing the feeding volume bin (3) on a high-precision electronic scale (4), weighing the weight, connecting with a regulating valve at an outlet of the negative pressure feeder (2), accurately controlling the weight of the copper sulfate pentahydrate through the joint process of the volume and the weight, slowly adding the copper sulfate pentahydrate into the preparation tank, and circulating for 2-4 hours; S2, removing particles and partial metal ions from the copper sulfate solution through a microporous filter I (7) and a resin barrel (8) after the preparation is finished, then, entering an electroplating solution preparation tank (9), starting a circulating heat exchange system of the electroplating solution preparation tank (9) to cool, and then sequentially adding ultrapure water, electronic grade sulfuric acid and electronic grade hydrochloric acid according to the proportion, so that the reagent is added for circulating cooling; And S3, sequentially adding an organic additive comprising a leveling agent, an inhibitor and an accelerator into the electroplating base solution, controlling the addition amount of the organic additive through a mass flowmeter (16), wherein the diameter of a feeding pipeline is smaller than 10mm, circulating for 3-6 hours after the addition of the additive is finished, sampling and detecting, and filling the electroplating solution into a packaging barrel after the electroplating base solution meets the quality requirement through a microporous filter II (13), wherein the addition amount of CuSO4 is 180-240 g/L, the electronic grade sulfuric acid is 45-80 g/L, the electronic grade hydrochloric acid is 40-80 ppm, the accelerator is 5-15 ppm, the inhibitor is 0.1-1 mg/L, and the leveling agent is 0.05-0.2 mg/L.
7. The method for preparing the copper sulfate plating solution for chip packaging according to claim 6, wherein the fixed-volume bin in the step S1 is elliptical, the bin body is smooth in radian, the regulating valve at the outlet of the negative pressure feeder (2) is interlocked with the weight of the electronic scale (4), and the regulating valve is automatically closed until the regulating valve is closed along with the weight approaching a target value.
8. The method of claim 6, wherein the S2 preparation process and the post-preparation temperature are both controlled at 25-35 ℃.
9. The method of preparing copper sulfate plating solution for chip packaging according to claim 6, wherein signals of a mass flowmeter (16) and a pneumatic valve (17) on the organic additive pipeline in the step S3 are connected to DCS, each reagent is added at 5-10min intervals, and the organic additives are added by adopting high-purity nitrogen back pressure.

Description

Copper sulfate electroplating solution preparation device and method for chip packaging Technical Field The invention relates to the technical field of chip packaging, in particular to a device and a method for preparing copper sulfate electroplating liquid for chip packaging. Background Copper electroplating is a common metal plating process that improves the appearance, performance and corrosion resistance of metals by plating the surface of the metal with a layer of copper. Copper metal is considered as an excellent metal interconnect material in a chip because of its excellent electrical conductivity, high thermal conductivity, low melting point, good ductility, and the like. Copper electroplating is a key technology for metal interconnection in packaging, and is not separated from high-quality electroplating liquid. Cuso 4 copper plating baths are a common type of copper plating bath and consist of copper sulfate (CuSO 4) and other auxiliary agents. Currently, in integrated circuit technology, a damascene copper interconnection technology is widely applied, a copper deposition technology is a key technology in the damascene copper interconnection technology, whether copper deposited in a micro groove (hole) is compact, has a void or crack or not, directly influences the resistivity and migration resistance of a copper interconnection line, a key semiconductor material for realizing the damascene copper interconnection technology is high-purity copper sulfate electroplating solution, the purity index of the product is very high, and otherwise, the reliability of copper wiring is influenced. At present, most of the methods for producing the ultra-clean high-purity copper interconnection copper sulfate electroplating solution at home and abroad are common chemical methods. The method comprises the steps of preparing a dilute copper sulfate solution by taking high-purity copper (the purity is more than 99.999%) and high-purity sulfuric acid, nitric acid and hydrogen peroxide (SEMI-CI grade or above) as raw materials, evaporating and concentrating the solution to saturation, cooling and crystallizing to separate CuSO 4·5H2 O crystals, and preparing the solution by using ultrapure water according to the technical requirements of products. The method has the advantages of long process route, high requirement on raw material quality, uncontrollable fluctuation of metal impurity content in the raw material, H 2O2 or HNO 3 removal after reaction, emission of waste gas and waste water, environmental pollution, high production cost and difficulty in guaranteeing reliability for line width design below 65 nm. Disclosure of Invention The invention aims to solve the problems and provide a device and a method for preparing copper sulfate plating solution for chip packaging. The technical aim of the invention is achieved through the following technical scheme that the electroplating bath comprises a copper sulfate pentahydrate storage tank, a negative pressure feeder, a feeding volume bin, an electronic scale, a copper sulfate solution preparing tank, a preparing pump I, a microporous filter I, a resin barrel, an electroplating solution preparing tank, a spiral spray head, a preparing pump II, a heat exchanger and a microporous filter II, wherein the copper sulfate pentahydrate storage tank is connected with the copper sulfate solution preparing tank through the negative pressure feeder, the feeding volume bin and the electronic scale, the copper sulfate solution preparing tank is communicated with the electroplating solution preparing tank through the microporous filter I and the resin barrel, the copper sulfate solution is added into the electroplating solution preparing tank through the preparing pump I after being prepared in the copper sulfate solution preparing tank, the electroplating solution preparing tank forms a circulating system with the preparing pump II and the heat exchanger, and electroplating solution is filled through the microporous filter II. The invention is further provided with a copper sulfate pentahydrate feeding pipeline and an ultrapure water feeding pipeline which are arranged at the top of the copper sulfate solution preparation tank, wherein the ultrapure water feeding pipeline is provided with a mass flowmeter and a pneumatic valve, and the copper sulfate pentahydrate feeding pipeline is provided with a feeding volume bin and a pneumatic valve. The electroplating solution preparing tank is further provided with an electronic grade sulfuric acid feeding pipeline, an electronic grade hydrochloric acid feeding pipeline, an ultrapure water feeding pipeline and an organic additive feeding pipeline, wherein the electronic grade sulfuric acid feeding pipeline, the electronic grade hydrochloric acid feeding pipeline, the ultrapure water feeding pipeline and the organic additive feeding pipeline are respectively provided with a mass flowmeter and a pneumatic valve, and electric signals of the mas