1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions 2012 07 25 N-Status No replacement A. Wedepohl, NA 2005 02 10 Revised Inserted 3.0; Deleted 3.1, 3.2, 3.7, 3.8, 4 1997 01 24 Activated M. Trace Controlled document at www.MATS Copyright 2012, Ford Global Technologies, LLC Page 1 of 3 SOLDER P
2、ASTE, 62 Sn/36 Pb/2 Ag, LOW VISCOSITY NOT FOR NEW DESIGN WSS-M11A47-A1 SOLDER PASTE, 62 Sn/36 Pb/2 Ag, SYRINGE NOT FOR NEW DESIGN WSS-M11A47-A2 DISPENSE 1. SCOPE The materials defined by these specifications are 62 Sn/36 Pb/2 Ag solder pastes with mildly activated rosin flux used for either screen p
3、rinting, stencil printing or syringe dispensing applications. These solder pastes are homogeneous suspensions of prealloyed solder powder in specially formulated screening and fluxing vehicle systems. 2. APPLICATION These specifications were released originally as conductive materials used as printa
4、ble solder for surface mount connections and other applications. These solder pastes were designed to be screen printed, stencil printed or syringe dispensed onto ceramic substrates and reflowed using either convection or infrared soldering. 3. REQUIREMENTS These solder pastes are homogeneous suspen
5、sions of prealloyed solder powder in specially formulated fluxing vehicle. All qualification testing shall be done 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 C
6、ompanys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.3 COMPOSITION (IPC-SP-819, Section 4.4, 50 gram sample required) A1 A2 Solder Metal, weight % 86.5 - 87.5 87.0 - 89.0 Vehicle Balance Balance 3.3.1 Solder Metal Composition, atomic percent (QQ-S-571F, Class 1 Impurity Levels)
7、 Tin 61.5 - 62.5 Silver 1.8 - 2.2 Zinc 0.005 max Antimony 0.50 max Bismuth 0.10 max Copper 0.08 max Iron 0.02 max Aluminum 0.005 max Cadmium 0.005 max Lead Remainder ENGINEERING MATERIAL SPECIFICATION WSS-M11A47-A1/A2 Copyright 2005, Ford Global Technologies, LLC Page 2 of 3 3.4 INDIVIDUAL COMPONENT
8、 PROPERTIES 3.4.1 Solder Powder (Powder sample prior to mixing) 3.4.1.1 Particle Size (IPC-SP-819, Section 3.2.2) % of Sample by Weight - Nominal Sizes Less than 1% larger than 45 microns Remainder between 45 - 25 microns 10% - 20% less than 25 microns 3.4.1.2 Particle Shape Spherical; (IPC-SP-819,
9、Section 3.2.3) Ratio = 1 - 1.5 3.5 VISCOSITY, poise (IPC-TM-650, Section 2.4.34.3, spiral pump viscometer, 25 +/- 0.25 C) A1 A2 5 RPM (5 minutes) 1000 - 1400 862 - 1598 30 RPM (1 minute) 350 - 550 313 - 637 3.6 SHELF LIFE, min 6 months Store an unopened container of solder paste at 2 +/- 2 C (35 +/-
10、 4 F) for the specified shelf life time period. The solder paste shall meet the viscosity requirements per para 3.5 of this specification. Shelf life is based on date of manufacture. The solder paste is to be delivered within two months of the date of manufacture. 5. GENERAL INFORMATION The informat
11、ion 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 contains a rosin based flux, GC spectra of the extracted flux are required. 5.1.1 Extraction Meth
12、od (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 portion with pipette and save for GC sample preparation. 5.1.2 GC Sample Preparation (a) Pipet 50 microl
13、iters of the extracted flux mixture and dispense into a GC sample vial. (b) To the sample vial, add 1 ampule Sylon BFT.* *The full name of Sylon BFT is Bis (trimethylsilyl) trifluoroacetamide (BSTFA)/ trimethylchlorosilane (TMCS). Sylon BFT must be stored in a refrigerator (shelf life - 1 year). It
14、may be obtained in ampule form from: ENGINEERING MATERIAL SPECIFICATION WSS-M11A47-A1/A2 Copyright 2005, Ford Global Technologies, LLC Page 3 of 3 Supelco, Inc. Supelco Park Bellefonte, PA 16823-0048 (c) Allow the mixture to stand for 5 minutes, then add 1.0 mL pyridine, and seal the vial. The mixtu
15、re is ready to be injected into the gas chromatograph. 5.1.3 Equipment Parameters for Gas Chromatograph Column DB-5 column, 0.25 mm ID, 0.25 um film, 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) Temperatur
16、e 260 C Air Flow 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, IR spectra of the extracted flux are required. Extract the paste with acetone and collect the liquid portion. The extracted flux is to be applied directly to the KBr window.
