Details
| Original language | English |
|---|---|
| Title of host publication | 2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016 |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| ISBN (electronic) | 9780988887398 |
| Publication status | Published - 7 Mar 2016 |
| Event | Pan Pacific Microelectronics Symposium, Pan Pacific 2016 - Big Island, United States Duration: 25 Jan 2016 → 28 Jan 2016 |
Abstract
With the growing demand for mechanically flexible circuits or systems in consumer electronics, e.g. mobile phones, portable computers, TFT displayers, RFID tags etc., chip-on-flex packaging has been developed to a great extent and is increasingly being implemented in a variety of applications. High-performance colored polymer films, such as polyimide, are most commonly employed as flex substrates. However, taking the feasibility for a wide range of optical applications and a low-cost procurement into account, transparent polymer foils, such as polymethyl methacrylate (PMMA), exhibit a greater prospect. A major challenge in using these polymer foils as flexible carriers lies in the thermal loading control depending on their low glass transition temperatures (Tg). Thus, we propose flip chip-based optodic bonding for chip-on-flex packaging by employing these cost-effective transparent polymer foils. In this bonding technology, conventional thermal loading is minimized since UV curable adhesives are used as bonding materials and an optode is correspondingly adopted. Additionally, the fine-pitch circuits on the flex substrates are designed according to the chips and fabricated by screen printing technology using silver nanoparticles. Considering the effects on the bonding performance, which result from the rheological behavior of the adhesives during dispensing and applying, contact angles between the adhesives and polymer foils are measured for determining the appropriate volume. In order to protect the silver interconnects as well as the applied adhesives from oxidation and thus attaining a long-term stability in respect to the electrical conductivity, a functionalized coating against ambient moisture is implemented onto the flex circuit. Through the performance tests of the final packages for a test chip and a bare optoelectronic component, this novel technology is verified as a promising solution for fine-pitch chip-on-flex packaging.
Keywords
- chip-on-flex packaging, contact angles, fine-pitch, flip chip bonding, functionalized coating, screen-printing, transparent polymer foils, UV-curing adhesives
ASJC Scopus subject areas
- Engineering(all)
- Electrical and Electronic Engineering
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
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2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016. Institute of Electrical and Electronics Engineers Inc., 2016. 7428418.
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Fine-pitch chip-on-flex packaging of optoelectronic devices using low temperature optodic bonding
AU - Wang, Yixiao
AU - Gauch, M.
AU - Ristau, Detlev
AU - Overmeyer, Ludger
PY - 2016/3/7
Y1 - 2016/3/7
N2 - With the growing demand for mechanically flexible circuits or systems in consumer electronics, e.g. mobile phones, portable computers, TFT displayers, RFID tags etc., chip-on-flex packaging has been developed to a great extent and is increasingly being implemented in a variety of applications. High-performance colored polymer films, such as polyimide, are most commonly employed as flex substrates. However, taking the feasibility for a wide range of optical applications and a low-cost procurement into account, transparent polymer foils, such as polymethyl methacrylate (PMMA), exhibit a greater prospect. A major challenge in using these polymer foils as flexible carriers lies in the thermal loading control depending on their low glass transition temperatures (Tg). Thus, we propose flip chip-based optodic bonding for chip-on-flex packaging by employing these cost-effective transparent polymer foils. In this bonding technology, conventional thermal loading is minimized since UV curable adhesives are used as bonding materials and an optode is correspondingly adopted. Additionally, the fine-pitch circuits on the flex substrates are designed according to the chips and fabricated by screen printing technology using silver nanoparticles. Considering the effects on the bonding performance, which result from the rheological behavior of the adhesives during dispensing and applying, contact angles between the adhesives and polymer foils are measured for determining the appropriate volume. In order to protect the silver interconnects as well as the applied adhesives from oxidation and thus attaining a long-term stability in respect to the electrical conductivity, a functionalized coating against ambient moisture is implemented onto the flex circuit. Through the performance tests of the final packages for a test chip and a bare optoelectronic component, this novel technology is verified as a promising solution for fine-pitch chip-on-flex packaging.
AB - With the growing demand for mechanically flexible circuits or systems in consumer electronics, e.g. mobile phones, portable computers, TFT displayers, RFID tags etc., chip-on-flex packaging has been developed to a great extent and is increasingly being implemented in a variety of applications. High-performance colored polymer films, such as polyimide, are most commonly employed as flex substrates. However, taking the feasibility for a wide range of optical applications and a low-cost procurement into account, transparent polymer foils, such as polymethyl methacrylate (PMMA), exhibit a greater prospect. A major challenge in using these polymer foils as flexible carriers lies in the thermal loading control depending on their low glass transition temperatures (Tg). Thus, we propose flip chip-based optodic bonding for chip-on-flex packaging by employing these cost-effective transparent polymer foils. In this bonding technology, conventional thermal loading is minimized since UV curable adhesives are used as bonding materials and an optode is correspondingly adopted. Additionally, the fine-pitch circuits on the flex substrates are designed according to the chips and fabricated by screen printing technology using silver nanoparticles. Considering the effects on the bonding performance, which result from the rheological behavior of the adhesives during dispensing and applying, contact angles between the adhesives and polymer foils are measured for determining the appropriate volume. In order to protect the silver interconnects as well as the applied adhesives from oxidation and thus attaining a long-term stability in respect to the electrical conductivity, a functionalized coating against ambient moisture is implemented onto the flex circuit. Through the performance tests of the final packages for a test chip and a bare optoelectronic component, this novel technology is verified as a promising solution for fine-pitch chip-on-flex packaging.
KW - chip-on-flex packaging
KW - contact angles
KW - fine-pitch
KW - flip chip bonding
KW - functionalized coating
KW - screen-printing
KW - transparent polymer foils
KW - UV-curing adhesives
UR - http://www.scopus.com/inward/record.url?scp=84964940724&partnerID=8YFLogxK
U2 - 10.1109/panpacific.2016.7428418
DO - 10.1109/panpacific.2016.7428418
M3 - Conference contribution
AN - SCOPUS:84964940724
BT - 2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - Pan Pacific Microelectronics Symposium, Pan Pacific 2016
Y2 - 25 January 2016 through 28 January 2016
ER -