ELECTRONICS INDUSTRIES Qualification and Performance ...

1 IPC-SM-840 DQualification andPerformance Specificationof permanent solder MaskDeveloped by the solder Mask Performance Task Group (5-33b) of theCleaning and Coating Committee (5-30) of IPCU sers of this publication are encouraged to participate in thedevelopment of future :IPC3000 Lakeside Drive, Suite 309 SBannockburn, Illinois60015-1249 Tel 847 847 :IPC-SM-840C -Amendment 1 - June 2000 IPC-SM-840C - January 1995 IPC-SM-840B - May 1988 IPC-SM-840A - July 1983 IPC-SM-840 - November 1977 ASSOCIATION CONNECTINGELECTRONICS INDUSTRIEST able of Contents1 SCOPE AND .. and Definitions .. (Cured solder Mask) .. Change (Cured solder Mask) .. (Conformal or solder Mask Coating .. (Cured solder Mask) .. (Cured solder Mask) .. (Cured solder Mask) .. 305 .. (Cured solder Mask) .. Mask .. (Cured solder Mask) .. ( solder Mask) .. 22 APPLICABLE .. Laboratories.)

2 Of Documents .. 33 .. Qualification and Conformance .. Board Process Qualification andAssessment .. Change .. Life .. Requirements .. (Metallic Surfaces) .. ( solder Mask) .. Requirements .. Mask Thickness .. Requirements .. Hardness .. Requirements .. to Fabrication Solvents, CleaningAgents and Fluxes .. Stability .. Requirements .. to Tin-Lead solder .. to Lead Free solder .. Requirements .. Strength .. Resistance .. Requirements .. and Insulation Resistance .. Migration .. Shock .. 84 QUALITY ASSURANCE for Testing/Inspection .. Qualification Testing .. or Inspection Facilities .. Inspection .. Size .. Routine .. Conformance Testing/Inspection .. of Product for Delivery .. of Specimens for Test .. Laboratory Conditions .. Selection .. 11 April 2007 IPC-SM-840 Diii5 PREPARATION OF solder MASK MATERIALFOR , Packaging and Packing.

3 116 solder Mask on PrintedBoards .. Requirements .. 11 FiguresFigure 4-1 IPC-B-25A (Note: No solder mask shallbe applied to contact fingers) .. 11 Figure 4-2 IPC-2221 Test Coupon E Layer 1( Y Configuration) .. 11 TablesTable 3-1 Requirements of Qualification .. 4 Table 3-2 Adhesion to Rigid Printed Boards(IPC-B-25A Test Board and/or ProductionPrinted Board) .. 6 Table 3-3 Moisture & Insulation Resistance .. 8 Table 3-4 Electrochemical Migration .. 8 Table 3-5 Thermal Shock Conditions .. 8 Table 4-1 Sample Requirements/Suggested TestSequence for Table 3-1, Column AIPC-B-25A Standard Test Boards .. 9 Table 4-2 Sample Requirements/Suggested TestSequence for Table 3-1, Column BIPC-B-25A Boards - Production Processor Conformance Coupons or ProductionPrinted Boards .. 10 IPC-SM-840 DApril 2007ivQualification and PerformanceSpecification of permanent solder Mask1 SCOPE AND ScopeThis specificationshalldefine the criteria forand method of obtaining the maximum information aboutand confidence in cured permanent solder mask materialunder evaluation with the minimum of test specificationshallestablish the requirements for: The evaluation of solder mask materials.

4 The conformance of solder mask material properties. The Qualification of the solder mask via the appropriatetest substrate. The Qualification assessment of the solder mask in con-junction with the production printed board PurposeThis specificationshallestablish therequirements, based on applicable test methods and condi-tions, for the evaluation of a solder mask material and forthe determination of the acceptability of use on a standardprinted board system. These same requirementsshallalsobe used to qualify a printed board production process basedon conformance criteria defined by the reliability require-ments of the end use environment. Acceptability and/orverification criteria of the production printed boardshallbedetermined in accordance with the applicable performancerequirements contained in IPC-6011, IPC-6012, IPC-6013and solder mask materials described herein, when appliedto the printed board substrateshallprevent and/or mini-mize the formation and adherence of solder balls, solderbridging, solder build-up and physical damage to theprinted board substrate.

5 The solder mask materialshallhelp retard electromigration and other forms of detrimentalor conductive : The determination of compatibility betweensolder mask materials and post soldering products andprocesses is beyond the scope of this specification . Theuse of Test Methods specified herein to determine thecompatibility and the requirement to do so shall be asagreed between user and supplier (AABUS).This specificationshalllist the base requirements for sol-der mask and solder mask production processes. The soldermaskshallbe cured per the manufacturer s recommendedprocess in accordance with those conditions specified forthat product. Additional requirements or deviations fromthese requirementsshallbe ClassesThis specification provides two classes ofrequirements, T and H, to reflect functional performancerequirements and testing severity based on industry/end userequirements.

6 Qualification to a particular classshall notbe extended to cover any other :The reference of a single class does not precludeinvoking or allowing specific requirements defined in TelecommunicationThis includes computers, tele-communication equipment, sophisticated businessmachines, instruments, and certain noncritical militaryapplications. solder mask on printed boards in this class issuitable for high Performance commercial and industrialproducts in which extended Performance life is requiredbut for which interrupted service is not life High Reliability/MilitaryThis includes that equip-ment where continued Performance is critical, equipmentdown-time cannot be tolerated and/or the equipment is alife support item. solder mask on printed boards of thisclass is suitable for applications where high levels of assur-ance are required and uninterrupted service is : Class Designations Previous versions of this and otherIPC specifications make reference to Class 1, Class2, and Class 3 end product classes.

7 For all practicalpurposes there is no Class 1 solder mask. The require-ments in this specification are not applicable for soldermask used in Class 1 end-product. Class 2 is equivalentto Class T (Telecommunications). Class 3 is the equiva-lent of Class H (Military/high reliability). solder mask types were previously described as Type Afor screen imaged (liquid) or coverlay for flex (dry), andtype B for all types of photo defined solder mask (liquidor dry film). A Type B1 solder mask was identified as aliquid solder mask and a Type B2 solder mask was iden-tified as a dry film solder PresentationDimensions and tolerancesshallbeexpressed in metric units. English units are shown in brack-ets [ ] and are not necessarily direct conversions or usablenumbers. Reference information is shown in parentheses( ). Deviations to thisshallbe Terms and DefinitionsThe definition of termsshallbe in accordance with IPC-T-50 and as stated in 2007 IPC-SM-840D1