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SOLDERED ELECTRICAL CONNECTIONS. esa Inspection Course based on: EUROPEAN COOPERATION FOR SPACE STANDARDIZATION ECSS-Q-ST-70-08, ST-70-38 ECSS-Q-ST-20 & ECSS-Q-ST-10-09 20140522. How Effective is Your Inspection?.
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SOLDERED ELECTRICAL CONNECTIONS esa Inspection Course based on: EUROPEAN COOPERATION FOR SPACE STANDARDIZATION ECSS-Q-ST-70-08, ST-70-38 ECSS-Q-ST-20 & ECSS-Q-ST-10-09 20140522
How Effective is Your Inspection? How many odd characters?.. OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOCOOOOOOOOOOOOOOOOOCOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOCOOOOO
How Effective is Your Inspection?READ THROUGH ONCE AND COUNT THE “F’s”: FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARSTotal number of “F’’s: _______
How Effective is Your Inspection?READ THROUGH ONCE AND COUNT THE “F’s”: FINISHED FILES ARE THE RESULT OF 3 YEARS OF SCIENTIFIC STUDY COMBINED 2 WITH THE EXPERIENCE OF YEARS 1 Total number of “F’s”: _6 !_
How Effective is Your Inspection?READ THROUGH ONCE AND COUNT THE “F’s”: The necessity of training farm hands for first-class farms in the fatherly handling of farm livestock is foremost in the minds of farm owners. Since the forefathers of the farm owners trained the farm hands for first-class farms in the fatherly handling of farm livestock, the farm owners feel they should carry on with the family tradition of training farm hands of first-class farms in the fatherly handling of farm livestock because they believe it is the basis of good fundamental farm management. Total number of “f’s”: _______
How Effective is Your Inspection?READ THROUGH ONCE AND COUNT THE “F’s”: The necessity of training farm hands for first-class farms in 5 the fatherly handling offarm livestock is foremost in the minds 4 offarm owners. 2 Since the forefathers of the farm owners trained the farm 5 hands for first-class farms in the fatherly handling offarm 6 livestock, the farm owners feel they should carry on with the 2 family tradition of training farm hands offirst-class farms in 6 the fatherly handling offarm livestock because they believe it 3 is the basis of good fundamental farm management. 3 Total number of “f’s”: _36!_
Inspection Procedure Remember that one purpose of inspection is to find opportunities to improve the manufacturing process through the use of data, not just sort, rework or repair defective product. Whatever the process stage, review the entire assembly upon receipt to ensure prior operations are complete and conform to the drawing and the specifications.
Inspection Procedure Before you inspect the assembly, check the following: 1.1 handle at an EOS/ESD safe workstation 1.2 proper packaging? 1.3 correctness of drawing/documentation package? 1.4 product assembly markings, part number and revision levels meet drawing requirements? 1.6 compliance with drawing requirements, drawing notes, Engineering Change Orders and Waivers? 1.7 classification if IPC (ie class 1, 2 or 3)? 1.8 certification status of yourself and the operators who built the assembly?
General Inspection Now examine the entire assembly for the following obvious damage: 2.1 Laminate damage • Burns / Delamination / Blisters / Haloing / Weave exposure 2.2 Warped Laminate • Bow and Twist 2.3 Missing components 2.4 Skewed components 2.5 Scratched or damaged conductors 2.6 Scratched or damaged soldermask (if present)
Detailed General Inspection Now examine the entire assembly for damage or non-conformance: 3.1 Solder mask damage (if solder mask is used) • Wrinkled / Cracked / Blistered / Voids bridging conductors 3.2 Conductors or laminate damage around break-off tabs 3.3 Burned, melted or discoloured connectors, sockets, jacks, switches etc
Cleanliness Now examine the entire assembly for general cleanliness: 4.1 Visible flux residues (cleanable fluxes) 4.2 Particulate and foreign matter • Solder balls • Solder Splatter • Wire strands • Insulation slugs • Temporary solder masks 4.3 White residues and white crystalline deposits
Component Mounting and Installation Now verify component markings and placement; verify parts for correct mounting and installation: 5.1 Correct part / Orientation / Polarity? 5.2 Missing parts? 5.3 Component mounting • Body height requirements? • Lead bend radius / stress relief? • Staking per drawing (adhesives and bonding agents)? 5.4 Correct placement of mounting hardware or mounting clips? • Correct sequence of electrical and mechanical fasteners? 5.5 Jumper wire placement?
Solder Inspection Now examine solder quality per the specification: 6.1 Inspect for overall solder quality, quantity and wetting 6.2 Solder defects and Process Indicators • Insufficient or Excessive • Cold • Fractured • Disturbed • Bridged • Pits • Voids • Icicles and Protrusions
INSPECTION ECSS-Q-ST-70-08 Clause 12.
IDEAL/PREFERRED Why is excessive solder a reject criterion ?
ECSS-Q-ST-70-08 clause 12.3 (17) • Exposed base metal on the copper ends of cut wire leads is acceptable. • Although uncoated lead ends is not a cause for rejection, it is bad practice • Do you know if the leads are copper? • Was the lead cut after soldering? Base metal exposed Concave: preferred
Maximum acceptable (midway between convex and concave)
• Excessive (convex) • Lead not discernible
hole
• Non-wetting • Cold solder joint • Poor wetting
Verification failure:R0705 assembled on a via-in-pad with dimple and low stand off