MCU is a PIC16F1827, a relatively new model in the enhanced mid-range line of PICs. All I/O pins are used. VPP pin is dedicated to ICSP.
There are four jumper links (three are visible in the photo)--two for VDD and two for ground. I don't know if I could've eliminated the jumpers had I placed the components differently and routed differently. I tried. I really tried to minimize the number of jumpers.
water heater timer board I've again left the photoresist on the traces. Only the photoresist on pads were cleaned off using acetone. And this was done immediately prior to soldering to prevent oxidation buildup. No further preparation of the pads was necessary. The freshly exposed copper took on solder easily.
The components of course were a different story. All leads which showed signs of tarnishing/oxidation were cleaned using the gray (abrasive) end of a Faber-Castel 7061B-50 rubber eraser. After which leads of all components were wiped down with isopronanol soaked cotton to remove oils and eraser debris.
Unfortunately I don't have any solder that's less than 1mm in diameter so the joints tend to have excess solder on them. The copper pour areas are the pads for the 78L05 voltage regulator. The larger copper area will aid in heat dissipation since the input voltage to the regulator is 12V and so there's a large headroom of 7 volts. Given approximately 50mA maximum current through the display, the 78L05 will be dissipating some 350mW. With a junction-to-ambient thermal resistance of 200C°/W for the TO-92, the regulator would reach a temperature of 0.35 x 200 = 70° above ambient. With an ambient of 30° the junction could reach 100° when "8" is being displayed. This is still below the absolute maximum of 125° but the lower the junction temperature the better.