Design007 Magazine


Issue link:

Contents of this Issue


Page 17 of 127

18 DESIGN007 MAGAZINE I JUNE 2021 Feature Article by Cherie Litson, CID+ LITSON1 CONSULTING Star Date 1978 "Change is the essential process of all existence." —Science Officer Spock In a cold (62°F), semi-dark room, there are banks of mainframe computers along one wall; a so light glows upward from the table in the corner. I take my kit—a variety of sizes of black, red, and blue tape, decals, and an X-Acto knife—and set it on the side table. On the top edge of the light table is a bar with pegs spaced about eight inches apart. A sheet of Mylar imprinted with a 1/10 th -inch grid is fitted over the pegs and taped down in the corners so it won't move. On top of this are two sheets of clear Mylar—one for the two sides of traces and one for the pad master of the circuit board I'm creating. Later, I'll add another sheet for all the reference designa- tors and part outlines. I have some decals for those, too. is is the first board I get to do myself from start to finish. I've been apprenticing for three years now. I've been drawing all the schemat- ics from napkins and scraps of notepaper from the engineers, creating the sepias for the fab- rication and assembly drawings, and being the gofer running all the files around to the photoshop and fab house. I have an engineer- approved schematic and I've made a rough sketch of where I want to place each part and the connections between them. Today, I start placing the decals and tape. I have to wear a warm jacket and hat in this room as I carefully place each component decal (most are 14-pin DIPs, resistors, caps, and a few transistor cans) on the intersec- tions of the grid lines and carefully align them to each other. Once I put them down, I don't want to move them as they won't stick so well then. is layout will be the typical 4:1 scale, so I need to place my targets outside the board for the photographer to sight on when they reduce the artwork. is is how we've been doing PCBs since the '60s. My Life in PCB Design

Articles in this issue

Archives of this issue

view archives of Design007 Magazine - Design007-June2021