scholarly journals Implementation of Non-Destructive Evaluation and Process Monitoring in DLP-based Additive Manufacturing

2017 ◽  
Vol 7 (1) ◽  
pp. 100-105 ◽  
Author(s):  
Iaroslav Kovalenko ◽  
Sylvain Verron ◽  
Maryna Garan ◽  
Jiří Šafka ◽  
Michal Moučka
Keyword(s):  
Control System ◽  
Process Monitoring ◽  
Continuous Measurement ◽  
Adhesion Force ◽  
3D Printer ◽  
Digital Light Processing ◽  
Non Destructive Evaluation ◽  
The Moment ◽  
Non Destructive

AbstractThis article describes a method of in-situ process monitoring in the digital light processing (DLP) 3D printer. It is based on the continuous measurement of the adhesion force between printing surface and bottom of a liquid resin bath. This method is suitable only for the bottom-up DPL printers. Control system compares the force at the moment of unsticking of printed layer from the bottom of the tank, when it has the largest value in printing cycle, with theoretical value. Implementation of suggested algorithm can make detection of faults during the printing process possible.

Non-Destructive Evaluation of Strains and Voiding in Passgvated Copper Metallizations

1993 ◽  
Vol 308 ◽  
Author(s):  
Richard P. Vinci ◽  
Thomas N. Marieb ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Strain State ◽  
Hydrostatic Stress ◽  
Strain Analysis ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
State Determination ◽  
Non Destructive ◽  
Voltage Scanning

ABSTRACTStress induced voiding in passivated Cu lines was investigated by x-ray strain analysis and in-situ high voltage scanning electron microscope (HVSEM) techniques. Cu lines on a Ta underlayer and Cu lines on an Al underlayer were patterned by a trilayer liftoff technique and passivated with Si3N4. For direct observation of stress voiding, specimens were heated to 350ºC in the HVSEM and then cooled and held at 150ºC. Identical samples were subjected to the same thermal cycle for strain state determination using x-ray techniques. The hydrostatic stress state at each temperature was calculated from the measured strains. Few initial voids were observed after passivation in either sample. After heating to 350ºC and cooling to the dwell temperature, no new voiding was seen in the Ta/Cu lines. Measured hydrostatic strains were half those measured in the Al/Cu lines. Heavy voiding was observed in the Al/Cu lines after cooling to the dwell temperature.

Non-Destructive Evaluation of Strains and Voiding in Passivated copper Metallizations

1993 ◽  
Vol 309 ◽  
Author(s):  
Richard P. Vinci ◽  
Thomas N. Marieb ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Strain State ◽  
Hydrostatic Stress ◽  
Strain Analysis ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
State Determination ◽  
Non Destructive ◽  
Voltage Scanning

AbstractStress induced voiding in passivated Cu lines was investigated by x-ray strain analysis and in-situ high voltage scanning electron microscope (HVSEM) techniques. Cu lines on a Ta underlayer and Cu lines on an Al underlayer were patterned by a trilayer liftoff technique and passivated with Si3N4. For direct observation of stress voiding, specimens were heated to 350°C in the HVSEM and then cooled and held at 150°C. Identical samples were subjected to the same thermal cycle for strain state determination using x-ray techniques. The hydrostatic stress state at each temperature was calculated from the measured strains. Few initial voids were observed after passivation in either sample. After heating to 350°C and cooling to the dwell temperature, no new voiding was seen in the Ta/Cu lines. Measured hydrostatic strains were half those measured in the Al/Cu lines. Heavy voiding was observed in the Al/Cu lines after cooling to the dwell temperature.

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