Engineering Services

CAM ENGINEERING

• Tooling time for up to 12 layers in 1.5 hours
• Tooling for 14-30 layers in 3.5 hours
• 24-hour CAM engineering support

• CAM stations
  • Frontline Genesis 2000 (Valor)
  • CAM 350 Station
• AOI Equipment (Mania-Barco)
  • AccuMatch2 for Silver Film Inspection
  • Medusa (Dual Camera) for Resist/Etched Cu Panels
• Photoplotter -- Mania-Barco SilverWriter
• ET -- Flying Probe and Universal Grid
• Polar Impedance Calculator

• World Wide Designs
• Efficiency through Automation
• Full design rule check
• Yield Enhancement Modifications
• Rules-Based Scripting

• Barco AOI Systems
• 100% Layer Inspection
• Film, Resist & Etch Inspection
• Verifies Production Panels and CAD data at the same time

• Universal Netlist Testing Download IPC-D-356 Netlist Generator (PADS Users)
• Flying Probe
• Universal Grid
• Verifies Final Product matches the original CAD data

IMPEDANCE MODELING REQUIREMENTS

Controlled Impedance The increase in processor clock speed and component switching speed on modern PCBs means that the interconnecting paths between components (i.e. PCB tracks) can no longer be regarded as simple conductors. At fast switching speeds or high frequencies (i.e. for digital edge speeds faster than 1ns or analog frequencies greater than 300 MHz) PCB tracks must be treated as transmission lines; i.e. for stable and predictable high speed operation the electrical characteristics of PCB traces and the dielectric of the PCB must be controlled. One critical parameter is the characteristic impedance of the PCB track (the ratio of voltage to current of a wave moving down the signal transmission line); this will be a function of the physical dimensions of the track (e.g. track width and thickness) and the dielectric constant of the PCB substrate material and dielectric thickness. The impedance of a PCB track will be determined by its inductive and capacitive reactance, resistance and conductance. PCB impedances will typically range from 25 to 120 Ohms. In practice a PCB transmission line typically consists of a line conductor trace, one or more reference planes and a dielectric material. The transmission line, (i.e. the trace and planes), form the controlled impedance. The PCB will frequently be multilayer in fabrication and the controlled impedance can be constructed in several ways. Whichever method is used, the value of the impedance will be determined by its: Physical construction and electrical characteristics of the dielectric material The width and thickness of the signal trace The height of the core or pre-preg material on either side of the trace The configuration of trace and planes The dielectric constant of the core and pre-preg material Impedance Matching Components themselves exhibit characteristic impedance so the impedance of the PCB tracks must be chosen to match the characteristic impedance of the logic family in use. If the impedance of the PCB tracks do not match the device characteristic impedance multiple reflections will occur on the line before the device can settle. This can result in increased switching times or random errors in high speed digital systems. The value and tolerance of impedance will be specified by the circuit design engineer and the PCB designer. However, it will be left to the PCB manufacturer to conform to the designer's specification and verify the finished boards meet the specification. Additional Controlled Impedance Articles Why Effective Er is NOT the same as Bulk Er Impedance Modelling on Multiple Dielectric Builds The Critical Length of a Transmission Line Controlled Impedance Testing Nickel-Gold Plating Copper PCB Traces Symmetric Stripline Edge-coupled Symmetric Microstrip Offset Stripline Reprinted with permission of Polar Instruments

Surface Microstrip Edge-coupled Surface Microstrip Embedded Microstrip Edge-coupled Coated Microstrip Coated Microstrip Edge-coupled Embedded Microstrip Edge-coupled Offset Stripline