DURAPOSIT TM SMT 810 Electroless Nickel

Transcription

1 DURAPOSIT TM SMT 810 Electroless Nickel For PWB Metallization Applications Regional Product Availability Asia Japan/Korea North America Europe Description DURAPOSIT TM SMT 810 is an electroless nickel system specifically formulated for use in combination with AUROLECTROLESS TM Immersion Gold. DURAPOSIT SMT 810 combined with AUROLECTROLESS SMT 520 Plating has excellent corrosion resistance and solderability, which is maintained at both high and low bath loading and throughout the solution life. The self-adjusting ph feature simplifies bath operation and makes the process ideal for use with Dow Electronic Materials automatic bath control systems. Advantages Excellent corrosion resistance Excellent solderability Stable deposition rate Easy to control Bath Make Up for 1 Litre Bath Component Deionized(D.I.) Water DURAPOSIT TM SMT 810 Make Up Solution DURAPOSIT R Nickel Replenisher D.I. Water Metric 850 ml 100 ml 42 ml To final operating volume Make Up Procedure 1. Add 850 ml/l D.I. water to a clean tank. 2. Add DURAPOSIT TM SMT 810 Make Up Solution with continuous stirring. 3. Add DURAPOSIT R Nickel Replenisher with continuous stirring. 4. Adjust to final volume with D.I. water. 5. Mix thoroughly. 6. Check ph and make the adjustment if necessary. (see Operation Parameters) Page 1 of 8

2 Operation Parameters Parameter Range Recommendation Nickel Concentration g/l 5.0 g/l Sodium Hypophosphite g/l 20 g/l ph Temperature o C 84 o C Loading factor dm 2 /L 0.5 dm 2 /L Agitation Continuous solution flow over a weir 10 solution volumes per hour (8-15); board movement and solution filteration plus filtered air beneath heaters. It is strongly recommended to use either vibration or bump agitation. Bath Life Deposition Thickness ~5 MTOs 4-5 microns in minutes under the optimum condition Replenishment Schedule Rplenishment Table for a 100 litre bath Nickel Concentration (g/l) DURAPOSIT R Nickel Replenisher DURAPOSIT SMT 810 Replenisher ml 170 ml ml 340 ml Analytical Procedures NICKEL CONTENT I. Equipment a) 1000 ml volumetric flask b) 250 ml Erleyenmeyer flask c) 100 ml measuring cylinder d) 10 ml pipette e) 50 ml burette II. Reagents a) 0.10M EDTA solution b) 50% Ammonium hydroxide solution c) Murexide Indicator Add 1 g of Murexide indicator to 100g of sodium chloride in a mortar. Pestle to mix thoroughly Page 2 of 8

3 III. IV. Procedures The bath must be at working volume and thoroughly mixed when the sample is taken. a) Pipette 10 ml bath sample (cooled to room temperature) into a 250 ml Erlenmeyer flask. b) Add 100 ml of D.I. water. c) Add 10 ml of ammonium hydroxide solution. d) Add 2 spatula tips of Murexide indicator (~0.2g) (use of larger amounts of indicator reduce the clarity of the end point). e) Titrate with 0.10M EDTA from brown to a purple end point. Record the number of ml of EDTA titrated. Calculation Nickel concentration (g/l) = ml titrated x molarity EDTA x 5.87 SODIUM HYPOPHOSPHITE CONCENTRATION I. Equipment a) 250 ml glass stoppered iodine flask b) 10 ml measuring cylinder c) 50 ml pipette d) 5 ml pipette e) 50 ml burette II. Reagents a) 0.05M iodine b) 0.10M sodium thiosulphate c) Freshly prepared starch indicator solution (~1%) d) 25% v/v Sulphuric acid WARNING! Proper care must be taken to avoid physical contact with Sulphuric acid solution as severe burns can result. The use of proper safety equipment is necessary, including chemical goggles, chemical gloves, and suitable protective clothing. III. Procedures The bath must be at working volume and thoroughly mixed when the sample is taken. a) Pipette 5 ml bath sample (cooled to room temperature) into a 250 ml iodine flask. b) Add 25 ml of 25% v/v sulphuric acid. c) Pipette 50 ml of 0.05M iodine solution into the flask. Immediately stopper the flask and part fill the collar with D.I. water. Swirl to mix thoroughly and place the flask in a cool dark place for 30 minutes. d) Titrate with 0.1M sodium thiosulphate solution until a pale straw-yellow colour is observed. e) Add a few ml of starch indicator solution to the flask. f) Continue to carefully titrate with the sodium thiosulphate solution until colour changes from blue-purple to a colourless end point. Page 3 of 8

4 g) Record the number of ml titrated. IV. Calculation Sodium hypophosphite concentration (g/l) = (100 x M (I 2) titre x M (ST)) x 10.6 DETERMINATION OF DEPOSITION RATE I. Equipment a) Analytical balance (minimum 2 d. p.) b) 7.5 x 10 cm 2 zinc coated Hull cell panel II. III. Procedures a) Remove zinc coating by immersion of 50% v/v HCl solution. b) Clean, dry and accurately weigh a 7.5 x 10.0 cm 2 clean steel rate panel. c) Suspend the panel in the DURAPOSIT TM SMT 810 Solution for specified time (minimum 20 minutes) at 85 C replenishing as required and adjusting ph if necessary. d) At the end of the specified time, remove the panel, rinse in D.I. water and dry. e) Reweigh the panel and calculate weight gain. Calculation Deposit thickness (in microns) = Weight gain (g) x Area (cm 2 ) 8.0 Deposit rate (in microns per hour) = Deposit thickness (from above) x 60 (immersion time in minutes) By Work Load By Analysis Method ph Control REPLENISHMENT If work load surface area is accurately known, replenishment can be made at a rate of 330 ml of DURAPOSIT R Nickel Replenisher and 660 ml DURAPOSIT SMT 810 Replenisher Solution per 5 m/m 2 plated. Replenish with DURAPOSIT TM SMT 810 Replenisher Solution and DURAPOSIT R Nickel Replenisher as required to maintain optimum concentration of sodium hypophosphite and nickel ml/l DURAPOSIT R Nickel Replenisher increases the nickel concentration by 1.0 g/l. 3.6 ml/l DURAPOSIT SMT 810 Replenisher Solution increases sodium hypophosphite concentration by 1.0 g/l. The ph of the solution should be maintained between ph measurement should always be made at room temperature. If ph adjustment of the process is necessary add either a 500 ml/l solution of reagent grade ammonium hydroxide or 25% v/v sulphuric acid manually as follows: 2 ml/l of 500 ml/l reagent grade ammonium hydroxide will increase ph by ~ ml/l of 25% v/v sulphuric acid will lower the ph by ~0.1. Page 4 of 8

5 WARNING! Proper care must be taken to avoid physical contact with Sulphuric acid solution as severe burns can result. The use of proper safety equipment is necessary, including chemical goggles, chemical gloves, and suitable protective clothing. When making ph adjustments, especially at operating temperature, frequently add small amounts of ph adjuster over the entire solution surface. Replacement The DURAPOSIT TM SMT 810 Solution should be replaced when a total of four times the nickel concentration has been replenished. Deposit Data Phosphorous Content 7 10 wt % by ICP or EDAX* analysis Hardness: HV 100 as deposited Density: g/cm 3 *Calibration with standard coupon is required. Please contact Dow Electronic Materials technical representative for further instructions. Notes 1. If the nickel metal concentration falls below 4.0 g/l, make the required additions in two equal portions, separated by 5 minutes. The R component should be added first followed by DURAPOSIT TM SMT 810 Replenisher. This should ideally be carried out on a laboratory scale first. Boards should not be processed, dummy panels being used, until the plating rate has been established. 2. If the nickel concentrated is less than 3.5 g/l solution replacement should be considered. 3. For precise control the use of an auto dosing controller is highly recommended. 4. Operating temperature should be maintained at C for optimum performance. Temperatures below 81 C will significantly reduce plating rate while temperature above 93 C will lead to solution decomposition. 5. Work load per solution volume (loading factor) of DURAPOSIT TM SMT 810 should be maintained between dm 2 /L. Continual under loading will result in low plating rates and eventual over stabilization, while overloading may lead to instability of the process. 6. In order to ensure optimum process performance, it is important to ensure that PWBs being processed through ENIG have been properly prepared. All residues of metal resist (tin or tin/lead) must be completely removed; solder mask compatibility with proper cure and registration must also be confirmed. Equipment Recommendations Tanks: Heaters: Filtration: Agitation: Extraction: Heat-resistant, stress-relieved natural polypropylene or stainless steel (Cr-Ni-Mo ) with anodic protection; typical applied voltage 0.9V is required Low surface wattage P.T.F.E. immersion heaters are preferred; temperature controllers with a 1 C capability should be used Continuous filtration through 5 10 microns bags or cartridges is essential; the filtration should be made of heat resistant plastic; a filtration rate of 8 to 15 turnovers per hour is recommended High solution flow preferably with sparger tubes, is recommended for optimum results; solution turnover should be at least 5 times per hour; air agitation to dissipate heat from around the heaters and avoid hotspots is acceptable; this air should not be directed near the PWBs being processed and must be oil free All plating tanks should be equipped with an exhaust system to Page 5 of 8

6 remove spray and steam; it is recommended that the process tanks are covered when not in use avoid contamination and evaporation losses Equipment Preparation Prior to make-up, the process tank and ancillary equipment should be thoroughly stripped and conditioned according to the following procedure. Stripping Solution Nitric acid (S. G. 1.42) Conditioning Solution Ammonium solution (S. G ) 300 ml/l 20 ml/l 1. Drain spent electroless nickel solution from the tank. 2. Thoroughly wash down the plating tank and ancillary equipment with tap water. Circulate water through filtration systems. Residual plating solution remaining in the tank will shorten the life and effectiveness of the solution. 3. Discard water. 4. Add stripping solution to the plating tank. Circulate through the filtration system for approximately 3 hours. 5. Allow the stripping solution to strip metallic nickel. If using a stainless steel tank with anodic protection, leave overnight to passivate the stainless steel equipment. 6. Transfer the stripping solution to an appropriate storage container. 7. Thoroughly wash down the plating tank and ancillary equipment with tap water. Circulate water through filtration system. 8. Discard water. 9. Add the conditioning solution to the plating tank and circulate through the filtration system for approximately 30 minutes. 10. Check the ph of the conditioning solution. If necessary increase to ph 7.0 with ammonia solution. 11. Discard the conditioning solution. 12. Thoroughly wash down the plating tank and ancillary equipment with tap water. Circulate water through filtration system. 13. Discard water 14. As a final rinse, use D.I. water. WARNING! Proper care must be taken to avoid physical contact with Nitric acid solution as severe burns can result. The use of proper safety equipment is necessary, including chemical goggles, chemical gloves, and suitable protective clothing. Product Data DURAPOSIT TM SMT 810 Make Up Solution Appearance: ph: Specific Gravity: Sodium Hypophosphite: Clear colorless to very pale yellow solution g/l Page 6 of 8

7 DURAPOSIT TM SMT 810 Replenisher Appearance: Normality: Specific Gravity: Sodium Hypophosphite: DURAPOSIT R Nickel Replenisher Appearance: Specific Gravity: ph: Clear colorless to very pale yellow solution N g/l Clear green solution Page 7 of 8

8 Handling Precautions Before using this product, associated generic chemicals or the analytical reagents required for its control, consult the supplier s Material Safety Data Sheet (MSDS)/Safety Data Sheet (SDS) for details on product hazards, recommended handling precautions and product storage. CAUTION! Keep combustible and/or flammable products and their vapors away from heat, sparks, flames and other sources of ignition including static discharge. Processing or operating at temperatures near or above product flashpoint may pose a fire hazard. Use appropriate grounding and bonding techniques to manage static discharge hazards. CAUTION! Failure to maintain proper volume level when using immersion heaters can expose tank and solution to excessive heat resulting in a possible combustion hazard, particularly when plastic tanks are used. Storage Disposal Considerations Store products in tightly closed original containers at temperatures recommended on the product label. Dispose in accordance with all local, state (provincial) and federal regulations. Empty containers may contain hazardous residues. This material and its container must be disposed in a safe and legal manner. It is the user's responsibility to verify that treatment and disposal procedures comply with local, state (provincial) and federal regulations. Contact your Dow Electronic Materials Technical Representative for more information. Product Stewardship Customer Notice Dow has a fundamental concern for all who make, distribute, and use its products, and for the environment in which we live. This concern is the basis for our product stewardship philosophy by which we assess the safety, health, and environmental information on our products and then take appropriate steps to protect employee and public health and our environment. The success of our product stewardship program rests with each and every individual involved with Dow products - from the initial concept and research, to manufacture, use, sale, disposal, and recycle of each product. Dow strongly encourages its customers to review both their manufacturing processes and their applications of Dow products from the standpoint of human health and environmental quality to ensure that Dow products are not used in ways for which they are not intended or tested. Dow personnel are available to answer your questions and to provide reasonable technical support. Dow product literature, including safety data sheets, should be consulted prior to use of Dow products. Current safety data sheets are available from Dow. For Industrial Use Only. This information is based on our experience and is, to the best of our knowledge, true and accurate. However, since conditions for use and handling of products are beyond our control, we make no guarantee or warranty, expressed or implied, regarding the information, the use, handling, storage or possession of the products, or the applications of any process described herein or the results sought to be obtained. Nothing herein shall be construed as a recommendation to use any product in violation of any patent rights. Contact: North America: Japan: (+81) Asia: (+852) Europe: (+41) Notice: No freedom from any infringement of patent owned by Dow or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer's use and for ensuring that Customer's workplace and disposal practices are in compliance with applicable laws and other government enactments. The product shown in this literature may not be available for sale and/or available in all geographies where Dow is represented. The claims made may not have been approved for use in all countries. Dow assumes no obligation or liability for the information in this document. References to Dow or the Company mean the Dow legal entity selling the products to Customer unless otherwise expressly noted. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED. Page 8 of 8