Product Description
The NL932 is a no-clean lead free solder paste designed to meet the requirements for reliable solder joints in Printed Circuit Board assemblies. NL932 displays previously unseen levels of repeatability and consistency even in a wide range of temperatures (65�-85�F) and relative humidity (25-65% RH). NL932 offers enhanced printing and reflow process windows. Aditionally, NL932's capability of IPC Class III for voiding and ROL-0 IPC classification ensures long-term reliability.
Material Safety Data Sheets (MSDS)
SAC305 Solder Paste MSDS
SN100C Solder Paste MSDS
Attributes
- Excellent print volume consistency with Surface (SAR) as low as 0.45
- Excellent wetting characteristics on all surface finishes, including OSP, Ni/Au, Ni/Pd/Au, SN100C HAL
- Clear residue
- High speed smt stencil printing up to 150mm/sec
- Excellent low-voiding performance that exceeds IPC Class III requirement
- Enhanced tack performance and printer open time
- Very shiny solder joints when used with SN100C
- Compatible in either Nitrogen or Air reflow
Product Information
| Alloys |
SN100C - MP = 227�C
SAC305 � MP = 218�C
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| Applications |
Automatic / Manual Printing
Automatic / Manual Dispensing
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| Powder Size |
Type-3 and Type-4 standard
Type-5 available upon request
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| Packaging |
500 gram jars or cartridges standard
Enclosed print head systems
Other packaging upon request
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| Repair Flux |
10CC and 30CC syringes
Larger package sizes upon request
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Printing
Stencil aperture design and stencil quality are major factors in achieving excellent print consistency with any lead free solder paste. Laser Cut stencils from Stencils Unlimited are recommended for optimal print performance, and can be custom designed to minimize and improve the yields of any process. Some general stencil aperture design guidelines follow:
- Fine pitch components (<= 0.020�)
A 0.001� reduction (L & W) to minimize bridging and create proper gasketing between the stencil and SMT pad
- Discrete components
A 0.002� reduction (L & W) for water washable and a 0.002� reduction (L & W), with �U-shaped� home-plates, for no clean to minimize mid-chip solder beads.
Printer Operation
| Solder Paste Bead Size: |
2cm (~0.75�) on startup
Add when bead < 1.4 cm (~0.5�)
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| Squeegee: |
Metal, Slic� blade preferred
60 degrees from horizontal
|
| Speed |
25 to 150 mm/sec. (1 to 6 in/sec)
Adjust printer for a pull or print demand process
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| Pressure: |
0.18-0.27 Kg/cm (squeegee length)
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| Underside Wipe: |
Slic� and Ultraslic� stencils should exceed >10 prints/wipe
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| Stencil life / Environment: |
>8 hours
30-65% RH and 20� C � 25� C
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| Tack Life: |
24hrs @ 25�C / 45% RH
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| Tack Force: |
1.5 grams/mm2
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| Slump 0.7mm Pads: |
0.4 @ 25�C / 1Hour
0.4 @ 80�C / 20 minutes
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| Slump 1.5mm Pads: |
0.4 @ 25�C / 1Hour
0.4 @ 80�C / 20 minutes
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Storage and Handling
- Cartridges should be stored tip down.
- No Clean Paste can be stored up to two weeks at room temperature.
- To prolong the shelf life of NL932, refrigerate between 5�C~10�C, (41�F~50�F). At this range the shelf life will exceed 8 months.
- NL932 should not be allowed to freeze.
- When refrigerated, lead free solder paste must be allowed to warm up to room temperature.
- Lead Free Paste must be >= 22�C, (~66�F) prior to applying to stencil for processing.
- Working range of NL932 is between 22-32�C, (~66�F - 89.5�F).
- First-In-First-Out (FIFO) inventory management practices should be used with all lead free solder pastes.
Heating
A linear ramp of 0.7�C to 2.0�C C/second is suggested to gradually remove the solvents and other volatile components in the lead free solder paste. This also helps in minimizing solder balls, beading and bridging from hot slump.
A linear ramp also helps minimize depletion of flux activity which can occur with excessive temperature, preheat times, and at very high reflow temperatures.
A profile with a soak between 200-210�C for less than 20 seconds can be used to reduce void formation on BGA and CSP devices. (Request FCTA�s profile guide to void reduction).
While a linear profile typically does not produce tombstoning, a short 10-20 second dwell prior to transitioning into the liquidus point of the solder, and minimizing the QR between soak and liquid temperatures will help minimize tombstoning if experienced.
Cooling
A cooling rate of 3�C-4�C per second is recommended for most lead/free reflow applications. These parameters should be utilized to insure a fine grain solder structure and minimal IMC layer.
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