Avoid the Void Plus Exceptional In-Circuit Testing Performance with Indium8.9HF1

Indium8.9HF1 is an air reflow, no-clean solder paste. Indium8.9HF1 offers unprecedented stencil print transfer efficiency to work in the broadest range of processes. In addition, the high probe testability of Indium8.9HF1 minimizes false failures in ICT.

Indium8.9HF1 is specifically formulated to deliver outstanding voiding performance for bottom-terminated components (BTC) - plus a soft pliable flux residue post reflow, providing unprecedented in-circuit testing (ICT) and flying-probe testing first pass yields.

Enhanced ICT Performance:

Indium8.9HF1 is a Pb-free, no-clean solder paste intended for both air and nitrogen reflow that produces:

• Fewer false testing failures which equates to faster cycle times and less rework
• Highest first-pass yields in ICT
• Soft post-reflow flux residue

Other Features:

• Halogen-free per EN14582 test method
• Outstanding BTC voiding minimization performance
• A high oxidation barrier eliminates grasping and HiP defects
• Provides a molten solder oxidation barrier that prevents further oxidation during reflow and Improves the coalescence of small deposits
• Excellent print transfer efficiency

Avoid shortened product life; avoid field failures; avoid customer dissatisfaction and a whole lot more with Indium Corporation’s advanced solder paste technology.

Indium Corporation’s suite of solder pastes offers formulations designed to deliver low-voiding, plus enhanced benefits such as improved response-to-pause, stability, HiP minimization, reliable in-circuit testing, and enhanced SIR performance.

Indium8.9HF-1 Solder Paste provides industry-leading ICT probing first-pass yields due to the ease of probe penetration through the soft residue.

The following data represents an evaluation of Indium8.9HF-1 vs. four competitive materials in a production environment. Indium8.9HF-1 produced the best ICT First Pass Yield and exceptional printing First Pass Yield.

Refrigerated storage will prolong the shelf life of solder paste. Solder paste packaged in cartridges should be stored tip down.

Solder paste should be allowed to reach ambient working temperature prior to use. Generally, the paste should be removed from refrigeration at least 2 hours before use. The actual time to reach thermal equilibrium will vary with container size. Paste temperature should be verified before use. Jars and cartridges should be labeled with the date and time of opening. If needed, unopened containers can be stored for up to 7 days at <25°C.

• Rework Flux: TACFlux 089HF, TACFlux 020B-RC
• Cored Wire: CW-807
• Wave Flux: WF-9945, WF-9958

Stencil Design:

Electroformed and laser cut/electropolished stencils produce the best printing characteristics among stencil types. Stencil aperture design is a crucial step in optimizing the print process. The following are a few general recommendations:

• Discrete components-A 10–20% reduction of stencil aperture has significantly reduced or eliminated the occurrence of mid-chip solder beads. The “home plate” design is a common method for achieving this reduction.
• Fine-pitch components-A surface area reduction is recommended for apertures of 20mil pitch and finer. This reduction will help minimize solder balling and bridging that can lead to electrical shorts. The amount of reduction necessary is process dependent (5-15% is common).
• For optimum transfer efficiency and release of the solder paste from the stencil apertures, industry-standard aperture, and aspect ratios should be adhered to.

Indium8.9HF is designed for no-clean applications; however, the flux can be removed, if necessary, by using a commercially available flux residue remover.

Stencil cleaning is best performed using isopropyl alcohol (IPA) as a solvent. Most commercially available non-water-based stencil cleaners work well.