Through Hole Plating Process

The increasing miniaturisation of integrated circuits, higher packing density and smaller layout-dimensions make high demands on PCB - manufacture. In many cases the production of a PTH board or multi-layer in high quality is required.

Since 1970 Walter Lemmen offers the complete range of PCB equipment to produce single or double-sided PCB as well as PTH or multi-layer boards.

Starting with double sided coated copper laminate up to the coating of the PCB with durable solderable finish all materials and machines are efficiently combined to achieve optimal results. The modern technology of the machines and our extensive experience allow to produce PCB (35 µm copper laminated) with track spacing up to 100 µm and drill hole of 0,4 mm.

The combination of the equipment depends mainly on customers requirements such as max. PCB size, copper finish (e.g. tin, gold, OSP) and others.

There are three methods of producing PTH board in high quality:

• Pattern Plating Process
• Panel Plating Process
• Panel Plating with isolation routing

To produce high quality PTH board, pattern or panel plating process are recommended. Especially with isolated routed PCB splashing of solder can cause short circuits. In the field of fine conductor technique and with large isolation areas, panel or pattern plating process is the choice to achieve a high quality and to reduce production time and costs.

For the production of prototypes or small runs the panel plating process is preferably used. In comparison to pattern plating, the panel plating process is easier to run and acid etchant can be used. During pattern plating process ammonia etchant is necessary.

For more detailed information on the panel plating process please refer also to the following web site of a German university in Würzburg: http://www.fh-sw.de/sw/fachb/et/labinfo/lpt/start1.htm ausführlich dargestellt.

The relatively complicated process of through hole plating is nowadays easy to handle by using graphite technology. The environmental friendly graphite process is very easy to run (3 step system) and gives high production security.

Graphite technology
3 step process for through hole plating

Advantages:
- Very easy to handle
- fast process
- environmental friendly because no heavy metals are used
- long shelf life of the chemicals
- high quality also for blind vias.

Our engineers will support you informally in detail to find your best choice concerning laboraty, technology and processes.