| abstract |
A substrate comprises a solder-through polymer layer formed by depositing a monomer using a low power continuous or pulsed wave plasma polymerization technique, wherein the monomer comprises the general formula: CnF2n+1Cm X2mCR1Y-COO-C(R2) = CH2, wherein n is 2 to 9, preferably 2 to 6, m is 1 to 9, X and Y are H, F, CI, Br or I; R1 is -H or an alkyl, e.g. -CH3, or a substituted alkyl, e.g. an at least partially halo-substituted alkyl; and R2 is -H or an alkyl or substituted alkyl, e.g. an at least partially halo-substituted alkyl. The polymer layer is preferably superhydrophobic (with a contact angle for water of greater than 100°) and/or superoleophobic, and has a thickness of 10 to 500 nm, more preferably 10 to 200 nm, more preferably 20 to 200 nm, and most preferably 40 to 70 nm. The polymer layer may also have a uniformity variation of less than 10%. The substrate is preferably a printed circuit board. |