DURACLEAN LPH-II

Description:

DURACLEAN LPH-II is an extremely efficient acid cleaner designed to function as an integral part of the DURATECH PROCESS. In this capacity it eliminates the need for aggressive preplate etchants and the "strike" or "flash" plating step prior to electroplating.

DURACLEAN LPH-II can be used for preplate cleaning of even thin deposition electroless copper without compromising the hole-wall integrity.

DURACLEAN LPH-II cleans, removes oxidation, and affords a very light, controlled micro-etch ideal for difficult preclean situations.

Benefits:

• Ideal for use with all types of Aqueous Resist Systems
• Removes even heavy oxides, as well as oils and dirt
• Eliminates the need for "striking" over thin electroless.
• Helps to remove adherent resist residues
• Gives a contrasting color to copper surfaces.

Properties:

Form:                                                Clear reddish/orange liquid
pH (as supplied):                            1.0
Acidity:                                            15 gms/liter (33% fresh make-up)
Specific gravity:                              1.02
Weight/Gallon                                 8.51 lbs
Solubility, water:                             Infinite
Max copper loading:                      .6 to .9 gms/liter (600 to 900 ppm)
Odor:                                                 Mild, characteristic

Applications:

DURACLEAN LPH-II can be used for preplate cleaning of resist coated electroless copper substrates. It can be used with any electroless copper including thin deposition types, and is compatible with all aqueous photoresist systems and screen links.

Directions For Use:

MAKE-UP:  33% by volume in water

TIME: 3 - 5 minutes. Do not exceed 5 minutes.

TEMPERATURE: 90°F ± 5°F. Do not operate below 80°F.

AGITATION: None required

OPERATION: Immersion only. Do not spray.

ETCH RATE: Average rate is 1.5 millionths/minute on electroless copper (fresh bath)

Equipment:

TANKS: polypropylene, PVC, PVDC, polyethylene or fiberglass

RACKS: 316 s/s - plastisol coated preferred.

HEATERS: Titanium, quartz, Teflon coated.

Maintenance:

The DURACLEAN LPH-II bath can be maintained by making additions based on a simple analysis for acidity. Frequent additions serve to maintain the etch rate as well as the cleaning power.

Control:

Bath Make-up can be checked by acidity. Bath Life is controlled by copper content.

Analytical procedure for acidity:

1. Equipment:
   1. 250 ml beaker
   2. 10 ml pipet
   3. 50 ml buret
2. Reagents
   1. Sodium Hydroxide, 0.1 Normal (0.1 N NaOH)
   2. pH 7-8 Phenol Red acid-base indicator mixture. (Mallincrodt IndicatAR 7-8).
3. Procedure
   1. Pipet 10 ml of fresh working bath into 250 ml beaker.
   2. Add 100 ml D.I. water
   3. Add 3 measures of Phenol Red Indicator (.3 to .4 grams)
   4. Titrate with 0.1 N NaOH from a clear yellow to a reddish pink end-point. Change is abrupt. Approach cautiously.
4. Calculations
   1. ml of titrate X Normality X 222 / ml of sample = gms/liter acid
5. Addition Schedule: A fresh 33% by volume LPH-II bath will have 15 gms/liter available acid. As acids are consumed during cleaning they may be compensated for by adding DURACLEAN LPH-II concentrate to the working bath as follows:
   1. For each gram/liter drop in acidity multiply by the number of liters in the bath.
   2. Divide that figure by 45 to determine the number of liters of LPH-II concentrate to add to the bath. EXAMPLE: a 378.5 liter bath (100 gallons) titrated at 13 gms/liter acid has consumed 2.0 gms/liter acid (15.0 - 13.0 = 2.0) Thus 2.0 X 378.5 = 757. Divide 757 by 45 to determine the liters of LPH-II concentrate to add to the working bath (757 / 45 =16.8 liters, or 4.4 gallons)

    

Control:

Bath control is by copper content. With regular additions the bath will hold up to 900 ppm (.9 gms / liter) before requiring replacement. With no replenishment the bath should be replaced at 600 ppm (.6 gms / liter) copper.

• Equipment:
  1. 10 ml and 100 ml measuring cyclinder
  2. 250 ml beaker
  3. 10 ml pipet
  4. 50 ml buret
• Reagents
  1. AR grade Sodium Sulfite (Na2SO3)
  2. Ammonium acetate, 10% in D.I. water
  3. 0.01 M EDTA (diSodium) solution.
  4. PAN indicator, 0.1% in ethanol.
• Procedure
  1. Pipet 10 ml of fresh working bath into 250 ml beaker.
  2. Dilute with 90 ml D.I. water.
  3. Add 1/2 gram sodium sulfite and miz for 5 minutes.
  4. Add 10 ml of 10% ammonium acetate solution
  5. Add 20 drops of PAN indicator from an eyedropper.
  6. Titrate with 0.01 M EDTA to the disappearence of the purple color. Solution will turn pink. Titrate unitl the pink turns to a yellowish-tan color. Approach slowly and cautiously. It is relatively easy to overshoot with this titration.
• Calculations
  1. Mililiters of titrate X 0.01 X 5.0 = grams/liter copper.
  2. Grams / liter X 1000 = ppm

Special Process Notes:

Do not attempt to clean tin/lead plated boards, or use racks with tin/lead plating on them. The result will be to turn the cleaner into an immersion tin bath, plating tin on copper circuitry. Do not operate bath below 80°F (26.67°C)

Safety:

DURACLEAN LPH-II is acidic. In case of skin contact flush with copious quantities of cool, fresh water. At the first sign of irritation consult a physician. Wear eye protection at all times. In case of eye contact, flush immediately with cool, fresh water for at least 15 minutes. Consult a physician. In case of ingestion consult a physician immediately.

Disposal:

1. Pump spent solution to a separate treatment tank.
2. Neutralize with Sodium or Potassium hydroxide to a pH of 8 or 9.
3. Add approximately 1/2 lb of Sodium Sulfide or Thiocarbamate to treat 100 gallons of spent solution for removal of metals such as copper, tin, and lead. NOTE: If solution is allowed to become acidic, poisonous hydrogen sulfide gas will form. Do Not let pH drop below 7
4. Filter the treated solution to remove heavy metals. Check solution after filtration by adding Sodium Sulfide to a sample. If no black precipitate forms the solution may be disposed. Heavy metals should be below one ppm after filtration.
5. Check with local city or country sanitation district on disposal to sewer. Generally the only requirements are neutralization to the pH ranch between 6 and 12 and removal of heavy metals. All materials in DURACLEAN LPH are biodegradable and have no effect on waste water treatment systems.

Storage:

Keep containers sealed until needed. Keep partial containers closed at all times. Store product between 40°F and 100°F. Keep away from sources of direct heat. Keep away from alkaline materials and strong oxidizing agents.

Shelf Life:

DURACLEAN LPH is guaranteed for six (6) months from date of receipt in unopened containers.

Containers:

Five gallon pails and 55 gallon nonreturnable plastic drums.

Classification:

National Motor Freight Classification NO. 48580, Sub 3
DOT Hazardous Material Description: Compound, cleaning, liquid
Hazard Class: Corrosive Material
I.D. Number: NA 1760, PPG III

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.