XT5P IR RReworrk SStation

www.pdr.co.uk

Operratorrs MManual

Worldwide Technical Support

This product was manufactured by PDR, UK and is supplied by a worldwide network of professional distributors whoprovide a full range of sales, local service and support services.

For latest information on Technical Support, new products, upgrades or who to call for assistance in USA,Europe or Asia. contact us at

PDREmail: support@pdr.co.ukWebsite: www.pdr.co.ukPhone: +44 1293 846000Fax: +44 1293 613600

Introduction

This manual is structured to enable a technician with no previous knowledge of the system to become familiar withthe operation and maintenance of the equipment. It contains a technical description to enable the reader tounderstand the design features of the equipment. The safety section of the manual explains the inherent dangerspresented by any type of desoldering/soldering equipment, and warnings to minimise the risk of injury throughignorance.

TerminologyThe following lists terms and abbreviations used in this manual, which may need explanation:

Term ExplanationAC Alternating current as found in mains suppliesIR Infra-redLow Voltage Voltage below 24 voltsPCB Printed circuit boardRF Radio FrequencySMT Surface Mount TechnologySMD Surface Mount Device

Safety

Health and Safety at WorkThe attention of users in the UK is drawn to the requirements of the Health and Safety at Work Act. Users in othercountries should familiarise themselves with the requirements of local health and safety legislation.

Warnings and CautionsFor the purposes of this manual a warning refers to a danger of injury to the operator whereas a caution refers to adanger of damage to the equipment. The warnings and cautions detailed below are basic safety requirements andare intended to ensure operator awareness of the dangers of the equipment.

Warnings1) Do not allow the Infra-Red spot from the lens unit (either directly or via mirror) to come into contact with the eyesas serious eye damage may occur.

2) Do not allow the Infra-Red spot from the lens unit to contact exposed skin other than for a very short period, sincetissue damage may result.

3) Do not place parts of the body near the bottom of the lamp or near the back heater, since there is a risk of burningor tissue damage.

4) When placing work under the lens, ensure the Infra-Red spot is switched off, to prevent unwanted localisedheating.

5) Death or serious injury may result from electric shock. It is therefore essential to isolatethe equipment from the mains before commencing repairs.

6) To eliminate the possibility of burns, allow time for the equipment to cool before commencing maintenance.

Cautions1) Damage due to overheating may result from the equipment being left in any state other than idling or shutdown forany period when the equipment is not in continuous use.

2) To eliminate the possibility of accidental operation of the footswitch ensure that it is located in a position wherenothing can rest or fall on it.

3) When using any selected lens attachment ensure that the minimum spot size used conforms to that stated in therelevant text. Failure to comply with this instruction may result in damage to the iris.

4) Do not allow the spillage of any liquid to fall on the ceramic emitter (back heater) as damage may result.

5) Due to the use of glass optical components the lens unit and all lens attachments should be handled with care.

PDR Focused IR Safety StatementExtensive tests have been conducted covering both Electrical and Infra-Red safety aspects on all of PDR's products.

The tests were administered by a National Physical Laboratory approved establishment: ERA based atLeatherhead, Surrey, England.

OpticalThe Infra-Red system was tested for its maximum emission produced during working operation and the followingresults obtained:

1. On a non reflective surface, i.e. FR4 substrate, if one's eye is placed 150mm away looking down at an angle onecould be subjected to approximately 0.9mW/cm2 at full power.

2. On a reflective surface, i.e. polished aluminium at a normal distance of 300mm, one would be subjected toapproximately 0.9mW/cm2.

ElectricalThe equipment is operator safe, tested for electrical safety in all aspects and complies with the relevant Europeanregulations.

XT5P Configuration and Installation

The XT5P was introduced early 2008 and has been developed to be able to be upgraded from a basic systemwithout BGA alignment to the full system as seen below.

Basic Features include: Focused IR Component Heating, Non-contact IR Temperature Sensor, Precision Pick-upwith Micro-rotation/Micro Z-movement, 1200W IR PCB Preheater, PDR T5 PC Controlled Controller withThermoActive V4 Software Control.

Optional Advanced Features: CCTV/Prism Based BGA Alignment System.

Installation

The XT5P should be installed by personel trained by PDR, or by a PDR Distributor. The systems are robust andforgiving but installing them incorrectly can result in loss of performance and dissatisfaction with the product.

The equipment must be sited on a firm surface at least 1.5m x 0.75m and at a height to suit the operator. Thelocation should be chosen to suit the flow of work.

Place the controller and PC monitor on the right of the main system (the T5 PC controlled controller should go to theback-right of the XT5P) and the CCTV monitor on the left.

The immediate areas must be free from draughts (airconditioning draughts are often a problem) that may reduce theheating efficiency. The lighting should not be so bright as to prevent the operator from viewing the I.R. spot or thedigital controller's L.E.D. displays. A mains electricity supply, free from R.F. interference, other noise, glitches etc.must be readily available.

Focused IR Component Heating

IR temperature Sensor

PC Control

CCTV/Split-beam PrismBGA Alignment System

IR PCB Preheater1600W X/Y Table

ComponentPick-up

Controller

Principle of Operation

OverviewThe principle of operation of the XT5P Infra-Red rework unit is that whilst being heated from above and below, asingle SMD is subjected to similar temperature/time profile during rework, as it experiences during reflow in theoriginal production process.

Temperature ProfileIn operation the component is put through a full reflow procedure. The XT5P Basic system uses a softwarecontrolled system 5-stage process including 2 preheat stages, a soak zone, followed by reflow and final soak stages.All parameters such as temperature levels and ramp rates are precisely controllable, as recommended by board andcomponent manufacturers.

The XT5P is designed for rework single/double sided and mixed technology printed circuit boards. The top heat isderived from a 150 Watt short wave I.R. lamp focused through a lens system. The bottom heater delivers 1600-2000 Watts medium wave IR. In normal use, approximately 30-40% of the energy is provided by the top heater, and60-70% of the energy is provided by the back heater. The above diagram shows how the energy is applied to acomponent.

Technical Description

Infra-Red Lamp/Lens SystemThe Infra-Red lamp/lens system comprises an Infra-Red lamp, an upper lens assembly, an iris assembly and a lensattachment.

Infra-Red LampThe 150 Watt Infra-Red (I.R.) Lamp is located in the lamp housing at the top of the unit. The lamp emits short waveI.R. radiation at approximately 1.0um

Upper Lens AssemblyThe purpose of the upper lens assembly is to collimate the radiation from the I.R. Lamp into a formatted beambefore projection through the iris assembly.

Iris AssemblyThe iris assembly is located between the upper lens assembly and the lens attachment, and serves in conjunctionwith the lens attachment, to vary the diameter of the I.R. beam spot size to suit the component to be removed.

Lens AttachmentsThe lens attachment focuses the beam into a spot. The spot size is determined by the divergence angle of the lensattachment. A range of interchangeable lens attachments are available to cater for different sizes of component.

The selection of the lens and spot size should allow for approximately a 5-10mm overlap of the component.

The minimum and maximum spot size of the lens attachments are as follows:

A frequency selective filter is fitted to the underside of the lens attachment to reduce the amount of visible lightpassed. The remaining red light is at a level which is comfortable for operator viewing and allows the user to viewthe spot.

Control SystemThe main Type 5 control box is used to provide electrical power to the various functionstop heat, back heat,vacuum, thermocouple inputs etc. Detailed operating instructions are described in the section 'Soldering andDesoldering'.

The XT5P models use the PDR T5 controller which are PC controlled using PDR software. Use of the software willbe described later in the section 'Soldering and Desoldering' but an illustration of what to expect is shown below.

Back Heat (PCB Preheater)The backheat is applied by a 1600 Watt (or optional 2000 Watt) medium-wave infrared emitter controlled by thesoftware/digital controller and performs three functions:

1. It reduces the risk of thermal shock and PCB de-lamination (PCB blistering)

2. It counteracts the heat sink effect of a power plane in the PCB.

3. It preheats the PCB and component.

ThermocouplesXT5P (software control) - up to four thermocouples (T/Cs) can be used and displayed. The raytek, IR non-contactthermocouple - T/C #1 is aimed at the component and is used to display and control the component temperature byswitching the Topheat. An optional IR non-contact thermocouple - T/C #2 is aimed at the PCB and is used to displayand control the PCB temperature by switching the Backheat. (Note: To use backheat T/C #2 must be plugged into itssocket even if it is not used. If it is not plugged in the controller will sense a sensor break and will switch off thebackheater)

Summary You now have a very basic explanation of the system. The main principle with the PDR rework system is to put asingle component through the same thermal cycle as in the reflow process during original production. A micro-ovenprocess. To use the system see the next section of help 'Soldering and Desoldering'.

Soldering and Desoldering with the XT5P

This section has 3 main parts1. Reference Information 2. Preparation3. Operating Procedures

Reference InformationThere are Four sections here - The Science in SMT Rework, General Principles, Control and Settings, Alignment

The Science in SMT ReworkA lot of time, money and intellect is employed in developing a successful SMT production process. More needs to bedirected towards rework. Why, because post production soldering/rework is a fact of life for many reasons. Thecause of 80% of field failures is down to 'reworked' joints and you either scrap a lot more product, or sort out the'soldering/rework' process by introducing industry standard, best practices. This article explains some of the scienceinvolved.

The metallurgical bonding process of SolderingSoldering is a metallurgical bonding process where two metal surfaces (e.g. copper pcb pads, and coppercomponent leads) are joined together by bonds formed with a 'bonding' material (a suitable metal alloy i.e. tin/leadsolder), which is heated above its melting point and below the melting points of the metals being joined.

The bonds are formed in one of two ways: by the formation of intermetallic compounds (an irreversible chemicalprocess), or by diffusion or absorption (a physical process).

When joining eutectic tin/lead solder (63Sn/37Pb) and other high tin alloys with copper, two intermetallic compoundsare formed. On the copper side is Cu3Sn and on the solder side, the relatively rough and irregular Cu6Sn5.

The intermetallic compounds of copper and tin form crystalline grains (in layers), whose structures are determined bythe length and intensity of the thermal interaction. Short reaction times form fine grains, which promote goodsolderability and solder joint strength. Long reaction times can result in coarse grains, and a thick intermetallic layer.A thick intermetallic layer creates poor solderability and joint strength, affecting the mechanical strength and long-term reliability.

Although the integrity of a solder joint is normally considered to be dependent on the thermal process duringassembly, metallurgical reactions can also take place during storage. Intermetallic layers continue to growcoarser/thicker even at ambient temperatures. Therefore, when parts or boards are solder coated or pre-tinned,prolonged or improper storage cause these layers to grow, severely affecting the solderability. Alternative leadfinishes and passivated copper pads can be used to combat these problems.

The function of FluxThe soldering process cannot happen unless clean, un-contaminated metal surfaces are present.

Lead finishes are normally covered by thin films of tarnish, which can be described as two layers, differentiated bythe way they are bound to a surface. Chemically bound are the layers of oxide, sulfide and carbonate, as well asproducts from any preceding production steps. On top of these layers are a physically bound residues includingwater, gases and residues from preceding reactions.

This is where flux plays its part. The main requirements for a flux are the:

a. removal of the outer residues. b. displacement of the chemically bound oxides etc. c. exposure of pure substrate molecules to enable the formation of intermetallic compounds during soldering. d. protection of the freshly cleaned surfaces from re-oxidation prior to reflow.

Flux starts to work at about 130/150C and needs to be present throughout the process.Typically low solids fluxes react in around 7 seconds. They have evaporated before you need

them. This is why gel/paste type fluxes (which can react for several minutes) are excellent for 'high end' reworkapplications.

The Reflow ProcessIn a soldering/rework operation, the objective of the 'reflow' process is to achieve high quality solder joints on all ofthe components' leads on a particular assembly, and do to this consistently.

The reflow process involves heating the component leads, pcb pads and solder/solder paste above the melting pointof the 'bonding' alloy (solder) so that the solder melts, bonds and forms a homogeneous fillet connecting the leads tothe pads. As well as solderability issues, consistency in the reflow process depends on the ability to control theapplication and variation of heat. This controlled heating is called the 'profile', or 'thermal profile'.

A typical profile in production includes preheat, soak, reflow (spike), and cooling zones. In a good rework operation itis becoming more important to develop a sophisticated profile very similar to the original used in production. Thereare slight differences in the requirements, mainly in that you are normally only trying to 'solder/de-solder' a singlecomponent with all the particular solderability and thermal considerations that may affect it, however the basicprinciples still apply.

The preheat zones gently raise the temperature of the component/pcb from ambient to about 130C, generally at aramp rate of 2C/second or less. This will minimize the potential for thermal shock on the components due to varyingheat capacities. The preheat zone also begins the volatilization of some of the solvents added to the cream forprinting and releasing.

The soak zone holds the component/pcb temperature at 130C for 30-60 seconds, continuing the drying process toprevent out-gassing and possible spattering of the solder paste (if used). This zone is also where the flux begins toremove the oxides from the surfaces of the leads, pads and the powder itself. The resins and/or higher boilingsolvents remain as a cover to prevent the re-oxidation that would readily occur at the elevated temperatures. Reworkoperations do not always include a soak zone, but theoretically they should do.

In the reflow, or spike zone, the temperature is more quickly raised 20-40C above the melting point of the bondingalloy. Known as the point at which reflow occurs, or 'reflow', the melting point is normally between 183C and 188Cfor standard solders (Lead-free solders have melting points 20-40C higher). It is above reflow that the solder wetsthe surfaces and forms the intermetallic bonds. The maximum temperature to be reached is normally 210-230C fortin/lead based solders. The maximum ramp rate in this zone is typically 4C/second and the period of time abovereflow (dwell time) is typically 30-60 seconds.

The dwell time should be long enough to allow for all of the joints to reach temperature and form the bonds. Too longa dwell time can lead to excessive intermetallic formation. Both of the intermetallics are brittle, and if they make up alarge portion of the fillet, can lead to premature failure of the joint.

The optimum profile is not the same for all components. In the real world, almost every assembly has differentthermal characteristics across the board due to different components or component densities. Variations in the boarditself can lead to large differences in thermal mass. However, it is easily possible to establish a pattern and developa range of profiles to take into account all the factors.

ConclusionIt is perfectly possible to establish a cost effective post production, soldering/rework process. A range of equipment isoften needed. Consideration of the basic science is vital. As well as the method of heating, it is as important toconduct extensive research, testing to be get the ability to control a process in a repeatable manner.

General PrinciplesThe principle of operation of the XT5P Infra-Red rework unit is that whilst being heated with IR from above andbelow, a single SMD is subjected to similar temperature/time profile during rework, as it experiences during reflow inthe original production process.

Temperature Profile

In operation the component is put through a full reflow procedure including 2 preheat stages, a soak zone, followedby reflow and dwell stages. All parameters such as temperature levels and ramp rates are precisely controllable, asrecommended by board and component manufacturers.

Back Heater (PCB Preheater)The Back Heater's function is to preheat the PCB and component, this protects the PCB from delaminating and thecomponent from thermal shock. The Back Heater also equalises the conductive effect of the ground plane of thePCB.

The quartz IR heater preheats the PCB and the heat conducts through the PCB and preheats the component, sowhen you introduce the Top Heat there is no chance of thermal shock. The balance of heat energy supplied shouldbe approximately 75 % from the Back Heater and 25 % from the Top Heat.

Top Heater (Focused IR Component Heater)The XT5P has a lens system that generates IR heat and projects it onto the component. The IR is very gentle andcovers the whole component to create a 'micro oven' environment without affecting adjacent components. The IRspot is adjustable using an iris and is adjusted to cover the desired component.

IR Temperature sensorThe XT5P is equipped with an accurate non-contact, IR temperature sensor to measure the component temperature.The sensor is aimed at the centre of the component from a distance of around 60mm. It averages the temperatureread over an area of about 12mm diameter and is used to measure component temperature at all times. The XT5Puses a T5 contoller/software combination to provide control.

Control and Settings - PDR T5 Digital Controller (XT5P - Computer Controlled System)

Control Software - Control Screens and FeaturesThe XT5P is controlled by PDR ThermoActive V4 software. This section illustrates different screens and features.

There are 3 main screens (Run Mode, Settings and Logging). The principle is that you set targets...the systemmonitors the component temperature with non-contact IR sensor (T/C1)....and then controls the componenttemperature by increasing or decreasing the topheat power. The result is logged and can be analysed, printed out(doulble click on graph to enlarge)...and also stored for reference. The logging is a vector image and is stored aspart of the profile.

The best method is to load a defaultprofile for your device and then save eachresult as default 01, 02, 03 etc. Thiskeeps a record of your rework.

The software indicates what PCB andcomponent have been selected. Thefolder name = the PCB indent. The filename = the profile = component type,ident, location etc.

Folder Name = Topline 967001 (PCB ident)

File name = BGA 225-U1-F700-01.lmd

Selected Profile

Starting, Pausing and StoppingStart begins the cycle. Pause allows you to pause the time but continue heating up to the temperature limit. Stopstops the cycle.

Vacuum and Align

PDR ThermoActive V4.03+ - Control Settings

IntroductionThe general principle of the PDR V4 software is basically there is a component/PCB temperature target glide-slopeand the system will use thermocouple information to control the process as desired. There are 3 modes to choosefrom to use the software,

Manual Profile Mode - the original on/off control mode Auto Profile Mode - new mode that adds automatic proportional control of component heating Fixed Power Mode - new mode for odd applications

Control ModesThe original 'Manual Profile Mode' consisted of a temperature/time based target. The Temperature/Time profile isset up and the system will follow the target during rework cycle. See examples below,

The system steps through the stages/zones (preheat/reflow/soak etc) based on a time, i.e. there is a clock tickingand the cycle progresses through the profile irrespective of the temperature reached.

In 'Auto Profile Mode' we have introduced component temperature ramp rate control and also a wait for PCB tempfeature. The system now automatically adjusts the intensity of the component heating to follow a desired maximumramp rate, can also pause to wait for a minimum PCB temperature to be achieved and only steps through to the nextphase when temperature targets are reached. See examples below,

Profiling is a lot easier. A mixture of ramp rate, temp and time targets can be used. In this example, there are 6zones: 1 - B/H Preheat (PCB preheater only up to 90C), 2 - Preheat (Topheat/bachheat up to 150C at a controlledramp rate), 3 - soak 1 (time based soak), 4 - reflow (Component up to 225C at a controlled ramp rate, PCB upto160C), 5 - soak 2 (time based soak), 6 - cool down (at a controlled ramp rate). The system is set to be gentleduring preheats and more aggressive during reflow.

Default ProfilesTo help, we have included various default profiles to try out with the software control. We strongly recommend youopen a default profile...Manual, Auto and Fixed Power Mode...and practice rework on dummy boards andcomponents before launching into action on your live pcbs. Profiles that you develop will probably not vary verymuch from original defaults and they generate better understanding of reworking with the XT5P. For more detailedtechnical information contact your PDR representative for help.

Settings Screen

Main Parameters

Parameter FunctionT/H Power% (max) Topheat intensity - max limit within that zone

Power% (min) Topheat intensity - min power for that zone (Manual Mode Only)Limit (temp) Max component temperature for zone

B/H Power% (max) Backheat intensity - max limit within that zoneLimit (temp) Max PCB temperature for zone

Time (sec) Duration for zoneWait for PCB Temp A tick in the zone 2 checkbox will make the software wait for the previous zones

B/H (PCB Temp) limit to be met before continuing with zone 2Ramp rate (C/Sec) a +ve value will set time for zone, T/H power will be adjusted to control to this value

a value=0, the software will maintain temps for the duration set (Soak)a -ve value, cool down, the software will control the temp descent, for the time set.

Number of Zones Between 1-10Align (Time and Power) Controls topheat for alignment of component within IR spotStandby Power Backheat standby intensity

Backheater Zone ControlZone 2 (on/off) Switches B/H zone 2(outer) on/off (checked/pressed = on)

Software SkinsPreferences Go here to change software skin to different colours just for

fun!!

Control Mode Select Run Mode/Settings/Logging Mode Select Tab

PCB Preheater Zone 2On/Off Select

Software Lock - Password Protected

Wait for PCB Temp Select

Power/Time/Temp Settings (For reference only - already preset in the default profiles)

TopHeat Power Settings (Max%)Attachment \ Zone Preheat1 Preheat2 Soak Reflow Dwell CoolF150 0 - 10 20 - 30 20 - 30 55 - 65 30 - 40 0F200 0 - 10 25 - 35 25 - 35 60 - 70 35 - 45 0F400 0 - 15 35 - 45 35 - 45 65 - 75 45 - 55 0F700 0 - 20 45 - 55 45 - 55 75 - 85 55 - 65 0Auto Mode 0 100 100 100 60-100 0-30

Backheater Power Settings (%)Rating Preheat1 Preheat2 Soak Reflow Dwell Cool750W 50 - 80 50 - 80 50 - 80 50 - 80 25-40 01600W 70 - 100 70 - 100 70 - 100 70 - 100 35-50 02000W 60 - 100 60 - 100 60 - 100 60 - 100 35-50 0

Typical Time Settings (Seconds)Attachment \ Zone Preheat1 Preheat2 Soak Reflow Dwell CoolF150 40 40 30-40 30 15 30F200 60 40 30-40 30 15 30F400 90 45 30-40 40 15 30F700 90-120+ 45-60 30-40 40-60 15-30 30-60

Typical Tempearture Target Settings (C)Zone Preheat1 Preheat2 Soak Reflow Dwell CoolComponent (T/C1) 100 150 150 220-230 220-230 150Lead-free (T/C1) 100 150 150 250-260 250-260 150

PCB (T/C2) 100 150 150 165 165 150

The tables only provide general guidelines as many factors influence the required settings (i.e. position of acomponent/thermal mass of PCB) therefore the same component on a different board may possess very differentthermal characteristics.

For more precise information on actual temperature reached on a component and/or PCB, the Data Logging featurein the software provides a graphical report of the temperatures reached during rework cycles.

BGA Alignment

The XT5P can be purchased with, or without, a CCTV/Prism based BGA alignment system. In practice it may not beneeded as BGAs are often placed within very accurate pcb markings to aid pick and place systems. For this reason,we have made the feature optional and fully upgradeable at a later date. The procedure for aligning and placing aBGA with the BGA alignment system is as follows,

1. lock pick-up and vision arms (using the black locking levers at the rear of the arms) before alignment andplacement. Lower Component to 1mm above pcb and macro align X/Y/rotation

2. Lift Component, move prism in, focus lens on pcb, move component down into focus, adjust rotation, x, y

3. Move Prism out to the left, carefully place component onto fluxed pads, move pick-up out, lens in..and reflow

Preparation

The procedure while preparing to rework SMT/BGA components is as follows,

a. Switch on and warm upb. Select 'profile' required for PCB/component (XT5P)c. Select lens attachment and set lens height + spotsized. Sort tools and fluxes required

Switch on and warm upThe following simple procedure will warm the system up

a. Switch on the XT5P Controller, Lightbox and PCb. Allow system to warm up - 5 to 10 minutes

Selecting a Profile to use (XT5P)The following simple procedure will get you started,

a. Press 'open' - bottom left in control panelb. Select required PCB - this is the 'folder' containing your component profilesc. Select component - the 'filename.lmd' within the opened folder

Main Control Panel

The 'Open' Screen

The default 'folder' is 'Profiles. You can create a new folder and it will appear as a folder within the default folder. Theidea is to name the folder as your PCB ident, and then name a profile with full reference to the component e.g.'BGA225 - U21.lmd'. We have created some default profiles (e.g. 'F700 Standard.lmd') which will give you a goodstarting point when using the system and creating new profiles.

The idea is to select say 'F700 Standard.lmd' to be used with the F700 lens attachment, to be used for most largeQFP, PLCC and BGA. This profile contains all the parameters needed (powers/ times/ temperature targets/ zonesetc) as displayed under the 'Settings' tab. (Tip - try the profile..if it does not rework successfully, alter the times notthe powers!! Temp Mode sorts itself out automatically)

Tech Note: Within Default Profiles folder are default profiles for use with F200, F400 and F700 Lens attachments.The profiles have all the correct power/temperature parameters for the respective attachments. Temperatures are forstandard solder. Lead free solder will require higher reflow temperatures (probably 250-260C). For you applicationtimes may need to be varied slightly if you are using Time mode.

ThermocouplesUp to four thermocouples (T/Cs) can be used and displayed. The raytek, IR non-contact thermocouple - T/C #1 isaimed at the component and is used to display and control the component temperature by switching the Topheat. Anoptional IR non-contact thermocouple - T/C #2 is aimed at the PCB and is used to display and control the PCBtemperature by switching the Backheat.

Lens Attachment Selection

The 'quick' procedure for lens attachment selection and setting is,

a. Select lens attachmentb. Press 'Align' c. Adjust lens height (lens to PCB distance)d. Adjust Spotsize (exceed component by 6 -10mm all round)

From the information provided in the table, select and fit a lens attachment to give a spot size appropriate for thecomponent to be removed or replaced.

Attachment Spotsize (mm) Lens to PCB Distance (mm) Typical ComponentsF150 4 - 18 37 Chips, SOICs, SOTs, PLCC44F200 8 - 28 60 uGAs, SOICs, PLCCsF400 12 - 35 73 uGAs, BGAs, QFP100, PLCCsF700 20 - 70 70 - 120 BGAs, QFP208, PLCC96

With a PCB fitted in the XY table jaws, and positioned under the lens unit, adjust the Lens height using the rack andpinion height adjuster. The correct 'lens to PCB' distance will be dependent on the lens attachment selected. Usethe above table as a guide.

Note: Lens to PCB distance can be set with a rule or by moving the lens until the spot is sharply focused when themachine is on and alignment is pressed (set the iris to the half open position and press the alignment button in thesoftware control panel).

Tools and fluxes requiredThe following are required for use in soldering/desoldering operations:

a. SMT Tweezers, fine tippedb. Flux Dispenser Bottlec. Low solids and Gel/paste flux

When using PDR IR Rework units, we recommend Alpha fluxes (or equivilant) for all soldering/desolderingoperations. It is vital to use correct materials for successful rework. We use two types, a low solids liquid flux forgeneral rework and a gel/paste flux for QFP/BGA rework.

The above tools/fluxes are available from PDR separately, or as a BGA Rework Start-Up Kit and SMT/BGA Flux Kit.

Preparation SummaryThe procedure while preparing to rework SMT/BGA components is as follows,

a. Switch on and warm upb. Select settings or 'profile' required for PCB/componentc. Select lens attachment and set lens height + spotsized. Sort tools and fluxes required

Operating Procedures - XT5P (Computer controlled system)

IntroductionHaving done the preparation, you are now ready to begin SMT/BGA rework. The basic SMT process for soldering acomponent is as follows...

1. Materials (Components, PCB, Flux and Solder)2. Alignment/Placement3. Reflow4. Test

To get good results you need to have absolute control over all variables in stages 1,2 and 3. It is important toexercise all the same care in SMT/BGA rework as is applied throughout the various stages of a typical SMT line. So,there are some variations but the following would be the recommendations from PDR for SMT/BGA rework.

Soldering a QFP (or other SMDs excluding BGAs)1. Apply solder paste (or just gel flux if all pads have sufficient and flat solder mounds)2. Align and place component3. Reflow4. Cool, clean (as necessary) and inspect

De-soldering a QFP (or other SMDs excluding BGAs)1. Apply a little liquid flux (use gel flux on a QFP to help joints flow and leave solder on PCB)2. Reflow3. Remove component4. Cool, remove old solder (as necessary), clean (as necessary) and inspect

Soldering a BGA1. Apply gel flux (solder paste if using Column Grid Arrays or if internal procedures demand)2. Align and place component3. Reflow4. Cool, clean (as necessary) and inspect

De-soldering a BGA1. Apply a little liquid flux under the BGA to help joints flow2. Reflow3. Remove component4. Cool, remove old solder, clean (as necessary) and inspect

Reworking with the PDR IR-XT5P

Removing a component (Desoldering)a. Put PCB in jaws - and position under lensb. Press Align - position component in the centre of the IR spot and adjust spotsize to be approx. 6 -10 mm

larger in area than the component.c. Apply flux - to solder joints. d. Press Start button - the system will automatically cycle through the Preheat, Reflow, Dwell and Cool Zones.

At about 150 C the flux will start working. There will be two bursts of smoke (flux fumes) and on the secondone you should have reached reflow at about 200-210C. The software takes you to 220-230C topsidecomponent temperature

e. Remove component - with tweezers, vacuum pen or the vacuum pick-up.

Replacing a component (Soldering)a. De-flux and cool the PCB - remove old flux residue and generally prepare the PCB.b. Put PCB in jaws - and position under lensc. Press Align - position component target in the centre of the IR spot and adjust spotsize to be

approx. 6 -10 mm larger in area than the component area.d. Apply flux - to solder pads - use gel on a cooled board for best activity. If the existing solder in insufficient

or has been reworked more than once, it may be necessary to remove all old solder and replace with a goodsolder paste.

e. Place and align component onto fluxed pads (or solder paste). For fine-pitch and BGA devices use the Pick-up, CCTV and split-beam facilities (see 'Alignment' section), for standard devices look visually down and align. Move the Pick-up out of the way during the heating cycle.

f. Press Start button - the system will automatically cycle through the Preheat, Reflow, Dwell and Cool Zones. At about 150 C the flux will start working. There will be two bursts of smoke (flux fumes) and on the secondone you should have reached reflow at about 200-210C.

g. During Reflow - tap the PCB very gently 1 or 2 times to help any mis-alignment (optional procedure). h. Cool - allow the PCB/component to cool to below 160C before moving.

Aftercarea. Clean flux residue off PCB if necessaryb. Check solder jointsc. Test

Standby and ShutdownThe XT5P has been well made but remember it is a heating system and therefore it could be very hot in places afteruse. Be careful nobody puts anything on the backheater. Create a 'standby' profile with the backheater standbypower turned right down (10%), or select the System Stand By.lmd profile.

If the equipment is to be left unused for more than one hour, switch it off using the controller's POWER switch andexit the PC software. The PC may be left running as required.

Maintenance, Troubleshooting and Calibration

There are 4 sections in this area of the manual

Main Equipment Maintenance General Troubleshooting Warranty Calibration

Main Equipment MaintenanceAll maintenance should be performed when the machine is switched off, and has been allowed to cool to avoid theoperator accidentally receiving burns from hot parts of the machine.

LubricationThe only lubrication necessary is the application of a thin coating of grease to the threads of the height adjuster andthe lens attachment. The recommended grease is a Lithium grease. After application all surplus grease should beremoved by wiping with a clean tissue. Bearings should not need lubrication.

Cleaning At the end of each working day wipe any surplus flux and/or solder paste from the equipment with a clean

cloth. Periodically clean the exposed surfaces of the equipment with a soft cloth slightly moistened with water. The lens assembly should be cleaned using Iso-Propylalcohol. Care should be taken to ensure that the lens

cloth is clean as any contamination of the cloth could cause scratching of the glass surfaces.

Caution: do not use solvents for cleaning any part of the equipment as they may damage the operation and finish.

Changing FusesFuses should only be changed with the equipment switched off, and the equipment isolated from the electricalsupply by removing the IEC socket from the machine.

The mains fuse is located at the back of the equipment and is changed by withdrawing the fuse holder andwithdrawing the fuse.

Changing the IR LampThe IR lamp may be changed by the following procedure:

Ensure that the equipment is switched off and mains cable is removed from the mains supply. Slacken the small screw securing the lamp housing to the lens unit. Lift off housing. Withdraw the lamp from the housing. Fit replacement lamp taking care to handle only the outside edges of

the glass reflector. If the bulb within the lamp is touched then the lamp may fail prematurely. Refit lamp housing to top of lens unit and secure clamp screw.

Cleaning the IR Lamp PinsThe lamp contact pins should be cleaned with mild abrasive paper if there is evidence of pitting or corrosion. Lampsocket should be changed every two months to avoid corrosion problems.

Calibration Procedures

All PDR systems leave our factory calibrated, working and in excellent overall condition. After careful installation byPDR approved personel, your system should be in the same original condition. Of course, during normal working usethe systems will eventually need cleaning, re-adjusting and calibrating. Calibration procedures include the following,

ControllerCheck all functions work

PC serial communication - RS232C - T5 (XT5P) Controller vacuum (working and effective - the pick-up nozzles may need cleaning with IPA alchohol) Backheat (working and effective - quartz heater panels should glow slightly at full power) Topheat (working and effective - measure IR lamp voltage at full power)

There is a measuring point inside the top of the lens unit. Undo 3 screws to open the top panel to reveal a ceramic connector block. With a true RMS voltage meter such as a Fluke 87, measure thelamp voltage at full power. It should measure between 14-15 volts d.c for the T5 (XT5P) controller.

TRIAC operation - check you have variable control over Topheat and Backheat. Set both to 50% and observe a reduction in output from full power.

Thermocouple inputs - use a thermocouple simulator to input known temperatures (100C and 200C) and check readings are within +/- 2C. The XT5P uses software - calibration adjustments can be made there - see settings screen, thermocouples.

IR Sensor - we heat a metal plate, coated with a high-temp matt black paint (such as barbeque paint), to aknown temperature (100C) and aim the sensor at the black surface. The sensor should not go out of settingand should be within +/- 2C.

Mechanical AssembliesCheck all assemblies and bearings are tightened, free moving and clean.

We are assuming here that the system has not been dismantled or tampered with since installation. If it has emailsupport for help. The systems are manufactured originally to very good standards and actually are very strong so weshould be able to help you.

Bearings - PDR use mostly THK linear bearings of the highest quality and our experience shows bearingswill last the life of the system. We have 15 year old systems coming back to PDR for servicing with bearingsresponding well to light cleaning (with dry cloth) to remove any flux residues or dirt.

Rust - We have always used aluminium plate, stainless steel bearings, screws and shafts so there should not ever be any rust problems.

Squareness - we set the pick-up, in its locked position, to be over the centre of the backheater. With a flat plate, or pcb in the jaws, we then check the pick-up nozzle makes square contact with the surface. Pick upa flat set piece and lower to the surface to check it touches down evenly - north, south, east, west.

With the pick-up now set and touching the surface, we now adjust the IR lens assembly to aim an IR spot atthe same target. This ensures the IR will aim at the same place as you place a component.

IR Lens/IR Lamp AssemblyEvery month do the following,

Check the Lens assembly is not damaged and the IRIS is working properly. Turning the adjuster ring should adjust the size of the IR spot and the IR spot should be a comfortable red colour.

Change the IR lamp Socket - every 2 months in normal use. The connections become corroded and will affect the IR output.

Check the IR lamp pins for corrosion - they can be cleaned, or the lamp changed Clean the IR Filter - with IPA alchohol to remove flux residue

CCTV/Prism based BGA Alignment AssemblyEvery month do the following,

Check the assembly is clean and undamaged. If necessary, clean the prism surfaces with a dry lens cleaning cloth to remove dust. There should be no flux residue on this assembly but if there is, moisten thecloth with IPA alchohol to carefully remove any residue.

Calibrate as follows,

1. Place Prism alignment plate in pcb jaws

2. with pick-up and vision arms locked, pick up top alignment plate

3. Lift plate to top of pick-up z-axis travel

3. Move prism in from left. Focus lens on bottom plate and lower top plate into focus.

4. Look at the CCTV monitor. X-axis is out (below left) and Y-axis is out

5. Physically adjust the prism assembly to correct the errors. Unlock and adjust (A) to correct X-axis error and unlock (B) and rotate prism body to correct Y-axis error

6. Lock up adjustment points. Prism assembly is now adjusted and calibrated correctly

If the whole prism assembly is well tightened and is not badly knocked, it should actually go out of calibration. Soevery month a quick check will ensure it is calibrated. If in use components are being placed off centre the prismassembly may need calibration. Remember always lock pick-up and vision arms (using the black locking levers atthe rear of the arms) before calibration is carried out and lock arms during alignment and placement.

General Troubleshooting

If in doubt, or further assistance is required, please do not hesitate to contact PDR Technical Support (Europe/Asiaemail: support@pdr.co.uk or throughout the Americas email: support@pdr-america.com ).

Full support is offered through PDR's world-wide network of sales outlets. Please contact your local agent or theagent the machine was purchased from.

Contacting Technical Support

When contacting Eurotec Technical Support, remember to provide the following information available:

Machine Model Serial Numbers Details of the fault

Mains Fuse

This should be checked first when any malfunction arises. The fuse (20mm, T/Anti-surge, 6.3A for 220V, 15A for110V operation) is located at the back of the controller between the mains input and the On/Off switch. Thefollowing table indicates the correct fuse for the appropriate system:

All internal fuses are Anti-surge (T), 30mm type, 15A/250V.

Bulb no longer worksThis may be caused by either a blown fuse, the lamp's age, corroded lamp pins or a defective lamp socket.

Lamp Age/LifeA lamp has a life expectancy of 30,000 cycles or 50 hours at full power. If burnt in appearance, replace with a newlamp.

Corroded Lamp PinsWhite residue on the pins of the lamp may prevent proper contact between the lamp's pins and the lamp socket.Therefore remove the lamp and clean pins with abrasive paper.

Backheater MalfunctionsCheck T/C#2 is plugged in (XT5P). Or, this may be caused by either blown mains or a backheater fuse.

Backheater FuseIf any malfunction occurs with the backheater you should check this fuse. It is located inside the controller, on thecircuit board attached to the transformer between the connector block and the mains voltage selector switches. Thebackheater fuse is the smaller one on the circuit board.

WARRANTY

Terms of Warranty

PDR (A Division of Eurotec Industries Limited, UK), warrants this product to be in good working order during theWarranty Period, from the date of delivery from PDR or a PDR authorised distributor until one year hence. Shouldthis product not be in good working order PDR will, as its option, repair or replace the product at no additionalcharge except as set forth below:

This warranty covers failure due to faulty materials or workmanship.

This warranty does not cover the repair of damage to the product resulting from accident, disaster, misuse, abuse,unauthorised repairs, the attachment of non PDR accessories or non PDR modifications.

Service under the conditions of this warranty may be obtained by delivering the product during the warranty period toPDR, or an authorised distributor.

Except as expressly stated herein, all conditions, warranties, representation and undertakings, express orimplied, are excluded.