ANTIOX PC-C

ANTIOX PC-C is a liquid oxidation inhibitor which reacts chemically with copper to form an electromechanical barrier to tarnish formation and oxidation.

ANTIOX PC-C treatment of electroless copper plated circuit boards produces a hydrophobic surface that enhances the adhesion of most resist films, eliminates flash plating, and results in cleaner developing and stripping.

Depending on the area of application, ANTIOX PC-C can eliminate scrubbing, edge lift, etch retardation, and oxidation as a source of resist breakdown.

• Eliminates scrubbing.
• Eliminates flash plating
• Inhibits oxidation
• Improves dry film adhesion (most films)
• Improves line resolution
• Eliminates undercut
• Reduces etch retardation

Properties:

Form:                                 Bright yellow liquid
pH (as supplied):             6.0 to 6.5
Flash point:                      205° F COC
Specific gravity:               1.02
Odor:                                 Mild, characteristic

ELECTROLESS COPPER: Anitox treatment of thin, medium, or high speed heavy deposition electroless copper stops oxidation and forms a base for the direct application of resist films without the need for scrubbing or flash plating (see ANTIOX PC-C Process Guide)

INNERLAYERS: Chemical preclean (see Duraclean ILC & Duratech 310) followed by Antiox PC-C stops oxidation and enhances resist adhesion, resulting in the elimination of edge lift and undercut, and cleaner development reduces of etch retardation.

BLACK or BROWN OXIDE: The presence of Antiox PC-C on etched innerlayers, either reapplied after stripping or because it survived the stripping process, increases the uniformity of oxide growth to the point that the oxide reducing step can often be avoided without suffering the advent of "pink ring" problems.

BATH MAKE UP:
Anitox PC-C 25% by volume with D.I. water.

OPERATION:
Static Tank: immerse 2 - 5 minutes @ 75° F +/- 5° F
Conveyorized Spray: 30 seconds to 2 min @ 100° +/- 5° F

Parts to be treated must be thoroughly clean, oxide free, and in a water-wet condition. Boards coming from an alkaline process, such as electroless copper, must be rinsed thoroughly and neutralized in 10% sulfuric acid prior to being treated.

TANKS: polypropylene, polyethylene, PVC, PVDC, S/S, mild steel

HEATERS: S/S, mild steel, quartz

PUMPS: plastic, S/S, mild steel, brass, or bronze

FILTER HOUSING: PVC, PVDC, S/S

PLUMBING: PVC or galvanized iron pipe.

BATH STRENGTH: maintain between 60% and 100% with additions of Antiox PC-C concentrate according to the schedule shown in the section on bath control and analysis

BATH pH: maintain pH between 4 and 6.5. Adjust daily with reagent grade sodium carbonate.

BATHCLEANLINESS: a recirculating 10-20 micron cartridge type filter is necessary to keep hard water precipitates and drag-in contaminates out of the bath. Continuos filtration during use is recommended.

PLUMBING; post Antiox overflow rinse module(s) must never back-flow into any overflow rinse module preceding it. NOTE: daily pH adjustments will shorten the life of the bath because of buildup of carbonate salts. Constant pH adjustment is the result of acid drag-in due to inadequate rinsing. An antiox bath requiring little or no pH adjustment can last a year or more before becoming cloudy and necessitating a fresh make-up.

SQUARE FOOTAGE: keeping track of the square feet of copper processed through the Antiox bath can greatly reduce titration frequency. Calculate as follows: theoretical bath yield is 500 sq. ft. per gallon working bath including allowance for drag-out. Thus, 200 sq. ft. per gallon will reduce a fresh bath to 60%. A 100 gallon bath will therefore process 20,000 sq. ft of copper (200 sq. ft. X 100 gals.) Before requiring replenishment. When using square footage count to monitor the bath, titration analysis should be done every fourth replenishment. Do not operate the Antiox bath below the minimum strength of 60% or below a minimum temperature of 70°F.

1. REAGENTS
   1. 0.1 normal silver nitrate
   2. 0.1 normal ammonium thiocyanate
   3. Concentrated ammonium hydroxide (30%)
   4. Concentrated nitric acid (70%)
   5. AR grade ferric ammonium sulfate
   6. Distilled water
2. APPARATUS
   1. Beaker, 500 ml
   2. One 10 ml & one 20 ml pipets
   3. One 50 ml buret
   4. A 50 & 100 ml measuring cylinders
   5. A 500 ml Buchner flask & funnel
   6. No. 5 Whatman filter paper. (5.5 cm paper for 6 cm funnel)
   7. Whatman cellulose powder, grd. CF-1
   8. Wash bottle
   9. Vacuum pump (Nalgene #6130-0020)
3. INDICATOR SOLUTION
   1. To 80 gms AR ferric ammonium sulfate add 10 ml conc. nitric acid
   2. Add distilled water to 200 ml
   3. Stir with mild heat (100° - 110°F).
4. PROCEDURE
   1. Pipet 10 ml of solution into 500 ml beaker. Add 125 ml of distilled water; 5 ml of concentrated ammonium hydroxide; and 20 ml of 0.1 normal silver nitrate. Stir well and let stand for 5 minutes to allow coagulation of the precipitate.
   2. Add 3 to 4 gms of cellulose powder to aid filtration and filter suspension through Buchner funnel using #5 Whatman paper. Be sure to transfer all of the solution and precipitate.
   3. Wash beaker with 3 X 50 ml portions of distilled water, and pour each increment through funnel to flush the filter cake. Return filtrate and washing to the breaker from the Buchner flask.
   4. Slowly stir 10 to 15 ml concentrated nitric acid into filtrate.
   5. Add one (1) ml of indicator (#3)
   6. Titrate to a pale orange end point with 0.1 normal ammonium thiocyanate.
5. CALCULATIONS
   1. The % of bath strength = [(A X N1)-(B X N2)] X 1.2693
      • The above is calculated where:
        • A=ml of silver nitrate added
        • N1=normality of silver nitrate
        • B=ml ammonium thiocyanate used
        • N2= normality of ammonium thyiocyanate
   2. Calculation X 100 = percentage (%)
6. REPLENISHMENT
   1. Determine bath strength in percent.
   2. Using the % bath strength guide below, for every ten (10) gallons of working bath add ANTIOX PC-C concentrate according to the schedule shown:
      100%                         0
      90 %                          0.25 gallons
      80%                           0.50 gallons
      70 %                          0.75 gallons
      60 %                          1.00 gallons
      50 %                          1.25 gallons
      40 %                          1.50 gallons
   3. Example: a 60 gallon bath at 80% would require three gallons of ANTIOX PC-C to bring it back up to 100% (60 gals / 10 X 0.50 = 3 gallons of PC-C

    

Antiox PC-C must be removed prior to electroplating. This is accomplished during preplate cleaning cycle using a cleaning system designed for the process, the film type, and the thickness of electroless copper being used. Duratech Industries, Inc. manufactures a variety of specialty preplate cleaners and systems for this application. Contact your Duratech dealer or Duratech Industries direct for information on these products.

Antiox presents little hazard. It contains propylene glycol monomethly ether which to date has not been found to have any significant health effects. When handling this product avoid contact with eyes. In case of eye contact flush immediately with copious quantities of fresh, cool water. Obtain medical attention. Take precautions to prevent prolonged or repeated skin contact. Wash contaminated skin with soap and water. Remove contaminated clothing and wash before reuse. Provide adequate ventilation.

Check with local EPA office for information on putting Propylene Glycol Methyl Ether into the sewer. The working Anitox bath will contain 2% by volume of this chemical. Other materials present in Antiox are either not regulated or are biodegradable and have no effect on waste water treatment systems.

Keep containers sealed. Keep partial containers closed at all times. Store product away from sources of excessive heat.

Anitox is guaranteed for (1) year from date of receipt in unopened containers.

Five gallon pails and 55 gallon nonreturnable plastic drums.

National Motor Freight Classification
NO. 149980, Sub 2, Class 55
DOT Hazardous Material No. Not regulated
Ship as: Water Based Paint Additive

The information contained herein is based on our experience and is believed to be reliable. However, since methods and conditions of use of our products as described are beyond our control, both the product and instructions for its use are offered without warranty, expressed or implied. No information on this data should be construed as a recommendation by DURATECH INDUSTRIES, INC., to use any product in contravention of any patent right.

This supersedes all ANTIOX PC-C data prior to 1-6-97