A kind of pre-selective pcb black hole-forming agent and preparation method thereof

Abstract

The invention discloses a pore-forming agent for a selective PCB before black porosity. The pore-forming agent is composed of the following raw materials in mass percentage: 25%-45% of triethanolamine, 1%-10% of octadecyl benzylbis (2-hydroxyethyl) ammonium chloride, 1%-5% of surfactant, 1%-5% of adhesive, 2%-4% of imidazole derivative, and 31%-64% of deionized water. A copper surface line can beeffectively prevented from being electrified during pore wall static electricity adjustment by pore conditioning, the adhesion of carbon on the copper surface line during the following black porositytreatment can be reduced, the time of post-sequence micro-corrosion is further reduced, the risk of excessive corrosion of high-rise plates with more than six layer is reduced, and the application scope of the black porosity treatment process is greatly widened.

Description

technical field [0001] The invention belongs to the field of direct metallization of flexible circuit boards, and in particular relates to a selective PCB hole-regulating agent before black hole formation and a preparation method thereof. Background technique [0002] The traditional circuit board through-hole process uses the method of depositing chemical copper on a non-metallic substrate to obtain a conductive copper plating layer so that the subsequent electroplating process can be performed. Due to the complexity of the process and the use of excessive heavy metals and formaldehyde, etc. Substances, nowadays, more flexible circuit boards replace the chemical copper process by depositing nano-carbon black. The aqueous solution of black (referred to as black hole liquid) enables the deposition of carbon black in the pores to achieve conductivity. However, after soaking in the black hole liquid, not only the carbon layer needs to be deposited in the non-metallic pores of t...

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Problems solved by technology

[0002] The traditional circuit board through-hole process uses the method of depositing chemical copper on a non-metallic substrate to obtain a conductive copper plating layer so that the subsequent electroplating process can be performed. Due to the complexity of the process and the use of excessive heavy metals and formaldehyde, etc. Substances, nowadays, more flexible circuit boards replace the chemical copper process by depositing nano-carbon black. The aqueous solution of black (referred to as black hole liquid) enables the deposition of carbon black in the pores to achieve conductivity. However, after soaking in the black hole liquid, not only the carbon layer needs to be deposited in the non-metallic pores of the carbon layer, but the carbon layer does not need to be deposited. A layer of carbon layer will also be deposited on the copper surface circuit. If this layer of carbon layer is not removed, the subsequent electroplating copper and copper substrate will be broken due to the different stress of the carbon layer in the middle. Therefore, the current process is After depositing the carbon layer, peel off a little copper layer on the copper surface by micro-etching to make the carbon lose its adhesion and fall off. However, this process is only applicable to some low-layer circuit boards. When the number of circuit boards exceeds six layers, the hole Copper layers between inner layers have a greater risk of being over-corroded due to this microetching