Influence of bonding process parameters on chip cratering and phase formation of Cu ball bonds on AlSiCu during storage at 200°C

2011 ◽  
Vol 51 (1) ◽  
pp. 107-112 ◽  
Author(s):  
S. Schmitz ◽  
M. Schneider-Ramelow ◽  
S. Schröder
2010 ◽  
Vol 148-149 ◽  
pp. 1129-1132
Author(s):  
Shahrum Abdullah ◽  
Mohd Nubli Zulkifli ◽  
A. Jalar

The nanoindentation test and geometry measurement have been conducted to evaluate the hardness and geometry changes of bonded Au ball bonds towards the changes of the selected wire bonding parameters namely bonding power, bonding time and bonding force. Three indentations were made on the bonded ball bonds to evaluate the variation of hardness properties with the location of indentation. It was noted that the increase of bonding or ultrasonic power will increase the hardness value for the indentations 1 and 3 located at the periphery of bonded ball bonds. The increase of bonding power also increased the deformation of bonded ball bonds. It was also shown that the increment of bonding time will increase the hardness value across the bonded ball bonds in almost even distribution. The application of the bonding force in the wire bonding process has the least effect on the hardness and geometry changes on the bonded ball bonds.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1018
Author(s):  
Giuseppe Fiorentino ◽  
Ben Jones ◽  
Sophie Roth ◽  
Edith Grac ◽  
Murali Jayapala ◽  
...  

A composite, capillary-driven microfluidic system suitable for transmitted light microscopy of cells (e.g., red and white human blood cells) is fabricated and demonstrated. The microfluidic system consists of a microchannels network fabricated in a photo-patternable adhesive polymer on a quartz substrate, which, by means of adhesive bonding, is then connected to a silicon microfluidic die (for processing of the biological sample) and quartz die (to form the imaging chamber). The entire bonding process makes use of a very low temperature budget (200 °C). In this demonstrator, the silicon die consists of microfluidic channels with transition structures to allow conveyance of fluid utilizing capillary forces from the polymer channels to the silicon channels and back to the polymer channels. Compared to existing devices, this fully integrated platform combines on the same substrate silicon microfluidic capabilities with optical system analysis, representing a portable and versatile lab-on-chip device.


Author(s):  
Elisabeth Brandl ◽  
Thomas Uhrmann ◽  
Mariana Pires ◽  
Stefan Jung ◽  
Jürgen Burggraf ◽  
...  

Rising demand in memory is just one example how 3D integration is still gaining momentum. Not only the form factor but also performance is improved for several 3D integration applications by reducing the wafer thickness. Two competing process flows using thin wafers are to carry out for 3D integration today. Firstly, two wafers can be bonded face-to-face with subsequent thinning without the need to handle a thin wafer. However, some chip designs require a face-to-back stacking of thin wafers, where temporary bonding becomes an inevitable process step. In this case, the challenge of the temporary bonding process is different to traditional stacking on chip level, where usually the wafers are diced after debonding and then stacked on chip level, which means die thicknesses are typically in the range of 50 μm. The goal of wafer level transfer is a massive reduction of the wafer thickness. Therefore temporary and permanent bonding has to be combined to enable stacking on wafer level with very thin wafers. The first step is temporary bonding of the device wafer with the temporary carrier through an adhesive interlayer, followed by thinning and other backside processes. Afterwards the thinned wafer is permanently bonded to the target wafer before debonding from the carrier wafer. This can be repeated several times to be suitable for example a high bandwidth memory, where several layers of DRAM are stacked on top of each other. Another application is the memory integration on processors, or die segmentation processes. The temporary bonding process flow has to be very well controlled in terms of total thickness variations (TTV) of the intermediate adhesive between device and carrier wafer. The requirements for the temporary bonding adhesive include offering sufficient adhesion between device and carrier wafer for the subsequent processes. The choice of the material class for this study is the Brewer Science dual layer material comprising of a curable layer which offers high mechanical stability to enable low TTV during the thinning process and a release layer for mechanical debond process. The release layer must lead to a successful debond but prevent spontaneous debonding during grinding and other processes. Total thickness variation values of the adhesive will be analyzed in dependence of the adhesive layer thickness as this is a key criterion for a successful implementation at the manufactures. Besides the TTV the mechanical stability during grinding will be evaluated by CSAM to make sure no delamination has happened. For feasibility of the total process flow it is important that the mechanical debonding requires less force compared to the separation of the permanent bonded wafers. Other process parameters such as edge trimming of the device wafer as well as edge removal of the mechanical debond release layer are investigated.


2019 ◽  
Vol 11 (8) ◽  
pp. 168781401987089 ◽  
Author(s):  
Yingshuai Xu ◽  
Zhihui Wan ◽  
Ping Zou ◽  
Qinjian Zhang

There are many problems and physical phenomena in turning process, like machined surface quality, cutting force, tool wear, and so on. These factors and the chip shape of workpiece materials, which is an important aspect to study the mechanism of ultrasonic vibration–assisted turning, go hand in hand. This article first introduces the types and changes of chip, meanwhile the chip formation mechanism of ultrasonic vibration–assisted turning is studied and analyzed, and the turning experiments of 304 austenitic stainless steel with and without ultrasonic vibration are carried out. The difference of chip morphology between ultrasonic vibration–assisted turning and conventional turning is contrasted and analyzed from the macroscopic and microscopic point of view. The influence of process parameters on chip shape and the impact of chip shape on machining effect are also analyzed. Results indicate that when process parameters (vibration frequency, ultrasonic amplitude, and cutting parameters) are suitably selected, ultrasonic vibration–assisted turning can gain access to better chip shape and chip breaking effect than conventional turning. By contrast with conventional turning, phenomenon of serrated burr on the chip edge and the surface defects of chip in ultrasonic vibration–assisted turning have improved significantly. Moreover, it is found that superior chip morphology in ultrasonic vibration–assisted turning can be acquired under the circumstance of comparatively small cutting parameters (cutting speed, depth of cut, and feed rate); at the same time, preferable chips can also obtain ranking machining effect.


2016 ◽  
Vol 75 (9) ◽  
pp. 255-264 ◽  
Author(s):  
R. Knechtel ◽  
S. Dempwolf ◽  
H. Klingner

2016 ◽  
Vol 716 ◽  
pp. 817-823
Author(s):  
Yi Wang ◽  
Idris K. Mohammed ◽  
Daniel S. Balint

Interfacial bonding has a significant influence on the quality of processed components formed by powder forging. Consequently, modelling the bonding process is important for controlling the condition of the components and predicting optimum forging process parameters (e.g. forming load, temperature, load-holding time, etc.). A numerical model was developed in the present work to simulate diffusion bonding (DB) during the direct powder forging (DF) process. A set of analytical equations was derived and implemented in the finite element (FE) software Abaqus via a user-defined subroutine. The DB model was validated using a two-hemisphere compression simulation. The numerical results demonstrated that the DB model has the ability to: 1) determine the bonding status between powder particles during the forging process, and 2) predict the optimum value for key powder forging process parameters. The DB model was also implemented in a representative volume element (RVE) model which was developed in an earlier work to simulate the powder forging process by considering particle packing and thermo-mechanical effects.


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