Assembling of Printed Circuit Boards | PEWTRONIC s.r.o.
Through Hole Technology (THT)
We dispose of devices for adjustment of axial and radial lead components, we carry out manual PCB assembly and automatic machine soldering (tin wave) with spray application of flux. We have possibility for maximal width of soldered PCB 350 mm. Used soldering alloy is Pb free and meet ROHS directive (65/2011/EU) as well as ROHS II (863/2015/EU).
Surface Mounting Technology (SMT)
As a part of this technology, we can offer semi-automatic screen printing of pastes and adhesives, very precise machine paste and adhesive dispensing, four pick na place machines with the possibility of mounting from SMD 01005, SMD 0201 and larger. The machines are also equipped with precision integrated camera guidance with a pitch of less than 0.4 mm so called fine pitch incl. BGA or microBGA packages. Soler paste remelting is carried out in a continuous convection oven (reflow) or a vapour phase furnace. The production line is optimized for lead-free production. The use of a lead solder paste is currently only at the customer’s request.
The service includes 100% optical control of the assembled PCBs.
The maximum format of the PCB frame is 390 x 305 mm and the real capacity of the automatic machines and follow-up technologies is now over 100,000 SMD for nominal work shift.
Cleaning of assembled PCBs
After PCB assembly we can wash the solder surfaces, which is normally done in an ultrasonic bath using an organic solvent, followed by inert rinsing and drying. We can customize your washing with isopropyl alcohol, demineralized water, mechanical brushes, multiple cycle washing etc. We recommend washing for PCBs intended for conformal coating.
We can cover the installed electronic assembly with a transparent varnish to increase insulation protection, reduce the effects of environmental factors or vibration stress. The machinery allows us to paint productively and repeatedly with maximum precision and layer strength. The specialty is the possibility of selective conformal coating of only critical parts, or omission of contact points. The high accuracy and equipment of the machine also enables the painting of areas in places subject to capillary phenomena. We exclusively use the top fluorescent varnish ELPEGUARD SL 1306 in a nominal layer of 50 micrometers in the dry state. Other varnishes can be used according to technical assessment. We will provide you with more information during the pre-production consultation. You will find basic instructions in the tab „Specification of technical documents for production“ paragraph h).
Program loading, parameters adjustings and functionality test
We can program your device by loading the code through the created interface, then adjusting the operating parameters and performing a functional test to bring to your hands full functional product. We can design needle adapters and various mechanical interfaces to ensure the measurement of recommended parameters. We always work very closely with the customer development team. For more complex electronic processor assemblies, is usual use customer´s testing equipments.
Extreme temperature test
We can now test your electronic assembly or just the PCB itself for thermal stress resp. sharp temperature fluctuations in the temperature range from -70 ° C to + 180 ° C with a very high heating or cooling slope of up to 8 K / min. This test can be set cyclically from a few hours to several days. The test should include diagnostics of the control unit error rate or monitoring of critical functional parameters, when the tested units are powered up and maintained in a functional state. Testing takes place in a chamber with a volume of 200 l and another option is a test with a simulation of relative humidity in the range from + 10% to + 98%. The equipment we offer you in the form of a service is calibrated in accordance with ČSN EN ISO / IEC 17025.
Mechanical assembly works
They usually close the production cycle and include all the work associated with the assembly of mechanical components, covers, components with bolts using torque screwdrivers, riveting, gluing, UV-stabilized glues, etc.
Hermetization and application of sealants
This is a suitable form of resolving electronic modules from the environment. In our company we mainly use the outstanding ISOPUR K760 two-component polyurethane subsatnce, which we machinery apply with great volume accuracy. Here customers can download the datasheet and statements to the ROHS and REACH II directives: Go to the websites
Local application of stuff can well serve to mask the signatures of electronic components or to increase the dielectric strength of part of the circuits. Complete overlay of the entire PCB ideally inserted in the mounting box or lost form, ensures resistivity against moisture penetration (absolute water resistance), chemical effects, mechanical stress and vibrations.
Applying the stuff will occur after curing to an unbreakable connection of electronics and matter. In case of an electronic circuit failure or destruction, eg by overloading, the possibility of repair is almost excluded. For these reasons, we require a functional test of the electronic equipment to be carried out before the casting by our staff only. Just this way can we be responsible for the flawless product at the output of the process.
Sometimes technology of the low-pressure injection in the form may be more advantageous, it call HotMELT. This way you can protect or aesthetically close your electronics and it is from other options that we would like to recommend eg.for USB modules, sensor circuits etc. Here you can find more information: Go to the website
Last update 18th January 2022
Your certified partner acc. to ISO9001:2015, IPC-A-610 soldering standard and wiring harnesses UL subject 764 CSA. The company PEWTRONIC has great experience since 2003.