CDR-integrated Sn-Ag-Cu-solder reflow-capable miniature 28-Gb/s × 4-channel optical modules

2015 ◽  
Author(s):  
Kazuya Nagashima ◽  
Tomofumi Kise ◽  
Yozo Ishikawa ◽  
Hideyuki Nasu
Keyword(s):  
Solder Reflow

Forming low resistance nano-scale contacts using solder reflow

2005 ◽  
Author(s):  
Hongke Ye ◽  
Zhiyong Gu ◽  
T. Yu ◽  
A. Bernfeld ◽  
T. Leong ◽  
...  
Keyword(s):  
Low Resistance ◽  
Nano Scale ◽  
Solder Reflow

Effect of microwave operating power and reflow time on the microstructure and tensile properties of Sn–3.0Ag–0.5Cu/Cu solder joints

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mardiana Said ◽  
Muhammad Firdaus Mohd Nazeri ◽  
Nurulakmal Mohd Sharif ◽  
Ahmad Azmin Mohamad
Keyword(s):  
Tensile Properties ◽  
Design Methodology ◽  
Solder Joints ◽  
Reflow Time ◽  
Sac305 Solder ◽  
Cross Sectional ◽  
Content Type ◽  
Solder Reflow ◽  
Microwave Hybrid Heating ◽  
Si Wafer

Purpose This paper aims to investigate the morphology and tensile properties of SAC305 solder alloy under the influence of microwave hybrid heating (MHH) for soldering at different microwave parameters. Design/methodology/approach Si wafer was used as susceptor in MHH for solder reflow. Microwave operating power for medium and high ranging from 40 to 140 s reflow time was used to investigate their effect on the microstructure and strength of SAC305/Cu solder joints. The morphology and elemental composition of the intermetallic compound (IMC) joint were evaluated on the top surface and cross-sectional view. Findings IMC formation transformed from scallop-like to elongated scallop-like structure for medium operating power and scallop-like to planar-like structure for high operating power when exposed to longer reflow time. Compositional and phase analysis confirmed that the observed IMCs consist of Cu6Sn5, Cu3Sn and Ag3Sn. A thinner IMC layer was formed at medium operating power, 80 s (2.4 µm), and high operating power, 40 s (2.5 µm). The ultimate tensile strength at high operating power, 40 s (45.5 MPa), was 44.9% greater than that at medium operating power, 80 s (31.4 MPa). Originality/value Microwave parameters with the influence of Si wafer in MHH in soldering have been developed and optimized. A microwave temperature profile was established to select the appropriate parameter for solder reflow. For this MHH soldering method, the higher operating power and shorter reflow time are preferable.

Parametric study of electronics components joining using reactive films for high temperature applications

2019 ◽  
Vol 2019 (HiTen) ◽  
pp. 000016-000021
Author(s):  
Rabih Khazaka ◽  
Donatien Martineau ◽  
Toni Youssef ◽  
Thanh Long Le ◽  
Stéphane Azzopardi
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Film Thickness ◽  
Void Ratio ◽  
Phase Distribution ◽  
Applied Pressure ◽  
Acoustic Microscopy ◽  
External Power Source ◽  
Solder Reflow ◽  
Joint Quality

Abstract In this paper, in order to assemble electronic components onto substrates, a local rapid soldering process using an exothermic reactive foil sandwiched between solder preforms was evaluated. Among others, the main interest of this technique is that it can allow the use of high temperature melting solders, without the need to heat the whole assembly above this melting temperature. The reactive foil is commercially available and is formed from alternatively stacked nanolayers of Ni and Al until it reaches the total film thickness. Once the film is activated by using an external power source, a reaction takes place and releases such an amount of energy that is transferred to the solder preforms. If this amount of energy is high enough, solder preforms melt and insure the adhesion between the materials of the assembly. The process was evaluated using a standard SAC305 and a high temperature Au80Sn20 preforms. The influences of the applied pressure, the reactive film thickness as well as the solder and the attached materials nature and thicknesses were investigated. The initial joint quality was evaluated using scanning acoustic microscopy, scanning electron microscopy, and shear strength measurements. It was shown that the applied pressure during the process has a strong effect on the joint initial quality. The voids ratio between metallized diode dice and an Active Metal Braze (AMB) substrate decreases from 64% to 26% for pressure values between 0.5kPa and 100kPa respectively. Otherwise, under a constant low pressure of 13kPa, reducing the substrate metal thickness on a low thermal conductivity insulator allows the improvement of the initial joint quality and a voids ratio of about 15% was reached when using 35μm of copper on FR4 substrate. The use of aluminum instead of copper as a metal for the ceramic metallized substrate (with the same gold finishing layer) led to a reduction in the void ratio in the joint. The microstructure of the AuSn joint achieved using the reactive films shows very fine phase distribution compared to the one obtained using conventional solder reflow process in the oven. The mechanical properties of the joint were evaluated using shear tests performed on 350μm thick silicon diodes assembled on AMB substrates under a pressure of 100kPa. The reactive films were 60μm thick and were sandwiched between two 25μm thick SAC preforms. The void ratio was about 37% for the tested samples and shear strength values above 9.5MPa were achieved which remains largely higher than MIL-STD-883H requirements. Finally, the process impact on the electrical properties of the assembled diodes was compared with a commonly used solder reflow assembly and results show a negligible variation.

Suppression of Kirkendall voiding in Sn-3.5Ag/Cu solder joints by pre-annealing process

2011 ◽  
Vol 2011 (1) ◽  
pp. 000337-000340
Author(s):  
S. H. Kim ◽  
Jin Yu
Keyword(s):  
Solder Joints ◽  
Void Formation ◽  
Annealing Process ◽  
Schematic Diagram ◽  
Cu Films ◽  
Joint Reliability ◽  
Organic Impurities ◽  
Solder Reflow ◽  
Kirkendall Voids ◽  
Annealing Method

In this study, electroplated Cu films were pre-annealed at T (T = 673, 773, 873 K) for varying times. Sn-3.5Ag solder reflowed over the Cu films and subsequently aged at 150°C for 240 hrs. Effects of pre-annealing on the microstructure of Cu films, as well as contents of organic impurities incorporated in the Cu films were investigated. After solder reflow, the formation of Kirkendall voids at Cu3Sn/Cu interface was observed from SEM micrographs. Results show that the pre-annealing process significantly suppressed Kirkendall void formation in the Sn-3.5Ag/Cu solder joints. A line fraction of voids at the Cu3Sn/Cu interface was definitely suppressed in the case of 500°C and 600°C pre-annealed samples compared to as-deposited Cu sample. SIMS analyses revealed that pre-annealing reduced the level of impurities in the Cu films, especially S and C. The mechanism of suppressing Kirkendall voids at the Cu3Sn/Cu interface was presented by schematic diagram, and it could be seen that pre-annealing method has a potential to enhance solder joint reliability.

Sign in / Sign up

Export Citation Format

Share Document