Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging
Abstract
:1. Introduction
- To demonstrate a fully additive process using exopy resins and polymer-based CBM technology to procure any desirable geometries on the FR-4 substrate.
- To show the selective metallization capability of the process by eliminating the etching process significantly (especially during the metallization), i.e., adapting an environmentally friendlier production approach.
- To present the feasibility of the fabrication technique at lower temperature (20–45 °C).
- To show the possibility of process implementation for the PCB fabrication segment of the industry towards miniaturization.
2. Materials and Methods
2.1. Sample Preparation
2.2. Fabrication Steps
- Step 1:
- Ultrasonic cleaning of the FR-4 substrate using deionized water (DIW).
- Step 2:
- Drying of the FR-4 substrate at room temperature.
- Step 3:
- Spin coating of the PU layer on top of FR-4.
- Step 4:
- UV soft baking for 1 min followed by surface hardening at room temperature.
- Step 5:
- Spin coating of HP-14 on PU.
- Step 6:
- Selective polymerization of the surface using actinic radiation and pattern file (optional in case of bulk Cu deposition).
- Step 7:
- Proper cleaning using DIW of the sample to remove the unexposed HP-14 solution from the sample surface before the Cu bath.
- Step 8:
- Electroless Cu bath (Predip, Activator, Reducer and Cu bath).
- Step 9:
- Final cleaning of the surface and characterization.
2.3. Characterization
3. Results and Discussion
3.1. Surface Mechanism of the Polymerization
3.1.1. Selective Polymerization with Patterns
3.1.2. Selective Metallization
3.2. Parameter Optimization
Significance Level of Parameters
3.3. Challenges in Fabrication
3.3.1. Inadequate Laser Exposure
3.3.2. Improper Metallization
3.4. Fabrication of Planar Inductor: A Use-Case
3.4.1. Objectives
3.4.2. Materials and Methods
3.4.3. Results
4. Summary and Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Sample Availability
References
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Electroless Copper Bath Parameters | |||||
---|---|---|---|---|---|
Type | Name | Concentration | Time (in Minutes) | Temperature (°C) | |
I | Predip | Precup-128 | 55.5 mL in 200 mL of DIW | 1 | 25 |
II | Activator | Catcup-207 | 55.5 mL in 200 mL of DIW | 6 | 42 |
III | Reducer | Boric acid + ACS-2075 | 2.4 g in 100 mL of DIW + 1.5 mL of ACS-2075 | 6 | 27 |
IV | Cu Bath | PEC-660 (A/M/B) | 9.25 mL of PEC-A + 6.75 mL of PEC-M + 9.75 mL of PEC-B in 100 mL of DIW | 4–6 | 25 |
Feature Size in the Pattern (in m) | Laser Gain (mW) | D-Step (80 m/s) | No. of Repetition |
---|---|---|---|
30 and above | 6.6 | 4.0 | 6.0 |
10 | 6.5 | 4.0 | 6.0 |
7.5 | 6.4 | 4.0 | 5.0 |
5 | 6.5 | 2.0 | 3.0 |
2.5 | 6.5 | 2.0 | 3.0 |
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Acharya, S.; Chouhan, S.S.; Delsing, J. Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging. Processes 2021, 9, 1634. https://doi.org/10.3390/pr9091634
Acharya S, Chouhan SS, Delsing J. Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging. Processes. 2021; 9(9):1634. https://doi.org/10.3390/pr9091634
Chicago/Turabian StyleAcharya, Sarthak, Shailesh Singh Chouhan, and Jerker Delsing. 2021. "Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging" Processes 9, no. 9: 1634. https://doi.org/10.3390/pr9091634