Photoworks
First of all the plots are made and Photoplots are developed according to the data supplied by the customer. The necessary Gerber data is extracted from the customer's data (Eagle, Protel, Target etc.)
Panelling
Then the PCB-Pool standard board as well as the drill layer and the sub-strata are panelised. The PCB-Pool standard board comprises of a 1.6mm thick base material which has an 18µm coating of copper on each side.
Drilling and pinning
At this stage the reference holes are drilled and the PCB-Pool standard board with drill layer and sub-strata is pinned.
CNC Drilling
With the help of CNC drill machines the through-hole plated and component drills are produced. During this process spindle speeds of up to 100,000 revolutions per minute are recorded.
Through-hole plating
Now an electrographic film (e.g. Palladium) is electroplated to the wall of the drill cavity, to allow for galvanisation with copper at a later stage.
Brushing
Because PCBs must be completley free of grease and dust, they are subjected to cleaning (e.g. by brushing) before proceeding to the next stage.
Resist laminating
Under extreme temperatures and pressures the whole PCB is laminated with a photosensitive dry resist (LAMINAR 5038).
Resist exposure
Using the previously generated photoplots the resist is exposed to light.
Resist development
Through cycle construction the exposed PCB is developped in a 1% sodium carbonate solution. The PCBs are thereby structured.
Electroplated Conductor Configuration
Those tracks and pads which are developed free of photo resist are copper-plated to a thickness of approx. 35µm and fused with a 6µm -10µm tin film, protecting the tracks and pads during the final etching process.
Resist stripping
The photoresist is stripped away with a 2.5% caustic potash solution. This lends itself to the immersion and spray coat processes.
Etching
The next step is the spraying on of a coat of ammonia solution onto the copper film, getting rid of any excess copper, while the galvanised tin protects the tracks and pads.
Tin stripping
Only then will the tin be removed using a nitric acid based tin-stripper. This lends itself to the dipping or spraying processes.
Soldermask application
The soldermask can be applied as a dry film or a liquid lacker in a hanging casting implement. After this come the screen-printing and spaying processes.
Soldermask exposure
Finally, using the previously generated photoplots the soldermask is exposed to light.
Soldermask development
The development of the exposed PCB is in turn achieved through a cycle construction in a 1% sodium solution. Hence all soldering points and pads, which are to be tin plated later, are cleared of soldermask.
Silkscreen
Using a Direct Legend Printer, the silkscreen is immediately printed onto the soldermask. In the process the printhead sprays the screenprint colour, defined by Gerber data, directly onto the PCB.
Burning-in
At a temperature of 150°C the soldermask is tempered over a period of approx. 60 minutes.
Hot Air Levelling (HAL)
On the surface coating the pads are tin plated in a hot-air tin-plating system at a temperature of around 270°C. In the process the PCB is immersed in liquid tin which is blown off with preheated air under a pressure of approx. 5 Bars.
The technical specifications sheet for the lead-free tin concerned can be found by using the following link: Specifications.
Pinning
At the same time the PCBs are locked in place for routing.
Routing
In the final stages the individual PCBs, with the aid of a CNC Routing machine are routed away from the standard PCB-Pool board. This operation involves spindle speeds of over 40,000 revs per minute and a feed rate of 1million per minute.
Photoworks
First of all the plots are made and Photoplots are developed according to the data supplied by the customer. The necessary Gerber data is extracted from the customer's files (Eagle, Protel, Target etc.)
Resist laminating
Under extreme temperatures and pressures the internal layers are laminated with a photosensitive dry resist (LAMINAR 5038).
Resist exposure
Using the previously generated photoplots the resist is exposed to light.
Resist development
Through cycle construction the exposed inner layers are developed in a 1% sodium carbonate solution.
Pressing
Only at this stage are the individual layers pressed in a Multi-layer press at a max. temperature of 175°C and a cyclic time of 90 minutes for the layer structure.
The next stage is drilling. The following manufacture process is equally valid for both multi-layer and double-sided PCBs.
