1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Changes 2014 06 11 N Status No replacement named L. Sinclair, NA 1996 10 23 Activated R. Gordon WP 3948-a Page 1 of 12 PRINTED CIRCUIT BOARDS, SINGLE SIDED WSF-M22P4-A1 NOT TO BE USED FOR NEW DESIGN 1. SCOPE This spec
2、ification defines the performance requirements for rigid single or double sided circuit boards without plated through holes (SSBs). A single sided circuit board is defined as a circuit board with one circuit layer or two circuit layers which are not interconnected electrically with copper plated via
3、s. 2. APPLICATION This specification was released originally as the performance requirements for single sided circuit boards to be used as the interconnect for electronic modules. 3. REQUIREMENTS 3.1 QUALITY SYSTEM REQUIREMENTS Material suppliers and part producers must conform to Quality System Req
4、uirements, QS-9000. Material specification requirements are to be used for initial qualification of materials. A Control Plan for ongoing production verification is required. This plan must be reviewed and approved by the relevant Ford Materials activity and/or Ford Supplier Technical Assistance (ST
5、A) prior to production parts submission. Appropriate statistical tools must be used to analyze process/product data and assure consistent processing of the materials. Part producers using this material in their products, must use Ford approved materials and must conform to a process control plan whi
6、ch has been approved by STA and/or the relevant Materials Activity. 3.2 INFRARED SPECTROPHOTOMETRY AND/OR THERMAL ANALYSIS Ford Motor Company, at its option, may conduct infrared and/or thermal analysis of material/parts supplied to this specification. The IR spectra and thermograms established for
7、initial approval shall constitute the reference standard and shall be kept on file at the designated material laboratory. All samples shall produce IR spectra and thermograms that correspond to the reference standard when tested under the same conditions. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4
8、-A1 WP 3948-b Page 2 of 12 3.3 CONDITIONING AND TEST CONDITIONS All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise s
9、pecified. 3.4 APPEARANCE Visually inspect the single sided circuit board under a minimum magnification of 1.75X for the following criteria. 3.4.1 Circuit Traces 3.4.1.1 Conductor Width Reduction from Design, max . Conductors greater or equal to 0.300 mm 20 % . Conductors less than 0.300 mm 0.075 mm
10、3.4.1.2 Cracks or Voids are not permitted. Thickness reductions are allowable provided they meet the minimum copper thickness requirements as designated on the engineering drawing. 3.4.1.3 Repair of broken traces is not permitted. 3.4.1.4 Rework of shorts between traces is permitted provided that re
11、worked circuit meets the requirements in para 3.4.1.1. 3.4.2 Spacing Width The minimum width between noncommon conductors is 0.150 mm. Small specks or stray, nonelectrically connected, copper or other metallization are permitted provided that the specks are covered with soldermask that extends a min
12、imum of 0.050 mm beyond the edge of each speck and a minimum of 0.100 mm spacing exists to any circuit trace. 3.4.3 Laminate (IPC-A-600, Laminate Defect Guidelines) Appearance irregularities such as measling, crazing and weave exposure of the base laminate are allowable if they meet IPC-A-600, Class
13、 III requirements. Foreign material is allowable if it is at least 0.25 mm from a conductor. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 3 of 12 3.4.4 Soldermask (IPC-SM-840, Class 3) . Cracked, peeled or delaminated soldermask is not permissible. . Missing soldermask is allowable
14、 provided that all conductors designed to be coated with soldermask are coated with soldermask and the soldermask extends a minimum of 0.050 mm into the adjacent space. . Voids are allowable provided that voids will not allow entrapment of flux. . Soldermask on solder pads is not allowable unless sp
15、ecified by the design. . Soldermask skips shall be acceptable provided that all conductors designed to be coated with soldermask are coated with soldermask and the soldermask extends a minimum of 0.050 mm into the space between two traces on at least one side of the space. 3.4.5 Component Diagram (L
16、egend Silkscreen) . The component diagram must be legible from a distance of 25 cm to an observer with vision corrected to 20/20. . The component diagram ink is not permitted on solderable surfaces. 3.4.6 NPTH Requirements Metallic nodules, legend silkscreen ink, soldermask or other obstructions are
17、 not permitted in holes designated as non-plated through holes. Missing holes are not permitted. 3.5 DIMENSIONAL 3.5.1 Hole Size (Non-Plated Through Holes (NPTH) The diameter of each NPTH hole size on each board on a panel shall be measured using pin gages or an alternative measuring instrument appr
18、oved by Materials Engineering. 3.5.2 Hole Location Measure the X and Y coordinates of 4 holes, one selected from each of the outer corners from each board on a panel. Hole locations shall be determined using an optical comparator. All measurements are to be determined to four decimal places with thr
19、ee place accuracy and be based on the datums defined on the applicable drawing. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 4 of 12 3.5.3 External Registration Visually inspect the SSB under a minimum magnification of 1.X. 3.5.3.1 Copper Conductor to Hole Location The minimum annu
20、lar ring as a function of the nominal annular ring is defined in the table below. The minimum annular ring shall not be less than 0.050 mm regardless of the nominal annular ring dimension. Nominal Annular Ring Minimum Annular Ring (mm) (mm) 0.300 0.150 3.5.3.2 Soldermask to Copper Conductor Measure
21、the true position location of the soldermask pattern relative to the copper conductor pattern using an optical comparator. All measurements must be determined to four decimal places with three place accuracy. The maximum misregistration requirements for a screen printed and photoimageable soldermask
22、 are listed below. Soldermask Type (Diametrical True Position) Screen Printed 0.280 mm Photoimaged 0.100 mm 3.5.3.3 Component Diagram (Legend Silkscreen) to Copper Conductor Measure the true position location of the component diagram pattern relative to the copper conductor pattern using an optical
23、comparator conductor. All measurements must be determined to four decimal places with three place accuracy. Diametrical True Position, max 0.280 mm 3.5.4 Bow and Twist (IPC-TM-650, Method 2.4.22) ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 5 of 12 3.6 CONSTRUCTION 3.6.1 Surface Co
24、pper The thickness of each copper layer shall be measured using a microsection per IPC-TM-650, Method 2.1.1. 3.6.3 Protective Coating The thickness of the protective coating, if applicable, covering unmasked copper areas shall be checked at three different locations on each SSB for each manufacturin
25、g panel using microsectioning techniques per IPC-TM-650, Method 2.1.1, X-ray fluorescence or an alternative method approved by Materials Engineering. An average of 4 measurements from the center of each quadrant of a representative SMD (surface mount device) pad shall be reported. The thickness meas
26、urements shall be taken such that the outer 0.025 mm wide periphery of each pad is excluded. Organic antioxidant treatments such as benzotriazole are exempt from this requirement. 3.7 ELECTRICAL All SSBs shall be tested for electrical continuity and isolation per the requirements of the particular d
27、esign. 3.7.1 Electrical Continuity The resistance between any two common conductors shall have a resistance of less than 10 ohms. 3.7.2 Electrical Isolation The resistance between any two non-common conductors shall be at least 10 megaohms when tested with a voltage between 100 to 300 volts. 3.8 GEN
28、ERAL 3.8.1 Cleanliness, max 1.5 ug NaCl/sq cm (IPC-TM-650, Method 2.3.26) The ionic cleanliness shall be measured before and after the application of soldermask using an Ionograph or method approved by Materials Engineering. Table 1 provides the maximum ionic cleanliness levels for common alternativ
29、e ionic cleanliness measurement techniques. Table 1 - Ionic Cleanliness Contamination Levels Method ug NaCl/cm2 Omega Meter 1.05 Ion Chaser 2.40 ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 6 of 12 3.8.2 Solderability (WSF-M22P1-A1) Class will be defined on the specific SSB print.
30、If no class is specified, class 1 is assumed. 3.8.3 Plated Through Hole Integrity 3.8.3.1 As Manufactured (Prior to Thermal Stress) Microsection NPTHs per para 3.5.4 and evaluate under a minimum of 100X magnification for the following requirements: . Burrs, nodules and glass fiber protrusions are al
31、lowed provided the minimum hole diameter is met. . Lifted external pads are not allowed. 3.8.3.2 After Thermal Stress (Solder Float) Thermally stress a NPTH coupon removed from a production representative circuit board per IPC-TM-650, method 2.6.8 with the following exceptions: . 4 h conditioning at
32、 standard conditions prior to thermal stress. (See para 3.3) . Test coupons shall not be baked prior to testing. . Solder bath temperature shall be 235 C. After thermal stress exposure, microsection NPTHs per IPC-TM-650, Method 2.1.1 and evaluate under a minimum of 100X magnification for the followi
33、ng requirements: . Cracks in the external copper pads are not permitted. . Laminate voids greater than 0.075 mm in dimension are not permitted. . Lifted external pads are allowed provided that 50 % of the pad annular ring width remains bonded to the base laminate. ENGINEERING MATERIAL SPECIFICATION
34、WSF-M22P4-A1 WP 3948-b Page 7 of 12 3.9 DURABILITY 3.9.1 Resistance to Solvents, weight 2 % gain, max (IPC-TM-650, method 2.3.3) No damage or degradation of the conductor pattern (legend silkscreen), soldermask or base laminate is permitted when exposed to the following solvents: Isopropyl Alcohol A
35、cetone 1 % Adipic Acid Solution in water 2 % Adipic Acid Solution in Isopropyl Alcohol Koki Flux 3.9.2 Moisture and Insulation 5 x 10E08 Ohms Resistance, min (IPC-TM-650, Method 2.6.3.1A) A set of non-common parallel circuit traces which run parallel for a minimum of 25 mm and are separated by a spe
36、cific designs minimum line spacing shall be tested. 3.9.3 Thermal Cycle Thermal cycle SSBs per the following temperature extremes listed in Table 2. The class for each circuit board shall be listed on the print. If no class is identified, class 3 is assumed. Successful qualification to a more severe
37、 thermal cycle requirement provides qualification to a less severe requirement. The thermal cycle profile is shown in Figure 1. The profile consists of 25 minutes at each temperature extreme with a minimum transition time of 5 minutes. The SSBs must meet the Appearance (para 3.7) requirements prior
38、to thermal cycling and be representative of SSB that can meet all aspects of this specification. After thermal cycling, the tested SSBs must meet the Appearance (para 3.4) and Electrical (para 3.7) requirements. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 8 of 12 Table 2: Thermal
39、Cycle Requirements based on Application Severity Class 1 Class 2 Class 3 Application Severity Mild Moderate Severe Thermal Cycle Range -40 to 85 C -40 to 105 C -40 to 125 C Number or Cycles 500 1000 1000 Figure 1: Thermal Cycle Profile 3.10 ADDITIONAL REQUIREMENTS Specific requirements for material
40、and/or manufactured parts shall be specified on the Engineering drawing, Engineering parts specification and/or performance specification. All critical areas with respect to these properties shall be clearly designated on the engineering drawing. 3.11 SUPPLIERS RESPONSIBILITY All materials supplied
41、to this specification must be equivalent in all characteristics to the material upon which approval was originally granted. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 9 of 12 Prior to making any change in the properties, composition, construction, color, processing or labeling of
42、 the material originally approved under this specification, whether or not such changes affect the materials ability to meet the specification requirements, the Supplier shall notify Purchasing, Toxicology and the affected Materials Engineering activity of the proposed changes and obtain the written
43、 approval of the Materials Engineering activity. Test data, test samples and a new code identification are to be submitted with the request. Substance restrictions imposed by law, regulations or Ford, apply to the materials addressed by this document. The restrictions are defined in Engineering Mate
44、rials Specification WSS-M99P9999-A1. 4. APPROVAL OF MATERIALS Materials defined by this specification must have prior approval by the responsible Materials Engineering activity. Suppliers desiring approval of their materials shall first obtain an expression of interest from the affected Purchasing,
45、Design and Materials Engineering activity. Upon request, the Supplier shall submit to the affected Materials Engineering activity a completed copy of their laboratory test reports, signed by a qualified and authorized representative of the test facility, demonstrating full compliance with all the re
46、quirements of this specification (test results, not nominal values), the material designation and code number, and test specimens for Ford evaluation. Fords engineering approval of a material will be based on its performance to this specification and on an assessment of suitability for intended proc
47、esses and/or applications. Upon approval, the material will be added to the Engineering Material Approved Source List. 5. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specification. 5.1 PSW/SREA REQUIREMENTS When sub
48、mitting the Parts Sample Warrant (PSW) for a specific SSB, certain of the requirements listed in paragraph 3 may reference data generated for a specific “family“ of SSBs. All other requirements must be evaluated for the specific design. A SSB “family“ is defined as a group of different SSB designs w
49、hich have the following common characteristics: . The laminate material is the same grade and comes form the same laminate supplier. . The minimum plated through hole diameter is greater than or equal to the minimum size tested to qualify the family. . The solder mask material is the same type and supplied by the same soldermask supplier. . The laminate dielectric thickness and construction are the same. ENGINEERING MATERIAL SPECIFICATION WSF-M22P4-A1 WP 3948-b Page 10 of 12 . The min
