PCB Global’s CAM Engineering department will invariably have a few EQ’s to confirm. This is dependant on the quality of the PCB design file package received. See below example of a typical EQ for plated and non-plated through holes:

Plated (PTH) and Non-Plated (NPTH) Through Holes

EQ from CAM:

Holes noted as plated through holes do not have any pads and holes with pads are noted as non-plated through holes.

Explanation:

Generally, holes that have no pads should be non-plated through holes as without a pad landing on the top and bottom layer, the hole wall integrity can be compromised. This causes weakening as chemical solutions can seep into these areas, reducing the long term reliability of the PCB.

With the non-plated through holes with pads, although this is not uncommon, it is still a EQ that is frequently asked. These holes are best fabricated with a copper pull back from the edge of the hole (about 10mill) to ensure that there are no copper burs after drilling.

Resolution:

With confirmation from our customer both these hole types were fabricated as non-plated through holes and the non-plated through holes had the copper pulled back 10mil to ensure quality of the PCB.

For further tips and information when designing and laying out your printed circuit board design file please do not hesitate to contact our PCB Global team at sales@pcbglobal.com

Depending on the quality of the PCB design file package received, PCB Global’s Computer Aided manufacturing (CAM) Engineering department will invariably have a few Engineering Questions, also know as, EQ’s to confirm. One example of a typical EQ is shown below:

Non-Plated Through Hole Cutting into Copper

EQ from CAM:

These 2 non-plated through holes during CNC drilling will intrude and cut into the copper Surface-Mount Technology (SMT) pads as highlighted below (see image).

Explanation:

As a rule, SMT pads must not to be cut or drilled especially with a non-plated hole as this process is fabricated during the final route stage when all the surface finish (immersion Gold, HASL, OSP, Immersion Silver, etc.) has been applied. Therefore, drilling now will result in an exposed copper area on the SMT pads.

Resolution:

In this case with the customer’s approval we shaved the SMT pads by 2mil to ensure no exposed copper.

For further tips and information when designing and laying out your printed circuit board design file please do not hesitate to contact our PCB Global team at sales@pcbglobal.com

Once the customer order and PCB design file is received the PCB Global production engineering team will process the manufacturing data which is required at every stage of PCB fabrication. This ensures that your Printed Circuit Boards are manufactured to your specifications. There are multiple combinations when it comes to PCB finishes and specifications. Listed below is an example of a typical 4-layer multi-layer data required on a job card to ensure that all customer manufacturing conformance is adhered to:

PART NUMBER– PCB GLOBAL 123456-A

LAYER – 4 layer

QUANTITY– 512pcs

PRODUCTION PANEL SIZE– 450 x 650 mm

PRODUCTION PANEL QUANTITY- 32

UNIT SIZE– 90 x 150 mm

PANEL SIZE– 300 x 200 mm

BOARDS PER PANEL– 4

MATERIAL– FR4 High TG=170 - S1170

PCB THICKNESS– 1.6mm

COPPER FOIL– 18um Copper

PRE-PREG– 7628HR RC: 47% 0.21mm

CORE – 1.0mm 35/35um Copper

SOLDER MASK COLOUR– Blue

COMPONENT LEGEND COLOUR–  Yellow

SURFACE FINISH– Immersion Gold – ENIG 2-3u”

PROFILING– Panel route with break tabs

This break-down ensures that the operators at each stage of fabrication will assume the precise finishes required on this part number as it flows through the production line. A typical workflow for a standard 4-layer through the PCB Global processes is demonstrated through many small processs.

Firstly the inner layer material is cut and the inner layer laminating and exposure is completed. Developing, etching and AOI inspection is the followed up by copper foil and pre-preg cut and multilayer lamination and pressing. Next the CNC drilling will take place in preparation for Desmear and Electrolysis Copper plating. Once this is complete, laminating and exposure is pattern plaited (Copper & Tin/Lead) and etched with a further AOI Inspection. LPI solder mask along with the component legend silkscreen is applied and then sent to bare board testing. Immersion gold is added with a further CNC routing. The boards are then clarified with deionised water before the final QA. The boards are then packed and dispatched to your requested delivery address.

PCB Global manufacture 1 layer, 2 layer and the high tech 4 layer Aluminium PCB’s for the worldwide electronics manufacturing industry. Applications for Aluminium PCB’s are found predominantly in the lighting, motor drives, relays, automotive, power conversion and 3D printer industries. Using Aluminium PCB Technologies assists in lower equipment operating temperatures which improves the LED’s with consistent colour and brightness, in turn, increasing the LED component life.

For solid state relays Aluminium PCB’s offer great thermal efficiency and are mechanically robust for all heavy industry applications. The correct dielectric choice will also provide the electrical isolation required to maintain operating parameters and meet safety regulations as well. Currently 80% of all Aluminium PCB’s are manufactured as 1 layer with the lighting industry being the largest consumers.

The stack as illustrated below consists of:

Base Metal Layer:Aluminium – generally 1.0 to 2.0mm thickness, 1.5mm being the standard.

Dielectric Layer:Not only to bond the copper circuit layer to the aluminium but more importantly offer the required electrical isolation with minimal thermal resistance.

Copper Foil:As per any standard printed circuit board, the copper foil will be processed and etched to the required circuit layer design.

PCB Global offer the above technologies for Aluminium Printed Circuit Boards on our easy to use online portal -  http://www.pcbglobal.com/quote/aluminium-pcbs/