Publications

December 2003

Better Phototools – Clean Machines

Do employees treat the photo lab as a

meeting room? If so, they may be

inadvertently spreading contaminants – and

reducing yields.

Fall 1992

Capability Analysis & Statistical Process Control Applied to Photochemical Machining

Using the concepts of Cp and CPk this paper demonstrates, with

the aid of worked examples, that Capability Analysis may be

usefully applied to PCM.

September 1999

CBF = Cheaper – Better – Faster …are tbe words that best describe the goal in production

today. Customers demand the highest quality. want

it just in time.

June 2005

Dr. David M. Allen and Dr. Heather J.A. Almond, School of Industrial and Manufacturing Science, Cranfield University, Bedford, UK

Characterisation of Aqueous Ferric Chloride Etchants Used in Industrial Photochemical Machining

Ferric cbloride (FeCI3) is the most commonly used etchant for photochemical machining (PCM) but there is a great variety in the grades of the commercial product.

Chemical Milling Gives Boost to TV Age

Chemically milled components used

in prototype cathode ray tubes have

made a large contribution to the

development of the Sinclair miniature

tv.

Dec. 2000

Chemical Polishing of Metal Alloys, or Knocking off the high spots

Chemical Polishing is, in simple terms, a

selective dissolution process by means of which

the high points of a rough surface are removed

preferentially, rather than uniformly.

Fall 1988

Chemically Machining the New York Throughway

One of my responsibilities involves the proper disposal of

waste etchant material. We dispose of roughly 70,000 gallons or

almost 400 tons of ferric chloride annually.

Dec 2007

Choice of Manufacturing Techniques for Fabricating Metal Aerospace Filter: A guide to process choice for design engineers

With recent advances in manufacturing techniques, aerospace system designers have new options for fabricating higher-quality, lower-weight, higher- capacity, cost-effective filters.

Winter 1996

Clean Stripping of Dry Film Photoresists on Non-Copper Surfaces

Dry film photoresists have been used in photochemical

machining since their advent for printed circuit boards in the

1960’s.

Winter 1997

Cleaning in the Chemical Milling Industry

Before I begin, I want to comment that my company

has had a lot of success selling cleaners to the

Chemical Milling industry.

December 2002

Company Profile: Gebr. Schmid GmbH + Company

For perfect printed circuit boards, chemical

milling and LCD technology world-wide,

Schmid offers a wide range ofproducts in any

configuration to suit your individual needs.

December

2003

Company Profile: HMS Pumice-Spray Machines for Ultra-Cleaning Micro Rough Surfaces Provide High Adhesion and Resolution

Gerold Muller-Ensslin, HMS Hollmuller

Computerised Information Retrieval of Literature Relevant to Photo Chemical Machining (continued)

Summer 1985

Dr. David Allen and Ms. Jane Arthur, Cranfield Institute of Technology

Spring 1981

Conductor Line Imaging

Prior to 1968, when dry films were first introduced, two materials

systems were employed in forming conductor lines onto substrates screen

printing inks and liquid photoimagable resists.

Winter 1997

Continuous Cleaning of Metallic Strip for Photochemical Etching

BMC Industries, Mask Operations, deans and photochemically

etches approximately 21×10 6 square

meters of surface area in its continuous, aperture mask

manufacturing process.

Winter 1995

Control of Negative Working Electro-depositable (ED) Photoresist Baths

The electrodeposition of organic materials (also

known as electrocoating or electrophoretic coating)

is a technique well known in a variety of industries.

Spring 1992

Conveyorized Electrolytic Cleaning

Reverse current, electrolytic cleaning (or anodic electrocleaning)

has been utilized for many years as a surface

preparation technique in a variety of industries.

Summer/

Fall 1994

Cooling Water Alternatives

The most common method of supplying cooling

water is the direct connection of the cooler to the

water main. In this method the inlet of the cooling

coil (or its water control valve) is connected directly

to the city water supply.

Spring 1993

Copper Etching Economics

Copper etching is very important in the electronics industry,

particularly in the fabrication of printed circuit boards (PCBs).

The thin electrolytic copper foil may be etched by many different

types ofetchant.

Fall 1991

Cupric Chloride Regeneration

Etchant regeneration equipment for extending the life of

copper and copper alloy etchants, is technically well defined. The

equipment automatically provides accurate and simple monitoring

and control, is relatively inexpensive to purchase, is easy to install,

operate and service, and is safe to use.

September 2003

Design Considerations in the Use of Board Level Shields

In today’s electronic devices, increasing use of

board level shields is appearing, especially in

small, portable hand-held devices such as cell

phones and PDAs.

Spring 1989

Development of the Application of Laser Diffraction Particle Sizing to Etchant Sprays

The following paper was presented by Dr. David Allen at the 22nd

Annual Winter PCM] Meeting, held in Anaheim, on March 6th,

1989.

March 2006

Digital Etch Mask Printing Using Ink-Jet Technology

Patterning Technologies Limited (PTL) is a technology

integrator with extensive know-how and

proprietary intellectual property for the application

of inkjet printing technology to industrial processes.

Sept 2007

Digital Inkjet Printing for Etching Circuits: Putting the Pieces in Place for Printed PCBs

The driver for using a digital inkjet printer to lay down

a UV etch resist for PCB inner layer fabrication is fairly

straightforward: elimination of all photolithography processes

and equipment (i.e., artwork generation, photoresist

exposure, and development).

March 2005

Directly Printed Etchmask

Patterning Technologies Limited has developed

its patented etch masking technology for use in

many different applications including photochemical

machining. printed circuit boards, die

cut tooling.

Spring 1987

Disposal and Waste Treatment Considerations for Spent Aqueous Resist Processing Effluents

Spent Resist Effluent

How can I dispose of it?

Does it contain TTO toxic organics?

Winter 1998

Dry Film Developing Tests Fan Nozzles vs. Cone Nozzles in an Oscillating Developer

The goal in developing a dry film image has always

been to completely remove the resist from between the

lines, especially where spaces are less than 5 mils (125

!lm), and to have a straight sidewall with no foot at the

intersection of the resist and the surface to be etched.

March 2009

Dry Film Imaging Considerations for Photochemical Machining

Adhesion is the key to the successful etching

of photochemical machining parts with dry ilm

photoresist. Speciically, the imaging process must

be optimized to gain suficient attachment between

the dry ilm and the metal surface to ensure survival

through the inal etching process.

Fall 1989

Dry Film Resist Stripping

Dry film photoresists have become the most widely used

plating and etching resists for photochemical machining operations.

They are classified into solvent, semi-aqueous and full

aqueous resists, based on the type of chemistry required to

ploce s the resist.

Fall 1991

Dry Film Waste Treatment: A Reliable and Cost-Effective Alternative to a Persistent Problem

Typically, companies involved in both

printed circuit board manufacturing

as well as Photo Chemical

Machining will utilize Dry-Film

Imaging technology for the development

of various images onto

metal substrates.