Status : Verified
| Personal Name | Lagsa, Earl Vincent B. |
|---|---|
| Resource Title | Viability of utilizing nanosilica-filled epoxy composites for improved package reliability in photodiode devices |
| Date Issued | 2 December 2022 |
| Abstract | Many of the encapsulated photodiode devices operate in harsh environments. To improve package reliability, there is a need to create such devices that are thermomechanically stable and moisture resistant. This is conventionally achieved by adding micron-size silica particles as encapsulant fillers. However, micron-size particles are unsuitable for photodiode device encapsulation due to significant light scattering resulting to reduced photocurrent output. Consequently, photodiode devices encapsulant without fillers tend to have inferior reliability (i.e., more susceptible to package crack due to sudden temperature change and high leakage current due to high humidity exposure). These can be addressed by utilizing nanocomposites of surface modified silica nanoparticles and epoxy. Despite recent advances in transparent epoxy-silica nanocomposites, it has not been utilized and investigated to improve photodiode devices package reliability. Commercially-available silica nanoparticles surface modified with two different silane organic moieties, R711 ([3-(Methacryloyloxy)propyl]trimethoxysilane) and R805 (octyltrimethoxysilane) were utilized to develop an epoxy-silica nanocomposite as liquid encapsulant for photodiode devices. As a key design requirement, filler loading must generate the lowest calculated thermomechanical stress σ_T=E∙∆T∙(α_encap-α_subs ). A 1%wt filler loading was found to have the lowest T. A counteracting effect between increased modulus and decreased coefficient of thermal expansion as a result of increased filler loading were noted. Furthermore, 1%wt filler loading was found to have no undesirable effect on key design constraints: viscosity, glass transition temperature, and optical transmission. The nanocomposite microstructure revealed a more even distribution and lesser degree of agglomerations in surface modified nanosilica fillers. A photodiode device embodiment utilizing such new encapsulants were shown to have maintained |
| Degree Course | PhD Materials Science and Engineering |
| Language | English |
| Keyword | epoxy-silica nanocomposites; reliability; photodiode device packaging; temperature cycling; temperature and humidity aging; package crack; dark current |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : I - Has patentable or registrable invention of creation.
Access Permission : Limited Access