PCB’s

Printed Circuit Boards By Think Radio
PCB design and prototyping

Think Radio ensures that costs in this area are kept low, and that customers can also access the design tools, should they wish to. Eagle and Ki-Cad are popular low-cost PCB design tools, and Think Radio is happy to work with them if that is the customer’s preference. But for ease-of-use, bug-free designs (even of significant complexity), Think Radio mainly uses DipTrace.

DipTrace

DipTrace is a low-cost PCB design tool suite, without the drawback of freeware such is Eagle or Ki-Cad (i.e. no official support if you hit trouble). DipTrace ports in and out of multiple other commercial and non-commercial tools, and uses the industry standard Gerber, and Extended Gerber RS-274X, (aka Gerber X1 And Gerber X2 respectively) files to send off PCB designs for manufacture.

Good design principles

Good PCB design starts with parts selection, schematic capture, physical dimensions for the board (positions of mounting points), critical layout details (especially if there is an antenna / radio), component placements (especially if it carries buttons/LED’s/connectors), heat and power considerations (heatsinks), and, in some cases, safety (high voltages, electrical isolation, legal compliance). In fact it is often an iterative process to find the smallest/most-economic/most-reliable/easy-to-manufacture compromise.

For prototype work it is often wise to leave vacant PCB locations for ‘nice to have’ accessory components, that may or may not be actually soldered to the board in the production version. Also wise is maximum access for test purposes! Adding connector headers and test points may save considerable costs in tracking down design issues. Vacant PCB slots cost nothing!

Think Radio can also use PCB technology to produce designs for Business Cards and novelties, and designs/stencils/apertures etc., in laser-cut stainless steel.

Board rework

Most modern PCB’s, where possible, no longer use through-hole components, for reasons of manufacturing costs, performance and to minimise the size of the PCB. This does however mean that making changes to prototypes is no longer a matter of applying a soldering iron. Think Radio has hot-air rework available, as well as the necessary skills to carry out repairs, swap components, squeeze in extra components (dead bug), and to skilfully modify PCB tracks. Standard 0603 and 0402 surface mount components are usually no problem, even if quite extensive rework is required. By using low melting point solder pastes, even dense double-sided boards can be reworked, without disturbing components on the opposite side.

Dead bug

Even where no pad exists for the desired component change, it’s possible to do ‘Dead Bug’ and glue down new components in an inverted position, and attach flying wires to the component legs. However this sort of thing is intended to correct PCB errors on prototypes, and the results don’t offer the standards of long-term reliability outside of the prototyping environment. Like wise it’s possible to cut tracks, re-route signals etc., provided that they appear on the outer surface layers of the PCB.