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Reflow Fixture Pallet DURAPOL Synthetic Stone and Durostone SMT Pallets
|Maximum Operation Temperature(C)||350||350||350|
|Tickness/weight(mm/kg)||3/17, 4/22||5/28, 6/33, 8/44||10/55, 12/66|
Features and Benefits
Wave solder pallets offer many advantages to the cost conscious Process Engineer. These advantages can usually pay back in a few weeks with cost savings and improved yields. By deploying a double reflow process, you can maximize your yields through the wave solder process.
Other advantages are:
1 Eliminate flooding by masking open areas and preventing board sag.
2 Reduce second hand load parts and hand soldering.
3 Save thousands of dollars in Kapton tape and the labor to add and remove.
4 The composite materials thermally protect bottom side SMD’s from shock.
5 Mask BGA vias from the wave ensuring reliable solder joints.
6 Lead Free grade optical material for higher temperatures
TOP SIDE STANDARD FEATURES
Chuangwei’s standard PCB hold down is our low profile. It is unbreakable, ESD safe and guaranteed for the life of the pallet. The non-marring design applies 12 pounds of downward pressure without having to lift. Just twist! We also offer a high profile hold down, cam-lock and custom hold downs for connectors.
Chuangwei does not ‘tap’ the composite, we use all “metal to metal” fasteners ensuring a reliable and long lasting fixture.
We offer two sizes of extruded aluminum stiffeners and solder dams; for smaller pallets we have a 3/8” tall and for larger pallets we have a 3/4” tall design.
All pallets are engraved with the board name and our work order number for handy reference. All data associated with your pallet is stored to that work order number.
BOTTOM SIDE STANDARD FEATURES
All bottom side fasteners are made from 316 grade stainless steel. This eliminates solder sticking or wetting to the fastener.
All fasteners are thread locked.
Our goal is to design and build a solution that will give you:
1. Highest yields with the largest process window possible.
2. Easy to use tooling that will survive your manufacturing environment.
3. Fastest delivery times possible.
The viability of this process route crucially relies upon being able to estimate the number and distribution of PTH components
which CAN'T be processed (with and without glue dotting) - These will have to be miniwaved or hand soldered.
which are likely to be poorly soldered - These will require further inspection and manual touch up.
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.
PTH Components Located Perpendicular to direction through wave.
A larger separation is required due to the solder having to flow "under"
Working your way around the underside of the PCB, identify which components
are parallel and perpendicular to the wave and assess the solderability of each
PTH connector by comparing the actual separation against the graph right.
Ideally you want to be above the line in all cases.
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.
Our production flow
Clients from electronic industry.