CN-115652384-B - Electrolytic copper foil with special coarsening morphology and preparation method thereof

CN115652384BCN 115652384 BCN115652384 BCN 115652384BCN-115652384-B

Abstract

The invention relates to an electrolytic copper foil with special coarsening morphology and a preparation method thereof, wherein the special coarsening morphology is characterized in that coarsening tissues of a treatment surface are in a sheet morphology and a spherical morphology. According to the invention, the fine copper nodules with special flaky morphology and spherical morphology are formed on the rough surface of the copper foil, and copper nodule particles cover the peaks and valleys of the whole rough surface, so that on one hand, the roughness is reduced, meanwhile, the lamination area of the surface of the copper foil and resin is increased, and on the other hand, the staggered copper nodule structure has more pores, and in the pressing plate process, the resin can be embedded into the pores to ensure the sufficient anti-stripping strength of the copper foil.

Inventors

ZHU HONGBO
ZHANG JIE
YANG HONGGUANG
JIN RONGTAO
ZHONG HONGJIE
CHEN XIANGHAO
LUO LIMIN

Assignees

九江德福科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20221107

Claims (5)

1. The electrolytic copper foil with the special roughened appearance is characterized in that the roughened structure of a treated surface is in a sheet-shaped appearance and a spherical appearance, the length of the roughened structure of the sheet-shaped appearance is 500-1200 nm, the thickness is 60-100 nm, the length-thickness ratio is 7-20, the diameter of the roughened structure of the spherical appearance is 200-600 nm, and the number ratio of the roughened structure of the sheet-shaped appearance to the roughened structure of the spherical appearance is 1:1-5:1.
2. A method for preparing the electrolytic copper foil with special coarsened morphology according to claim 1, comprising the steps of: (1) Performing electrochemical polishing pretreatment on the rough surface of the copper foil by adopting a pulse power supply to remove an oxide layer and oil stains on the surface of the copper foil; (2) Forming a roughened layer on the roughened surface of the copper foil by adopting an additive-assisted roughening treatment technology, sequentially roughening and solidifying the roughened surface of the copper foil subjected to pretreatment for a plurality of times by using a direct current power supply in the roughening solution containing the additive, wherein the roughening current density is 8-13A/dm 2 , the solidifying current density is 10-15A/dm 2 , the solid-to-solid ratio is 1.0-1.3, and the roughening time is 5-10 s; (3) And after the roughening treatment is finished, carrying out passivation treatment of a metal barrier layer and silane coating on two sides of the copper foil, and finally drying with hot air to prepare the finished copper foil.
3. The method of claim 2, wherein the electrochemical polishing pretreatment in step (1) has a pulse frequency of 500-1800 Hz, an average current density of 3-6A/dm 2 , a duty cycle of 20-50%, and a treatment time of 5-10 s.
4. The method of claim 2, wherein the additive in the step (2) is two or more of benzylated polyethylenimine, titanium sulfite, a diamino urea polymer, polyethylene glycol, sodium dimethylformamide sulfonate and chloral hydrate, and the concentration of each additive is 0.0005-0.01 wt%.
5. The method of claim 2, wherein the passivation in the step (3) has a current density of 0.5-0.8A/dm 2 and a plating time of 10-20 s.

Description

Electrolytic copper foil with special coarsening morphology and preparation method thereof Technical Field The invention belongs to the field of copper foil, and particularly relates to an electrolytic copper foil with special coarsening morphology and a preparation method thereof. Background In recent years, the trend of thinning of PCB boards and the low transmission loss characteristic of high frequency and high speed circuits are becoming more important, and at higher frequencies, the surface morphology or roughness of conductors is required to achieve sufficient peel strength while having lower roughness. The roughness and the peeling strength are mutually restricted, so that the production difficulty of the high-frequency high-speed copper foil is improved, and more severe requirements are put on the performance of the copper foil. Therefore, it is critical to the copper foil manufacturing technology to simultaneously achieve low roughness and sufficient peel strength. The surface of the raw foil, which is in contact with the cathode roller, is called a smooth surface or an S surface, the other surface of the raw foil is called a rough surface or an M surface, the smooth surface is in mirror phase relation with the cathode roller, the surface is smooth and has low roughness, and the microscopic appearance of the rough surface is in a wavy mountain-like structure and has high roughness. The surface treatment of the raw foil is to carry out electroplating roughening on the treated surface, and is actually a process of metal electric crystallization, and crystal nucleus generation and growth are carried out simultaneously, wherein the speeds of the two processes determine the thickness degree of copper nodules, when the generation speed of the crystal nucleus is greater than the growth speed of the crystal nucleus, a coarsened layer with fine crystals and compact arrangement can be obtained, and the coarsened layer is coarse in structure crystallization. In the surface treatment process of the copper foil rough surface, the rough surface is in a peak-shaped structure to have a tip discharge effect, and coarsened copper nodule particles are concentrated at the top of the peak to grow so as to cause the phenomenon of spike and uneven coarsening of the coarsened layer, so that the roughness of the finished foil is higher, and the signal transmission and insulation safety are affected. Disclosure of Invention The invention aims to solve the technical problems of providing an electrolytic copper foil with special coarsening morphology and a preparation method thereof, which are characterized in that fine copper nodules with special sheet morphology and spherical morphology are formed on the rough surface of the copper foil, copper nodule particles cover the peaks and valleys of the whole rough surface, on one hand, the roughness is reduced, and meanwhile, the lamination area of the surface of the copper foil and resin is increased, on the other hand, the staggered copper nodule structure has more pores, and the resin can be embedded into the pores in the pressing plate process so as to ensure the sufficient anti-stripping strength of the copper foil. The invention provides an electrolytic copper foil with special coarsening morphology, which is characterized in that coarsening tissues of a treatment surface are in a sheet morphology and a spherical morphology. The length of the flaky morphology roughened tissue is 500-1200 nm, the thickness is 60-100 nm, the length-thickness ratio is 7-20, the diameter of the spherical morphology roughened tissue is 200-600 nm, and the number ratio of the flaky morphology roughened tissue to the spherical morphology roughened tissue is 1:1-5:1. The coarsened structure uniformly covers peaks and valleys of the whole rough surface, and has strong deep plating capability. When a laser confocal microscope is used for microscopic parameter analysis, the roughness Rz of the treated surface is measured to be 8.0-10.0 mu m, the root mean square roughness Rq is 1.40-2.00 mu m, the surface roughness Sz is 12-17 mu m, the peak density Spd is 9000-13000 mm -2, the peak curvature Spc is 300-500 mm -1, and the interface expansion area ratio Sdr is 40-100%. The peel strength between the copper foil and the IT968G type PPO resin substrate is not less than 1.30kgf/cm. The insertion loss of the copper foil and the PCB formed by IT968G type semi-curing processing is between-1.10 and 2.00dB/inchch when the signal frequency f=4 GHz. The invention also provides a preparation method of the electrolytic copper foil with special coarsening morphology, which comprises the following steps: (1) Performing electrochemical polishing pretreatment on the rough surface of the copper foil by adopting a pulse power supply to remove an oxide layer and oil stains on the surface of the copper foil; (2) Forming a roughened layer on the roughened surface of the copper foil by adopting an additive-assisted roughenin