SMT Fixtures Tooling for Large and Small Pcbs Adjustable Wave Solder Pallets

Surface-mount technology (SMT) is the leading factor driving higher circuit densities per square inch on PCBs. Directly attaching components and devices to the surface of circuit boards has enabled products to perform with much higher circuit speeds, allowed greater circuit density, and requires fewer external connections. These advances have greatly lowered costs, improved performance and product reliability. However, these benefits do not come without their challenges. Printing solder paste on diminishing pad sizes, placing smaller components, and reflowing entire assemblies with their varieties of termination finishes and materials are just a few of the technical challenges that process engineers face every day.

ADJUSTABLE PALLETS FOR LARGE PCBS

Accommodates PCBs 8.00” x 9.100”
Supports a PCB on all sides
Available in sizing up to 18”W x 28”L
Additional center slides can be added for multiple PCB processing
ADJUSTABLE PALLETS FOR SMALL PCBS
Accommodates PCBs 0.100”
Adaptable for the smaller PCB where the production process line requires a more versatile, multiple-array tooling/fixture
Low-cost alternative to custom tooling
Not only does the adjustable fixture accommodate PCBs as small as 0.100”, but it will also accommodate PCBs as large as 8.00” x 9.100” simply by removing a couple of the center slide bars.

This particular tooling/fixture will also carry the PCBs through the conformal coat process and, with a slight hardware upgrade, the reflow oven as well.

ADJUSTABLE SCREEN PRINT PICK-N-PLACE REFLOW PALLET

Adaptable for the Smaller PCBs designed to go through the entire SMT line, and will adapt for non-rectangular PCBs as well
Uses edge tension to secure the board in place
Fiducial orientation mark located on corner of pallet
Each pallet has rail steps on all four sides
Pallet centers the PCB and offers recognized placement of one corner for multiple pallets to maintain alignment
360-degree Fixture
This fixture allows for 360-degree rotation adjustments for optimized angle to receive the solder wave application.
This option provides the best results for minimizing bridging and opens.
45-degree Fixture
This 45-degree fixture allows 80 degrees of rotation adjustment with a lower cost adjustable as compared to the above 360-degree fixture.
This option provides the best results for minimizing bridging between pins.

Specification:

Our sales network

This estimation may be done in three ways

If a PCB is available (preferably populated) - our sales engineers can rapidly evaluate your board.
If PCB design data is available we will process, analyse and remotely assess it.
You can do it using the rules presented below - our customers quickly find that the above two methods are easiest.

Gerber, Excellon and other data required

Pin Land to SMT pad clearance evaluation

The two figures below each show part of a CSWSC in plan and section views. The right hand figure shows that more clearance
is required when the connector orientation is perpendicular to the wave.

PTH Components Located Parallel to direction through wave

The clearance required between the pin land and SMT pad can be made quite
small, as the solder does not have to flow "under" the component pockets.

PCB Design Implications - for Board Designers - or respin

We are often called upon by our customers to help with identifying design respin opportunities.

We will identify problem areas within a board and suggest appropriate movements of components. (Ideally before the PCB is fabricated)

However for board designers reading this, can you remember another four "rules" (to compete with the hundred other rules you have to have floating
around in your head).

Keep large (height) SMT components away from PTH areas.
Leave the leading and trailing areas around PTH components as clear as possible.
DON'T put any SMT components within 3mm (0.12") of any PTH components.
DON'T put all PTH components in line along one edge of a board - leave some space to allow us to support the masking in the centre of the board.