Press Fit Rework Project Project Update HDPUG Meeting Kawasaki, Japan 10/12/14

© HDP User Group International, Inc. Since late 60’s or early 70’s First press fit was a square peg into a round hole using a fixed geometry solid pin construction, original pin designed for 1.5 mm diameter finished holes Recent years, compliant pins, finished holes just 0.22 mm diameter Source: Tyco Electronics Background

When performing press fit component rework, the plated holes and their annular rings could easily get damaged. Questions that need to be answered are: – How much hole wall deformation does one, or several, rework(s) cause? – How is the pin insertion force affected by the rework(s)? – How is the pin retention force affected by the rework(s)? – Will the gas tight connections be intact? There is a need to evaluate press fit component rework, especially for new components, boards and designs. © HDP User Group International, Inc. Background cont.

Project Goals The goal with this project is to understand and to document how rework affects press fit connection strength, hole wall deformation and gas tightness for new high-speed press fit connectors 0, 1x, 2x and 3x rework shall be performed on assemblies with: – Different, new, high-speed, small pin sizes, connectors – Three different hole sizes for each component (minimum, nominal and maximum specified diameters ) – Hole plating, ENIG and ImSn – Moreover, standard board materials and designs shall be used © HDP User Group International, Inc.

Expected Outcome The outcome of this project shall be a document that specifies how press-fit rework affects – Pin insertion force – Pin retention force – Hole wall deformation – Gas tight connection The project shall tell which pin and design combinations that work well to rework and what strength and hole wall deformations that could be expected © HDP User Group International, Inc.

Flow Chart © HDP User Group International, Inc. Basic Work

Connector rework test © HDP User Group International, Inc. 0x 1x 2x 3x

Total insertions & retentions 24 populated boards © HDP User Group International, Inc. ImSn, min holesImSn, nom holesImSn, max holes ENIG, min holesENIG, nom holesENIG, max holes

Gas Tight Test The activities in the flow chart below shall be performed on X pins per component/5 components per board/24 boards After the gas tight test cross sectioning shall be performed on these boards © HDP User Group International, Inc.

Contact Resistance © HDP User Group International, Inc. David Wice, Ciena

Cross Sectioning Use the boards from gas tight test for cross sectioning © HDP User Group International, Inc.

Pin retention test © HDP User Group International, Inc. 0x 1x 2x 3x

Total insertions & retentions 24 boards © HDP User Group International, Inc. ImSn, min holesImSn, nom holesImSn, max holes ENIG, min holesENIG, nom holesENIG, max holes

Test Processes Initial mechanical measurements of all used materials Insertion/Retention test – Demand on retention and insertion force in Telcordia GR CORE Visual inspection according IPC-001, IPC-610, Telcordia GR-78 R4-10, GR-1217-CORE and IEC (hole deformation, delamination etc.) – Directly after insertion – After rework – After retention of pins Electrical contact resistance measurements after aging (gas tight test) shall be performed for all components © HDP User Group International, Inc.

The backplane connectors in the following series will be used: DIN reference pin (Molex) ZDHD (Erni) ExaMezz (FCI) Impel (Molex) Strada Whisper (TE) Components

Need of Components If two different surface finishes are chosen, one base materials and min, nom and max hole diameters are used for each component: – 0x rework, 1 x 1 x 2 x 3 = 6 – 1x rework, 2 x 1 x 2 x 3 = 12 – 2x rework, 3 x 1 x 2 x 3 = 18 – 3x rework, 4 x 1 x 2 x 3 = 24 – 0x rework, 0 x 1 x 2 x 3 = 0 (pin retention test) – 1x rework, 1 x 1 x 2 x 3 = 6 (pin retention test) – 2x rework, 2 x 1 x 2 x 3 = 12 (pin retention test) – 3x rework, 3 x 1 x 2 x 3 = 18 (pin retention test) Total component needs = 96 (a few extra are needed for incoming inspection and measurement) © HDP User Group International, Inc.

Test Board Test board design suggestion exists 100mm x 100mm side lengths © HDP User Group International, Inc.

Suggested PCB parameters: – Surface metallizations: ENIG and ImSn – Base material: Isola 370HR – Hole sizes: Min, Nominal, Max (if possible) – Amount of layers: 6 – Distances between layers: L1-L2: 0.1mm, L2-L3: 0.5mm, L3-L4: 0.6mm, L4-L5:0.5mm, L5-L6:0.1mm – Board thickness 1.8mm – Outer copper layer thickness: 0.050mm (±0.020mm) – Inner copper layer thickness: 0.017mm (+0.003/-0.007mm) – L2, a full ground layer – Board size: 100mm x 100mm PCB Parameters

Connector Header Drill Hole Size Requirement Less than Nominal DrillNominal Drill Greater than Nominal Drill FCI ExaMax ".425mm ".45mm " # " Molex Impel ".425mm ".45mm " # " TE Strada Whisper 0.42mm+/-0.013mm (0.0165”) # ".425mm ".45mm " Erni ZDHD 0.55mm +/-0.02mm ( ”) # ".55mm " # Molex DIN mm +/-0.025mm (0.0452”) 1.125mm " 1.15mm " # " Decided drill sizes: Drill Sizes

Need of Boards One board for each hole size (min, nom, max) and surface finish (ENIG, ImSn) is needed for incoming board hole inspection/measurement – 3 hole sizes and 2 surface finishes give 6 boards Four boards are needed for each hole size and surface finish for the rework test (i.e. for 0x, 1x, 2x and 3x rework) – 4 boards, 2 surface finishes, 3 hole sizes, 1 base material give 24 boards Four boards are needed for each hole size and surface finish for the pin retention test (i.e. for 0x, 1x, 2x and 3x rework) – 4 boards, 2 surface finishes and 3 hole sizes give 24 boards Altogether 54 boards are needed © HDP User Group International, Inc.

Order test board – After agreed design – Each connector manufacturer check “their“ hole pattern Collect all components – For the actual test there will be a need of at least 120 components of each type – Need of extra single pins for each connector type Collect all needed information about press parameters and tooling – Borrow the tooling? – Find suitable site(s) to perform the press fit rework test Next Step

Plans for the Nearest Future Finalized and agreed design of test board – Dec 2014 Order test boards – Jan 2014 Received all necessary rework information and tools – Jan 2014 Start assembly and rework tests – March 2015 © HDP User Group International, Inc.

Test Questions Who shall manufacture the test board? Where shall the rework tests be performed? Where shall the gas-tight test be performed? – Contact Research Who shall do the cross-sectioning? Who shall do the analysis? © HDP User Group International, Inc.

Team List Team List: Participating Companies: – Dell – Philips – GE – Delphi – Curtis Wright – PWB Corp – Nihon Superior – Ericsson – Alcatel-Lucent – Multek – Cookson © HDP User Group International, Inc. – TTM – Juniper – ASUS – Oracle – Flextronics – Plexus – Cisco – Fujitsu – Ciena – Isola – IBM – ASE – Continental – Panasonic – Emerson – IST Group – Boeing – Fujitsu – ZTE – Sytech

Tentative Schedule Kick off - San José 2012 Idea Stage-Q Definition-Q Implementation-Q Publish Report-Q © HDP User Group International, Inc.