Temperature-Dependent Die Warpage Measurements Up to 400°C

Author(s):  
Tobias Mittereder ◽  
Bernhard Ferstl ◽  
Terry Heidmann ◽  
Christian Hollerith

Abstract Temperature-dependent die warpage measurements show the possibility to analyze the thermomechanical behavior during assembly, e.g. within soldering processes. The warpage data acquisition is realized by confocal chromatic white light profilometry in combination with a precision heating/cooling chuck encapsulated in a chamber with optical access. The combination of these two tools allows precise die warpage evaluation under varied device temperature up to +400°C. This method helps to solve emerging challenges due to warpage during assembly of state of the art packages including thin dies and stacked dies as in e.g. 3D-SIPs.

2021 ◽  
pp. 1-9
Author(s):  
Horacio Merchant-Larios ◽  
Verónica Díaz-Hernández ◽  
Diego Cortez

The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment’s role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief review intends to outline the history of scientific efforts that corroborate our current understanding of the state-of-the-art in TSD using chelonian species as a reference.


2018 ◽  
Vol 7 (4) ◽  
pp. 2569
Author(s):  
Priyanka Chauhan ◽  
Dippal Israni ◽  
Karan Jasani ◽  
Ashwin Makwana

Data acquisition is the most demanding application for the acquisition and monitoring of various sensor signals. The data received are processed in real-time environment. This paper proposes a novel Data Acquisition (DAQ) technique for better resource utilization with less power consumption. Present work has designed and compared advanced Quad Data Rate (QDR) technique with traditional Dual Data Rate (DDR) technique in terms of resource utilization and power consumption of Field Programmable Gate Array (FPGA) hardware. Xilinx ISE is used to verify results of FPGA resource utilization by QDR with state of the art DDR approach. The paper ratiocinates that QDR technique outperforms traditional DDR technique in terms of FPGA resource utilization.  


2018 ◽  
Vol 35 (4) ◽  
pp. 702-726 ◽  
Author(s):  
Muhammad Yaseen ◽  
Kashif Saleem ◽  
Mehmet A. Orgun ◽  
Abdelouahid Derhab ◽  
Haider Abbas ◽  
...  

2018 ◽  
Vol 22 (09n10) ◽  
pp. 821-830 ◽  
Author(s):  
Zheng Wang ◽  
Jian-Hua Zhang ◽  
Cheng-Yi Zhu ◽  
Shao-Yun Yin ◽  
Mei Pan

Bipodal ligand 5,15-bis(4-carboxyphenyl) porphyrin (H[Formula: see text]DCPP) was designed and synthesized. By adjusting the molar ratio of H[Formula: see text]DCPP, ancillary ligand 4,4-bipyridine (bpy) and zinc acetate salts, three novel coordination assemblies, namely, zero-dimensional dimeric [Zn[Formula: see text](H[Formula: see text]DCPP)[Formula: see text] ·bpy] ·4H[Formula: see text]O ·4DMF (Zn-D), two-dimensional polymeric {[Zn[Formula: see text](DCPP) ·bpy[Formula: see text] ·H[Formula: see text]O ·DMF[Formula: see text]] ·solvent}[Formula: see text] (Zn-2D), and three-dimensional polymeric [Zn[Formula: see text](DCPP) ·bpy[Formula: see text]][Formula: see text] (Zn-3D) were assembled. Due to the delicate integration of multiple chromophores in the coordination space combining bpy, DCPP and MLCT emissions together, photoluminescence (PL) of the three porphyrin-zinc coordination assemblies differ from each other and color tone is tunable from blue to orange with changes of the excitation wavelength. In particular, white light emission (WLE) can be observed by the excitation of 270 to 290 nm, representing the first examples of single component WLE compounds based on porphyrin ligands. Furthermore, temperature-dependent luminescence results in a linear [Formula: see text]–[Formula: see text] relationship in Zn-2D and Zn-3D assemblies, applicable for long wavelength red-emitting thermometers.


RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90499-90507 ◽  
Author(s):  
Shaoan Zhang ◽  
Yihua Hu ◽  
He Duan ◽  
Li Chen ◽  
Yinrong Fu ◽  
...  

We gained insight into the temperature-dependent relative emission intensity of La3GaGe5O16: Mn4+phosphor, and the luminescence quenching temperature and the activation energy for thermal quenching (ΔE) were obtained.


Author(s):  
Sajjad Z. Meymand ◽  
Milad Hosseinipour ◽  
Mehdi Ahmadian

This paper discusses the development of a state of the art single-wheel roller rig for studying contact mechanics and dynamics in railroad applications. The use of indoor-based simulation tools has become a mainstay in vehicle testing for the automotive and railroad industries. In contrast to field-testing, roller rigs offer a controlled laboratory environment that can provide a successful path for obtaining data on the mechanics and dynamics of railway systems for a variety of operating conditions. The idea to develop a laboratory test rig started from the observation that there is a need for better-developed testing fixtures capable of accurately explaining the relatively unknown physics of the wheel-rail contact mechanics and dynamics. Developing a better understanding of such physics would assist with designing faster, safer, and more efficient railroad systems. A review of the existing roller rigs indicated that many desired functional requirements for studying contact mechanics are not readily available. The Virginia Tech Railway Technologies Laboratory (RTL) has embarked on a mission to develop a state-of-the-art testing facility that will allow experimental testing for contact mechanics in a dynamic, controlled, and consistent manner. The VT roller rig is intended to allow for actively controlling all the wheel-rail interface degrees of freedom: cant angle, angle of attack, and lateral displacement. Two AC synchronous servomotors, accompanied with proper gearheads, accurately drive the rotating wheels. A novel force measurement system, suitable for steel on steel contact, is configured to precisely measure the contact forces and torques. The control architecture is developed based on the SynqNet data acquisition system offered by Kollmorgen, the drive-motor and actuator supplier. The Synqnet provides a unified communication protocol between actuators, drives, and data acquisition system; therefore eliminating any difficulty with data conversion among these units. Other auxiliary sensors and measurement systems are implemented to help with characterizing the contact mechanics and contact geometry. This paper will describe the main steps in the design process of the VT roller rig and the final design solution selected. It will also present the testing capabilities of the rig. The design analysis indicates that the rig can successfully meet the set requirements: additional accuracy in measurements, and better control on the design of experiments.


1992 ◽  
Vol 45 (5) ◽  
pp. 155-173 ◽  
Author(s):  
A. Aziz

This article is devoted to the review of the literature on optimum dimensions of extended surfaces losing heat by pure convection to the surroundings. The review covers straight (longitudinal) fins, annular (radial) fins, and spines of different profile shapes. The optimum dimensions for each shape are given both in terms of the volume of the material as well as the heat dissipation. The effects of tip heat loss, variable heat transfer coefficient, internal heat generation, temperature dependent thermal conductivity, base convection, and primary surface thickness on the optimum dimensions are discussed. The optimization procedure is illustrated with several numerical examples. Areas of extended surface technology where further optimization studies are needed are identified. It is hoped that the article would serve the dual purpose of the state-of-the-art as well as a pedagogical review.


Sign in / Sign up

Export Citation Format

Share Document