1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 03 2012 03 20 N Status No replacement named A N. Benipal, NA 2006 03 22 Revised Inserted 3.0; Deleted 3.1, 3.2, 3.3, 3.11, 3.13, 4 1991 08 21 Released DF00E00107002058 L. Rumao Controlled document at www.MATS Copyright 2012, Ford Global T
2、echnologies, LLC Page 1 of 3 COATING, CONFORMAL, SOLVENT FREE SILICONE NOT FOR NEW DESIGN WSF-M99J377-A COATING, CONFORMAL, SOLVENT FREE SILICONE, WSF-M99J377-A2 LOW VISCOSITY 1. SCOPE The materials defined by these specifications are one component, primer-less, thermal curing, solvent free, silicon
3、e conformal coatings. The material shall consist of both vinyl and hydride functional methyl siloxane polymers, platinum catalyst, proprietary inhibitors, and adhesion promoters. A colored or UV fluorescent dye is included when specified on the Engineering Drawing. 2. APPLICATION These specification
4、s were released originally for conformal coatings used for high reliability electronic assemblies. These coatings are suitable for application by dip, flow, spray and brushing, and provide good wetting characteristics to a wide variety of substrates. It is intended that conformal coatings qualified
5、to these specifications be mutually compatible reducing the need for complete flushing of recirculating type coating systems during material changeover. 3. REQUIREMENTS Material specification requirements are to be used for initial qualification of materials. 3.0 STANDARD REQUIREMENTS FOR PRODUCTION
6、 MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). A A2 3.4 APPEARANCE Bulk Liquid Transluscent Transluscent Cured Coating Transparent Transparent 3.5 VISCOSITY, mPa.s 600 - 1500 400 - 600 (ASTM D 1084, Brook
7、field Model LVF, #3 spindle at 60 rpm) 3.6 NON-VOLATILE, %, min 97 97 (ASTM D 2369) ENGINEERING MATERIAL SPECIFICATION WSF-M99J377-A/A2 Copyright 2012, Ford Global Technologies, LLC Page 2 of 3 3.7 MECHANICAL PROPERTIES 3.7.1 Sample Preparation Cast a slab of conformal coating 3 to 4 mm thick in a m
8、old coated with a suitable non-silicone mold release. After filling the mold, allow the uncured conformal coating to stand for 1 h. Cure the conformal coating for 16 h at 50 C followed by 1 h at 105 C. After curing, the sample shall be conditioned per para 3.3. A A2 3.7.2 Tensile Strength, MPa, min
9、0.40 0.06 (ASTM D 412) 3.7.3 Elongation, %, min 100 10 (ASTM D 412) 3.7.4 Hardness 15 - 35 55 - 80 (ASTM D 2240) (Shore A) (Shore 00) Stack slab samples to a minimum of 15 mm prior to measuring hardness. 3.8 ELECTRICAL PROPERTIES 3.8.1 Dielectric Strength, min 11.8 kV/mm 11.8 kV/mm (ASTM D 149, 10 M
10、Hz) Prepare a sample slab per para 3.7.1 with the exception that the sample shall be 0.1 to 0.2 mm thick. 3.8.2 Dielectric Constant, max 3.5 3.5 (ASTM D 150, 10 MHz) Prepare a sample slab per para 3.7.1. 3.8.3 Dissipation Factor, max 0.005 0.005 (ASTM D 150, 10 MHz) Prepare a sample slab per para 3.
11、7.1. 3.9 FUNCTIONAL PROPERTIES 3.9.1 Silicone Volatiles, max 0.5% (FLTM AV 102-01) 3.9.2 Adhesion in Shear Must fail in (ASTM D 1002, except as noted) cohesion Prepare lap shear samples using ASTM D 709, Grade FR4 unclad laminate test strips which have been cleaned in isopropanol and dried for 1 h a
12、t 105 C. After preparation, dip 25 to 40 mm length of the test strips in the uncured coating. Let the dipped test strips drip for 10 seconds, and then prepare the lap joint by pressing the strips together. Cure the lap joint for 30 minutes at 150 C. ENGINEERING MATERIAL SPECIFICATION WSF-M99J377-A/A
13、2 Copyright 2012, Ford Global Technologies, LLC Page 3 of 3 3.10 DURABILITY PROPERTIES (Mil-I-46058 (latest revision), Silicone Resin (Type SR), coating thickness to as obtained in the normal manufacturing process). 3.10.1 Fungus Resistance Must meet 3.10.2 Insulation Resistance Must meet 3.10.3 The
14、rmal Shock Must meet 3.10.4 Moisture Resistance Must meet 3.10.5 Hydrolytic Stability Must meet A A2 3.12 SHELF LIFE 6 months 1 month Manufacturer shall certify that the material will meet the specification when stored in the original sealed container at 35 C for the specified period. 5. GENERAL INF
15、ORMATION The information given below is provided for clarification and assistance in meeting the requirements of these specifications. 5.1 COMPATIBILITY Compatibility of coating materials with substrates must be established prior to implementation. The presence of certain chemical compounds will cau
16、se inhibition of cure. Generic categories of these materials include sulfur compounds, amines, certain organometallic compounds (most commonly tin soaps), and plasticizers/mold release agents found on components. The presence of contaminants can contribute to adhesion failures when exposed to humidity and temperature cycling.
