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How to test electronics:

highly accelerated life test (HALT): Environmental stresses are applied in a HALT procedure,[1]

eventually

reaching a level significantly beyond that expected during use. Failure rate data used to characterize any

device in a product must correlate with the stress levels in the product or application. Temperature cycling and

repetitive shock, power margining and power cycling are the most common forms of failure acceleration forelectronic equipment. It is a method used in industry. Humidity, physical strain. weibull analysis

Does it look robustly designed? Are there obvious mechanical stress points? Is there proper

strain relief wherever something flexes? Are all the datasheet limits carefully adhered to in

all possible corners of normal operation with some reasonable margin? Does the design

handle the obvious expected abuse? This is both mechanical like someone yanking on it or

stepping on any part of it, and electrical like ESD shocks.

Failure Mode and Effects Analysis (FMEA) was one of the first systematic techniques forfailure analysis. Itwas developed byreliability engineersin the 1950s to study problems that might arise from malfunctions of

military systems.

Consider every physical property, e.g. voltage, current, temperature (in and out of service),

vibration, power, duty cycle, mechanical shock, etc.

MTBF mean time between failures

Soldering processes

Dip soldering is a small-scalesolderingprocess by whichelectronic componentsaresolderedto aprinted

circuit board(PCB) to form an electronic assembly.

Reflow soldering is a process in which asolder paste(a sticky mixture of powderedsolderandflux) is used to

temporarily attach one or several electrical components to theircontact pads, after which the entire assembly is

subjected to controlled heat, which melts the solder, permanently connecting the joint.

Wave soldering:The name is derived from the use of waves of molten solder to attach metal components to

the PCB.

http://en.wikipedia.org/wiki/Highly_accelerated_life_test#cite_note-1http://en.wikipedia.org/wiki/Highly_accelerated_life_test#cite_note-1http://en.wikipedia.org/wiki/Highly_accelerated_life_test#cite_note-1http://en.wikipedia.org/wiki/Failure_analysishttp://en.wikipedia.org/wiki/Failure_analysishttp://en.wikipedia.org/wiki/Failure_analysishttp://en.wikipedia.org/wiki/Reliability_engineeringhttp://en.wikipedia.org/wiki/Reliability_engineeringhttp://en.wikipedia.org/wiki/Reliability_engineeringhttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Solder_pastehttp://en.wikipedia.org/wiki/Solder_pastehttp://en.wikipedia.org/wiki/Solder_pastehttp://en.wikipedia.org/wiki/Solderhttp://en.wikipedia.org/wiki/Solderhttp://en.wikipedia.org/wiki/Solderhttp://en.wikipedia.org/wiki/Flux_(metallurgy)http://en.wikipedia.org/wiki/Flux_(metallurgy)http://en.wikipedia.org/wiki/Flux_(metallurgy)http://en.wikipedia.org/wiki/Contact_padhttp://en.wikipedia.org/wiki/Contact_padhttp://en.wikipedia.org/wiki/Contact_padhttp://en.wikipedia.org/wiki/Contact_padhttp://en.wikipedia.org/wiki/Flux_(metallurgy)http://en.wikipedia.org/wiki/Solderhttp://en.wikipedia.org/wiki/Solder_pastehttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Reliability_engineeringhttp://en.wikipedia.org/wiki/Failure_analysishttp://en.wikipedia.org/wiki/Highly_accelerated_life_test#cite_note-1

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Ultrasonic soldering is process that uses ultrasonic energy tosoldermaterials

Finish and Quality:

Quality depends on proper temperatures when heating and on properly treated surfaces.

Defect Possible causes Effects

Cracks Mechanical Stress Loss of Conductivity

Cavities

Contaminated surface

Lack of flux

Insufficient preheating

Reduction in strength

Poor conductivity

Wrong solder thickness

Wrong solder temperature

Wrong conveyor speed

Susceptible to stress

Too thin for current load

Undesired bridging between paths

Poor Conductor Contaminated solder Product Failures

Thermal Profiling: is a complex set of time-temperature data typically associated with an objected heat up andcool down.

http://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Solderinghttp://en.wikipedia.org/wiki/Soldering