Backside optical measurements of picosecond internal gate delays in a flip-chip packaged silicon VLSI circuit

1991 ◽  
Vol 3 (7) ◽  
pp. 673-675 ◽  
Author(s):  
H.K. Heinrich ◽  
N. Pakdaman ◽  
D.S. Kent ◽  
L.M. Cropp
Keyword(s):  
Flip Chip ◽  
Optical Measurements ◽  
Vlsi Circuit ◽  
Silicon Vlsi

16 x 16 VCSEL array flip-chip bonded to CMOS VLSI circuit

2000 ◽  
Vol 12 (8) ◽  
pp. 1073-1075 ◽  
Author(s):  
A.V. Krishnamoorthy ◽  
K.W. Goossen ◽  
L.M.F. Chirovsky ◽  
R.G. Rozier ◽  
P. Chandramani ◽  
...  
Keyword(s):  
Flip Chip ◽  
Vlsi Circuit ◽  
Cmos Vlsi

Measuring Die Tilt Using Shadow Moiré Optical Measurements; New Techniques for Discontinuous and Semi-Reflective Surfaces

2016 ◽  
Vol 2016 (1) ◽  
pp. 000612-000617
Author(s):  
Neil Hubble
Keyword(s):  
High Speed ◽  
Flip Chip ◽  
Elevated Temperatures ◽  
Semiconductor Industry ◽  
Measurement Techniques ◽  
Optical Measurements ◽  
Measurement Technology ◽  
Full Field ◽  
Shadow Moire ◽  
Shadow Moiré

Abstract When dealing with production of Flip Chip Packages in semiconductor packaging, the angle between the die and package substrate is critical for maintaining product yield and reliability. Current outgoing quality checks for die tilt can be time consuming to measure heights via point to point measurement techniques. Existing die tilt measurement approaches can also have reproducibility issues from user to user. Shadow moiré technology is a full field optical inspection technique commonly used for flatness characterization in the semiconductor industry, particularly at elevated temperatures. Two limitations to shadow moiré apply when discussing outgoing QC of die tilt: 1) shadow moiré requires a diffuse reflective surface for measurement; 2) shadow moiré is unable to measure sudden step heights. This paper discusses applications techniques and real world examples to overcome or mitigate the limitations of shadow moiré technology and use this full field and high speed measurement technology to measure die tilt. Using shadow moiré for this measurement technology can reduce measurement and user time as well as improve consistency of measurements from user to user. As shadow moiré tools are often used for at temperature flatness measurements, this added application can reduce the number of different measurement tools needed in QA labs.

A Hybrid Approach to Investigate Effect of Flip-Chip Packaging on RF MEMS Devices Performance

2008 ◽  
Author(s):  
Li Sun ◽  
Shawn Cunningham ◽  
Art Morris ◽  
Changsoo Jang ◽  
Bongtae Han
Keyword(s):  
Flip Chip ◽  
Rf Mems ◽  
Numerical Models ◽  
Actuation Voltage ◽  
Hybrid Approach ◽  
Optical Measurements ◽  
Mems Devices ◽  
Element Analysis ◽  
Flip Chip Packaging ◽  
Mems Device

A hybrid numerical/experimental scheme to investigate the effect of flip-chip packaging, with and without underfill, on MEMS device performance will be described. Finite element analysis (FEA) is used to model the MEMS assembly and is verified with Twyman/Green (T/G) and Moire´ interferometry, and good agreement between FEA and optical measurements is obtained. The die warpage in assemblies with and without underfill are approximately 0.36 μm and 1.1 μm, respectively. The performance of MEMS devices, fixed-fixed beams, in the packages is characterized by Capacitance-Voltage (C-V) measurement sweeping the actuation voltage yielding the “ON” state and “OFF” state capacitances. Beams in packages without underfill exhibit good actuation behavior while beams in packages with underfill are already in the down-position after packaging. Because die warpage of packages with and without underfill are significantly different, beam anchor relative displacement (BARD), which is affected by the warpage, is used to understand the C-V performance. From numerical models, BARD of packages without underfill is 50 nm and 162 nm for packages with underfill. Compared to a simplified critical BARD calculation (BARDcrit = 57 nm), the large BARD of packages with underfill implies that beams may have buckled, which results in the poor C-V performance. Further modeling of varied die thicknesses and coefficients of thermal expansion (CTE) of the underfill shows that the reduction of BARD is limited because of strong underfill-induced coupling between the die and substrate. It is concluded that the MEMS device and package have to be considered as a coupled design problem to minimize the adverse packaging effect on MEMS devices.

Picosecond backside optical detection of internal signals in flip-chip mounted silicon VLSI circuits

1992 ◽  
Vol 16 (1-4) ◽  
pp. 313-324 ◽  
Author(s):  
H.K. Heinrich ◽  
N. Pakdaman ◽  
J.L. Prince ◽  
D.S. Kent ◽  
L.M. Cropp
Keyword(s):  
Flip Chip ◽  
Optical Detection ◽  
Vlsi Circuits ◽  
Silicon Vlsi

16×16 VCSEL Array Flip-chip bonded to CMOS VLSI Circuit

1999 ◽  
Author(s):  
A. V. Krishnamoorthy ◽  
K. W. Goossen ◽  
L M. F. Chirovsky ◽  
R. G. Rozier ◽  
P. Chandramani ◽  
...  
Keyword(s):  
Flip Chip ◽  
Vlsi Circuit ◽  
Cmos Vlsi

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Analysis of Characteristics of Halogen and LED Automobile Lamps

2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Power Consumption ◽  
Flip Chip ◽  
Weather Conditions ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Colour Temperature ◽  
Study Results ◽  
Calculation Results ◽  
Mandatory Rules ◽  
Halogen Lamps

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.

Magnetic and optical measurements and signatures of reconnection in the cusp and vicinity

2015 ◽  
Vol 185 (6) ◽  
pp. 655-663
Author(s):  
V.V. Safargaleev ◽  
T.I. Sergienko ◽  
A.V. Safargaleev ◽  
A.L. Kotikov
Keyword(s):  
Optical Measurements
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