Si Excel – PCB Controlled Impedance Field Solver – single and multiple dielectric PCBs

Si Excel Interface option – Microsoft Excel® interface to PCB Controlled Impedance Field Solver – lossless modelling for Si8000m and Si9000e

Si Excel Lossless Field Solving Impedance Design System

The Field Solvers in the Si Excel Interface allow you accurately to graph impedance against changing PCB parameters. The Si Excel Interface Lossless Controlled Impedance Design System is a comprehensive controlled impedance design aid which provides modeling for a wide variety of structures as a set of functions through a Microsoft Excel user interface.

Si Excel versions

The Si Excel Interface / Si Excel x64 Interface is licensed for Si8000m or Si9000e.

  • Si Excel Interface is supplied for 32-bit versions of Microsoft Excel/Office (recommended version).
  • Si Excel x64 Interface is supplied for 32 & 64-bit versions of Microsoft Excel/Office.

Using Si Excel Interface spreadsheet functions

A package of Microsoft® Excel spreadsheets allows direct access to the field solver; you can graph any parameter you choose using the pre-prepared Microsoft Excel workbooks or build your own workbooks to model your process. The Si Excel functions included in Excel format enable advanced decision making; adding to the features currently available from the Si8000m / Si9000e Sensitivity Analysis tab, the Si Excel Interface provides access to the lossless field solving functions from within Excel, offering an extremely flexible and powerful way to calculate and graph the effects of a range of a parameter value changes.

The Si Excel Interface supports single or multiple dielectric builds in a comprehensive range of trace and dielectric configurations, providing models for structures with dielectric layers above and below traces, soldermask modeling and including compensation for resin rich areas between traces. The Si Excel Interface functions may be licensed for the Si8000m Lossless Field Solver or the Si9000e Lossy Line Field Solver, allowing you to build customised spreadsheets based on direct access to the boundary element field solving engine.

SiExcel index

The Field Solver functions for each controlled impedance structure are built into Si Excel and SiExcel Expert Microsoft Excel workbooks as user-defined functions. This allows rapid and convenient analysis of lossless trace characteristics such as impedance, propagation delay, inductance and capacitance against multiple varying board parameters.

Si Excel model

Click to see full graphic

Si Excel and Si Excel Expert workbooks

Each worksheet in the Si Excel workbook serves as a pre-built sample data worksheet incorporating tables of functions and their associated parameters for most popular controlled impedance structures. The sample worksheet comprises the graphic associated with the chosen model, a table with predefined values and an embedded chart that uses the table as its data source (typically set to chart impedance against substrate height). The chart source data can be redefined to show results for other parameters.

The Si Excel Expert includes the Excel functions needed to call the Polar field solver calculator engine, and is the most efficient tool to use when building customized spreadsheets from scratch for any of the Si8000m or Si9000e structures. The functions and their associated parameters are made available through the familiar Excel Paste Function formula palettes for ease of use. Results may be displayed through the standard Excel charting tools.

However, either the Si Excel or Si Excel Expert workbook may be used to build a customized Excel book. A customised book is particularly useful for analysis tasks which are performed repeatedly on certain trace configurations. For example, the attached custom spreadsheet (click the selection below to view full model) evaluates the impedance deviation of a differential pair as the various trace parameters (black background) drift from their target values (light blue) by increments (blue) during the manufacturing process. The source workbooks (ECSM_sensitivity_x86.xlsx for SiExcelExpert and ECSM_sensitivity_x64.xlsx for SiExcelExpert64) are both available here

(You will need the Si Excel or Si Excel Expert (x64) workbooks open to perform calculations on the sample workbook.)

Si model

Click to view full model

The graph above of Zdiff against Height (H1) clearly compares the relative impact of each parameter and reveals those which require the closest monitoring in process. In this example, the target parameters for a design are copied from Quick Solver (below.)

(In the Si8000m or Si9000e Quick Solver Click on “Edit” then “Copy Current Input Parameters to Clipboard”.

Switch to the Excel worksheet location, press “<Ctrl> v” and the incremental values for the variables entered into the blue fields.

The entire time for setup and computation of the study amounts to only a few seconds.

Si8000m specifications


Properties extracted

Single ended and differential impedance
(Zo, Zdiff, Zodd, Zeven, L/unit, C/unit, Tpd)

Field solving engine

Boundary element method (BEM)

Si Excel Interface – Controlled Impedance Field Solver Excel Interface

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