4702075100 - AMPHENOL - Datasheet.Live

Amphenol TCS

200 Innovative Way, Suite 201

Nashua, NH 03062

603.879.3000

www.amphenol-tcs.com

AMPHENOL TCS

TB-2082

DFM and SMT Assembly Guideline

Revision “H“

Specification Revision Status

Revision SCR No. Description Initial Date

“-“ 33277 Initial Release J. Marvin 1/16/01

“A” 36994 Update stencil design, JEDEC tray info, add weight

table & GenRad ref, delete AirVac detail. J. Proulx 10/19/01

“B” 39831 Revised in it’s entirety and refor matted. J. Proulx 9/17/02

“C” 42921 Clarify board warp re q, add stand-off req, change

handling to reflect new packaging, changes to paste

process – add selection matrix, reflow process –

additional thermal probe and plug note, and reflow

verification and de-bug.

J. Proulx 8/13/03

“D“ S0043 Replaced template format M. Lee 02/07/06

‘E’ S0802 Updated copyright information C Palmer 02/26/08

‘F’ S1760 Changed reference of solder ball diameter to 28mil

Added Lead-Free information

Modif ied the solder paste aperture recommendations

for the 28mil solder ball

Added Pin A1 al i gnment and m ore reflow pr ofi l e in fo .

J. Proulx 6/09/11

‘G’

‘H’ S2031

S2658 Clarify Vacuum cap removal in section 8.3

Added Section 3.6.1 Allowable mate angles, expected

mating forces and suggested mechanical structure for

heavier assemblies.

D. Covey

J. Proulx 5/09/12

1/17/14

DFM and SMT Assembly Guideline TB-2082

Revision “H“

Table of Contents

1.0 DFM Guideline Introduction

1.1 Scope

1.2 Purpose

1.3 Reference Documents

1.3.1 Customer Use Drawings

2.0 Design Introduction – NeXLev Connector

3.0 Design Requirements

3.1 NeXLev Solder Joint Definition – Reliability Factors

3.2 Landing Pad Footprint

3.3 PCB General Requirements and Suggested Routing

3.4 Connector Pin A1 Alignment

3.5 Connector Float Allowance and PCB Fabrication Tolerances

3.6 Layout and Orientation for Multi-Connector Applications

3.6.1 Connector Mating Forces and Allowable Mate and Un-Mate Angles

3.7 Mechanical Requirements

3.7.1 Suggested Mechanical Structure for Heavier Assemblies

3.8 Keep-out Zone and Clearances – Connector height < 10.5mm

3.9 Keep-out Zone and Clearances – Multi Connector and Connector height > 15.5mm

4.0 Manufacturing Introduction

4.1 Connector Inspection

5.0 Connector Handling

6.0 Solder Paste Process

7.0 Placement Process

7.1 Placement Alignment – “Best-Fit”

7.2 Placement - 15.5 and 23.5mm Receptacles

7.3 Feeders

7.4 JEDEC Tray Set-up

8.0 Reflow Process

8.1 Reflow Process – Reflow Profile Recommendations

8.2 Reflow Process – Detailed Verification and De-bug

8.3 Vacuum “Pick-up” Cap Removal

9.0 Double Sided Reflow Process

10.0 Rework Process

Addendums:

A. NeXLev Connector Weights

B. NeXLev DFM Check Sheet - used for design reviews, and process start-up.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

1.0 DFM Guideline Introduction

This document is intended to provide design criteria and process information that will promote

automation, cost and cycle time reduction, and help to produce designs that will yield high quality for the

solder attach of NeXLev connectors. The NeXLev connector will be used in many assembly processes,

and because all processes are different, this document provides a starting point, or “baseline” criteria for

application process development. This document is not intended to be the final process definition,

nor is it intended to constrain designs. If customers cannot meet/follow all of the recommendations,

they should contact TCS to discuss the best alternatives.

1.1 Scope

This document has been prepared to communicate the application guidelines for the NeXLev

Surface Mount Connector. It provides Printed Circuit Board (PCB) footprint and layout criteria, and

“starting-point” process recommendations for SMT assembly. Updates and revisions will be issued on a

continuous basis to expand the guidelines, address changes in technology and manufacturing

capabilities, and cover modifications and/or additions to current criteria.

1.2 Purpose

DFM is the sharing of manufacturing guidelines developed from industry standards and the

knowledge gained from design and production. Applying these guidelines concurrently, in new product

development with the design and application of Amphenol TCS’s NeXLev connector, can positively

impact cost, time to market, and quality of the end product.

1.3 Reference Documents

Located at: http://www.Amphenol TCS.com/prods/tcs/products/hpi/NeXLev/drawings.html

1.3.1 Customer Use Drawings

C-471-1025-500 Plug (drawing for application)

C-470-1075-500 Receptacle (drawing for application)

471-1025-500 Plug (drawing for inspection)

470-1075-500 Receptacle (drawing for inspection)

1.4 Levels of Requirement

For each requirement, an impact and benefit statement is included to quantify the requirement.

Some requirements are stated as being recommended or preferred per the following:

Recommended: The minimum processing requirement – a deviation will most likely impact

manufacturability and cost.

Preferred: Should be done when possible – a deviation could impact manufacturability and

cost.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

2.0 Design Introduction – NeXLev Connector

The NeXLev connector is a wafer construction organized in a 10-row by up to 30 columns of

signal contacts, with each signal wafer having integral strip-line shielding. This wafer construction

allows for the contacts to be spaced on a 1.5mm x 1.75mm grid. The connector can be specified in

separation heights ranging from 10mm to 30mm.

The connector is a completely SMT attach, utilizing ball grid technology for termination to the

board. Designed with solder joint reliability in mind, the connector has a mechanically compliant

structure, and is readily applied using standard SMT processes. Standard versions of the NeXLev

connector contain either 10, 20 or 30 wafers. (100, 200, or 300 positions)

The connector is different than a standard BGA device, due to the compliant structure, which has

a 0.71 mm (28mil) solder ball, re-flowed on the end of a formed pedestal. There are two solder ball

alloys available – Tin/Lead (eutectic) or Lead Free (SAC305).

S-Bend

Compliant Lead

Ground Shield Ball is attached to a

p

edestal at the end of

the “S-Bend”

Compliant Lead

One wafer contains 10 signal and 9 ground

balls and the connector is provided in 10,

20, and 30 wafer configurations.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.0 Design Requirements

3.1 NeXLev Solder Joint Definition – Reliability Factors

The recommendations made below have a direct impact on the reliability of the NeXLev solder joint,

and play an important role in facilitating the connectors' ability to self-center and achieve the best possible

location tolerances. This is especially important when multiple connectors are being used.

Requirements DFM Impact/Benefit

 Recommend using a “Copper Defined”

landing pad as opposed to a “Solder-

Mask Defined” pad.

 “Copper defined” better insures a round, accurately located

pad – critical to part location tolerance.

 “Copper defined” pad produces a more reliable solder joint –

allowing solder to wrap around the pad edge.

 Pad Size = .60mm (.024”)  Smaller pad will result in decreased ball-to-pad angle,

based on solder volume – increasing the risk of solder

fracture.

 Larger pads will increase the risk of shorting.

 Solder mask should be clear around pad



In-accurate registration will result in solder mask

encroaching onto copper pad.

Angle is critical to solder

joint reliability – a

smaller pad will result in

a fatter ball, decreasing

angle and creating weak

points in the joint

PCB

Solder mask is clear

around pad

Copper defined pad yields highest quality solder joint –

compared to Solder Mask defined:

- Doesn’t inhibit connectors ability to self-center

- Solder wraps around pad edge - maximum strength

Solder Mask

Copper Pad

S-Bend Compliant

Lead

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.2 Landing Pad Footprint

Refer to customer drawings, C-471-1025-500 Plug and C-470-1075-500 Receptacle, for overall landing

pad layout. See below for the detail of a single pad and via design. The exact landing pad and via design

will depend on several factors including design goals, routability, customer specific design for

manufacturability (DFM) guidelines, and PCB fabricator capabilities. The diagram below offers a starting

point, with the critical parameters in bold.

Requirements DFM Impact/Benefit/Alternatives

 Amphenol TCS recommends a .60mm (.024”)

“Copper Defined” landing pad over a “Solder-

Mask Defined” pad.

 See previous section for impact

 Minimum .22mm (.009”) Solder Mask Dam

between pad and via.

 Prevents solder from wicking away from pad and into

via, causing insufficient solder joints.

 It’s preferred to mask the vias if design

allows, or if a .22mm min dam can’t be held.



Via drill sizes can be changed based on PCB fabricators

board thickness aspect ratio, but must insure a

minimum solder mask dam.



0.64mm (0.025”)

Via Pad and inner pad

diameter

*Note: Insure PCB Fabricators solder mask registration capabilities



0.34mm (0.0135”) Drill diameter

–

Dependant on fab shop aspect

ratio ca

p

abilit

y



0.44mm (0.017”)

Via solder mask aperture

(Component Side)

0.63mm (0.025”)(Via Pad Side)

N

ote: Eliminate this aperture if

minimum dam can’t be achieved

0.70mm (0.028”)

0.22mm (0.009”)

Minimum Dam*

N

ote: Solder Mask Dam

Is maximized using a “D”

shaped aperture

0.30mm (0.012”)



0.70mm (0.028”)

Pad Solder Mask Aperture

(Insure that mask is clear of Pad)*

0.60mm (0.024”)

Pad Diameter

Board Pad and Via Detailed Footprint

Exposed Solder-able surface

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.3 PCB General Requirements and Routing Example

The NeXLev connector can be routed from one side using five layers - each with two 6 mil traces with a

7 mil space. Routing from both sides may further reduce the layer count. The following pattern shows a

“Serpentine” trace pattern, and this routing pattern can be achieved using the exact pad and via footprint

stated previously. The diagram below is an example of a possible starting point.

Requirements DFM Impact/Benefit

 Maximum recommended board warp – 7 mils/inch*.

(Sufficient for surface finishes that have less than

.001” thickness variation such as OSP, ENIG,

Immersion Tin and Silver.)

 Minimizes the risk of opens

 Preferred maximum board warp - 5 mils/inch*.

(May be required if using a HASL surface finish)

 Minimizes the risk of opens while allowing for

other variables such as solder paste height and

pad flatness*.

*Note: The recommended board warp is also based on the assembly process stencil thickn ess

used. For more detail, see selection matrix in section 6.0 – “Solder Paste Process”

Trace Routin

g

Details

Landing Pad Layout

Connector Side

Example – Differential Routing: Shows a 6-mil trace with a 7-mil space, in a “serpentine” pattern allowing for

two runs. *Note: the runs are parallel to the wafer – providing the most routing space.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.4 Connector Pin A1 Alignment

Requirements DFM Impact/Benefit

 The pin A1 pad for the plug should align with the

pin A1 pad of the receptacle when the mother and

daughter card are mated – see below

 Ensures correct pin-outs

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.5 Connector Float Allowance and PCB Fabrication Tolerances

The NeXLev connector is designed to accommodate SMT assembly and PCB fabrication tolerances.

Below are the total allowances for the connector design, and the recommended PCB fabrication tolerances.

+/- 0.10mm Max error from

nominal location

+/- 0.20mm Max error from

nominal location

Silkscreen outline – visible

after component placement.

Total Connector Float Allowance

Recommended PCB Footprint True Position Tolerance

Assume this connector

footprint center to be the

“Datum Point”

X,Y TP < 0.10 mm

From “Datum Point”

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.6 Layout and Orientation for Multi-Connector Applications

Layout: Requirements DFM Impact/Benefit

 Preferred to align connectors in the same direction  Ease of multi-board mating alignment

 Connectors are parallel across the larger span, and

in series on shorter spans.

 Maximizes designed-in “float” tolerances

 Max span is dependant on board fabrication

tolerances – reference section 3.4.



Board tolerance exceeds connector max alignment

tolerance.

 Layout should include a slightly larger silkscreen

outline of the component housing.



Silkscreen is visible after connector placement, and

allows for “first-piece” visual inspection of

polarity/orientation.

Mating and Un-Mating:

Connectors are placed

in same orientation Connectors are not placed

in same orientation

Preferred Not preferred

Acceptable Not Recommended

Preferred Preferred

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.6.1 Connector Mating Forces and Allowable Mate and Un-mate Angles

Requirements DFM Impact/Benefit

 Figure 1 - When mating/un-mating connectors

where you rotate on connector width – max angle

is 8 degrees

 Prevents connector damage

 Figure 2 - When mating/un-mating connectors

where you rotate on connector length – max angle

is 4 degrees

 Prevents connector damage

 Blind mates should include standoffs or

mechanical alignment hardware (guide pin) to

assist. (See section 3.7 for details)

 Completes gross alignment allowing connector

housings to begin next level of align.

Expected Connector Mating and Un-Mating Forces

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.7 Mechanical Requirements

The NeXLev connector should NOT be used as the mechanical structure of two mated boards

within a system. Board assembly weight and shock and vibration forces should be supported by other

mechanical means such as standoffs or structural hardware.

The following describes minimum requirements for mechanical packaging.

Requirements DFM Impact/Benefit

 Provide sufficient hold down forces to retain mated

cards.

 Insure connectors stay mated during shipment,

vibration and other static and dynamic forces

 Standoffs between boards are required for all

applications.

 Rigid mechanical structures should be used for

heavier assemblies and/or higher stack heights. See

Maintain minimum wipe regardless of shock,

vibration and board warp tolerances.

 Support the mated boards and protect the BGA

solder joints.

 Minimizes mechanical stresses on the solder joints

 PCB holes for standoff fasteners must permit a true

position misalignment of .20mm and an angular

displacement of .05 degrees minimum (Board-to-

board fastening must comply to the connector

alignment)



Allows connector to act as the primary alignment

feature of mated boards

 Prevents stresses to connector and/or printed

circuit board

 Stand-off lengths should be 0.15mm greater than

nominal connector stack height – see below

 Minimize board or connector stresses.

 Stand-offs should be placed outside the connector

keep-out zones.



Allows for connector rework without having to

remove stand-offs

 Number of stand-offs and pattern of placement

should prevent all mechanical stresses to the solder

joint.



Insures no solder joint failures due to shock and

vibration.

Example:

Nominal Connector Stack Height = 15mm

Recommended standoff length = 15mm + 0.15mm = 15.15mm

15mm Plug

Receptacle

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.7.1 Suggested Mechanical Structure for Heavier Assemblies

Standoff weakness with greater weight and stack height

Preferred Rigid Mechanical Structure

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.8 Keep-out Zone and Clearances – Connector height < 10.5mm

The NeXLev connector keep-out zone is required for re-work capability. This allows clearance around

the connector housing for rework tooling and nozzles.

Requirements DFM Impact/Benefit

 The recommended minimum clearance required is

3mm – preferred clearance is 4mm to non-fragile

adjacent components.

 Rework nozzle - physical clearance

 It’s preferred to have 5mm clearance to adjacent

devices that are very fine pitch with small thermal

mass, and could re-reflow – this is dependent on

board thickness, copper weight and NeXLev height

 Prevents re-reflow of adjacent device, which

could cause shorts/defects on that device.

5mm Preferred clearance

to fragile devices

R

ewo

rk

No

zzl

e

Fragile Devices –

Micro BGA, CGA,

Leaded Fine Pitch, etc.

Bottom Side

Top Side

3mm Minimum - physical

clearance for rework nozzle

4mm Preferred clearance

to Non-fragile devices

Non-Fragile Devices –

Leaded - 50 mil pitch,

chips, etc.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

3.9 Keep-out Zone and Clearances – Multi Connector and Connector heights > 15.5mm

This NeXLev connector keep-out zone is required for re-work capability of taller devices with taller adjacent

components.

Requirements DFM Impact/Benefit

 Preferred to have 5mm clearance between

tall, > 15.5mm NeXLev connectors, or, to

other surrounding components of similar

height.

 Allow room/clearance for site cleaning and preparation,

and manual paste application using micro stencil.

 Prevents re-reflow of adjacent device, which could

cause shorts/defects on that device.

 Eliminates the need for reflow shielding of smaller

thermal mass components

5mm minimum preferred

clearance to fragile

devices

Fragile Device – Micro

BGA, CGA, Leaded

Fine Pitch, etc.

Bottom Side

Top Side

5mm Preferred clearance

between tall components

Tall adjacent

co

m

po

n

e

n

ts

DFM and SMT Assembly Guideline TB-2082

Revision “H“

4.0 Manufacturing Introduction – NeXLev Connector

The NeXLev connector is a wafer construction organized in a 10-row by up to 30 columns of

signal contacts, with each signal wafer having integral strip line shielding. This wafer construction

allows for the contacts to be spaced on a 1.5mm x 1.75mm grid. The connector can be specified in

separation heights ranging from 10mm to 30mm.

The connector is a completely SMT attach, utilizing ball grid technology for termination to the

board. Designed with solder joint reliability in mind, the connector has a mechanically compliant

structure and is readily applied using standard SMT processes. Standard versions of the NeXLev

connector contain either 10, 20 or 30 wafers. (100, 200 or 300 positions)

The connector is different than a standard BGA device, due to the compliant structure, which has

a 0.71 mm (28mil) solder ball, re-flowed on the end of a formed pedestal. There are two solder ball

alloys available – Tin/Lead (eutectic) or Lead Free (SAC305).

The compliant structure requires that the connectors be handled with more care than a standard BGA

device. The connector is not as fragile as a fine-pitch leaded device, but does require some of the pre-

cautions. Improper handling can bend the compliant lead and result in ball locations outside of true position

tolerances.

S-Bend

Compliant Lead

Ground Shield

One wafer contains 10 signal and 9 ground

balls and the connector is provided in 10,

20, and 30 wafer configurations.

Ball is attached to a

p

edestal at the end of

the “S-Bend”

Compliant Lead

DFM and SMT Assembly Guideline TB-2082

Revision “H“

4.1 Connector Inspection

NeXLev connectors are 100% laser inspected before leaving Amphenol TCS. Each ball is las er scanned

and checked for radial true position, co-planarity and minimum ball-to-ball spacing. This is done using an

automated 3-D laser inspection system.

Requirements DFM Impact/Benefit

 Visual inspection is not suggested.  Requires manual handling of part –

removal/replacement from JEDEC tray, if not done

carefully, can cause lead damage

 Visual inspection is inherently inaccurate due to the

subjective nature.

 Incapable of determining ball position accuracy to a

best-fit grid.

 Parts/JEDEC tray should be removed from

packing material and the JEDEC tray placed

directly onto the placement machine.

 Eliminates manual handling

Why is visual inspection inaccurate?

Example: Picture of a connector shown when you visually inspect the balls by

tipping the part at an angle – ball appears out of position.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

4.1 Connector Inspection – cont’d

This shows what the above connector looks like when looking straight at the ball field. If

the ball is compared to it’s neighbors, it appears to be out of spec.

However, when ball positions are accurately determined, and then compared to the best-

fit grid, the ball position is not out of spec. The ball position differences are split -

minimizing the variation.

* This is the ball that was visually determined to be a problem.

Note: This is a picture of the

connector placed on a glass

template using a best-fit

placement algorithm. The

black circles represent the

footprint pads.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

5.0 Connector Handling

The NeXLev connector is an assembly, with the solder balls attached to leaded pedestals, and is thus

more susceptible to handling damage than a standard BGA device.

Requirements DFM Impact/Benefit

 Connectors should be kept in the original

packaging until they’re used.

 Protects the ball field until it can be loaded into the

placement machine

 Once the assembly run is complete, tray should

be removed from machine, placed back into the

bottom pan, replace top cover, and Velcro strap

together – as shown below. (For more detail refer

to TB-2121)

 Protection of ball field.

 It is not necessary to bag and re-vacuum seal*

the tray, if the parts are used within a reasonable

time frame for eutectic solder balls – shelf life is

dependent on stockroom environmental

conditions.



NeXLev Connector materials are not moisture

sensitive, and do not require pre-bake.

 Place tray flat on rack for storage or transport –

don’t place on edge.



Prevents parts from moving out of tray slot, and

potentially bending leads, which support the solder

balls.

 SMT operators should minimize the handling of

the part that could cause bent leads, such as

moving parts around in the JEDEC tray,

removing from sticky tape during program

verification, placing the part on a workbench

with the ball field down, etc.



Minimizes bent leads, true position problems, and

post reflow shorting.

Partially loaded tray

Molded Top Cover

Bottom Pan and JEDEC Tray

Two Velcro straps

located as shown.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

6.0 Solder Paste Process

Requirements DFM Impact/Benefit

 Liquid Photo-Imageable (LPI) solder mask

over bare copper is preferred.



Most common – provides best adhesion for

solder mask - preventing peeling and flaking of

mask during assembly processes.

 Preferred to use a 6 mil stencil (Minimum

stencil thickness of 5 mil)*  Minimizes the risk of opens

 Recommended to use a 1:1 aperture - 0.024”

 Over pasting a 0.026-0.028” aperture can

also be used depending on the application

 This is application dependent – a good process

starting point is the 1:1 aperture.

*A 5 mil stencil thickness can be used, but requires either a .005”/inch board warp spec, or a .001” pad

co planarity spec on surface finish thickness variability. (HASL finishes can exceed this limitation.)

Board Warp Matrix - The following matrix defines the board warp spec required for each of the listed

variables – Stencil Thickness and Pad Finish Co-planarity

Pad Finish Co-planarity

<.001” <.002”

Stencil Thickness

and Paste Process

Variation

5 mil +2/-0 mil .007” .005”

5 mil +2/-.5 mil .005” Not Recommended

6 mil +2/-0 mils .007” .007”

6 mil +2/-.5 mil .007” .005”

DFM and SMT Assembly Guideline TB-2082

Revision “H“

7.0 Placement Process – (All connectors up to and including 10.5mm height)

This range of connector heights fall within the 0-1/2” range of focal length – most common placement

machine capabilities. (Note: if customers placement equipment standard height range is less than ½” – refer

to section below for more info.)

Requirements DFM Impact/Benefit

 “All-ball” field alignment is preferred



Most accurate placement

 Housing align, back-lit black-body align, or

mechanical align not recommended



Plastic housing to ball field tolerance stack-up will

result in less than optimal placement accuracy

 Full circular side lighting is preferred – see

below



Ability to most accurately find the ball, without

background lighting issues.

 Connector should be pre-oriented for machine

vision system alignment.



Prevents nozzle slip/skew, between camera and

placement, due to connector weight.

 Placement location/centroid of the part should

be based on the ball locations, and placed using

a best-fit alignment – see next page for best-fit

alignment detail



Minimizes the percentage of ball that is off-pad.

Side Lighting

- Not affected by background

- Found to be more accurate/robust

- Better suited for NeXLev

Sample image showing a portion

of one wafer

Lead Frame

Pedestal Knee

White shows reflection

back to the camera when

light is flashed on

Gray indicates no

reflection

Background, lead frame and

pedestal knee are washed

out

Crosshair is placed

where machine finds

ball center

*Note: Set-up should be verified for placement repeatability and accuracy.

Contact Am

p

henol TCS for information on verification tools.

Camera Resolution

- Less than 3 mil/pixel finer resolution

cameras are reco mmended to better

filter-out background issues

DFM and SMT Assembly Guideline TB-2082

Revision “H“

7.1 Placement Alignment – “Best-Fit”

Ball positional tolerances are greater for NeXLev than standard BGA devices, due to the wafer

construction and S-bend compliant design. This variation in ball location requires the use of a “best-fit”

placement algorithm to minimize the percentage of ball that is off-pad. See examples below for detail.

Fixed End Row

This is an example of the same

part with a placement that uses

only the first row of balls to

determine placement location.

First row of balls are centered.

Shorting risk is high on signal balls

Solder Ball

Board Pa

d

“Best-Fit”

This is an example of a

placement where the overall

resulting solder ball alignment

variation is minimized using a

best-fit placement.

The bes

t

-fit

p

lacement s

p

lits the difference

The worse case solder balls are less than 25% off pad.

Placement Comparison

DFM and SMT Assembly Guideline TB-2082

Revision “H“

7.2 Placement Process – 15.5 and 23.5mm Receptacles*

These connector heights exceed the 1/2” maximum height for most common placement machines, and

have the same requirements as the 0-1/2” range with the following added restrictions.

Requirements DFM Impact/Benefit

 Shortened “custom” nozzle may be required.

(Refer to placement machine specs for more

info)



Part can be presented within the camera’s focal

plane, avoid part interferences with machine

conveyor, board sensors, and placement head

hardware

 Specific placement order and connector location

on board assembly may be required.



Avoid interference of previously placed part, as the

placement head moves across the board to place a

second part.

 Large bore nozzle is required for maximum

vacuum force – placements should be verified to

insure correct nozzle selection.

 Prevents nozzle slip/skew, between camera and

placement, due to connector weight.

 Connector should be pre-oriented for machine

vision system alignment.

*Contact Amphenol TCS for more

detailed SMT application instructions on

taller NeXLev connectors

DFM and SMT Assembly Guideline TB-2082

Revision “H“

7.3 Placement Process – Feeders

Requirements DFM Impact/Benefit

 Connectors are shipped in standard JEDEC

outline trays and are equipped with a cap that

provides a flat vacuum surface – see below and

next page.



Meets the requirements of industry standard

placement equipment

 The caps can be removed by hand after reflow



See reflow process section for more info

 There are six different tray sizes –

(3) Plug: 10, 20 and 30 wafer lengths.

(3) Receptacle: 10, 20 and 30 wafer lengths.



The only size variation in the trays are slots that

hold the connector. Overall tray length and width

are standard. See next page.

 Trays should be loaded into machine with the

“tray-notch” in the upper left hand corner - for

both the plug and receptacles. See diagram next

page.



Allows for part set-up standardization across the

product line.

 Consistent loading of all parts minimizes the risk of

reversed loading of the tray into the placement

machine.

 Plug trays are blue, Receptacle trays are black



Minimizes the risk of reversed loading of the part

into the tray.

 Minimizes the risk of putting the wrong part in the

wrong tray.

Plug

Vacuum Ca

p

Receptacle

Vacuum Ca

p

Plu

g

Rece

p

tacle

DFM and SMT Assembly Guideline TB-2082

Revision “H“

7.4 Placement Process - JEDEC Tray Set-up

Dimension “A” Dimension “B” "C" Dimension “Z”* Tray Part #

471-1025-100 23.63 29.75 9 14.95 801-2225-000

471-2025-100 30.53 50.75 5 14.95 801-2226-000

471-3025-100 35.30 61.10 4 14.95 801-2227-000

471-1045-100 23.63 29.75 9 16.95 801-2225-000

471-2045-100 30.53 50.75 5 16.95 801-2226-000

471-3045-100 35.30 61.10 4 16.95 801-2227-000

471-1065-100 23.63 29.75 9 18.95 801-2225-000

471-2065-100 30.53 50.75 5 18.95 801-2226-000

471-3065-100 35.30 61.10 4 18.95 801-2227-000

470-1075-100 23.63 29.75 9 13.95 801-2228-000

470-2075-100 30.53 50.75 5 13.95 801-2229-000

470-3075-100 35.30 61.10 4 13.95 801-2230-000

470-1105-100 23.63 29.75 9 16.95 801-2228-000

470-2105-100 30.53 50.75 5 16.95 801-2229-000

470-3105-100 35.30 61.10 4 16.95 801-2230-000

470-1155-100 23.63 29.75 9 21.95 801-2228-000

470-2155-100 30.53 50.75 5 21.95 801-2229-000

470-2155-100 35.30 61.10 4 21.95 801-2230-000

470-1235-100 23.63 29.75 9 29.95 801-2228-000

470-2235-100 30.53 50.75 5 29.95 801-2229-000

470-3235-100 35.30 61.10 4 29.95 801-2230-000

* “Z” is the height from the bottom of the tray to the top of the vacuum “pick-up” cap

Into Placement Machine

Tray Notch

JEDEC Tray With 30-Wafer Connectors – shown for referenc e

(Dimensions are in mm)

(3X) 28.00

25.95

“A” “B” “C” = # of “B” spaces

135.90

315.00

(3.8)

DFM and SMT Assembly Guideline TB-2082

Revision “H“

8.0 Reflow Process

Requirements DFM Impact/Benefit

 To determine correct oven settings, follow

standard reflow profile processes for set-up and

placement of thermal probes.

 Insure even heat distribution across the part.

 Locate one thermal probe on top of the

connector housing during reflow profiling – It is

preferred to keep the plastic below 260C with a

max allowable temperature of 280C.

 Insures against plastic over-heating and damage.

 Locate at least (2) thermal probes – one on an

outer ball, and one on an inner ball – may

require drilling through the board

 Insures balanced reflow profile definition for all

of the solder joints.

 Set process to the solder paste vendor’s

recommended profile.

 This varies by the chemical make-up of each

solder paste, and also varies from one paste

vendor to the next.

 After first-side reflow process, inspect connector

to insure that housing is seated to the board

surface – see below.

 This insures good reflow and balls have

completely collapsed. Unseated connectors are

due to improperly reflowed balls, and could result

in long-term reliability failures.

Note: NeXLev plugs are more commonly profiled incorrectly. The housing is open, and the plug wafer

construction transfers heat more readily than the receptacle. The plug ball-field can get to reflow

temperatures much quicker than the board. This thermal differential may require the lower oven heaters

to be set hotter than the upper heaters, providing thermal balance between the board and connector.

PCB

Connector housing is

seated to PCB

NeXLev Assembled to PCB After First Reflow

Locate one thermal probe

on housing Locate one thermal probe

on outer ball

Locate one thermal probe on inner ball

(Primarily required for larger receptacle connectors

and may require drilling through board)

DFM and SMT Assembly Guideline TB-2082

Revision “H“

8.1 Reflow Process – Reflow Profile Recommendations

Requirements DFM Impact/Benefit

 Set process to the solder paste supplier’s

recommended profile.

 This varies by supplier and specific flux

chemistry

 Recommend using a Soak Profile over a straight

ramp to peak.

The soak time and temperature is defined by

the paste manufacturer based on optimal flux

chemistry activation temperatures.

 Minimizes void formation and risk of pillow head

defects

 Minimizes delta T’s across thermally heavier

parts

Note: Melting Points of the NeXLev Solder Balls are:

Tin/Lead - 183ºC

SAC305 - 217ºC

DFM and SMT Assembly Guideline TB-2082

Revision “H“

8.2 Reflow Process – Detailed Verification and De-bug

Below is the recommended method for process debug or 100% verification of process set-up and

establishing the best profile. (This method is destructive and requires the use of a solder sample)

 Inspect connector to insure that the housing has completely settled to the board surface

 Pry the housing from the board surface using a sharp edge - wedged between the housing and board

surface – pry the ends only. Insure wedge doesn’t go too deep and catch a wafer.

 Housing will break away from wafers at heat-staked joint.

Pry Points

Pry Point

 Lift housing off wafers parallel

to the board surface



Spread wafers to reveal ball field

 Solder joints are

exposed to allow

100% visual

inspection

DFM and SMT Assembly Guideline TB-2082

Revision “H“

8.3 Reflow Process – Vacuum “Pick-up” Cap Removal

Requirements DFM Impact/Benefit

 Post reflow vacuum cap removal  Vacuum cap can be removed after reflow/inspection.

(Note: A new vacuum cap is required for connector

rework)

 Remove cap as shown in Figure 1 for the

Plug, and Figure 2 for the receptacle.

 By pulling the cap straight up from the connector, the

housing shell could be damaged, and separate from the

wafers

1. Push cap to one side

2. Peel cap away, by rotating up.

1

Figure 2

Receptacle

2

1

2

CAUTION: Failure to follow proper vacuum cap removal for the plug could result in damaged housing.

Figure 1

Plug

1. Push cap to one side, this will

disengage the cap from the

housin

g

on one side

2. With one side of the cap disengaged lift the cap and rotate off

1

2

1

2

DFM and SMT Assembly Guideline TB-2082

Revision “H“

9.0 Double Sided Reflow Process

Because of the surface tension forces created by a NeXLev solder joint, the majority of connector sizes

can run upside down in a double sided reflow process.

Requirements DFM Impact/Benefit

 The majority of the connectors can run upside

down in a double-sided reflow process.

 Surface tension forces of the solder joint are greater

than the weight/ball forces.

 Preferred to run the heavier* NexLev

connectors through the 2nd pass of a double-

sided reflow process.

 Prevents the need to run heavier devices through

reflow upside down – minimizing the risk of the

connector falling off or sagging away from the

board.

 Before running connectors upside down,

inspect connector to insure that housing is

seated to the board surface – see Reflow

Process section for more info.

 Improperly seated connectors indicate incorrect

reflow and possible cold and/or insufficient solder

joints, therefore reducing the surface tension forces

required to hold the part on the board.

* Refer to Addendum “A” for more detailed information on weight/ball by part number. All connector

sizes up to, and including 10.5 mm tall, should not be an issue. However, because every assembly

process is not the same, the customer should verify this in their proces s. The 15.5 and 23.5 mm

receptacles will require specific testing for each process and design application, because the

weight/ball is above the allowable limits of calculated surface tension forces.

Note: The final decision to run NexLev connectors upside down without any secondary method of

retention, is with the customer. For more information on possible methods of retention – contact

Amphenol TCS.

DFM and SMT Assembly Guideline TB-2082

Revision “H“

10.0 Rework Process

The rework of a NeXLev connector, for solder shorts and opens, requires that the connector be

completely removed and replaced with a new connector.

Requirements DFM Impact/Benefit

 Use specialized BGA rework equipment for connector

removal and replacement, and should include thermal

profiling and temperature measurement capability.

 Achieves an all-ball reflow at point of removal

without excessive heat to t he connector an d PCB, or

insufficient heat causing lifted pads.

 Locate one thermal probe on top of the connector

housing during reflow profiling – It is preferred to keep

the plastic below 260C with a max allowable

temperature of 280C.

 Insures against plastic over-heating and damage.

(See reflow section for m ore detail.)

 Placement location/centroid of the part should be based

on the ball locations, and placed using a best-fit

alignment – see next page for best-fit alignment detail



Minimizes the percentage of ball that is off-pad.

 Semi-Automated placem ent capability is preferred –

including vacuum pick-up and placement.

 This will provide consistent place ments.

 Split Vision alignment systems are required to allow a

ball-field best-fit alignment to PCB footprint.

 Allows blind alignment of ball to pad - minimizing

placement error.

 Hand/Manual placement is not recommended.  Manual placement is inconsistent, and blind/housing

align does not provide the required placement

accuracy.

 Using custom NeXLev nozzles is preferred for the

taller receptacles (15.5 and 23.5 mm)

 Because of the higher thermal masses, more

consistent/even heat distribution is required.

 Follow normal rework processes for PCB site cleaning

and prep, and reflow profile development.

 Improves rework yield and insures reliable solder

joints

 “Flux-only” processing is not recommended.  Inconsistent amount of metal left on pad during site

prep, resulting in excessive pad co-planarity

variation – increased risk of solder opens.

 Paste deposition is recommended using either an

automated dispensing system or manual micro stencils

– resulting in a 6 mil tall x 21 mil diameter deposit.

 Prevents opens/shorts with high reliability solder

joints.

 Re-balling of NeXLev connectors is not recommended.  Re-balling processes not available for NeXLev.

The most popular rework systems, which have NeXLev custom nozzles, and have also developed a

full process for all the different sizes, include Air-Vac and VJ Electronix. For more info go to the

following Web Sites:

Air-Vac http://www.air-vac-eng.com/nozzleconnector.htm

VJ Electronix http://vjelectronix.com/index.html

DFM and SMT Assembly Guideline TB-2082

Revision “H“

Addendum “A”

NeXLev Connector Weights

TCS p/n Description

# of

solder

balls

Weight,

without cap

(grams)

Weight/ball,

without cap

(grams)

Weight,

with cap

(grams)

Weight/ball

with cap

(grams)

4701075100 7,5mm NeXLev RCPT, 100 posn 190 4.0 0.0211 4.6 0.0242

4701105100 10,5mm NeXLev RCPT, 100 posn 190 6.0 0.0316 6.6 0.0347

4701155100 15,5mm NeXLev RCPT, 100 posn 190 8.0 0.0421 8.6 0.0453

4701235100 23,5mm NeXLev RCPT, 100 posn 190 12.0 0.0632 12.6 0.0663

4702075100 7,5mm NeXLev RCPT, 200 posn 380 6.0 0.0158 6.6 0.0174

4702105100 10,5mm NeXLev RCPT, 200 posn 380 10.0 0.0263 10.6 0.0279

4702155100 15,5mm NeXLev RCPT, 200 posn 380 14.0 0.0368 14.6 0.0384

4702235100 23,5mm NeXLev RCPT, 200 posn 380 23.1 0.0608 23.7 0.0624

4703075100 7,5mm NeXLev RCPT, 300 posn 570 8.0 0.0140 8.6 0.0151

4703105100 10,5mm NeXLev RCPT, 300 posn 570 13.1 0.0230 13.7 0.0240

4703155100 15,5mm NeXLev RCPT, 300 posn 570 21.0 0.0368 21.6 0.0379

4703235100 23,5mm NeXLev RCPT, 300 posn 570 33.7 0.0591 34.3 0.0602

4711025100 2,5mm NeXLev PLUG, 100 posn 190 4.0 0.0211 4.6 0.0242

4711045100 4,5mm NeXLev PLUG, 100 posn 190 4.5 0.0237 5.1 0.0268

4711065100 6,5mm NeXLev PLUG, 100 posn 190 6.0 0.0316 6.6 0.0347

4712025100 2,5mm NeXLev PLUG, 200 posn 380 6.0 0.0158 6.6 0.0174

4712045100 4,5mm NeXLev PLUG, 200 posn 380 8.3 0.0218 8.9 0.0234

4712065100 6,5mm NeXLev PLUG, 200 posn 380 10.0 0.0263 10.6 0.0279

4713025100 2,5mm NeXLev PLUG, 300 posn 570 8.0 0.0140 8.6 0.0151

4713045100 4,5mm NeXLev PLUG, 300 posn 570 12.2 0.0214 12.8 0.0225

4713065100 6,5mm NeXLev PLUG, 300 posn 570 16.0 0.0281 16.6 0.0291

Note: cap refers to vacuum pickup cap

DFM and SMT Assembly Guideline TB-2082

Revision “H“

Addendum “B”: DFM and Assembly Readiness Check Sheet

Item Sect Check Change/Comments Wh o Status

PCB

Design 3.1  Copper defined .60mm (024”) pad – clear of solder mask

3.2  Mi nimum .22mm (.009”) Solder Mask dam to Via, or via

masking

3.3/6.0  Specify board warp spec per process variables

3.4/ 3.5  Multi connector ori entati on is the sam e

 Long side of connector is parallel across the larger spans

 Layout includes sli ghtly oversized silkscreen outline of

connector.

Inspection 4.1  Ma nual component inspecti on not recommended

Handling 4.0/

5.0

 Removal/replacement from JEDEC tray is not

recommended – minimize manual handling

 Handling process should include re-packaging and

handling pre-cautions.

Solder

Paste 6.0  Stencil thickness is 6 mils – 5-mil thickness is acceptable.

 Stencil aperture should be 21 mils

Placement 7.0  Set-up should include ball-field align, full circular side

lighting, and pre-orient align.

7.1  Best-Fit placement is required

7.2  Custom programming and nozzles may be required for

the taller connectors.

Reflow 8.0

 Follow solder paste manufacturer’s recommended

profile.

 When profiling, include thermal probe attachment to the

top of housing, to insure against p lastic over-heating.

8.1  Insure the reflow profile includes a soak zone.

8.3  Follow recommended process for vacuum cap removal.

Double

Sided

Reflow

9.0  All connect ors up to and including 10.5mm tall, may

require verification in specific process.

 15.5 and 23.5 will require verification in process.

Rework 10.0

 When profiling, include thermal probe attachment to

the top of housing, to insure against plastic over-

heating.

 Placement with ball-field align and best-fit

 Manual placement not recom mended

 Use custom dedicated nozzles for the taller connectors.

 Paste deposition should be 5-6 mils high and 24 mil

diameter

 “Flux-only” processing not recommended