lead frame package design flow using cds … · the world leader in high performance signal...

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Lead Frame Package Design flow

using CDS Electronics Packaging

Designer (EPD) and Cadence Chip

Package Design tools

—Analog Devices Confidential Information— 1

Take away from this paper

CAD Design Software’s - Electronics Packaging Designer (EPD) provides the means to bring the lead frame packages into Cadence System in Package (SIP) tools.

SIP tools are integrated with various EM field solvers which provide designers the flexibility to run analysis on an entire package design.

Potential solution for connectivity management.

Empowers the designer to run the analysis on her/his own.


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Electronic Package Designer (EPD)

EPD is from the third party vendor CAD Design Software.

EPD is built on AutoCAD tool; it adds intelligence to the package by adding the pin numbers on the package, tack points for wire bond connections and via-type connections at the Gull wings. The Gull wings connect to the PCB substrate.

EPD converts the AutoCAD .dxf file as an input and translates, and instantiates it in a SIP database.

The intelligence built on the lead frame package by EPD facilitates integration with system level electrical simulation tools.


The EPD software is built on AutoCAD tools.

It adds extra menu options to the AutoCAD interface; for the

recognition and manipulation of package input files.


CDS Menu is

added to the

AutoCAD

menus and

contains

commands to

process Lead

Frame

Designs

User interface to select an existing technology file built on

Custom Environment and Default Design Settings ….


The .TCH or ‘Technology File’

contains default settings that

can be shared with other

users. After initial setup, the

New Design Environment and

Settings can be saved to a

configuration file to be used

again.

Create or Modify a Technology file.


Set the Environment for

Measurement Units, Design

type, number of Layers and

the Material Stack-up.

Setting the Material Stack-up is

used when Describing the Level

Thickness, and Material Type that

will be used in Cadence. Built-in

and Custom Material Types are

available.

Once the settings with units, material stack-up, thickness

and tolerance is captured the following package drawing

will be loaded into the Design environment.


AutoCAD line or Polylines

were used in the DXF to draft

the design. Using Automatic

the EPD tools, the design is

first cleaned up and the

polylines will be ‘Joined’ and

‘Closed’.

Lead Frame Intelligence

software can now analyze the

drawing to make intelligent for

processing and also make

ready for Export to Cadence.

After the cleanup (Join and Closed polylines) and

intelligizing, the package name and pin numbers are

assigned.


By specifying which entities

are to be assigned as Metal,

Nets, lead assignments etc,

the LFINTEL command will

block and create the Lead Tips

and Paddels.

The tack points are added for the wire bond attachments

from the die to the package


Single or Multiple Tack points

can be automatically added to

the Intelligent Lead Tips.

Additional points may be

added manually.

Translation of the Lead Frame Package and instantiation in

a SIP database

Using the EPD2SKL conversion utility the Lead frame package is converted to the SKILL file.

So <Package_name>.il and EPD2SKL.scr files are available to play.

The lead frame Package appears in the SIP layout XL


Lead Frame Package imported into SIP.

—Analog Devices Confidential Information—

The pin numbers are

highlighted in red.

The tack points at

end of the leads for

wirebond

connection from the

die.

The gull wings at the

backend of the Lead

connects to the substrate

Lead Frame Package with the die placed in the package


Die Placed in newly

imported Lead Frame

Lead frame Package with the die and the wire bonds

attached. Once the Package is in SIP, bring the Die from the

schematic front end, place the die in the package and start

wire bonding to the package.


Connectivity (Method 1)

The netlist file is generated from SIP. For smaller Packages the net names for the wirebonds and the connectivity between the die and the package can be checked.


Connectivity (Method 2)


Schematic symbol for the die

and the package.

Die and the Package in SIP

with rats-nest attached.

Connectivity Driven Bonding diagram


3D Viewer in SIP


Assembly rules in SIP


Constraint Manager in SIP


Reports generated in SIP


Export to Agilent ADS Momentum and

Sigrity tools


Lead Frame Package in ADS Momentum


Cookie cutter section of the

package in ADS. Full package in ADS

Summarize advantages of bringing

Leadframe Package in SIP

Connectivity management for the Die and the package.

Ability to generate the connectivity driven bonding diagram.

3D capability enhances the view of wire loops, vertical and

horizontal separations of wire bonds.

Access to assembly rules checker with about 40 assembly

rule checks

Wire bond reporting with Net Name, Pin numbers, Finger

Name, wire angle etc

Robust constraint management tool for all physical and

spacing constraints

Ability to export the Die and the Package data to Simulation

tools


Conclusion

The Sub-Contractors changing the design on is a biggest issue at present which can be avoided if we have greater control and verify everything at our end, before it goes to the sub-contractor

This solution gives ADI greater control of the design database from early design exploration, through physical implementation to functional verification - by providing access to connectivity management, constraint management, simulation tools, and assembly rules checks.

The control over design database is extremely important through out the design cycle to avoid many iterations with the Sub-Contractors


Conclusion Continued…

The entire design process flow is less error prone due to the efficiency gained in this solution.

This solution not ONLY offers greater control of the design database to the business units/product lines, it also considerably reduces design cycle time, improves efficiency and overall product delivery to the ADI customer; thereby improving the Time to Market.


lead frame package design flow using cds … · the world leader in high performance signal...

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