Dry Film Photoresist

The Fortex range of aqueous processable Dry film Photo resists have being designed to be Laminated, Exposed then developed and stripped using the Fortex Developer and Stripper Solutions or other mainstream chemistry.   The Laminating Dry film Photoresist comprises of three layers a cover sheet, photopolymer Photo resist and Polyolefin separator sheet.

This range of Dry Film Photo resists after laminating can be exposed with LDI or standard UV Exposure units/Lamps.  The Fortex Dry film offers superior performance and resistance to Leaching in the all of the most commonly used processes in Chemical Metal Etching/Milling and Printed circuit board PCB manufacturing. This range of Dry Film Photo resists are highly resistant to all acid chemical etching processes.

These Dry Film Photoresists are available in a range of different custom widths by request.  As well as different length roll sizes for use with the Fortex range of Dry Film Laminators or any industry standard Dry Film Laminators.

The Fortex Dry Film Photo resist is extremely flexible offering reliable tenting, even over large tooling holes. The Dry Film Photo resist has a market leading adhesion and resolution definition properties producing very high yields on fine line technologies.  Other thicknesses are available by request.

Packaging

All rolls of Dry film resist are supplied on 3″ (75mm) cores as standard but alternative core sizes can be supplied by request.

Storage should be in UV Free conditions with a temperature of 20-25 degrees (59-68 Degrees Fahrenheit) and a relative humidity of 40-70%

Pre-Lamination Cleaning

We recommend good surface cleaningof the panels that are to be laminated in order to obtain optimal performance from our Dry film resist.  A well cleaned panel/board should be able to keep a water film for at least 20 seconds.   A chemical Microetch pre-cleaner available from Fortex can be used or Mechanical methods can be utilised with a brush or pumice

Lamination

The panels to be Laminated with the Dry Film Photoresist must be thoroughly dry prior to Lamination.

Preheating of the panels to be Laminated is strongly recommended, the panels should ideally be heated to give a panel surface temperature of 35 Degrees (95 Degrees Fahrenheit)

Laminator Hot Roll Temperature 105-125 Degrees Celcius (221-257 Degrees Fahrenheit)

Laminator Hot Roll Pressure  2.5-3.5 Bar (35-50 PSI)

Lamination Speed 1-3m (3-10 Feet / min)

Board Exit Temperature >50 Degrees Celcius (122 Degrees Fahrenheit)

Hold Time

Minimum hold time after Lamination is the duration of time necessary for the panels to cool down to room temperature.

Maximum hold time to maintain best tenting performance 15 days

Exposure

We recommend the Laminated panels are exposed with your artwork using standard U.V. Exposure Units or a laser source with an emission peak of 360-380nm for exposure.

Sensitivity / Resolution

Using a Stoufer Step Wedge SST21 Place the step wedge under a transparent area of the Photographic master artwork, exposure levels should be optimised within the below range:-

Stouffer Step Wedge                                 6-9

UV Exposure Energy                                30-35mJ/cm2

Lines um                                                      40

Space um                                                      40

Film Emulsion Thickness                 40μm (1.6mils) Other thicknesses available by request

The Dry film resist has a very good printout after exposure useful for registration

The film goes from Light blue to Dark blue.

After exposure we recommend a hold time of a minimum of 10 minutes maximum 3 days.

Development

Using Fortex Dry Film Developer a typical developing time of the Exposed Laminated Panel of 30 seconds is normal when the developer is at a temperature of approximately 29 degrees Celcius.  The rinse water used after developing should be at a temperature preferably above 20 degrees Celcius.

Stripping

After Etching of the Panel the Dry Film needs to be Stripped.  Using the Fortex Dry Film Stripper Typical stripping times at an optimum temperature of 50 degrees Celcius should be around 100 seconds.

If  deeper etching of over 0.4mm depth in Ferrous metals such as Stainless Steel is required, then please order the special version of Dry Film Photoresist as listed.

All supporting chemistry such as Cleaner, Developer and Stripper are also available to purchase online.  All processing of the Dry film should be carried out in UV Yellow safe light conditions using suitable Window UV blocking Films and Light Filter Sleeves all available to purchase on the Fortex website.

Fortex can also supply a range of permanent dry films and supporting chemistry for Specialist MEMS applications (Micro Electro Mechanical Systems), Sealing application and Biochips.  These solvent type permanent films are commonly used for the production Micro fluidic devices.  These films are designed for excellent adhesion to Glass, Mylar, Silicon and Kapton   Please contact us for full details.