1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2013 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP1332DAEROSPACERECOMMENDED PRACTICEARP1332 REV. DIssued 1974-03 Reaffirmed 1994-07
5、 Revised 2007-02 Stabilized 2013-08 Superseding ARP1332C Wave Soldering Procedure RATIONALEARP1332D designates a stabilized status for this document due to broader use of industry consensus standard IPC J-STD-001.STABILIZED NOTICE ARP1332D has been declared “STABILIZED“ by AMS Committee B and will n
6、o longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability of technical requirements. Newer technology may exist. The last technical update of this document occurred in August, 1998. Users of this document should refer any certifi
7、cation issues (e.g. exceptions listed on the certification report) to the cognizant engineering organization for their disposition. CAUTION: In many cases the purchaser is not the cognizant engineering organization (i.e. purchaser may be a sub tier supplier). AMS Committee B recommends that the foll
8、owing similar specification be used for future procurement. This does not constitute authority to substitute IPC J-STD-001 for the “STABILIZED” specification. Authority for substitution should be granted by, or approved by, the cognizant engineering organization. IPC J-STD-001, Requirements for Sold
9、ered Electrical and Electronic Assemblies. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL ARP1332D Page 1 of 12 1. SCOPE 1.1 The purpose of this recommended practice is to provide
10、recommendations concerning the procedure for wave soldering.1.2 The detailed recommendations are based on manufacturing experience and laboratory experiments. The recommendations reflect those design practices and fabricating procedures that have been found to be most effective in producing function
11、al electronic modules for critical communications or control systems. Electronic modules include assemblies, components, and printed circuit (PC) or printed wire (PW) boards. 1.3 In the following text, references to printed circuit (PC) boards shall be construed to include printed wire (PW) boards.1
12、.4 Safety-Hazardous Materials While the materials, methods, applications and processes described or referenced in this procedure may involve the use of hazardous materials, this document does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensu
13、re familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved. 1.5 Warning The solder used in this document may contain cadmium. The use of cadmium has been restricted and/or banned for us
14、e in many countries due to environmental and health concerns. The user should consult with local officials on applicable health and environmental regulations regarding its use. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted wit
15、hout license from IHS-,-,-SAE INTERNATIONAL ARP1332D Page 2 of 12 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document u
16、nless a specific document issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply. 2.1 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 1
17、9428-2959, Tel: 610-832-9585, www.astm.org.ASTM D 257 DC Resistance or Conductance of Insulating Materials ASTM D 1193 Reagent Water 2.2 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, T
18、el: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/.MIL-STD-202 Electronic and Electrical Component Parts 2.3 Other Publications American Society for Metals Handbook3. GENERAL 3.1 A soldered joint is formed when the molten solder “wets“ the surfaces of the substrates. Wetting creates a metallur
19、gical bond by formation of intermetallic compounds of tin with the substrate. Penetration into re-entrant cavities and filling of space between surfaces occur by capillary action. Best soldering results are achieved when substrates and leads are wetted quickly and completely by the molten solder. Th
20、e entire substrate surface should approach perfect wetting conditions. 3.2 Surface contamination will impede this metallurgical reaction. Substrate surfaces should be free from oxides and other contaminants to ensure reliable, repeatable soldering conditions required for rapid reaction in the solder
21、 wave, where dwell time may be less than 2 seconds. All components and printed circuit board conductor runs should be determined, by lot acceptance test, to possess the optimum surface condition for best solderability. Manipulation of fluxing and soldering often will overcome marginal solderability
22、but can only provide minimum help to components possessing poor solderability. 3.3 The solder wave machine uses a vertical wave of molten solder usually produced by an impeller immersed in a sump of molten solder. The impeller pumps the solder between parallel plates so that a crest of solder will e
23、xist above the quiescent solder level. Other means of producing a solder wave are acceptable. The electronic module assembly passes over the wave by means of chain-driven conveyor set at a critical angle with respect to the wave crest axis. The depth of board penetration into the solder crest is cri
24、tical. Depth should be great enough to cause hydrostatic displacement of flux in holes and allow molten solder to flow through the holes by capillarity. Depth should not be so great as to cause solder to break across the component side of the PC board. Advanced soldering lines now incorporate in-lin
25、e fluxing and pre-solder/post-solder cleaning systems. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL ARP1332D Page 3 of 12 4. SOLDER BATH 4.1 The optimum composition of tin is 59.
26、5 to 63.5% with the balance of the solder bath consisting of lead and the items in 4.2.2. 4.2 Contamination and composition change of the solder bath will occur during operation. The solder should be sampled and analyzed on a periodic basis or when the quality of the soldering decreases. Certain met
27、allic elements are soluble in molten solder and gradually contaminate the solder bath. 4.2.1 Extremely heavy deposits of gold plating on electronic components may alloy with molten solder to cause degradation of solidified solder fillets by formation of brittle gold-tin intermetallic compound phases
28、. Surface dewetting will be more prevalent as gold content in the bath increases. Thin (under 120 microinch (3 m) thickness) coatings of pure gold are extremely solderable and do not cause degradation of solder joints because all the gold is dissolved away during the soldering operation. 4.2.2 Some
29、elements such as zinc, aluminum, and cadmium render the solder sluggish and porous. Other elements such as copper and nickel render the solder hard and brittle. Metals such as silver and antimony have little detrimental effect on the solder. Nonetheless, impurities should be maintained at levels as
30、low as possible, preferably below the following limits: TABLE 1 Content, % by Weight Content, % by Weight Element min max Antimony 0.2 0.5 Copper (4.2.2.1) - 0.3 Bismuth - 0.25 Gold (4.2.2.1) - 0.20 Silver - 0.10 Arsenic - 0.03 Iron - 0.02 Nickel - 0.01 Phosphorus - 0.01 Aluminum (4.2.2.1) - 0.006 C
31、admium (4.2.2.1) - 0.005 Zinc (4.2.2.1) - 0.005 Sulfur - 0.001 4.2.2.1 Total of copper, gold, aluminum, cadmium, and zinc should not exceed 0.4% by weight. 4.2.3 When chemical analysis indicates impurity levels greater than the individual contaminant levels, the entire bath should be discarded or sh
32、ould be restored by addition of virgin solder to maintain low impurity level. A low contamination level is needed to control solder bath fluidity at a given temperature. 4.3 The molten solder should be temperature controlled at 230 to 290 C (450 to 550 F) for best results. Higher temperatures can ca
33、use component degradation and dewetting. Lower temperatures can cause solder bridging, icicling, and poor wetting. 4.3.1 The balance between carriage speed and solder temperature is also critical. Because metal component leads and laminate conductor runs or pads possess greater inherent heat capacit
34、y than the dielectric board material, the electronic module assembly may be wave soldered at faster speed when the solder temperature is higher with less component or dielectric damage than when wave soldered at slower speed and lower solder temperature.Copyright SAE International Provided by IHS un
35、der license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL ARP1332D Page 4 of 12 4.4 Oil Intermix 4.4.1 A tinning oil serves to inhibit dross formation and to promote the solder wetting process. Tinning oil is superior to vegetable oil fo
36、r use in oil intermix systems. Several proprietary formulations are satisfactory. 4.4.2 A daily machine cleaning discipline is necessary to maintain peak soldering performance. Some intermix oils should be changed after 4 hours of operation. Any oil should be changed daily. Weekly, monthly, and quar
37、terly machine cleaning and maintenance schedules should be established. Remove all oil-derived solids from the solder machine sump and other cavities or surfaces on a monthly basis, or sooner if solder quality decreases. 5. RECOMMENDATIONS 5.1 Presolder Cleaning 5.1.1 To ensure a soldered product wi
38、th adequate solder wetting and filleting and improved post-solder cleanliness levels, it is imperative that presolder cleaning be performed. Boards will be contaminated with polar, nonpolar, ionic, and insoluble residues. Each type of residue should be treated individually. Plating or other masking
39、tape should be removed prior to any cleaning operation. 5.1.2 Nonpolar contaminants such as grease, oil, fatty acids, and organic resin residues from plating or masking should be removed from the board prior to other cleaning steps. This kind of contamination is usually hydrophobic and will repel ot
40、her subsequently applied solvents. A nonpolar solvent may be selected from the following list: a. Halogenated hydrocarbons, such as 1,1,1-trichloroethane, and either generic compounds or proprietaryformulations.b. Ethers or esters (excellent nonpolar solvency). c. Ketones or ketone derivatives (exce
41、llent nonpolar solvency). d. Aromatic hydrocarbons, including benzene and xylene (excellent nonpolar solvency). 5.1.3 Metal oxides and polymerized varnish should be removed prior to the soldering operation. Sand or particle blasting is not recommended because microscopic particles will become embedd
42、ed in the softer surfaces and promote dewetting during soldering. Certain oxides, however, will be removed by chemical action of the solder flux. Other foreign particles should be removed prior to the soldering operation. 5.1.4 The polar and ionic contaminants such as body salts, perspiration, plati
43、ng residue, etching residue, and other ambient contamination should be removed prior to the wave soldering operation. A polar solvent may be selected from the following list: a. Alcohol, alcohol blends, and alcohol azeotropes. Although alcohol is bipolar, this solvent provides excellent polar solven
44、cy. b. Reagent grade water, preferably at elevated temperature provides excellent polar solvency. See ASTM D 1193 Type II. 5.1.5 As much contamination prior to soldering should be removed as is consistent with economics and specified reliability standards of the electronic module being fabricated. C
45、opyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE INTERNATIONAL ARP1332D Page 5 of 12 5.2 Flux and Flux Application 5.2.1 Rosin-base fluxes suitable for use in the wave soldering process contain act
46、ivators that react with the surfaces to be joined by the solder. Both RMA (mildly activated) and RA (activated) fluxes contain activator compounds and the activated flux residues should be completely removed by proper cleaning procedures. While RA flux provides superior solderability, special precau
47、tions should be taken to ensure complete removal of the flux residue, otherwise residual corrosive ions may produce malfunction through the slow accumulation of corrosion products long after the soldered component has been placed in service. Strict adherence to the cleaning procedures recommended he
48、rein should provide adequate protection. 5.2.2 Flux viscosity may be controlled by adding a solvent or thinner to the flux. The thinner is usually a higher alcohol, such as isobutanol or isopropanol. The specific gravity of the flux should be maintained within 3% of the manufacturers value. 5.2.3 Flux should be applied to the surface of the board to be soldered by a method that will produce an evenly coated surface. When desired, flux may be applied to both sides of the PC board. Wave soldering machines usually incorporate a foam fluxer. Improved soldering results are obtained i
