Heterogeneous & SiP Assembly

SiP & Heterogeneous Integration & Assembly (HIA)

From water-soluble to no-clean soldering solutions, Indium Corporation’s portfolio of products meets current and evolving challenges encountered in
fine-pitch SiP and HIA applications.

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Proven Materials. Technical Expertise.

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>5,000,000,000 SiP Packages

Used Indium Corporation materials in mobile FEM SiP devices in the last 5 years

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Wafer-Level Package. Ultra-Small Passives.

Recommended Semiconductor Fluxes for HIA

Material Type Material Name Flux Type Halogen-Free Application Comments
Wafer Bumping Flux WS-3543 Water-wash Yes Spin coating High viscosity for taller copper pillars and larger bumps (>40 microns)
WS-3401 Water-wash Yes Spin coating Low viscosity for smaller pillars and bumps
Flip-Chip Flux WS-446 Water-wash No Dipping Best flux for poor solderability
WS-446HF Water-wash Yes Dipping Best all-around halogen-free flip-chip flux, easily cleaned
WS-641 Water-wash Yes Dipping For chip-on-wafer, high-density Cu-pillar application
NC-26-A Ultra-low residue
no-clean
Yes Dipping Best compatibility with CUF/MUF
NC-26S Ultra-low residue
no-clean
Yes Dipping Avoids capillary flow up to die surface for fine-pitch devices
NC-699 Near-zero residue Yes Dipping Controlled solderability, compatible with wide variety of CUF/MUF
Ball-Attach Flux WS-446-AL Water-wash No Pin transfer Best flux for poor solderability
WS-446HF Water-wash Yes Pin transfer Suitable for one-step Cu OSP process for sphere size 0.25mm and above
WS-823 Water-wash Yes Pin transfer Best all-around halogen-free ball-attach flux, easily cleaned
WS-829 Water-wash Yes Printing and pin transfer For sphere size <0.25mm and fine-pitch high-density ball-attach, best cleanability

Recommended Semiconductor Solder Pastes for HIA

Material Type Material Name Flux Type Halogen-Free Alloy Comments
Jetting Paste PicoShot NC-5M Solvent- or aqueous-based chemistry or no-clean Yes SAC305 For dot jetting of 300µm diameter and above, and fine-line dispensing for metal lid-attach
Indium12.8HF SAC305 and other
Pb-free alloys
For dot jetting down to 800µm diameter and above, and fine-line dispensing for metal lid-attach
SiPaste® Solder Paste SiPaste® 3.2HF Water-wash Yes SAC305 and other
Pb-free alloys
Type 6-SG solder paste suitable for ultrafine-pitch printing
SiPaste® 8.9HF Solvent- or no-clean
SiPaste® SMQ77 No-clean
Die-Attach Solder Paste SMQ75 No-Clean ("Power-Safe") Yes All high-Pb and Sb-containing alloys Ultra-low residue "Power-Safe" (no-clean) paste suitable for
clip-bonded devices
BiAgX® Solvent-clean BiAgX® mixed alloy system High-temperature Pb-free solder paste >260°C
Indium3.2HF Pb-Free Water-Soluble SiPaste®

SiPaste®

Indium Corporation’s proven SiPaste® series is specifically designed for fine-feature printing with fine powders ranging from Type 5 to Type 7. They help Avoid the Void®, reduce slumps, and demonstrate consistent superior printing performance. SiPaste® 3.2HF has been adopted by leading OSATs and has been used in more than 5 billion mobile FEM SiP modules.

SiPaste® 3.2HF formulation offers consistent, repeatable printing performance combined with a long stencil life and sufficient tack strength to handle the challenges of today’s miniaturization in System-in-Package (SiP) design. In addition to consistent printing and reflow requirements, this solder paste offers superb wetting to the various Pb-free metallizations and has exceptional low-voiding performance on fine-pitch components, including BGAs and CSPs.

  • Exceptional printing
  • Long stencil life
  • Good response-to-pause
  • Wide reflow profile window
  • Outstanding slump resistance
  • Excellent wetting capability
  • Superior fine-pitch soldering ability
  • Low-voiding
  • Halogen-free
WS-446HF Ball-Attach and Flip-Chip Flux

WS-446HF Ball-Attach and Flip-Chip Flux

WS-446HF is a robust, halogen-free, water-wash flux designed to provide one simple solution to complicated applications, especially those with a single cleaning step for both BGA ball-attach and flip-chip processes.

  • Promotes excellent solderability and wetting on a wide range of surfaces
  • Cleans well with room temperature DI water
  • Eliminates ECM or dendrite formation caused by residue
  • Minimizes die skew, non-wet-opens, and “missing balls”
  • Designed for Pb-free applications
  • Halogen-free – per IPC and IEC specifications
  • Ensures consistent joint quality by providing consistent dipping, pin transfer, and printing performance over extended periods
  • Promotes strong, low-voiding joints
  • Eliminates warpage due to “prefluxing” with lower process costs
  • Reflows in air or nitrogen
  • Stable at room temperature for up to 1 year
Near-Zero and Ultra-Low Residue Flip-Chip Fluxes

Near-Zero and Ultra-Low Residue Flip-Chip Fluxes

Indium Corporation’s near-zero residue and ultra-low residue flip-chip fluxes are halogen-free, no-clean dipping fluxes, designed to leave a very small amount of a benign, solid, clear residue after reflow. By reducing the residue quantity, the flux allows the flow of capillary or molded underfills (CUF/MUF) without underfill voiding, and its benign chemical nature optimizes the strength of the flux/underfill interface. By eliminating the cleaning process, these fluxes also eliminate the excessive stresses on the die and solder joints caused by every aspect of flux cleaning: jet impingement, ultrasonic and megasonic vibration, air-knife drying, warpage during drying, and unnecessary handling.

  • Copper-pillar and standard bump flip-chip dipping
  • Suited for high-tin alloys
  • Near-zero or ultra-low residue levels (NZR/ULR) post-reflow
  • Halogen-free (NIA)
  • No-clean
  • Residues compatible with CUF/MUF
Ball-Attach Flux

WS-829 Ball-Attach and LED Die-Attach Flux

WS-829 is a halogen-free water-soluble ball-attach and LED die-attach flux designed for use in pin transfer and printing applications for ball-attachment to substrates (BGA manufacturing) and wafer/panel (WLP/PLP manufacturing), as well as in miniLED and microLED die-attach applications.

  • Halogen-free—per IPC and IEC specifications
  • Flux rheology suitable even for smallest sphere size
  • Thixotropic property ensures good print definition with minimal slump
  • Promotes excellent solderability and wetting on a wide range of surfaces
  • Promotes strong, low-voiding joints
  • Cleans well with room temperature DI water
  • Designed for Pb-free applications
  • Ensures consistent joint quality by providing consistent pin transfer and printing performance over extended periods
  • Reduces “double ball” and “missing balls”
  • Reflows in air or nitrogen
  • Stable at room temperature for up to 6 months
Jetting and Microdispensing

Jetting and Microdispense Solder Pastes

Jetting and microdispense solder pastes are specifically formulated for fine-pitch and ultra-fine dispensing/jetting for various applications. Indium Corporation’s jetting and microdispensing pastes provide reliable dispensing of consistently sized and shaped deposits in automated dispensing or jetting equipment.

  • Long-term collaboration with leading jetting and microdispense equipment manufacturers has led to specific recommendations
  • Exceptional jetting and microdispensing performance for halogen-free SAC305 solder pastes
  • Precision flux and paste manufacturing eliminates air bubbles and inhomogeneity
  • Variety of syringe types and sizes available

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Experts

 
Photo of Sze Pei Lim
Sze Pei Lim

Regional Product Manager

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Richard McDonough, PhD

Global Application Engineer
Semiconductor Product Specialist