1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions 2012 07 25 N-Status No replacement A. Wedepohl, NA 2005 02 09 Revised Inserted 3.0; Deleted 3.1, 3.2, 3.7, 3.8, 4 1997 01 10 Activated M. Trace Controlled document at www.MATS Copyright 2012, Ford Global Technologies, LLC Page 1 of 3 SOLDER P
2、ASTE (62 Tin/36 Lead/2 Silver, RMA NOT FOR NEW DESIGN WSS-M11A44-A6 Flux, No-Clean, Stencil Printable) 1. SCOPE The materials defined by this specification are RMA 62 Sn/36 Pb/2 Ag solder pastes. These solder pastes are a homogeneous suspension of a pre-alloyed solder powder in a specially formulate
3、d screening and fluxing vehicle system. 2. APPLICATION This specification was released for conductive material used as a printable solder for surface mount connections and other applications where the use of a corrosive flux must be avoided. Post reflow cleaning may not be required. This solder past
4、e was designed to be stencil or screen printed on circuit boards and reflowed using either convection or infrared soldering. 3. REQUIREMENTS This solder paste is a homogeneous suspension of a prealloyed solder powder in a specially formulated fluxing vehicle. All qualification testing shall be done
5、at 25 +/- 2 C and 50 +/- 3% relative humidity, unless otherwise specified. 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.3 COMPOSITION (IPC-SP-819, Section 4.4,
6、50 gram sample required) Solder Metal, weight % 89.6 - 90.6 Vehicle Balance 3.3.1 Solder Metal Composition, Percent Tin 61.5 - 62.5 Silver 1.8 - 2.2 Zinc 0.003 max Antimony 0.30 max Bismuth 0.25 max Copper 0.08 max Iron 0.03 max Aluminum 0.005 max Other Elements 0.08 max Cadmium 0.005 max Lead Remai
7、nder ENGINEERING MATERIAL SPECIFICATION WSS-M11A44-A6 Copyright 2012, Ford Global Technologies, LLC Page 2 of 3 3.3.2 Vehicle Composition, weight percent (IPC-SP-819, Section 4.4, 50 gram sample required) Bake reflowed solder bead at 160 C for 5 hr and calculate flux percent using the following equa
8、tion: Wp - Wc - Wb x 100 = Wf% Wp - Wc Wp = Weight of paste before reflow Wc = Weight of cleaned solder bead Wb = Weight of baked solder bead Wf% = Weight percent of flux Flux, % 65.4 Solvent Balance 3.4 INDIVIDUAL COMPONENT PROPERTIES 3.4.1 SOLDER POWDER (Powder sample prior to mixing) 3.4.1.1 Part
9、icle Size 25 - 53 microns (IPC-SP-819, Section 4.2.3) 3.4.1.2 Particle Shape Spherical; (IPC-SP-819, Section 4.2.3) Ratio = 1 - 1.5 3.4.2 Flux Vehicle (Flux sample prior to mixing) 3.4.2.1 Copper Mirror No complete (IPC-TM-650, Section 2.3.32) copper removal 3.4.2.2 Halide Content, max 200 ppm of (I
10、PC-TM-650, Section 2.3.35) vehicle composition 3.5 VISCOSITY, Poise (IPC-TM-650, spiral pump viscometer, 25 +/- 0.25 C) 5 RPM 1500 - 2100 10 RPM 835 - 1355 15 RPM 605 - 1055 20 RPM 485 - 865 30 RPM 350 - 650 3.6 SHELF LIFE, min 6 months Store an unopened container of solder paste at 35 +/- 2 C for t
11、he specified shelf life time period. The solder paste shall meet the viscosity requirements per Section 3.5 of this specification. Shelf life is based on date of manufacture. The solder paste is to be delivered within one month of the date of manufacture. ENGINEERING MATERIAL SPECIFICATION WSS-M11A4
12、4-A6 Copyright 2012, Ford Global Technologies, LLC Page 3 of 3 5. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specification. Contact for questions concerning Engineering Material Specifications. 5.1 If the material
13、 contains a rosin based flux, a GC spectra of the extracted flux is required. 5.1.1 Extraction Method (a) Extract 2.0 g of paste with 3.0 mL of 50% isopropanol/50% toluene solution. (b) Mix well and then use centrifuge to separate the metal particles from the liquid portion. (c) Collect liquid porti
14、on with pipette and save for GC sample preparation. 5.1.2 GC Sample Preparation (a) Pipet 100 microliters of the extracted flux mixture and dispense into a GC sample vial. (b) Place the vial under a fume hood for 24 h to evaporate solvent. (c) To the sample vial, add 1 ampul Sylon BFT.* *The full na
15、me of Sylon BFT is Bis(trimethylsilyl) trifluoroacetamide (BSTFA)/trimethylchlorosilane (TMCS). It may be obtained in ampul form from: Supelco, Inc. Supelco Park Bellefonte PA 16823-0048 (d) Allow the mixture to stand for 5 minutes, then add 1.0 mL pyridine, and seal the vial. The mixture is ready t
16、o be injected into the gas chromatograph. 5.1.3 Equipment Parameters for Gas Chromatograph Column: DB-5 column, 0.25 micrometres ID, 30 m long Column Flow Rate: 1 mL/minute, 1:80 split ratio Sample Injection Quantity: 1.0 microliter Injector Temperature: 260 C Detector (FID) Temperature: 260 C Air F
17、low Rate: 400 mL/minute H2 Flow Rate: 32 mL/minute He makeup flow rate: 30 mL/minute Temperature Profile: Hold the temperature at 70 C for 4 minutes, ramp to 260 C at 10 C/minute, and hold on 260 C for 17 minutes. Total run time is 40 minutes. 5.2 If the material contains a polymer based flux, an IR spectra of the extracted flux is required. Extract the paste with acetone and collect the liquid portion. The extracted flux is to be applied directly to the KBr window.
