ALPHA OM-340 Processing Guidelines
STORAGE and HANDLING
Refrigerate to guarantee stability @ 0-10°C (32-50°F)
PRINTING
Recommend Cookson
®
Electronics ALPHA CUT ,
®®
ALPHA NICKEL-CUT , ALPHA
®
TETRABOND , or ALPHAFORM stencils @ 0.100mm - 0.150 mm (4-6 mil) thick for 0.4 - 0.5 mm (0.016” or 0.020”) pitch. Stencil design is subject to many process variables. Contact your local Cookson Electronics stencil site for advice.
Metal (recommended)
PASTE ROLL: 1.5-2.0 cm
diameter and make additions when roll reaches 1-cm (0.4”) diameter (min). Max roll size will depend upon blade
PRESSURE: 0.45 to 0.7 kg/inch 25 to 150mm per second (1 to 6 inches per second). : 3-10mm/sec.
PRINT PUMP HEAD: Passes DEK ProFlow® compatibility test
REFLOW (See Figure 1)
Clean-dry air or nitrogen atmosphere.
Acceptable reflow / coalescence for feature size down to 8 mil (200 μm). IPC Class III
voiding obtained for both straight ramp and soak profiles.
CLEANING
ALPHA OM-340 residue is
designed to remain on the board after reflow.
If reflowed residue cleaning is required, the following aqueous cleaners are recommended: In-line or Batch Cleaners - ALPHA BC-2200 - Zestron Vigon A201 - Zestron Vigon A250 - Zestron Vigon US
Manual or solvent cleaning: - ALPHA SM-110 and SM-110E - BioactTM SC-10 and SC-10E
Misprints and stencil cleaning may be done with the following cleaners:
ALPHA SM-110E ALPHA SM-440
Zestron Vigon SC200
TM
Bioact SC-10E
Shelf life of refrigerated paste is 6 months.
Paste can be stored for 2 weeks at room
o
temperatures up to 25C (77°F) prior to use.
When refrigerated, warm-up of paste container to room temperature for up to 4 hours. Paste must be
oo
≥19C (66F) before processing. Verify paste
temperature with a thermometer to ensure paste is
oo
at 19C (66F) or greater before setup. Printing can
oo
be performed at temperatures up to 32C (89F).
Paste can be manually stirred before use. A rotating, centrifugal force mixing operation is not required. If a rotating/centrifugal force mixing is used, 30 - 60 seconds at 300 RPM is adequate.
Do not remove worked paste from stencil and mix with unused paste in jar. This will alter rheology of unused paste.
These are starting recommendations and all
process settings should be reviewed independently.
Note 1: Refer to component and board supplier data for thermal properties at elevated temperatures. Lower peak temperatures require longer TAL for improved joint cosmetics. Keeping the peak
temperature below 240°C will lower the amount of voiding.
Figure 1: ALPHA® OM-340 SAC305 Typical Reflow Profile