627.000.000 Iphonessince 1. quarter 2012

25.080.000.000 screws

Each Iphone containsapx 40 screws each

Data package for fixture builders

Correct and relevant data =

Reduces fixture engineering cost

- DXF-file- Standard fixture specifaction document

PCB outline and tooling holes

Bottom side components

Bottom side PCB supports

Test points

TP Ref numbers

Top side components

Top side push fingers

Roundtooling hole

Guide pins for PCB outline

Conclusion

Reduced fixture engineering costReduced risk of errorEarlier ordering of fixture Improved documentation

And where are the fails that leads to bad pointing accuracy?

What is a reasonable achievable accuracy without adding to much efforts and cost into a “standard” PCB fixtures?

The PCB and its tooling holesThe test probe Tolerances on the drill holes in the probe plate Installation of receptacle and tooling pinsFixture design/concept

What has impact on the actual target accuracy in a ”standard pcb fixture”?

The PCB and its tooling holes

Oblong tooling hole

In general tooling pin 0,1 mm smaller than tooling hole

Round tooling hole

Max distance

Guide pins

Operator side

Guide pins

Test probe repeatable accuracy +/- 0,1 mm

Mid close design

Top close design

The probe plate accuracy

Use high precisionmachinery with repeatable accuracybetter than 0,01 mm.

Always use good tools

Installation of receptacles

VERY important part….. Use correct and good tool

The press ring is weakestpart during installation

Coaxial force

Bend of receptacleduring installation

Installation of receptacles

Distance from press ring to probe tip is 15,78 mm2 degree misalignment gives a deviation of 0,52 mm!!

15,78 mm

Installation of receptacles

Calculation of misalignment in drill hole

Tooling hole

Pattern of TP marks in center of test pads

Offset of pattern of TP marks in center of test pads

Fixture top plate typical 4-6 mm

PCB

”Standard” PCB fixture plate design

Push finger

PCB support typical 2-5 mm

Probe plate typical 10 mm

Typical distance 9-10 mmTypical distance from probeplate to test probe tip is apx12 mm

Probe plate

2 degree angledtest probe

PCB

The longer probe tip = the worse accuracy

The tolerances worst case

Ø1 mm test points

And where are the fails that leads to bad pointing accuracy?

What is a reasonable achievable accuracy without adding to much efforts and cost into a “standard” PCB fixtures?

+/- 0,3 mm measured from center of test pad

- installation of receptacles- long tip probes and distance between probe plate and pcb- wrong, bad or even missing tooling holes in PCB

Test pad sizeRule of thumb 0,8 x pitch50 mill = 1,00 mm75 mill = 1,50 mm100 mill = 2,00 mm

Thanks for your attention

Time for questions

Or out for dinner…