Ultra Fine RDL Structure Fabrication Using Alternative Patterning and Bottom-Up Plating Processes

Hollman, Richard; Dimov, Ognian; Malik, Sanjay; Hichri, Habib; Arendt, Markus

doi:10.1109/ectc.2018.00017

Cited by 10 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Limited by the wavelength of the CO

laser of

= 9.2–10.6 µm, microvia diameters are restricted to about 40 µm [ 12 ]. In turn, by using nanosecond pulsed lasers with emission in the ultraviolet (UV) spectral region of

= 193–355 nm, minimum hole diameters of <25 µm are achieved [ 3 , 13 , 14 , 15 ]. In addition, in this spectral range high absorption rates are reached for ablation of individual PCB materials such as copper, resin, and glass fiber composite material [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials

Franz

Häfner²,

Kunz³

et al. 2022

Materials

View full text Add to dashboard Cite

We report on a comprehensive study of laser percussion microvia drilling of FR-4 printed circuit board material using ultrashort pulse lasers with emission in the green spectral region. Laser pulse durations in the pico- and femtosecond regime, laser pulse repetition rates up to 400 kHz and laser fluences up to 11.5 J/cm2 are applied to optimize the quality of microvias, as being evaluated by the generated taper, the extension of glass fiber protrusions and damage of inner lying copper layers using materialography. The results are discussed in terms of the ablation threshold for FR-4 and copper, heat accumulation and pulse shielding effects as a result of pulse to pulse interactions. As a specific result, using a laser pulse duration of 2 ps appears beneficial, resulting in small glass fiber protrusions and high precision in the stopping process at inner copper layer. If laser pulse repetition rates larger than 100 kHz are applied, we find that the processing quality can be increased by heat accumulation effects.

show abstract

“…Limited by the wavelength of the CO

laser of

= 9.2–10.6 µm, microvia diameters are restricted to about 40 µm [ 12 ]. In turn, by using nanosecond pulsed lasers with emission in the ultraviolet (UV) spectral region of

Section: Introductionmentioning

confidence: 99%

Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials

Franz

Häfner²,

Kunz³

et al. 2022

Materials

View full text Add to dashboard Cite

show abstract

“…Laser direct writing (LDW) incorporated with a mask-free pattern transfer method is also one of the flexible electronics technologies for micro-structure printing [20][21][22]. In recent years, some of the direct laser patterning with dual damascene metallization process were also proposed for ultra-thin advanced packaging [23,24]. However, such processes still involve metal removal methods.…”

Section: Introductionmentioning

confidence: 99%

Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging

2021

View full text Add to dashboard Cite

Advancements in production techniques in PCB manufacturing industries are still required as compared to silicon-ICs fabrications. One of the concerned areas in PCBs fabrication is the use of conventional methodologies for metallization. Most of the manufacturers are still using the traditional Copper (Cu) laminates on the base substrate and patterning the structures using lithography processes. As a result, significant amounts of metallic parts are etched away during any mass production process, causing unnecessary disposables leading to pollution. In this work, a new approach for Cu metallization is demonstrated with considerable step-reducing pattern-transfer mechanism. In the fabrication steps, a seed layer of covalent bonded metallization (CBM) chemistry on top of a dielectric epoxy resin is polymerized using actinic radiation intensity of a 375 nm UV laser source. The proposed method is capable of patterning any desirable geometries using the above-mentioned surface modification followed by metallization. To metallize the patterns, a proprietary electroless bath has been used. The metallic layer grows only on the selective polymer-activated locations and thus is called selective metallization. The highlight of this production technique is its occurrence at a low temperature (20–45 °C). In this paper, FR-4 as a base substrate and polyurethane (PU) as epoxy resin were used to achieve various geometries, useful in electronics packaging. In addition, analysis of the process parameters and some challenges witnessed during the process development are also outlined. As a use case, a planar inductor is fabricated to demonstrate the application of the proposed technique.

show abstract

“…References [ 9 , 10 ] designed the coaxial TSV structure containing two layers of conductors, the measured S 21 of a TSV is −0.48 dB at 10 GHz. By optimizing the important electroplating process in the TSV manufacturing process [ 11 , 12 , 13 ], TSV can achieve bottom-up Cu filling, and a single TSV will have low DC resistance of 36.7 mΩ to ensure low RF loss. To our knowledge, the best test result is demonstrated by [ 14 ], which has an insertion loss of 0.53 dB at 75 GHz for a single TSV.…”

Section: Introductionmentioning

confidence: 99%

A RF Redundant TSV Interconnection for High Resistance Si Interposer

Wang

Jin

et al. 2021

Micromachines

View full text Add to dashboard Cite

Through Silicon Via (TSV) technology is capable meeting effective, compact, high density, high integration, and high-performance requirements. In high-frequency applications, with the rapid development of 5G and millimeter-wave radar, the TSV interposer will become a competitive choice for radio frequency system-in-package (RF SIP) substrates. This paper presents a redundant TSV interconnect design for high resistivity Si interposers for millimeter-wave applications. To verify its feasibility, a set of test structures capable of working at millimeter waves are designed, which are composed of three pieces of CPW (coplanar waveguide) lines connected by single TSV, dual redundant TSV, and quad redundant TSV interconnects. First, HFSS software is used for modeling and simulation, then, a modified equivalent circuit model is established to analysis the effect of the redundant TSVs on the high-frequency transmission performance to solidify the HFSS based simulation. At the same time, a failure simulation was carried out and results prove that redundant TSV can still work normally at 44 GHz frequency when failure occurs. Using the developed TSV process, the sample is then fabricated and tested. Using L-2L de-embedding method to extract S-parameters of the TSV interconnection. The insertion loss of dual and quad redundant TSVs are 0.19 dB and 0.46 dB at 40 GHz, respectively.

show abstract

Ultra Fine RDL Structure Fabrication Using Alternative Patterning and Bottom-Up Plating Processes

Cited by 10 publications

References 6 publications

Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials

Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials

Fabrication Process for On-Board Geometries Using a Polymer Composite-Based Selective Metallization for Next-Generation Electronics Packaging

A RF Redundant TSV Interconnection for High Resistance Si Interposer

Contact Info

Product

Resources

About