Immersion Tin SN 30 1

Transcription

1 Immersion Tin SN 30 1 Immersion Tin SN 30 1 is a process for the electroless deposition of tin on copper and copper alloys in charge exchange. The process is so also be suitable to brighten lead- or tin-lead coatings. Smooth bright tin layers approx. 1-2 µm thick are deposited on copper surfaces at a temperature of 70 C, still enabling solderability after tempering (e. g. 4 h/155 C). Immersion Tin SN 30 1 is renewable. The copper accumulated in the electrolyte during operation can be separated. Components required for deposition can be replenished according to analysis. Therefore it s not necessary to dispose the tin plating solution like usual for the conventional immersion tin processes. The additives required for electrolyte make-up and operation do not contain any alkylphenol ethoxylates (nonylphenol ethoxylates). The layers deposited from this electrolyte meet the requirements of the RoHS (Restriction of (the use of certain) Hazardous Substances) EU Directive 2011/65/EU relating to the limit of lead, mercury, cadmium, Cr(VI), Polybrominated Biphenyls and Polybrominated Diphenyl Ethers. The information in this data sheet is based on laboratory as well as practical experience. Figures quoted for operating limits and replenishment quantities are for guidance. Actual values necessary will depend on the components being plated (material and geometry), their application and plating plant conditions. Important: Please read this instruction carefully prior to the use of the process and carefully follow all the parameters that have a direct influence on the operation. We reserve the right to make technical changes. In the interest of safety, please pay attention to the hazard warnings on the labels of the containers. The minimum shelf life of the products is included on the labels and is also available in the appropriate Quality Assurance (QA03). The current IMDS number of the layer deposited from the process is available on the internet at For the storage of chemical products the TRGS 510 must be followed. If the additives used in this process contain a SVHC-substance, then this will be specified in the corresponding Material Safety Data Sheet, section 15. BATH E Page 1 of 5 Issue

2 1.0 TECHNICAL INFORMATION AND EQUIPMENT REQUIREMENTS Tanks: Local Exhaust Ventilation: Part-/Electrolyt Agitation: Filtration: Heating/Cooling: polypropylene, no PVC required recommended recommended; always make sure that no PVC pipes are used; PVC is attacked by Immersion Tin SN 30 1 and leads to interferences in the tin plating solution; in case of doubt the quality to be used must be verified on its applicability porcelain or PTFE coated immersion heaters 2.0 MAKE-UP AND OPERATING CONDITIONS 2.1 Product names List of products required Product name Article no. (AN) SG Make-up Concentrate SN Make-up Concentrate SN Activating Salt SN Additive CULMO AN Requirements for a 100 litre bath AN SG Quantity Make-up Concentrate SN ltr. Make-up Concentrate SN ltr. Activating Salt SN kg Additive CULMO AN ltr. 2.3 Make-up sequence for a 100 litre bath All tanks and associated equipment must be thoroughly cleaned prior to use. fill 50 litres water into tank add 10 kg of Activating Salt SN 33 and dissolve while stirring add 11.3 litres of Make-up Concentrate SN 31 mix thoroughly add 16 litres of Make-up Concentrate SN 32 add 1 litre of Additive CULMO AN 11 1 mix well make up with water to final volume The electrolyte is ready for use when the operating temperature has been reached. BATH E Page 2 of 5 Issue

3 2.4 Concentrations and operating conditions Range Optimum Tin g/l Make-up Concentrate SN ml/l Activating Salt SN g/l Additive CULMO AN ml/l Temperature Range C Exposition time depends on the required layer thickness, see table below Layer thickness [µm] depends on temperature and exposition time: Exposition time [min] Temperature [ C] Consumption and replenishment Deposition basis is the charge exchange reaction between copper and tin. Depending on the quantity of tin deposited an equivalent amount of copper is dissolving. As soon as a copper concentration of 6-8 g/l is reached, copper can be separated as a good crystallizing compound by cooling down to room temperature. To avoid caking of the crystal compound, constant stirring of the solution is recommended while cooling to room temperature. The crystallized copper compounds are easy to filter using simple bag filters. In the filtrate free acid, tin content and the concentration of Activating Salt SN 33 will be analyzed and replenished accordingly. 3.0 PROCESS SEQUENCE 3.1 Pre-treatment The parts to be plated are pre-treated as usual. Detailed information on suitable pre-treatment products are given upon request. 3.1 Process sequence Electroless tin plating of PCBs BATH E Cleaner SLOTOCLEAN S 20 activating in BATH E Copper Activator S 40 activating in 75 ml/l of Acid Concentrate FF (AN ) Immersion Tin SN 30 1 drying BATH E Page 3 of 5 Issue

4 4.0 MAINTENANCE AND FUNCTION OF THE INDIVIDUAL BATH COMPONENTS 4.1 Make-up Concentrate SN 31 Make-up Concentrate SN 31 contains the acid required for the operation of Immersion Tin SN An analytical determination of the acid content is possible. Lack of acid is replenished by Make-up Concentrate SN 31. Lack of 1 g/l of acid is replenished with 0.75 ml/l of Make-up Concentrate SN Make-up Concentrate SN 32 Besides acid, Make-up Concentrate SN 32 contains also the tin necessary for the operation of Immersion Tin SN Tin concentration shouldn t fall below 10 g/l of tin when tin is deposited onto copper. The tin concentration may be monitored analytically. To raise the tin concentration by 1 g/l, the electrolyte must be replenished with 8 ml/l of Make-up Concentrate SN Activating Salt SN 33 Activating Salt SN 33 is required for a trouble-free tin deposition. The concentration of Activating Salt SN 33 shouldn t drop below 75 g/l, and can be monitored analytically. The difference between the required value and the value determined by analysis is directly for replenishment of Activating Salt SN Additive CULMO AN 11 1 Additive CULMO AN 11 1 is a special wetting agent which improves wetting of the copper surface and helps to produce a fine crystalline, silky deposit. Lack of Additive CULMO AN 11 1 may result in step plating respectively uneven, stained deposition. In this case, additions of 5 ml/l of Additive CULMO AN 11 1 should be made. The consumption is mainly due to drag-out. The continuous replenishment should be performed in the same ratio like Activating Salt SN 33. For each 1 kg of Activating Salt SN 33, 0.1 litre of Additive CULMO AN 11 1 must be replenished. 5.0 TROUBLE SHOOTING 5.1 Fault finding chart Fault Cause Correction stained deposition lack of Activating Salt SN 33 analysis of Activating Salt SN 33, replenish to optimum black surface contamination by organics treatment with 4 g/l activated carbon, filtration stained surface lack of Additive CULMO AN 11 1 addition of 5 ml/l Additive CULMO AN 11 1, repeat if required BATH E Page 4 of 5 Issue

5 6.0 EFFLUENT Legal regulations must be observed for disposal of the Immersion Tin SN Different regulations normally apply for the additives and the ready-made electrolyte. Please refer to section 13 of the appropriate Material Safety Data Sheet for disposal code and recommendations. The following detoxification sequence is only considered to be an aid: Effluent treatment can be performed either with Precipitant AW 10 (organosulfide) according to the usual method or according to method described below: dilute effluent in ratio 1 : 10 up to 1 : 25 (related to the electrolyte volume) add 25 ml/l of hydrogen peroxide, (30 %) to a dilution of 1 : 10 and 10 ml/l to 1 : 25 min. 6 h reaction time (preferably over night) adjust ph to 9.0 using lime milk filtrate after 2-6 h through a filter press Caution Copper compounds separated off from the solution during regeneration must be dumped as heavy metal residues. 7.0 SAFETY Reasonable care is required when handling chemical products. Only personnel specially trained on working with chemicals should be deployed with their handling. EC Material Safety Data Sheets must be made available to all personnel dealing with the chemicals to ensure they have all required information about product composition, hazards identification, first-aid measures, handling and storage, exposure controls, toxicological and ecological information, etc. It is required to ensure the supply and use of suitable protective clothing and -equipment. The user must verify the designated purpose of the electrolyte. Previous experience has shown that not all metal surfaces are suitable for a trouble-free electroplating. The above mentioned data are made according to our best knowledge. Consistent operation of the working solution requires appropriate maintenance. Immersion Tin SN 30 1 is a process of GmbH & Co KG. It can only be operated with the products described in this technical data sheet. Use of other chemicals (also partly) will impair quality and invalidates our service- and quality commitments (quality assurance). BATH E Page 5 of 5 Issue