Proprietary Information of

Marlow Industries, Inc.

TEC CUSTOMER VISUAL INSPECTION CRITERIA

Cage No.: 55686

Document Number: 130-0670

Revision: B Page: 2 of 6

1.0 PURPOSE

1.1 To provide condensed visual inspection requirements of Thermoelectric Coolers (TECs).

The condensed visual inspection criterion is to be used with standard, catalog, and custom products.

2.0 APPLICATION

2. 1 A microscope adjusted to a maximum of 15X shall be required for this inspection. Gold surfaces to be viewed

using the unaided eye.

3.0 DEFINITIONS

3.1 TEC - Thermoelectric Cooler

3.2 TE Material - Thermoelectric material used to produce elements.

3.3 Element - TE column or pellet between ceramics.

3.4 Metallized Ceramic - Substrate that has been processed with a plated metal conductive pattern.

3.5 Scratch - A surface condition caused by an abrasion of one surface to another exposing base metal.

3.6 Base Metal - The base metal of a component, but not including protective finish and solderable coatings.

3.7 Solder - A fusible metallic alloy used to join metal surfaces at a temperature below the melting temperature of

the metals being joined.

3.8 Solder Joint - The connection of similar or dissimilar metals by applying molten solder with no fusion of the

base metal.

3.9 Cold Solder - The solder has a stacked up or piled up, dull appearance and shows signs of improper flow or

wetting action.

3.10 Disturbed Solder - The solder joint may under magnification reveal cracks or fractures. Movement of the

parts during the critical plastic phase, just before solidification, will cause this type of defect.

3.11 Bumps - less than 25 microns (0.001”) in height and covering less than 1% of the surface area are

acceptable.

3.12 Blisters - on pad metallization covering up to 1% of the pad surface area and less than 25 microns (.001”) in

height are acceptable. Blisters on full face patterns greater than 0.005” [0.127 mm] in diameter and covering

more than 10% of the surface area are unacceptable. Blisters on Full-face pattern must not exceed 25 microns

(.001”) in height.