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, 3.11, 4 1991 10 04 Released DF00E00107002071 Louis Rumao Controlled document at www.MATS Copyright 2012, Ford Global Technologies, LLC Page 1 of
2、4 SOLDER PASTE (63 Tin/37 Lead, RMA Flux, No-Clean) NOT FOR NEW DESIGN WSF-M11A44-A 1. SCOPE The material defined by this specification is a RMA 63 Sn/37 Pb solder paste. This solder paste is a homogeneous suspension of a prealloyed solder powder in a specially formulated screening and fluxing vehic
3、le 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 paste was designed to be stencil
4、printed on circuit boards and reflowed using 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 at 25 +/- 2 C and 50 +/- 3% relative humidity, unless otherw
5、ise 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). 3.2 COMPOSITION (IPC-SP-819, Section 4.4, 50 gram sample required) Solder Metal 89 - 90% (weight perce
6、nt) Vehicle Balance 3.2.1 Solder Metal Composition, Atomic Percent (ASTM B 32, Grade 63 B) Tin 62 - 64 Zinc 0.005 max Antimony 0.20 - 0.50 Bismuth 0.25 max Copper 0.08 max Iron 0.02 max Aluminum 0.005 max Other Elements 0.08 max Lead Remainder ENGINEERING MATERIAL SPECIFICATION WSF-M11A44-A Copyrigh
7、t 2012, Ford Global Technologies, LLC Page 2 of 4 3.2.2 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 equation: Wp - Wc - Wb x 100 = Wf% Wp - Wc Wp = Weight of paste be
8、fore reflow Wc = Weight of cleaned solder bead Wb = Weight of baked solder bead Wf% = Weight percent of flux Flux 74% Solvent Balance 3.3 VISCOSITY (IPC-TM-650, spiral pump viscometer) 10 RPM 2070 - 2530 cps 15 RPM 1665 - 2035 cps 20 RPM 1440 - 1760 cps 30 RPM 1125 - 1375 cps 3.4 SLUMP (IPC-SP-819,
9、Section 4.6.2, Modified) Modification requires the use of the stencil in Figure 1 to deposit solder paste using a steel squeegee. Patterns 1 (IPC-SP-819, Section 4.2.3) Ratio = 1 - 1.5 3.9.2 Flux Vehicle (flux sample prior to mixing) 3.9.2.1 Copper Mirror No complete (IPC-TM-650, Section 2.3.32) cop
10、per removal ENGINEERING MATERIAL SPECIFICATION WSF-M11A44-A Copyright 2012, Ford Global Technologies, LLC Page 4 of 4 3.9.2.2 Halide Content, max 0.002% (IPC-TM-650, Section 2.3.35) 3.10 SHELF LIFE, min 4 months Store an unopened container of solder paste at 35 +/- 2 C for the specified shelf life t
11、ime period. The solder paste shall meet the viscosity requirements per Section 3.3 of this specification. Shelf life is based on date of manufacture. 5. GENERAL INFORMATION The information below is provided for clarification and assistance in meeting the requirements of this specification. 5.1 Each
12、lot of material shall include a certification that the solder paste meets the requirements of this specification. A viscosity curve per para 3.3 shall be included with each lot. Figure 1 (1) and (2) 1.27 mm Pitch, 0.63 mm x 2.03 mm Pad (3) and (4) 0.63 mm Pitch, 0.33 mm x 2.03 mm Pad Stencil Thickness 0.2 mm 4. 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
