​Copper clad laminate upgrades rely more and more on powder!

In recent years, the application of Fillers technology in copper clad laminates (CCL) has now become an important topic in the development of CCL technology.

Case 1: Lead-free copper clad laminate

The European Union's RoHS decree in 2006 announced the arrival of the lead-free era in PCB assembly.

Case 2: Preparation technology of high thermal conductivity halogen-free aluminum-based copper clad laminate

Aluminum-based copper clad laminate has excellent comprehensive properties such as high thermal conductivity, high heat resistance, high heat dissipation, and high insulation.

The core and key technology of aluminum-based copper clad laminates lies in the development of insulating dielectric layers with high thermal conductivity.

Case 3: High frequency and high speed copper clad laminate

The high frequency and high speed of electronic information products put forward higher requirements for the high frequency characteristics of copper clad laminates.

The main problem of using fillers in the industry is the dispersion of fillers.

1.

The most commonly used method of filler dispersion is to destroy the bonding force between filler molecules through the shear force generated by mechanical stirring.

2.
Surfactant method

The organic functional group of the surfactant is used to chemically adsorb or chemically react with the surface of the particles, so that the surfactant covers the surface of the particles, which reduces the surface energy and reduces the chance of mutual bonding between the particles.
Commonly used surfactants are: titanate coupling agent, stearic acid, surfactants and so on.

3.
Inorganic coating

The filler surface generally has a large amount of -OH, which is relatively hydrophilic, which is not conducive to dispersion in polymers such as epoxy resin.
Inorganic coating is to coat a layer of oxide on the surface of the filler to improve the dispersibility of the filler.
At present, the inorganic coating materials mainly include SiO2 and Al2O3, among which SiO2 is the most commonly used, and its dosage is generally 1%-10% of the filler mass.

4.
Organic coating

The raw materials for organic coating mainly include organosilicon coupling agent, titanate coupling agent, etc.
Regarding the reaction mechanism of organosilane coupling agent, it is generally considered to be divided into two steps.
In the first step, the coupling agent first discovers the hydrolysis reaction, -OCH3 is hydrolyzed to -OH:

The hydroxyl groups generated by the hydrolysis of the organosilane coupling agent are highly reactive.
They can condense by themselves under heating, and can also condense with the hydroxyl groups on the surface of the filler to form an organic layer on the surface of the filler.
These reactive groups can interact with the organic The substance reacts and combines.
Therefore, through the use of silane coupling agents, molecular bridges can be built between the interface of inorganic substances and organic substances, and the two materials with very different properties can be connected together to improve the performance of the composite material and increase the bonding strength.

Inorganic coating and organic coating can improve the dispersibility of fillers, and at the same time, coating with a layer of SiO2 helps to improve the chemical resistance and heat resistance of certain fillers.

references:

1.
Research on the surface treatment of copper clad laminate filler; Guangdong Shengyi Technology Co.
, Ltd.
; Chai Songgang, Zeng Xianping, Tang Junqi, etc.