Surface Activated Flip-Chip Bonding of Laser Chips

2005 ◽  
Author(s):  
Eiji Higurashi ◽  
Masao Nakagawa ◽  
Tadatomo Suga ◽  
Renshi Sawada
Keyword(s):  
Low Temperature ◽  
Flip Chip ◽  
Bonding Temperature ◽  
Ambient Air ◽  
Failure Criteria ◽  
Rf Plasma ◽  
Cavity Surface ◽  
Si Substrate ◽  
Plasma Irradiation ◽  
Flip Chip Bonding

This paper reports the results of low-temperature flip-chip bonding of a vertical cavity surface emitting laser (VCSEL) on a micromachined Si substrate. Low temperature bonding was achieved by introducing the surface activation by plasma irradiation into the flip-chip bonding process. After the surfaces of the Au electrodes of the VCSEL and Si substrate were cleaned using an Ar radio frequency (RF) plasma, Au-Au bonding was carried out only by contact in ambient air with applied static pressure. At a bonding temperature of 100°C, the die-shear strength exceeded the failure criteria of MIL-STD-883.

Improvement of Adhesion and Microwave Transmission Characteristics of Indium Bump by Silver Coating for Low Temperature Flip-Chip Applications

2004 ◽  
Vol 833 ◽  
Author(s):  
Kun-Mo Chu ◽  
Jung-Hwan Choi ◽  
Jung-Sub Lee ◽  
Han Seo Cho ◽  
Seong-Ook Park ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flip Chip ◽  
Heating Temperature ◽  
Coplanar Waveguide ◽  
Fused Silica ◽  
Cavity Surface ◽  
Silver Coating ◽  
Flip Chip Bonding ◽  
Indium Bump ◽  
Polymeric Waveguide

ABSTRACTWe have conducted low-temperature flip-chip bonding for both optical interconnect and microwave applications. Flip-chip bonding of vertical-cavity surface-emitting laser (VCSEL) arrays was performed on a fused silica substrate that provides propagation paths of laser beams and also supports a polymeric waveguide. To avoid thermal damage of the polymeric waveguide during the flip-chip bonding, indium bumps were used and the bonding condition of the flip-chip was determined as a heating temperature of 150 °C and a pressure of 500 gf. Experimentally, a thin silver (Ag) layer coated on the indium bump was very effective to enhance the adhesion strength between the indium bump and the VCSEL chip pads. In addition, the microwave characteristic of coplanar waveguide (CPW) package was slightly improved by the Ag coating.

Low Temperature flip chip bonding technology applicable to flexible hybrid electronics in the IoT era

2019 ◽  
Vol 2019 (DPC) ◽  
pp. 000474-000518
Author(s):  
Hiroshi Komatsu
Keyword(s):  
Screen Printing ◽  
Flip Chip ◽  
Bonding Temperature ◽  
Complex Form ◽  
Fine Tuning ◽  
Electric Resistance ◽  
Flip Chip Bonding ◽  
Strong Adhesion ◽  
Bonding Technology ◽  
Ag Paste

Since its early days of the industry, electronics apparatus has been in a rigid and flat surfaced case. ICs have been soldered on rigid substrate at high bonding temperature. However, in the IoT era, electronics components connect with the variety of applications which require different forms and shapes of outlook which lead substrate and board should be flexible and complex form. Conventional flip chip bonding technology, such as solder bump and copper pillar, need to raise bonding temperature around 260-degree C, eventually does not satisfy this flexile hybrid electronics (FHE) application requirement. We have originally developed flip chip bonding technology which consists of the bump formation by Conductive Paste (CP) printing followed by Non-Conductive Paste (NCP) dispensing and flip chip bonding at temperature as low as 120-degree C. Bumps with silver particle loaded epoxy resin on substrate were formed by screen printing. This enable us to make fine bump formation down to 60um minimum bump pitch and 30um bump diameter with tuning of screen-printing process. After the bump formation, NCP dispensing and flip chip bonding at 120-degree C which secure reasonable low electric resistance, 8×1E-4 ohm cm2, and strong adhesion of chip and substrate. The bonding temperature of this technology can be lowered down to 80-degree C without much difficulties, but just by fine tuning of Ag paste and its contents. This momentum will create a lot more of future applications and be one of the core technologies in the coming IoT era in FHE.

Low Temperature Wafer Level Bonding Using Benzocyclobutene Adhesive Polymers

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 1-24
Author(s):  
Michael Gallagher ◽  
Jong-Uk Kim ◽  
Eric Huenger ◽  
Kai Zoschke ◽  
Christina Lopper ◽  
...  
Keyword(s):  
Low Temperature ◽  
Wafer Bonding ◽  
Flip Chip ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Curing Temperature ◽  
Wafer Level ◽  
Mechanical Adhesion ◽  
3D Stacking ◽  
Dry Etch

3D stacking, one of the 3D integration technologies using through silicon vias (TSVs), is considered as a desirable 3D solution due to its cost effectiveness and matured technical background. For successful 3D stacking, precisely controlled bonding of the two substrates is necessary, so that various methods and materials have been developed over the last decade. Wafer bonding using polymeric adhesives has advantages. Surface roughness, which is critical in direct bonding and metal-to-metal bonding, is not a significant issue, as the organic adhesive can smooth out the unevenness during bonding process. Moreover, bonding of good quality can be obtained using relatively low bonding pressure and low bonding temperature. Benzocyclobutene (BCB) polymers have been commonly used as bonding adhesives due to their relatively low curing temperature (~250 °C), very low water uptake (<0.2%), excellent planarizing capability, and good affinity to Cu metal lines. In this study, we present wafer bonding with BCB at various conditions. In particular, bonding experiments are performed at low temperature range (180 °C ~ 210 °C), which results in partially cured state. In order to examine the effectiveness of the low temperature process, the mechanical (adhesion) strength and dimensional changes are measured after bonding, and compared with the values of the fully cured state. Two different BCB polymers, dry-etch type and photo type, are examined. Dry etch BCB is proper for full-area bonding, as it has low degree of cure and therefore less viscosity. Photo-BCB has advantages when a pattern (frame or via open) is to be structured on the film, since it is photoimageable (negative tone), and its moderate viscosity enables the film to sustain the patterns during the wafer bonding process. The effect of edge beads at the wafer rim area and the soft cure (before bonding) conditions on the bonding quality are also studied. Alan/Rey ok move from Flip Chip and Wafer Level Packaging 1-6-12.

Low temperature Au-Au flip chip bonding with VUV/O3 treatment for 3D integration

2012 ◽  
Author(s):  
Akiko Okada ◽  
Masatsugu Nimura ◽  
Naoko Unami ◽  
Akitsu Shigetou ◽  
Hirokazu Noma ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flip Chip ◽  
3D Integration ◽  
Flip Chip Bonding

15-µm-pitch Cu/Au interconnections relied on self-aligned low-temperature thermosonic flip-chip bonding technique for advanced chip stacking applications

2014 ◽  
Vol 53 (4S) ◽  
pp. 04EB04 ◽  
Author(s):  
Bui Thanh Tung ◽  
Fumiki Kato ◽  
Naoya Watanabe ◽  
Shunsuke Nemoto ◽  
Katsuya Kikuchi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flip Chip ◽  
Flip Chip Bonding ◽  
Bonding Technique
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