Patent Application
20080032109
Copper-plated PCB blanks are cleaned in 20% phosphoric acid solution at room temperature for 5 min, rinsed in water and dried in a furnace at 100° C. for 5 min, so as to form a hydrophilic surface. The PCB blanks are then immersed for 15 min in a 1.5% 6-mercapto-1-hexanol-ethanol solution at room temperature, rinsed with pure ethanol and then dried in a furnace at 100° C. for 5 min.
Then, by immersing the carriers in 3% octadecyl trichlorosilane-cyclohexane solution at room temperature for 15 min and subsequently placing the carriers into a furnace for hardening at 120° C. for 10 min, a further monolayer is created and thickened by repeating the above process. The PCB blanks are then wet-hardened for several hours at room temperature in a highly moist atmosphere (more than 85% atmospheric humidity). The thus-coated PCB blanks are then immersion-coated in a 3% polysilane-co-polyacrylate base solution (pH=9), then immersion-coated in a 3% polysilane-co-polyacrylate ethanol solution, then dried in a furnace at 120° C. for 15 min.
Since this is only a test, patterning by means of a laser was not carried out, but the coated PCB blanks were etched with a strong acid etching solution (HCl—CuCl2-CuCl) and then treated with a (NaOH/2 propanol 20%) solution at 60° C. for 5 min. The hydrolysis method can be accelerated by immersion in an ultrasonic bath. The inorganic and organic impurities or residues, respectively, are removed from the metal surface by using an HF/H2O (1%) and HCl/H2O (5%) acid solution. Then the PCB blanks are rinsed with water and dried in a furnace or in hot air. By this, a very clean and structured copper-plated surface was again obtained on the PCB blanks.
Copper-plated PCB blanks are cleaned by removing the natural oxide by immersion in a diluted HNO3 solution (10% in deionized water) for 5 min. Then, after repeated cleaning with water and isopropyl alcohol, the PCB blanks are dried in a flow of nitrogen gas so as to form a hydrophilic surface.
The first monolayer is then formed by immersion of the freshly cleaned PCB blank in a 3% solution of octadecyl-trichlorosilane, dissolved in hexadecan, at room temperature for 15 min. Die PCB blanks provided with a first monolayer are hardened in a furnace for 10 min at 120° C., and then the process is repeated. The two-fold coating generates a homogenous film on the surface of the PCB blanks. The PCB blanks are then wet-hardened for one hour in a high humidity box (moisture of more than 85% atmospheric humidity).
The coated PCB blanks are immersion-coated in 3% poly(styrene-alt-maleic acid), sodium salt solution (pH=9) and then dried in a furnace at 120° C. for 15 min.
Copper-plated PCB blanks are immersed in 4N HCl solution for 5 min. The PCB blanks are then rinsed with water and dried in a furnace for a short time at 80° C. The clean PCB blanks can be wetted with water, demonstrating a hydrophilic surface. The cleaning process is carried out less than 1 h before the first monolayer is produced so as to minimize impurities. Before the coating, the PCB blanks are stored in a chamber with a controlled relative humidity of 55%.
The cleaned PCB blanks are then immersed in a 3% 1-octadecanethiol/ethanol solution at room temperature for 15 min, rinsed with pure ethanol and then dried in a furnace at 100° C. for 5 min. The coating process can be repeated any number of times.
The coated PCB blanks are then immersion-coated in 3% polystyrene methacrylate-terminated cyclohexane solution and dried in a furnace at 120° C. for 15 min.
Copper-plated PCB blanks are cleaned in 20% phosphoric acid solution at room temperature for 5 min, rinsed in water and dried in a furnace at 100° C. for 5 min, so as to form a hydrophilic surface. The pretreated PCB blanks were then immersed in a 1.5% 11-mercapto-undecyl-acid ethanol solution at room temperature for 15 min, rinsed with pure ethanol and then dried in a furnace at 100° C. for 5 min.
Then immersion of the monolayer-provided PCB blanks in 3% octadecyl-trichlorosilane-cyclohexane-solution at room temperature for 15 min and subsequent placing of the PCB blanks in a furnace for hardening at 120° C. for 10 min and repeating of the above process yields two further monolayers. The coated PCB blanks are wet-hardened in a highly moist atmosphere (more than 85% atmospheric humidity) for several hours at room temperature.
The coated PCB blanks are then immersion-coated in 3% polysilane-co-polyacrylate base solution (pH=9), then immersion-coated in 3% polysilane-co-polyacrylate-ethanol solution, then dried in a furnace at 120° C. for 15 min.
Since this is a only test, patterning by means of a laser is not performed, but the coated PCB blanks are etched with a strong acid etching solution (HCl—CuCl2—CuCl) and then treated with a (NaOH/2-propanol 20%) solution at 60° C. for 5 min. The hydrolysis method can be accelerated by immersion in an ultrasonic bath. The inorganic and organic impurities or residues, respectively, are removed from the metal surface by using an HF/H2O (1%) and HCl/H2O (5%) acid solution. Then the PCB blanks are rinsed with water and dried in a furnace or in hot air. By this, a very clean and structured copper-plated surface was again obtained on the PCB blanks.
| Number | Date | Country | Kind |
|---|---|---|---|
| A 726/2003 | May 2003 | AT | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/AT04/00168 | 5/13/2004 | WO | 00 | 4/12/2007 |
