Ms. Michelle Velderrain Profile

Michelle Velderrain

Technical Specialist and Sales Representative at NuSil Technology LLC

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 6 February 2012 Paper

Designing low permeability, optical-grade silicone systems: guidelines for choosing a silicone based on transmission rates for barrier applications

Michelle Velderrain

Proceedings Volume 8280, 82800O (2012) https://doi.org/10.1117/12.910642

KEYWORDS: Silicon, Oxygen, Polymers, Silica, Water, Light emitting diodes, Refractive index, Optical design, Chemistry, Epoxies

Read Abstract +

Unprotected electronic components exposed to moisture from high humidity may fail due to corrosion of metal leads or other unfavorable reactions on chemically sensitive components. This is of high interest for silicones that encapsulate Light Emitting Diodes (LEDs) dies. For these applications, moisture and oxygen may react with materials, such as phosphor, used to make white LEDs for back-lighting applications and decrease or change the light output and color over time. Of the polymeric adhesives and sealants commercially available, silicones are used for their thermal stability, clarity, and comparably low modulus that provides stress relief during thermal cycling. In addition, silicones are also known to be very permeable to low molecular weight gases such as water vapor and oxygen. Recently, several types of silicones were tested for the oxygen and water vapor transmission rates, and it was found that they can have drastically different results. Silicone properties strongly affecting permeability are polymer backbone chemistry, crosslink density and fillers. Phenyl (C₆H₅) and trifluoropropyl (CF₃CH₂) groups are used to optimize the refractive index of optically clear silicones. The effect of chemical composition on the water vapor transfer rate (WVTR) and the oxygen transfer rate (OTR) at 40⁰ C and 90% Relative Humidity was investigated on several silicones with various refractive indices and compared to polydimethylsiloxane (PDMS) with similar durometers. It was found that polymer backbone chemistry had a significant influence on the permeation rates and will assist in material selection when designing for low-permeable barriers to improve package reliability.

Proceedings Article | 15 September 2010 Paper

Ultra Low Outgassing silicone performance in a simulated space ionizing radiation environment

M. Velderrain, V. Malave, E. Taylor

Proceedings Volume 7817, 781707 (2010) https://doi.org/10.1117/12.861749

KEYWORDS: Silicon, Gamma radiation, Aerospace engineering, Solar cells, Polymers, Platinum, Control systems, Ionizing radiation, Device simulation, Satellites

Read Abstract +

The improvement of silicone-based materials used in space and aerospace environments has garnered much attention for several decades. Most recently, an Ultra Low Outgassing™ silicone incorporating innovative reinforcing and functional fillers has shown that silicone elastomers with unique and specific properties can be developed to meet applications requiring stringent outgassing requirements. This paper will report on the next crucial step in qualifying these materials for spacecraft applications requiring chemical and physical stability in the presence of ionizing radiation. As a first step in this process, selected materials were irradiated with Co-60 gamma-rays to simulate the total dose received in near- Earth orbits. The paper will present pre-and post-irradiation response data of Ultra Low Outgassing silicone samples exposed under ambient air environment coupled with measurements of collected volatile condensable material (CVCM) and total mass loss (TML) per the standard conditions in ASTM E 595. The data will show an insignificant effect on the CVCMs and TMLs after exposure to various dosages of gamma radiation. This data may favorably impact new applications for these silicone materials for use as an improved sealant for space solar cell systems, space structures, satellite systems and aerospace systems.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years