FAQ’s

What kind of board types can Minnitron produce?

Single-sided conventional
Double-sided conventional
Plated through-hole
Multilayer (up to 10 layers)
Unclad spacers, insulators, washers
Front panels
Aluminium-backed (IMS) substrate

Which industry approvals does Minnitron hold?

We can supply boards to UL796 & UL94V-0 in accordance with our file number E218872.

All our processes are now fully RoHS compatible.

We have gained BS EN ISO9001:2008 by NQA certificate number 16105.

What types of delivery schedule does Minnitron offer?

Our standard delivery schedules are as follows:

3 working days
5 working days
10 working days

Our standard delivery time for smaller orders is 10 working days – this is our Economy delivery. If you would like any other delivery, please do not hesitate to contact us. We regularly process orders for 24 hour and 2 working day deliveries.

Does Minnitron offer gold plating?

We have in-house electrolytic gold plating facilities and can plate edge connectors, and whole panels (maximum size 8″ x 8″), and selectively plate gold pads.

Standard thickness depends on the application but, as a guideline, 2.5 microns is used for minimal insertions and 5.0 microns for multiple/repeated insertions.

What type of finishes can Minnitron provide?

Solder Masks
Photoimageable solder masks (PI) is a high definition ink used for surface mount applications. However, we now use it on all our boards.

We have it in the following colours:
Green
Black
Red, black, yellow and clear are normally available.

Notation (silk screen)
The standard colour for the notation (also known as ident or silk screen) is white. We do also have black and yellow, which can make a nice contrast with different colours of solder mask.

Lead-free HAL (hot air levelling)
One of our standard finishes for PTH and multilayer boards is lead-free hot air level. This means that the solder mask is applied over bare copper. The board is then dipped into a molten alloy of tin, copper and nickel, thus coating the exposed copper areas, i.e. the pads and holes, with a highly solderable finish.

Immersion silver
In addition to the HAL finish and to comply with the RoHS directive, we have an immersion silver line. This finish provides an extremely flat and solderable finish that is completely lead-free. Major investment has enabled us to fully automate the process so that we can offer it as an alternative to HAL at no additional cost.

Electroless nickel immersion gold (ENIG) or Ni/Au
Gold is an excellent choice for a circuit board finish. Its strengths lie in the flat surface appearance, superior solderability and excellent shelf life – making it the ultimate finish for high-quality, high-performance boards.

What is the shelf life of Minnitron products?

Under normal storage conditions, a shelf life of 6 – 12 months is expected.  The boards should be packaged to protect them from oxidation and stored at room temperature.  If boards are removed from the packaging, it is important to re-seal the packaging. (See solderability tests carried out as attached.) As a general overview, results are found to be excellent, providing the silver finish is protected from contamination and/or oxidation. Sulphur or chloride environments will affect the silver surface (resulting in a blackened or yellowed appearance respectively), reducing the solderability.

The silver finish regularly passes the Siemens Shelf Life Test, (155 deg C, 4 hours), with good subsequent solderability.

What level of solderability do Minnitron finishes offer?

The silver finish has excellent solderability characteristics for all applications, including wave and reflow operations.  For reflow, it is important that assembly parameters are per the paste manufacturers’ recommendations.

In practical terms, solderability will be equivalent to a HASL finished board.  It should be noted, however, that as with any other alternative solderable finish to HASL (electroless nickel immersion gold, tin, organic etc.), the surface is more susceptible to surface contamination and fluctuations in assembly parameters. For customers used to assembly using HASL finished boards, it may be necessary to ensure assembly parameters are at optimum, e.g. solder temperatures, and/or reflow thermal profiles are correct for the solder and materials being used.

Does Minnitron offer bare-board testing?

Minnitron’s ATG A3 flying probe bare-board test system enables complex and small volume circuit boards to be tested to net-list data.