Common PCB Misconceptions

In the PCB industry, there are many misconceptions ranging from the design stages to fabrication and assembly and even using PCBs in the field. Many of these misconceptions can result in lost money and time. In this article a few of the more common misconceptions will be covered.

Layouts vs Materials

The exact same layout of a PCB will give you different results depending on the materials used in the fabrication of the boards. The following electrical properties, at minimum, should be considered when selecting materials for your design: dielectric constant(Dk), dielectric loss tangent(Df), volume resistivity, and surface resistivity. Of course, there are also the thermal, chemical, and mechanical properties of the materials to consider such as glass transition temperature (Tg), flammability rating, and peel strength.

When using less common materials for applications such as metal core PCBs, RF PCBs, and flexible PCBs the various properties of the materials become even more important.

Size vs Cost

In most cases, the idea that a smaller object that uses up less material is cheaper than it’s larger counterpart is entirely correct. However for PCBs when you get to the very small dimensions (less than 0.4”x0.4” at Bittele are considered under-sized) the costs associated with the fabrication of such a small board begin to increase due to the extra care and handling that is required.

Other Technical Misconceptions

Though it may initially sound like a bad idea to put a via in a pad that is to be used to carry a signal, it is not necessarily a bad idea if extra care is taken. Through Bittele’s via on pad process, it is possible for the pad to retain its electrical properties with a via being drilled through it. If you require this process on your project please let us know during the quotation stages of your projects.

Another common misconception is that a non-conductive fill of a via will not do a good job of passing an electrical signal. This is not true because the barrels of the via itself will still be plated with copper and thus allow for the electrical signal to remain unaffected.

Although the combination of a green solder mask and white silkscreen is very popular, and at Bittele it is our default when not specified, almost any colour can be used for your solder mask and silkscreen. Other less common combinations include black solder mask with white silkscreen, white solder mask with black silkscreen, red solder mask with white silkscreen, and blue solder mask with white silkscreen. If you would like a particular colour of solder mask to be used in your project please mention it to your sales representative during the quotation stages.