Rework Solder Materials
Technical Needs, Gaps and Solutions
This section covers Rework Solder Materials technology issues, 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. Rework Solder Materials Gaps, and Today’s Technology Status with Respect to Current and Future Needs
TECHNOLOGY ISSUE | ROADMAP TIMEFRAME | |||
TODAY (2024) | 3 YEARS (2027) | 5 YEARS (2029) | 10 YEARS (2034) | |
Rework Solder Materials (Solder and Flux) | ||||
TODAY (2024) | 3 YEARS (2027) | 5 YEARS (2029) | 10 YEARS (2034) | |
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #1: Low temperature, high bismuth flux lead-free cored wire is very limited | ||||
NEED | As low-temperature alloys become more mainstream the need to rework increases | |||
CURRENT TECHNOLOGY STATUS | Solutions need optimization | |||
The manufacturing yield for high Bi containing flux cored wire is very low | ||||
GAP | Manufacturing drawing technology for brittle materials | |||
CHALLENGE | Difficult to manufacture high Bi flux cored wire | |||
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #2: Rework flux reliability after rework 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. | |||
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #3: Flux spatter and solder balling issues with flux cored wire | ||||
NEED | Flux spatter during soldering may result in solder balls around solder joints | |||
CURRENT TECHNOLOGY STATUS | Solutions need optimization | |||
Low spatter flux cored wire is available but further improvement with zero spatter is desired | ||||
GAP | Lack of flux chemistries | |||
CHALLENGE | Development of flux materials which do not spatter | |||
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. Rework Solder Materials Potential Solutions
TECHNOLOGY ISSUE | EXPECTED TRL LEVEL* | ||||
Rework Solder Materials (Solder and Flux) | POTENTIAL SOLUTIONS | TODAY (2024) | 3 (2027) | 5 (2029) | 10 |
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #1: | Development of wire drawing technology | 3 | 5 | 7 | 8 |
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #2: | Formulation optimization and novel chemistries for improved SIR | 4 | 4 | 4 | 5 |
REWORK SOLDER MATERIALS (SOLDER AND FLUX) ISSUE #3: | Formulation optimization and novel chemistries | 5 | 6 | 7 | 8 |
Rework Solder Materials (Solder and Flux) Conclusions
Development of low-temperature, high bismuth solder containing flux cored wire
Improving rework flux SIR reliability after rework soldering
Board Assembly Acronyms
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