Track Pitch Measurements
 using DiscTrack Plus™


The problem

There are many challenges in manufacturing discs in the new high density (DVD) format. Mastering and replication equipment must now support both the CD and DVD formats. A number of companies in the CD industry have identified track pitch as one area of particular concern because track pitch errors such as incorrect mean value and excessive jitter (range) may cause playback problems. This makes customers unhappy and results in costly returns. Until now there has been no adequate test method for DVD track pitch.

The solution

DiscTrack Plus™ directly measures track pitch on compact discs using scanning probe microscope images. It tabulates individual values of track pitch. Quantitative graphs and statistical parameters give a firm basis for assessing disc quality and allow you to decide whether a disc passes or fails the track pitch specification. For example, both Disc 1 and Disc 2 had mean track pitch within the specified window (0.74 +/- 0.01 mm), but the range of pitch values for Disc 1 exceeded the specification (0.74 +/- 0.03 mm). Results for the calibration standard show that individual features can be measured with a precision of 1 nm.

Disc 1

(mean = 744 nm, std. dev. = 27 nm)

Disc 2

(mean = 736 nm, std. dev. = 6.8 nm)

Calibration standard

(mean = 288 nm, std. dev. = 1.1 nm)

Who needs DVD and CD track pitch information? Anyone who is concerned about playback quality. Manufacturers of discs, disc production equipment (such as laser beam recorders and replication presses), and disc players are all concerned about track pitch. Track pitch errors create noise and signal distortion, leading to data errors. By knowing whether track pitch is under control (and quantitatively how well it is controlled), you can make a wiser purchasing decision, optimize your process more quickly, and assure consistent performance.

We provide Disc Track Plus™ Measurement Systems for companies with Atomic Force Microscopes, or Disc Track Plus™ Measurement Services for companies without AFM's or who need additional outside assistance.

DiscTrack Plus™ Measurement System

Overview. DiscTrack Plus™ software can be installed on existing Scanning Probe (Atomic Force) Microscopes or on any Windows PC. You can now get high accuracy measurements of track pitch. You will be able to easily distinguish between discs of different quality. The precise, quantitative results will help you decide which disc meets specifications and which disc fails. The complete DiscTrack Plus™ system includes the following components:

Software features and benefits:

Calibration specimens:

Other information:

Calibration samples - see our calibrator guide 

Measurement Service:

You can also get high accuracy measurements of track pitch using our measurement services. You will be able to easily distinguish between discs of different quality using our comprehensive report of pitch results. These precise, quantitative results will help you decide which discs meet specifications and which discs fail.

We recommend capturing sufficient AFM images to include 100-120 individual measurements of track pitch.  This may require 6-10 images. On DVD, we often measure 2 nearby 10-um images at each of 5 different radial positions on a stamper.

Service Benefits and features:

What is a Scanning Probe Microscope(SPM)? An SPM is an instrument which uses a physical probe to trace the hills and valleys of a surface, producing a high magnification 3-D image. The Atomic Force Microscope(AFM) is one type of SPM.

Corporate profile. Advanced Surface Microscopy, Inc. is an independent analytical service and research laboratory. Since 1991, we have been helping many companies in the disc industry to solve materials and processing problems. Our proprietary DiscTrack™ technology was developed to meet your industry's needs.


To improve disc quality, please contact:

Advanced Surface Microscopy, Inc.

3250 N. Post Rd., Suite 120
Indianapolis, IN  46226 USA
Phone: +1-317-895-5630
Toll Free: 1-800-374-8557 (US & Canada)
FAX:  +1-317-895-5652
http://www.asmicro.com
e-mail: info@asmicro.com

Request information

Back to ASM home page.

disctrak.htm last updated 04/09/2007

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