02-07-2014, 12:34 PM
Software &MANIFACTURING PROSESS OF PCB’S
Software &MANIFACTURING PROSESS OF PCB’S.pptx (Size: 516.05 KB / Downloads: 13)
THERE ARE SIX OPTIONS OF PCB’s MANUFACTURING
STANDARD .
MINIBOARD .
PRODUCTION .
4- LAYER PRODUCTION .
PROTOpro .
4- LAYER PROTOpro .
HOW EXPRESS PCB’s WORK ?
there are two parts of express PCB’s and our free electronics design software and our low cost printed circuit board manufacturing s service .
The express PCB’s software are available on WWW.EXPRESS PCB’S DEMO.COM
Download ExpressPCB-
Start by downloading our free CAD software. It includes ExpressSCH for drawing schematics and ExpressPCB for circuit board layout. The software is easily installed, and a snap to learn and use. Both run with Windows XP through Windows 7.(Should you choose not to keep our software on your system, simply uninstall it using Add or Remove Programs found in your computer's Control Panel
Instant Quotes
After completing your layout, you can determine how much it will cost and how long it will take to have your boards made.
The ExpressPCB program displays the exact manufacturing cost by selecting the Compute Board Cost command from the Layout menu
TIPS FOR DESIGNING PCB’s
The engineers at ExpressPCB have assembled a few general rules-of-thumb that can help beginners design their first circuit board. These tips are not specific to using our CAD software, but instead provide an overview to help explain how to position the components on the board and how to wire them together
Placing Components
Generally, it is best to place parts only on the top side of the board.
When placing components, make sure that the snap-to-grid is turned on. Usually, a value of 0.050" for the snap grid is best for this job.
First place all the components that need to be in specific locations. This includes connectors, switches, LEDs, mounting holes, heat sinks or any other item that mounts to an external location.
Give careful thought when placing component to minimize trace lengths. Put parts next to each other that connect to each other. Doing a good job here will make laying the traces much easier.
Arrange ICs in only one or two orientations: up or down, and, right or left. Align each IC so that pin one is in the same place for each orientation, usually on the top or left sides.
Position polarized parts (i.e. diodes, and electrolytic caps) with the positive leads all having the same orientation. Also use a square pad to mark the positive leads of these components.
You will save a lot of time by leaving generous space between ICs for traces. Frequently the beginner runs out of room when routing traces. Leave 0.350" - 0.500" between ICs, for large ICs allow even more.
Parts not found in the component library can be made by placing a series of individual pads and then grouping them together. Place one pad for each lead of the component. It is very important to measure the pin spacing and pin diameters as accurately as possible. Typically, dial or digital calipers are used for this job.
After placing all the components, print out a copy of the layout. Place each component on top of the layout. Check to insure that you have allowed enough space for every part to rest without touching each other.
Placing Power and Ground Traces
After the components are placed, the next step is to lay the power and ground traces. It is essential when working with ICs to have solid power and ground lines, using wide traces that connect to common rails for each supply. It is very important to avoid snaking or daisy chaining the power lines from part-to-part.
One common configuration is shown below. The bottom layer of the PC board includes a "filled" ground plane. Large traces feeding from a single rail are used for the positive supply
Placing Signal Traces
When placing traces, it is always a good practice to make them as short and direct as possible.
Use vias (also called feed-through holes) to move signals from one layer to the other. A via is a pad with a plated-through hole.
Generally, the best strategy is to lay out a board with vertical traces on one side and horizontal traces on the other. Add via where needed to connect a horizontal trace to a vertical trace on the opposite side.
A good trace width for low current digital and analog signals is 0.010".
Traces that carry significant current should be wider than signal traces. The table below gives rough guidelines of how wide to make a trace for a given amount of current
Checking Your Work
After all the traces are placed, it is best to double check the routing of every signal to verify that nothing is missing or incorrectly wired. Do this by running through your schematic, one wire at a time. Carefully follow the path of each trace on your PC layout to verify that it is the same as on your schematic. After each trace is confirmed, mark that signal on the schematic with a yellow highlighter.
Inspect your layout, both top and bottom, to insure that the gap between every item (pad to pad, pad to trace, trace to trace) is 0.007" or greater. Use the Pad Information tool to determine the diameters of pads that make up a component
RESOURSE OF ENGINEER
Tektronix TDS-1000
The Tektronix TDS-1000 is a great low-cost digital storage oscilloscope for the microprocessor developer. We have the old model TDS-220 and love it. The ability that storage scopes have to capture and display a single event make them extremely handy for micro controller development. This model's very compact size also makes it great in the field. We do however consider that an analog scope may still be a better choice for doing sensitive analog work. These scopes are somewhat noisy at low voltages
Our mission
Our mission is to solve the software and manufacturing problem for low cost, quick turnaround prototyping. Our software does this by giving you a tool at no cost with all the right features that can be mastered in a single evening. We solve the manufacturing problem by combining the speed and world-wide coverage of the Internet and overnight delivery, with a first rate fabrication house that is focused on efficient manufacturing of double-sided and four-layer PC boards.