Issue link: https://iconnect007.uberflip.com/i/1327102
JANUARY 2021 I DESIGN007 MAGAZINE 35 Edmund Optics, a renowned provider of optical com- ponents, continuously expands its product offering to reflect market developments and customer needs. New products are added each month to better serve the industry. EO just released Laser Grade C-Axis Sapphire Windows, which are ideal for use with high-powered lasers and TECHSPEC Cw Series Fixed Focal Length Lenses, which are designed for exposure to water, moisture, and humidity. Laser Grade C-Axis Sapphire Windows are precision optical windows cut to the C-axis of sapphire eliminating inherent birefringence. C-axis sapphire provides high transmission from the UV to the mid-IR, excellent chemical resistance, and high surface hardness. These laser windows feature 10-5 surface quality, λ/10 transmitted wavefront distortion, and are available uncoated or with an ion-beam sputtered (IBS) antireflection (AR) coating for 1000-1100nm Nd:YAG, Yb:doped fiber, or Yb:YAG laser applications. TECHSPEC Cw Series Fixed Focal Length Lenses are waterproof versions of the TECHSPEC® C Series Fixed Focal Length Lenses, designed to meet IPX7 and IPX9K IEC Ingress Protection Codes and are ideal for food, pharma, automotive, and security applications. These lenses are able to withstand water exposure up to a 1m in depth for 30 seconds and oper- ate in close-range, high-pressure, high- temperature water spray downs. (Source: PRNewswire) New Laser and Imaging Optics for High Powers and Harsh Environments experience multiple lamination cycles, such as HDI boards. • (CTE)—Coefficient of thermal expansion occurs in both the X/Y-axis and the Z-axis. The glass weave moves in the X/Y-axis. This is of concern for warpage threaten- ing solder joints. Boards are thin in the Z-axis as compared to the X/Y-axis; there- fore, Z-axis can be of greater concern as it threatens the reliability of plated holes. Electrical parameters: • (Ԑr or Dk)—Dielectric constant, also called permittivity or relative permittivity, is the ratio of capacitance of electrodes with a specific material. This is critical for imped- ance calculations and is of high value to high-speed digital circuits. It should be noted that the approximate Dk of resin is 3.0 and glass weave is about 5.0 with a resultant Dk of about 4.0. • (Df)—Dielectric loss is the absorption of electromagnetic energy by the board material in a varying electric field. This is critical for minimizing dB loss calculations and is of high value to RF circuits. Copper comes in several forms such as foil layers, electro-deposited or electroplated. Cop- per foil is typically utilized on the outer two layers and it has a smooth side and a rough side. The rough side provides adhesion to the resin in the prepreg and the smooth side is bet- ter suited as an energy transfer surface reduc- ing energy loss. There are many great laminate manufactur- ers in our industry. Yes, I think ours are the best and I'm always eager to make that case. But as designers, you need to pick the best material for your needs, always working early with your supply chain. What I want you to remember is to get the best use from the best material by understanding all three perspec- tives (DFS, DFP and DFM) and not just pursu- ing one or two perspectives. DESIGN007 Michael R. Creeden, CID+, MIT, is technical director of design education at Insulectro.