Managing Voids in Adhesives for Medical Devices

2014 ◽  
Vol 2014 (1) ◽  
pp. 000567-000571
Author(s):  
M. Ruales ◽  
J. Merced ◽  
R. Ramos
Keyword(s):  
Medical Devices ◽  
Adhesive Layer ◽  
Microelectronic Packaging ◽  
Void Content ◽  
Curing Process ◽  
Curing Time ◽  
Optimal Process ◽  
Thermal Transfer ◽  
Device Reliability ◽  
Packaging Industry

Void content within the adhesive layer dispensed over the connector module in neuromodulation devices is critical. Voids can affect the thermal transfer, bond strength, and stress decoupling of the adhesive, which can eventually lead to degraded device reliability. The effects of voids are investigated for a silicone based adhesive used in these medical devices. There are many challenges associated with the curing process that this adhesive undergoes which drive the need for unique and specific testing to determine optimal process settings. The parameters evaluated included curing time, temperature, thickness, and relative humidity. Reduction in void content was linked with mechanical properties including hardness and tensile strength. Achievement of void free medical adhesives will encourage today's microelectronic packaging industry to meet the challenges of smaller and denser medical devices.

Optimization of the Uncooked Oratosquilla Oratoria Curing Process via Response Surface Methodology

2014 ◽  
Vol 1073-1076 ◽  
pp. 1793-1797
Author(s):  
Qi Wei Mao ◽  
Jun Rui Wu ◽  
Xi Qing Yue
Keyword(s):  
Pathogenic Bacteria ◽  
Raw Materials ◽  
Curing Temperature ◽  
Curing Process ◽  
Curing Time ◽  
Optimal Process ◽  
Curing Conditions ◽  
Oratosquilla Oratoria ◽  
Sensory Score ◽  
Total Bacteria

Oratosquilla oratoria was the experimental raw materials in the paper. Design expert8.0.6 and Excel2007 was used to analyze the optimal process with the factors which were curing time, curing temperature, curing salt contention and the index which was the total bacteria. The pathogenic bacteria and sensory score under various curing conditions were determined simultaneously. After analyzing the significance of the various factors and interactions, the results showed the optimum curing conditions of oratosquilla oratoria were as follows: curing time 7.14h, curing temperature 14.34°C, curing salt contention 8.3%. Under this condition no pathogenic bacteria was detected and the sensory score was the highest.

Solvent diffusion mechanism of PMMA/ acetone coated glass fiber fabric during curing process

2021 ◽  
pp. 152808372110362
Author(s):  
Zhenrong Zheng ◽  
Yuejiao Bi ◽  
Lihuan Tong ◽  
Yalan Liu
Keyword(s):  
Glass Fiber ◽  
Diffusion Mechanism ◽  
Coating Film ◽  
Curing Process ◽  
Curing Time ◽  
Solvent Concentration ◽  
Solvent Diffusion ◽  
Coated Glass ◽  
Drying Model ◽  
Fiber Fabric

Fabric it is not an impermeable substrate because of fiber porosity. To study the solvent diffusion mechanism of coated fabric in the curing process, the drying model of PMMA/acetone coated glass fiber fabric was established. This drying model was verified by confocal Raman spectroscopy. Finally, the impact of fabric structure, thickness and porosity on the solvent diffusion process in coated fabrics was studied by the model. It was shown that the predicted solvent concentrations by the model were consistent with the experimental values. This model can be used to quantitatively calculate the solvent concentration at any position and at any time inside the coating film during the drying process. Moreover, it can also predict the curing time and residual solvent concentration of the coating fabric required to reach drying equilibrium. Compared with coated 3/1 twill, 5/3 satin and 2/1 twill, the solvent diffusion of coated plain fabric was faster during curing. Under the same environmental conditions, the thinner the fabric was and the greater the porosity was, the shorter the curing time was. The fitting equations for fabric thickness, fabric porosity and drying time were obtained, which can provide a theoretical guidance for the preparation, performance research and drying conditions optimization of PMMA coated textile materials.

The Study of Underfill Epoxy Hardness in Reducing Curing Process Time for Flip Chip Packaging

2011 ◽  
Vol 462-463 ◽  
pp. 1194-1199
Author(s):  
Zainudin Kornain ◽  
Azman Jalar ◽  
Rozaidi Rashid ◽  
Shahrum Abdullah
Keyword(s):  
Thermal Expansion ◽  
Flip Chip ◽  
Ball Grid Array ◽  
Process Time ◽  
Curing Process ◽  
Curing Time ◽  
Hold Temperature ◽  
Flip Chip Packaging ◽  
Time Cycle ◽  
The Impact

Underfilling is the vital process to reduce the impact of the thermal stress that results from the mismatch in the co-efficient of thermal expansion (CTE) between the silicon chip and the substrate in Flip Chip Packaging. This paper reported the pattern of underfill’s hardness during curing process for large die Ceramic Flip Chip Ball Grid Array (FC-CBGA). A commercial amine based underfill epoxy was dispensed into HiCTE FC-CBGA and cured in curing oven under a new method of two-step curing profile. Nano-identation test was employed to investigate the hardness of underfill epoxy during curing steps. The result has shown the almost similar hardness of fillet area and centre of the package after cured which presented uniformity of curing states. The total curing time/cycle in production was potentially reduced due to no significant different of hardness after 60 min and 120 min during the period of second hold temperature.

Effect of Adhesive Thickness on the Impact Toughness of Butt-Joints

2011 ◽  
Vol 230-232 ◽  
pp. 1350-1354 ◽  
Author(s):  
Min You ◽  
Jing Rong Hu ◽  
Xiao Ling Zheng ◽  
Ai Ping He ◽  
Cun Jun Chen
Keyword(s):  
Impact Toughness ◽  
Adhesive Layer ◽  
Curing Temperature ◽  
Curing Time ◽  
Optimum Thickness ◽  
Adhesively Bonded ◽  
Butt Joints ◽  
Notched Specimen ◽  
Adhesive Thickness ◽  
The Impact

The effect of the adhesive thickness on the impact toughness of the adhesively bonded steel joint under impact loading is studied using the experimental method. The results obtained show that the impact toughness increases when the adhesive thickness increased then it decrease as the adhesive thickness increase. When the curing time is set as a constant, the higher the curing temperature is, the lower the impact toughness of the joint. The optimum thickness of the adhesive layer for the specimen of impact toughness test cured at 60 C for 1 h is 0.6 mm and it is 0.4 mm to 0.6 mm for the specimen cured 1 h at temperature of 90 C or higher than it. It is recommended using the notched specimen to decrease the testing deviation.

Managing Voids in Underfill Process with 5-micron Gap Under Large Die

2012 ◽  
Vol 2012 (1) ◽  
pp. 000376-000383
Author(s):  
Hanzhuang Liang ◽  
Nordson Asymtek
Keyword(s):  
Flip Chip ◽  
Substrate Surface ◽  
Microelectronic Packaging ◽  
Flip Chips ◽  
Indium Bumps ◽  
Packaging Industry ◽  
Complex Features ◽  
Capillary Fluid ◽  
Near Future ◽  
Careful Design

Microelectronic packaging is continuously becoming smaller and denser, thus allowing for more functionalities and smaller devices including portable products. Flip-chip among other technologies continues to enable such trends. In fact denser arrays such as copper pillars or micro bumps of various metallurgies seem to be the technology of choice for the near future electronic interconnect. A technique is reviewed for successfully underfilling a 3cm2 Indium Phosphide flip-chip die mounted on a silicon substrate with 5 microns gap and large number of I/O (about 0.3 million indium bumps) connected in daisy chains. The method that resulted in a void-free underfill consisted of line dispensing along one side of the die such that the flow of the capillary fluid was normal to the direction of the daisy chains. For dot-dispense, substrate surface treatment and more careful design of dispense sequence helped to reduce voids. This study was compared to a manual dot-dispense technique that was unable to meet production throughput requirement, accuracy, repeatability and void-free. Achievement of void-free automated underfill into a 5-micron gap with complex features underneath a large flip chips will encourage today's microelectronic packaging industry to meet the challenges of smaller and denser components.

Void Content Determination of Fiber Reinforced Polymers by Acid Digestion Method

2013 ◽  
Vol 795 ◽  
pp. 64-68 ◽  
Author(s):  
M Hafiz Hassan ◽  
Abdul Rahim Othman ◽  
S. Kamaruddin
Keyword(s):  
Test Sample ◽  
Substantial Effect ◽  
Fiber Reinforced Polymers ◽  
Void Content ◽  
Testing Time ◽  
Curing Process ◽  
Fiber Reinforced ◽  
Acid Digestion ◽  
Test Procedures ◽  
The Matrix

Porosity of the fiber-reinforced polymer (FRP) is one of very important quality characteristics for the advanced use of the material in order to ensure full performance properties are attained. It was found that the porosity values of FRP in typical aircraft composite parts must be lower than 2.5 % to achieve the required mechanical properties. The most common method for measuring the void content is through acid digestion testing or burn-off method, since it provides the true values that could be used to generate the database properties of the materials. Thus, this paper discussed the detail of the acid digestion test procedures for the void content measurement of FRP, especially with regards to the suitable testing time and chemical volumetric quantity required to ensure the matrix of test sample has been completely extracted. In order to attain this, different test samples for different processing techniques were prepared. Subsequently, the findings were discussed within the context of void content in cured monolithic composite for different types of process, in which the samples from the VBO-oven curing process were compared with those of the autoclave-cured samples. In the VBO-oven curing process, the use of an intensifier during the curing provided higher void content of 15.52% in comparison with those achieved through the debulking process (10.91%). It has been clearly observed that the debulking produced a substantial effect towards the air evacuation mechanism within the laminate.

scholarly journals Effects of Post-Curing Time on the Mechanical and Color Properties of Three-Dimensional Printed Crown and Bridge Materials

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2762
Author(s):  
Dohyun Kim ◽  
Ji-Suk Shim ◽  
Dasun Lee ◽  
Seung-Ho Shin ◽  
Na-Eun Nam ◽  
...  
Keyword(s):  
Vickers Hardness ◽  
Color Change ◽  
Clinical Performance ◽  
Three Dimensional ◽  
Degree Of Conversion ◽  
Curing Process ◽  
Curing Time ◽  
Color Tone ◽  
Curing Conditions ◽  
3D Printed

Three-dimensional (3D) printing is increasingly being utilized in the dental field. After fabricating a prosthesis using a 3D printed resin, a post-curing process is required to improve its mechanical properties, but there has been insufficient research on the optimal post-curing conditions. We used various 3D printed crown and bridge materials in this study, and evaluated the changes in their properties according to post-curing time by evaluating the flexural strength, Weibull modulus, Vickers hardness, color change, degree of conversion, and biocompatibility. The obtained results confirmed that the strength of the 3D printed resin increased when it was post-cured for 60–90 min. The Vickers hardness, the degree of conversion, and biocompatibility of the 3D printed resins increased significantly around the beginning of the post-curing time, and then increased more gradually as the post-curing time increased further. It was observed that the color tone also changed as the post-curing time increased, with some groups showing a ΔE00 value of ≥ 2.25, which can be recognized clinically. This study has confirmed that, after the printing process of a 3D printed resin was completed, a sufficient post-curing time of at least 60 min is required to improve the overall clinical performance of the produced material.

Morphology-Controlled Synthesis of 1D ZnO Nanostructures by Hydrothermal Technique

2011 ◽  
Vol 266 ◽  
pp. 17-21
Author(s):  
Zhi Duan Cai ◽  
Lin Dong ◽  
Guo Xi Cao ◽  
Xing Yan Zhang ◽  
Shao Kang Guan
Keyword(s):  
Room Temperature ◽  
Controlled Synthesis ◽  
Curing Process ◽  
Zno Nanostructures ◽  
Curing Time ◽  
Photoluminescence Spectra ◽  
Structural And Optical Properties ◽  
Hydrothermal Technique ◽  
Room Temperature Photoluminescence

A two-step hydrothermal synthesis technique has been developed to obtained 1D ZnO nanostructures with adjustable aspect ratio and size distribution. The pre-curing process has important influence on the morphological, structural and optical properties. The LO phonons of the nanowires obtained by pre-curing for 24 h exhibit slight batho-shift in comparison with nanorods. The increase of the intensity ratio of ultraviolet to visible emissions in room-temperature photoluminescence spectra show the improvement in the quality of ZnO nanostructures as the pre-curing time prolonged. The fitting result of EX energy at T=0 is 3.382 and 3.370 eV for ZnO nanowires and nanorods, respectively.

PENINGKATAN DAYA TAHAN BAMBU DENGAN PROSES PENGASAPAN UNTUK BAHAN BAKU KERAJINAN

2014 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
Effendi Arsad
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Curing Process ◽  
Curing Time ◽  
Materials Used

Bamboo in South Kalimantan has not been used optimally, it is because bamboo susceptible organisms, including termites and powder. Research durability of bamboo with a curing process for raw materials craft has been done. This study aims to improve the durability of bamboo as raw material craft. The type of raw materials used are bamboo lear (Gigantochloa smear Kurz) and Bamboo betung (Gigantochloa atter). Old fumigation 5 days, 10 days and 15 days. Long trial against termites feed bamboo strips 10 days, 20 days and 30 days. Long curing time can improve the durability of bamboo strips against destructive organisms. 30 days storage of small attacks against the bamboo strips. Curing process can be used as a way of preservation of bamboo as raw material for handicrafts. Keywords: bamboo, fumigation, durability, organisms

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