Automated Depanelling Technology

• Why Depanel Automatically• Process Parameters and Control• Machine types, Technologies and

System overview.

Why is Automated Depanelling Important• When a circuit Board is singulated – removed from its frame or matrix panel - it

will be subject to mechanical forces induced by the tool used to break the tab.• The systems employed vary but include:

• Hand breaking• Pizza Cutter [opposing rotating discs – don’t cut they tear]• Shear• Punch• Router or Saw

• Today lead free alloys compound the issue and challenges of limiting the mechanical stress due to being less ductile and malleable. This makes them more prone to micro cracks.

• The cost to repair a soldered PCB is considered to be 10X that of a non soldered PCB. Choosing the right tool to accurately remove the Circuit while protecting the value added investment of parts and process cost down stream is critical.

Why is Automated Depanelling Important

Life Failures• The most insidious types of failures, and the hardest to predict. Most

expensive to rectify• Often a result of a partial mechanical failure resulting in total failure after

environmental exposure

Causes• Poor process• PCB layout• Singulation methodology

Cure• Minimize the mechanical stress exerted on the board throughout the

assembly process particularly after the soldering process has been completed.

Cutting & Breaking.

Generally accepted lim

its for strain in singulation

Cutting and breaking PCBs, Shears and Pizza style devices will exert considerable more strain than Routing or Sawing. Often 10X the recommended levels.

Board stress analysis

Stress from PunchingPunching of 3 tabs Peak Stress points – 5x recommended

Board stress analysis

Stress from RoutingRouter diameter: Ø1,5mm Speed: 42000 rpm Feed: 50mm/ sec

Board stress analysis

Stress from SawingDisk thickness: 0,7mm Diameter: 75mm Speed: 12000rpm Feed: 3 m/min

Stress “Free” separation

• Stress incurred from Punching or manual breaking >2500µm/m

• Stress incurred from routing <150µm/m

What if – The V score is too shallow

The Natural tendency to “Work” the board until it breaks results in multiple levels of strain being exerted for extended periods. In this instance 5.5 seconds before the circuit separates from its surrounding material.

SMD Placement Break out

Bare PCB Fully assembled PCB

Print Reflow Test

Value Aggregation& the potential for loss

Relative REWORK costs through the

Process

Choice of an appropriate depanelling system insures the value

invested in building the PCB

Machine Design

Stand-Alone Machine Outline Single and dual-pallet systems available High speed, air cooled spindle

Optional dual cutting heads for maximum throughput reduces cycle time by more than 50%

Multiple fixture options: Universal Fixtures for Proto and low volume runs. Rigid, dedicated pin fixtures for production use Vacuum Fixtures for Flex circuits Single and multi-up board designs on the same pallet Independent fixtures per table Concurrent processing maximizing throughput

Panel sizes: Min: 51 mm x 51 mm (2” x 2”) Max: 500 mm x 650 mm (20.50” x 25.6”)

Machine Design

In-Line Machine Outline Single and Dual Table Systems Patented dual-pallet shuttle Full Robotic [X,Y,Z offload per part] or

simpler gang pick and place. Routing and Saw configurations Panel sizes:

2” x 2” (51mm x 51mm) to 13.7” x 12.2” (350mm x 310mm)

Pre-routed or solid panels Integration with Test systems prior to

determine good and bad boards for sorting at offload.

• Getech Gantry Design has the Y1 Y2 & X axis working independently.• This will eliminate the possibility of deflection during cutting, especially for

big PCB panel• This kind of Cartesian robot design is commonly used in the CNC lathe

machines. It can support heavy cutting force and high speed positioning.• Very stable CPK with high cutting tolerance. [Cpk 1.66]• However the costs for this design are high.

Getech Gantry Design

Router Technology - Summary

Advantages Stress “Free” High flexibility Smooth edge quality, dimensional stability Controlled process High through-put Accommodates a wide range of panel

layout configurations Servo driven system maintains a high

degree of accuracy Multiple solutions for in-line and stand

alone processing On-board vacuum systems to clean

resulting debris

Saw Technology - Summary

Advantages High Speed Long cuts without the need for Pre-Routes Smooth edge quality, dimensional stability Controlled process Very High through-put Alternative to V Score and break out

methods Only able to accommodate straight cuts Servo driven system maintains a high

degree of accuracy In-line and stand alone processing On-board vacuum systems to clean

resulting debris

Machine Platforms

ESR

GSR

GSR 22

IRM

GAR

RBM

GSS

IDM

Standalone Routing In-Line Routing Singulation by Saw

Depanelling Process Control

The depanelling process is dependant upon the following factors:

Machine Gantry and Control: Specification and mechanical stiffness. Motion control and capability to program non linear cuts. Software system that can integrate tool wear with process needs. Alignment options.

Fixtures/Tooling: Consistent PCB location is 50% of the Process and needs to adhere to parameters of positional

repeatability without drift – panel to panel. Ease of use in operation and at changeover.

Cleanliness: Depanelling creates abrasive p[articles which can be harmful to machinery and people. Vacuum systems must be able to capture and filter debris insuring a clean product, work environment and

machine moving members. Tool selection and Feed rates:

The right tool and the correct RPM and linear feed rate will play a significant role in cut quality and dimensional stability.

Process Control

Mechanical Design – Vibration and PositioningGuide A

Guide B

Air Cylinder

Poor Overall Control. Poor positional accuracy and weak positional strength.

TABLE

Ball ScrewAC Servo

Poor Torsional Control. Induces a Yawing moment when accelerating the table.

TABLEAC Servo

Great Overall Control. Zero Yaw in drive system and zero rotation on table, maximum positional accuracy.

• Vibration will occur as a result of both poor fixturing and machine instability.

• Machine instability can only be alleviated by the appropriate mechanical design and use of closed loop servo control.

Guide A

Guide B

Guide A

Guide B

TABLE

Table

BOSCH Module

TABLEMotor

Hardened Linear Bearing slides

nut system

nut system

Mechanical Design – GETECH Table Design

Compact Modules

The ready-to-install Compact Modules from B0SCH1. Fully enclosed – free from dust2. Bosch factory aligned ball screw and linear bushings

and shafts 3. High load capacities and rigidities.

• Getech Gantry Design has the Y1 Y2 & X axis working independently.• This will eliminate the possibility of deflection during cutting, especially for

big PCB panel• This kind of Cartesian robot design is commonly used in the CNC lathe

machine. It can support heavy cutting force over time• Very stable CPK with high cutting tolerance.• However the costs for this design are high.

Getech Gantry Design

Air Cylinder

Table Positioned by Air Cylinder

Cutting of PCB creates a Lateral Load on the PCB AND the Table

Lateral Load creates deflection in Table position

Pneumatic Gantry Design issues

Air Cylinder

Table Positioned by Air Cylinder

When Cutting tool moves in Z axis to transition to next tab, Lateral load is released.

When Lateral Load is released. Table Springs back to initial position. System has very poor positional accuracy.

Pneumatic Gantry Design issues

Fixture Design

Poor Fixture design can result in beveled edges, undercut or oversized tab stubs.

• Beveled Edges result from PCB lift

Lift

Hei

ght

PCB Thickness

Resulting Bevel Edge

PCB edge Undercut due to poor lateral stability of the fixture/PCB locations

Poor location results in undercut or oversized tab

Dimensional difference due to panel deflection

• PCB Undercut and Oversized Tab Remnants

Fixture Design

Machine Table

Tall

com

pnen

ts to

75M

M

Tapered Pins Provide secure location and ease of load/unload

Top plate with SSD compliant foam holds PCB firmly on the pins

Clearance slots in the top plate allow the router tool to pass.

Fixture Design

PCB Board

Open catchTop clamp

Top Plate latches in position to secure the PCB on the fixture.

Resulting in:• Dimensional Accuracy and repeatability.• Very low vibration and stress on PCB• Faster Cycle times.• Cleaner edge quality

Dedicated Fixtures allows for a consistently higher Cpk value

• Facilitates a more efficient and reliable means of loading and unloading

• Substantially reducing the risk of damage to the PCBs.

• Higher yields

• Down cut generally gives better finish but secure tooling and fixtures are required

Down cutUp cut

Clockwise rotation

Up cut vs. down cut programming.

Vacuum Adequate vacuum strength is critical to routing performance

Vacuum blower is designed into the machine to reduce Noise and footprint

Getech vacuum consists: 2 x 5hp blowers. 3-stage filtration system capable of meeting class 100 clean room demands Includes filter and micro-filter to evacuate dust particulates up to 3 microns

Ionizers for improved fine dust control

Debris formation and tool breakage are significantly improved by adequate vacuum

Pre-routed vacuum slots should be used to assist in air flow and debris removal

Fixture Design should allow Adequate air flow through the Fixture

Ionizers can be deployed to improve

fine dust control

Vacuum Layout

External vacuum tanks for easy maintenance

3 stage dust filtration• 1st Disposable bag

(20 micron)• 2nd. Dacron filter• 3rd. Poly Filter

Vacuum Drawn at cutter - source of dust

2x Vacuum pump inside machine to shield noise

Pressure Foot Brush condition can also significantly affect vacuum

• Pressure foot brushes should be inspected daily

Good WORN BRUSH

Vacuum - Pressure foot

Bad

Managing ESD

Metal Bearing

Static Dissipative Brush

Earth

EarthOhmR

Current (I) = Voltage (V)/ Resistance (R)

The Spindle is running at a very high speed. At time the shaft is floating. Having no contact with the metal bearings, to ground.

ESD

ESD generated during routing

Gradual discharge of ESD 1000 volt

Vacu

um

du

st I

nle

t

EOS is caused by an unusual spike in voltage applied to the system that causes damage at the component or board level, rendering system or component failure. The event usually lasts from microseconds to seconds (short pulses range in the nanoseconds). EOS damage is typically not visible because the damage is at the transistor level.

Signs of EOS include: 1.Blown metal line – Thermal Damage 2.Molten damage – High Power Consumption 3.Electrostatic Discharge (ESD) is a subset of EOS. 4.The event occurs within pico to nanoseconds and is usually caused by human contact. The

impact is similar with blown metal lines.

What is electrical overstress (EOS)?

Types of Anti-Static Brushes:

1.Conductive brushes are used for applications where it is necessary to reduce the static charge to 0v because even a small charge obstructs the operation and the medium being discharged is not sensitive to high current flow.

2.Static Dissipative brushes are used for applications where high current flow would be damaging to the product being discharged. Static dissipative brushes introduce a high resistance [R] between the charged surface and ground thereby reducing the current flow proportionally.

PCBA

EARTH

Resistor

What is electrical overstress (EOS)?

Machine Standard Features

Vision System and software interfaceProgrammingSoftware optionsVacuum and dust management

Vision System

Standard vision system. All machines supplied with an analogue CCD video camera,

calibrated to the manipulator and mounted on the x-axis of the system.

Optional vision system. Advance vision system for capturing PCB Fiducial locations.

(Provides means of automatically compensating for misalignment that may result from inconsistencies in board).

Step and repeat programming from 3 points.

Vision System

Windows-based Software

Windows based interface software is user-friendly and intuitive for diagnostics and programming

Multiple security level settings – from operator to maintenance to engineering

Helpful operator prompts and notifications: Tool bit diameter optimization to increase tool life

Tool break notification

Pre-set filter change intervals

Rapid video-aided programming with onboard camera Program verification using camera to validate cut tolerance

Automated teach mode using known positions Step and repeat programming feature cuts programming time

significantly no matter how complex the assemblies

Tool control features in Software

• Cutting tool management• Tool wear compensation• Tool life monitoring• Programmable Z travel

( Allowing full use of tool length) • Tool break detection

Programming

Straight line and interpolation capabilities Jog and teach programming Live visual programming of tool path programs: no scrap while setting up Utilizes same concept as “G code” programming tool to edge of work piece Comprehensive editing / copying facilities Fiducial capability linked to step and repeat offset programming. Matrix Programming

Useful when routing panels containing a large number of duplicated PCBs in rows/columns Used in conjunction with either or both the “Manual Transformation ” and “Table Program”

Transformation Programming Useful tool when universal fixtures are utilized for securing the panel The <Product> is programmed with 2 known reference points on the panel using fiducials.

Software Options

Matrix Programming• Useful when routing panels containing a large number of duplicated

PCBs in rows/columns• Used in conjunction with either or both the “Manual Transformation

” and “Table Program”

Software Options

Fiducial Recognition The router will automatically align every panel to 2+ fiducial points prior to

cutting

Software Options

Bar Code Software 1D and 2D barcodes can be utilized. The barcode reader in the machine is controlled by the GSR

software Reading a code creates a link to an external server for

instructions or simple data recording.

Typical commands may include whether to rout the segments or have an error to prompt on the screen.

Tool Life Optimization• Preferable cutter depth of 0.8 to 1.5 mm during routing

• Full length of the tool can be used by incrementing Z-axis• 5 steps down, 5 up and repeat. ! Increment per finished Panel. • Increment programmable >= 0.5mm

• Tool compensation feature will verify tool diameter wear or to make global offset to a routing program

• Z-offsets can be programmed to rout a board with different routing heights

0.8

to 1

.5m

m

PCB 1 PCB 2 PCB 3 PCB 4 PCB 5

Parameters are highly dependent on product type and customer quality requirements. Data analysis should be performed at customer site to determine ideal parameters.

Tool Diameter (mm)

Plunge Rate (mm/sec)

Spindle Speed (KRPM)

Typical Feed (mm/sec)

0.80 300- 500 61-73 20

1.00 300- 500 48-57 23

1.60 300- 500 30-37 63

1.80 500 27-33 67

2.00 500 24-29 67

2.40 500 20-24 84

2.50 500 19-23 84

Router Bit Parameters

Stand Alone vs.

In-Line

Considerations

PCB Size and thickness Post process handling needs Work flow in the factory Budget Test sequence pre depanelling and Sorting post depanelling.

In-Line Machine Features

• Manipulators• Input shuttle• Post route board handler [X,Y Z]• Controller• Auto tool change system• Tool optimization and compensation• High Power Spindle• Vision system• High Precision Servo Control

In-Line Routing Process – Twin Table Machine

• Routing starts when the input shuttle receives a panel. The shuttle loads the free work station with the panel, and routing commences.

• While the first panel is being routed, the shuttle loads the second work station, which then stands by waiting for the first to complete.

• When the first station has completed, the board handler picks up the separated PCB’s and places them onto the conveyor, or onto the customers interfaced utility

Getech direct contacts

Asia Address

201, Woodlands Ave 9, #05-50, Spectrum 2, Singapore 738955

Sales & Marketing: +65 6756 9722/3Email: sales@getecha.com General Enquiry: +65 6756 0777Fax: +65 6756 0770

America’s & Europe • Address

• 320 East Vine Dr. Fort Collins, Colorado, 80524, USA

• Sales & Marketing: +1 970 412 6759Email: allen_d@getechsys.com

Local Agents details may be found athttp://www.getecha.com/contact-main.html