Engineering and Technical Support Group
School of Information Technology & Electrical Engineering

Drilling Options

  1. Before continuing, the method undertaken to drill and cut out the board must be defined as this will determine the process by which the artwork is produced
  2. Will the board be drilled and cut using a numerically controlled process?
    1. YES = refer to the EEL Standard Procedure: PCB Artwork Gerber Files - NC Drilling
    2. NO = refer to the EEL Standard Procedure: PCB Artwork Gerber Files - Manual Drilling

Artwork

  • Refer to EEL Standard Procedure: Photoplotter K144 - Artwork Production

OH&S Requirements

  1. Ensure you have either completed a Risk Assessment or read (and confirmed as being read) the relevant Risk Assessment before attempting to operate this equipment
  2. The Processing ID which refers to the general risk assessment regarding activities in the Darkroom / PCB Etching Facility is 19251 and addresses the use of chemicals and equipment used in conjunction with PCB manufacturing and production
  3. Wear safety glasses, gloves and a lab coat before you begin
  4. Clean room protocols apply to the Darkroom / PCB Etching Facility

Preparation of PCB Material

  1. Remove the PCB material from the refrigerator and take to the Darkroom / PCB Etching Facility
  2. Will the board be drilled and cut using a numerically controlled process?
    1. YES = Cut the PCB material to suit the drilling template file applicable to this task and return surplus material to the refrigerator.  Drill 2 location holes in the PCB material equi-spaced about the centre using drilling template K163 and 3mm drill
    2. NO = Cut the material to the required size and return surplus material to the refrigerator

Artwork Alignment

  1. Allow material to stand until it has stabilised at room temperature before continuing
  2. The following procedures must be carried out under yellow safelight
  3. Carefully remove the protective film from the PCB
  4. Will the board be drilled and cut using a numerically controlled process?
    1. YES = Ensure artwork is accurately aligned with the pre-drilled location holes in the PCB.  Failure to accurately align the artwork will result in inaccuracies during the NC drilling phase.
    2. NO = Align artwork as required

Exposure

Expose the PCB to UV light using exposure unit K059

  • PCB > EEL97-01-01 = 8 minutes (may be reduced to 5 minutes if Amb Temp > 23oC)
  • PCB > EEL 97-01-02 = 8 minutes (may be reduced to 5 minutes if Amb Temp > 23oC)
  • PCB > EEL 97-01-03 = 8 minutes (may be reduced to 5 minutes if Amb Temp > 23oC)
  • PCB > EEL 97-03-01 = 8 minutes (may be reduced to 5 minutes if Amb Temp > 23oC)
  • PCB > EEL 97-02-01 = 3 minutes
  • PCB > EEL 97-04-01 = 2 minutes

Developing Requirements

 a.  Develop the PCB using the solution specified

  • PCB > EEL 97-01-01 = 50% water mixed with 50% developer EEL 51-01-01
  • PCB > EEL 97-01-02 = 50% water mixed with 50% developer EEL 51-01-01
  • PCB > EEL 97-01-03 = 50% water mixed with 50% developer EEL 51-01-01
  • PCB > EEL 97-03-01 = 50% water mixed with 50% developer EEL 51-01-01
  • PCB > EEL 97-02-01 = 60% water mixed with 40% developer EEL 51-01-01
  • PCB > EEL 97-04-01 = 100% no dilution required developer EEl 51-01-01

Minor variations in the developer characteristics may be experienced between batches.  This, plus local environmental conditions, especially temperature, can significantly affect the developing process.  Light brushing may assist in the removal of the photo resist and is at the discretion of the operator.

 b.  Ensure all traces of unwanted photo resist have been removed from the board
 c.  Rinse the PCB with water and thoroughly dry before continuing

Etching Requirements

Refer to the EEL Standard Procedure: Spray Etcher K145 Operating Instructions

Drilling Options

  1. Will the board be drilled and cut using a numerically controlled process?
    1. YES = refer to EEL Standard Procedure: Protomat K045 Drilling & Routing
    2. NO = drill manually if required, then continue

Cleaning Phase

  1. If not already done, remove all remaining photo resist from the PCB using acetone
  2. Rinse with water and ensure the PCB is thoroughly clean and dry before continuing

Solder Mask

  1. Does the board require tinning or a solder mask?
    1. YES = refer to the EEL Standard Procedure: Laminator K146 Solder Mask Lamination Instructions & EEL Standard Procedure: PCB Tinning Procedure
    2. NO = Spray the PCB with a thin layer of clear printed circuit board lacquer EEL 30-06-01 or leave untreated depending upon EEL technical instructions
  2. The manufacturing process is complete

Amendments to Procedure

Inform the Engineering & Technical Support Manager at the earliest opportunity if this procedure has, or needs to be altered in any way