Wave Solder Materials
Technical Needs, Gaps and Solutions
This section covers technology issues surrounding Wave Solder Materials, the associated needs, technology status of those needs, as well as gaps and challenges to overcome, are summarized below in Table 1. The time period considered is from 2024 to 2034. Assessments of to address these gaps and challenges is presented in Table 2 as a set of potential solutions for each set of issues.
Technology Status Legend
For each need, the status of today’s technology is indicated by label and color as follows:
In-table color + label key | Description of Technology Status |
|---|---|
Solutions not known | Solutions not known at this time |
Solutions need optimization | Current solutions need optimization |
Solutions deployed or known | Solutions deployed or known today |
Not determined | TBD |
Table 1. Wave Solder Gaps, and Today’s Technology Status with Respect to Current and Future Needs
TECHNOLOGY ISSUE | ROADMAP TIMEFRAME | |||
Wave Solder Materials (Solder and Flux) | ||||
TODAY (2024) | 3 YEARS (2027) | 5 YEARS (2029) | 10 YEARS (2034) | |
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #1: Generation of solder dross especially with low melting temperature alloys | ||||
NEED | The industry is looking towards low melting alloys in wave soldering to improve hole-fill and reduce energy costs | |||
CURRENT TECHNOLOGY STATUS | Solutions need optimization | |||
Soldering under nitrogen reduces dross generation but is costly | ||||
GAP | Low-temperature alloys contain high content of Bi which easily oxidizes more than Sn at soldering temperatures which generates solder dross | |||
CHALLENGE | Development of dross reduction technology for wave soldering alloys, lead-free and especially low temperature high Bi alloys. | |||
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #2: Hole-fill (topside solder with through hole joints) improvement with the increase board thicknesses and current carrying capabilities. | ||||
NEED | More robust fluxes are needed to survive long solder contact times | |||
CURRENT TECHNOLOGY STATUS | Solutions need optimization | |||
Soldering under nitrogen with nitrogen tunnels increases flux survivability but further improvement is needed | ||||
GAP | Available benign flux chemistries | |||
CHALLENGE | Development of wave solder fluxes which can survive up to 10 seconds of contact time. | |||
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #3: Wave flux Improved reliability of wave solder flux after soldering | ||||
NEED | High SIR/ECM for no-clean fluxes | |||
CURRENT TECHNOLOGY STATUS | Solutions need optimization | |||
High SIR/ECM fluxes are available but further improvement is desired | ||||
GAP | Lack of suitable alternatives or development. Flux activators may not be fully evaporated during soldering | |||
CHALLENGE
| Compatibility with conformal coating/ underfills etc. And availability of high SIR flux materials. | |||
Approaches to address Needs, Gaps and Challenges
Table 2 considers approaches to address the above needs and challenges. The evolution of these is projected out over a 10-year timeframe using technology readiness levels (TRLs).
In-table color key | Range of Technology Readiness Levels | Description |
|---|---|---|
2 | TRL: 1 to 4 | Levels involving research |
6 | TRL: 5 to 7 | Levels involving development |
9 | TRL: 8 to 9 | Levels involving deployment |
Table 2. Wave Solder Materials Potential Solutions
TECHNOLOGY ISSUE | EXPECTED TRL LEVEL* | ||||
Wave Solder Materials (Solder and Flux) | POTENTIAL SOLUTIONS | TODAY (2024) | 3 (2027) | 5 (2029) | 10 |
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #1: | Development of dross reducing technologies (Machine, alloy additions, de-drossing chemicals) | 4 | 4 | 4 | 5 |
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #2: | Formulation optimization and novel chemistries, adoption of lower temperature Bi-containing lead-free alloys | 4 | 6 | 8 | 8 |
WAVE SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #3: | Formulation optimization and novel chemistries for improved SIR | 4 | 4 | 4 | 5 |
Conclusions
Reduction in the generation of solder dross especially with low melting temperature Bismuth-containing lead-free alloys
Improving SIR reliability of wave solder flux after soldering
Board Assembly Acronyms
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