July 2019 – Page 2 – Paul Wu's Blog

Paper making

Paper making can be trace back long time ago. I did notice there is a saying that Egyptians first invented paper; however based on the education I received, it is a Chinese named Cai Lun who invented paper at the time around 100 AD. Anyway, modern paper making is much more complicated and different from these ancient process. The following is a short history of paper making.

Polymer hard coat

Hard coat is an indispensable materials in consumer electronics, building, automobile, medical, and optics industries to add on more multifunctions to the base materials, e.g. anti-reflection (AF), anti-glare (AG), Anti-smudge, Anti-fingerprint and more.

OCA formulation

Due to better refractive index matching between optical film and OCA, optically clear adhesive, compared to only air gap, OCA dramatically enhances display performances; there it have been broadly applied in the displays, solar cells, automobiles, buildings, et. al. In addition to provide suitable adhesion, it is also required to be optically transparent, colorless, weathering/aging resistant (no yellowing, no bubbles), and sometimes it requires to able to sustain high temperature, dissipate stress and more as required by specific applications.

Wafer dicing and grinding

Some nice videos from DISCO company website. Always good to understand the process in order to select or recommend most suitable materials for the best results.

UV release tape

In the semiconductor processing, e.g. dicing, grinding, wafers or similar objects need to be held with enough adhesion; after the process completed, the finished parts need to be peeled off easily from the holder. UV release tapes (UVR) are quite suitable for such applications.

EMI and Absorbers

With the increasing density of electronic components in consumer electrics or any other devices, electromagnetic interference become an increasing challenge that designers and engineers have to face. In the materials level, EMI or absorbers are great tools to tackle this problem.

Embedded Thin Film Resistor

Since Embedded Thin film resistors or ETFR can shorten the transmission distance, reduce electromagnetic interference, decrease the installation cost, save the space of the circuit board, it has been broadly adopted in printed wiring board (PWB)

Calendared Copper foil Vs Electrolytic Copper foil

The following is a short comparison between Calendared (also called RA copper foil) and Electrolytic copper foil (ED copper foil).

Super cooling technology: VC & graphene

There are two ways to combine Vapor Chamber and Graphene and deliver super cooling effects:

Heat Pipes & Vapor Chambers

Due to limited space in consumer electronics, traditional heat sinks and fans become irrelevant anymore. Besides, thin film graphite sheets, from 20-100um thick, gradually phase out as well due to limited thermal dissipation capability and weak mechanic performances, particularly poor layer to layer cohesion. Meanwhile slim heat pipes and vapor chambers are taking the momentum.