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Surface Mounting SMT LED Indicator Components Application Note 1060 Contents Surface Mount LED Indicators Standard EIA Tape and Reel Packaging Moisture Barrier Envelope Packaging SMT LED Device Lead Material PC Board Pad Design Automatic Placement Equipment Considerations Solder Paste Convective IR Reflow Soldering Type 2 PC Board Processing with LED Components Through-The-Wave Soldering Surface Mount LED Indicators Circuit board assemblies using surface mount technology (SMT) are now common and SMT LED indicators are being used on many of these SMT board assemblies. There are currently three basic types of Agilent Technologies SMT LED indicator components: 1. HLMx-xxxx domed and flat top subminiature lamps with formed leads: • Option 011 “gull wing” leads. • Option 021 “yoke” leads. • Option 031 “Z-bend” leads. 2. HSMx-xxxx Chip LED and flip chip LED indicator components. • HSMx-C670, -C650, -H670, -H690, -S670, -S690 top emitting components. • HSMx-H630, -H730 reverse mount components. • HSMx-R661, -R761, -S660, -C660 right angle emitting components. 3. HSMx-Axxx-xxxxx PLCC SMT LED All these LED indicator component types may be mounted to a printed circuit (pc) board using automatic placement equipment and attached using a reflow solder process. This application note provides information on how to successfully attach SMT LED indicators onto a pc board. Standard EIA Tape and Reel Packaging SMT LED lamps are packaged tape and reel in accordance with EIA Standard 481, Taping of Surface Mount Components for Automatic Placement. Reel and tape dimensions conform to EIA standards with individual SMT LED lamps in the embossed carrier tape spaced on 4 mm (0.157 in.) centers. Figures 1a through 1e show the typical EIA standard dimensions for the reels and embossed tapes. Moisture Barrier Envelope Packaging The optical grade materials used in SMT LED components absorb moisture directly out of the air. Absorbed moisture in SMT LED components that have been reflow soldered to a pc board is typically of minor concern. However, moisture absorption in SMT LED components prior to reflow soldering is of serious concern. If moisture is absorbed by SMT LED components prior to soldering, the entrapped moisture turns to superheated steam during the solder process. The pressure of this superheated steam fractures the packages of the components causing catastrophic failure. Therefore, it is of vital importance to protect SMT LED components from absorbing moisture prior to soldering. To protect the SMT LED components from moisture absorption during shipping and handling, reels for SMT LED components may be packaged in moisture barrier envelopes, as illustrated in Figure 2.

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  • Surface Mounting SMT LED IndicatorComponentsApplication Note 1060

    Contents Surface Mount LED

    Indicators Standard EIA Tape and Reel

    Packaging Moisture Barrier Envelope

    Packaging SMT LED Device Lead

    Material PC Board Pad Design Automatic Placement

    Equipment Considerations Solder Paste Convective IR Reflow

    Soldering Type 2 PC Board Processing

    with LED Components Through-The-Wave SolderingSurface Mount LED IndicatorsCircuit board assemblies usingsurface mount technology (SMT)are now common and SMT LEDindicators are being used onmany of these SMT boardassemblies. There are currentlythree basic types of AgilentTechnologies SMT LED indicatorcomponents:

    1. HLMx-xxxx domed and flattop subminiature lamps withformed leads: Option 011 gull wing leads. Option 021 yoke leads. Option 031 Z-bend leads.

    2. HSMx-xxxx Chip LED and flipchip LED indicatorcomponents. HSMx-C670, -C650, -H670,

    -H690, -S670, -S690 topemitting components.

    HSMx-H630, -H730 reversemount components.

    HSMx-R661, -R761, -S660,-C660 right angle emittingcomponents.

    3. HSMx-Axxx-xxxxx PLCC SMTLED

    All these LED indicatorcomponent types may bemounted to a printed circuit(pc) board using automaticplacement equipment andattached using a reflow solderprocess.

    This application note providesinformation on how tosuccessfully attach SMT LEDindicators onto a pc board.

    Standard EIA Tape and ReelPackagingSMT LED lamps are packagedtape and reel in accordance withEIA Standard 481, Taping ofSurface Mount Components forAutomatic Placement. Reel andtape dimensions conform to EIAstandards with individual SMT

    LED lamps in the embossedcarrier tape spaced on 4 mm(0.157 in.) centers. Figures 1athrough 1e show the typical EIAstandard dimensions for thereels and embossed tapes.

    Moisture Barrier EnvelopePackagingThe optical grade materials usedin SMT LED components absorbmoisture directly out of the air.Absorbed moisture in SMT LEDcomponents that have beenreflow soldered to a pc board istypically of minor concern.However, moisture absorption inSMT LED components prior toreflow soldering is of seriousconcern. If moisture is absorbedby SMT LED components priorto soldering, the entrappedmoisture turns to superheatedsteam during the solder process.The pressure of this superheatedsteam fractures the packages ofthe components causingcatastrophic failure. Therefore,it is of vital importance toprotect SMT LED componentsfrom absorbing moisture prior tosoldering.

    To protect the SMT LEDcomponents from moistureabsorption during shipping andhandling, reels for SMT LEDcomponents may be packaged inmoisture barrier envelopes, asillustrated in Figure 2.

  • 2

    Figure 1a. 12 mm Embossed Cavity Carrier Tape Detail for HLMP-6XXX/-PXXX Series Subminiature SMT LED Lamps.

    2

    CATHODE LEAD

    D

    P0

    P2

    F

    E

    W

    D1PFEED DIRECTION

    "GULL WING" LEAD OPTION 001 TAPE DETAIL

    t

    K0

    CATHODE LEAD

    "YOKE" LEAD OPTION 021 TAPE DETAIL

    CATHODE LEAD

    "Z-BEND" LEAD OPTION 031 TAPE DETAIL

    NOCOMPONENTSCOMPONENTS

    NOCOMPONENTS

    END TAPE START

    USER DIRECTION OF FEED

    LEADER500 mm (19.7 IN.)

    TRAILER160 mm (6.3 IN.)

    LABELTHIS SIDEOF REEL

    12 mmEMBOSSED CAVITYCARRIER TAPE

    DIMENSIONS PER ANSI/EIASTANDARD RS-481.ALL DIMENSIONS ARE INMILLIMETERS (INCHES)

    D 1.55 (0.061) DIA.

    D1 1.00 (0.039) DIA.

    E 1.75 (0.069)

    F 5.50 (0.127)

    KO 3.05 (0.120)

    P 4.00 (0.157)

    PO 4.00 (0.157)

    P2 2.00 (0.079)

    t 0.30 (0.012)

    W 12.00 (0.472)

    THICKNESS OF TOP COVERTAPE 0.10 (0.004) MAX.

    Figure 1a. 12 mm Embossed Cavity Carrier Tape Detail for HLMP-6XXX/-PXXX Series Subminiature SMT LED Lamps.

  • 3

    Figure 1b. 8 mm Embossed Cavity Carrier Tape Detail for HSMX-C650, -C670, -H670, -S670, -C655 Chip LED Lamps

  • 4

    Figure 1c. 8 mm Embossed Cavity Carrier Tape Detail for HSMX-H630 and HSMX-H690, -S690 Chip LED Lamps.

  • 5

    Figure 1d. 8 mm Embossed Cavity Carrier Tape Detail for HSMX-C660, -S660 and -R661 Right Angle Chip LED Lamps

  • 6

    Figure 1e. 7 Inch and 13 Inch Reel Details.

    A

    N C

    T

    D2

    OPERATOR ___________________AGILENT PART NO. _____________DATE CODE ___________________TAPING DATE _________________ELEC. VALUE _________________TOLERANCE __________________QUANTITY ____________________CUSTOMER PART NUMBER _____

    OPERATOR ___________________AGILENT PART NO. _____________DATE CODE ___________________TAPING DATE _________________ELEC. VALUE _________________TOLERANCE __________________QUANTITY ____________________CUSTOMER PART NUMBER _____

    13 INCH REEL DETAIL

    A

    N C

    T

    D2

    OPERATOR ___________________AGILENT PART NO. _____________DATE CODE ___________________TAPING DATE _________________ELEC. VALUE _________________TOLERANCE __________________QUANTITY ____________________CUSTOMER PART NUMBER _____

    7 INCH REEL DETAIL

    DIMENSIONS PER ANSI/EIASTANDARD RS-481ALL DIMENSIONS ARE INMILLIMETERS (INCHES)

    7 INCH REEL 13 INCH REEL

    A 178.0 (7.0) 330.2 (13.0)

    C 13.0 (0.512) 13.0 (0.512)

    D2 20.2 (0.795) 20.2 (0.795)

    N 60.0 (2.362) 100.0 (3.937)

    8 mm 8 mm14.4 (0.567) 14.4 (0.567)

    12 mm 12 mm18.4 (0.724) 18.4 (0.724)

    T

  • 7

    Each envelope containsdesiccant. To assure themoisture barrier seal, it isimportant to protect theseenvelopes from being puncturedby sharp objects such as staples.Once opened, SMT LEDcomponents should be handledin accordance with therecommendations for theirappropriate moisture sensitivityclassification. The Joint IndustryStandard J-STD-020, Moisture/Reflow Sensitivity Classificationfor Plastic Integrated CircuitSurface Mount Devices, issuedby the EIA/JEDEC JC-14.1Committee establishes thenecessary handlingrecommendations for eachmoisture sensitivityclassification. For informationon the appropriate moisturesensitivity classification ofAgilent Technologies SMT LEDcomponents, contact yourAgilent Technologiesrepresentative.

    SMT LED Device Lead MaterialThe lead base metal and surfacefinish for SMT LED componentsare listed in Table 1. Thesubminiature lamp componentsutilize a lead frame in theirconstruction. The various chipLED and flip chip LEDcomponents utilize a pc board asthe device substrate.

    PC Board Pad DesignThe design of the pc boardmetallic attachment pads isimportant to assure bothposition on and attachment toan SMT board assembly. Soldercoated one ounce copper padsare best for reflow soldering.

    PC Board Pad Design Considerationsand Device-to-Device Pad AlignmentPlacing an SMT LED componenton the pc board so its axis isoriented perpendicular to thelong dimension side of theboard, as shown in Figure 3, willtend to reduce stress on thedevice during temperaturecycling. Placing the axis of anSMT LED component parallel tothe long dimension side of the pcboard will increase theprobability of defects. Theproper design of pc boardattachment pads, as illustratedin Figure 4, will increase theprobability of proper reflowsolder connections. Pad sizeshould not exceed recommendedpad dimensions by more than0.25 mm (0.010 in.). Accurateplacement of the SMTcomponents onto the pc boardattachment pads enhances theprobability of proper alignmentafter solder freeze. When the pcboard pads are of the correctsize in relation to the deviceleads, the SMT LED componentswill self center align withrespect to the pads, assisted bythe capillary attraction/wettingforces of the hot liquid solder.

    PC board traces should connectto the center of each attachmentpad. Traces that connect to theouter edges of pads impart atorque to the SMT LEDcomponent which contributes toskewing and off centeringproblems. Adjacent attachmentpads for SMT LED componentselectrically connected in seriesshould be connected with a tracethat is a maximum of 0.20 incheswide. Solder resist maskingshould be well defined aroundthe perimeter of the attachmentpads, without voids or smearsover the pads that will inhibitthe formation of good solderconnections.

    Subminiature Lamp ComponentsFigure 5 shows the mountingorientation to a pc board for theOption 011 gull wing, Option021 yoke, and Option 031 Z-bend lead subminiature lampcomponents. All three optiondevices are for mounting on thecomponent side (non-solderside) of a pc board, with boththe yoke and Zbendcomponents mounted upsidedown through a hole in the pcboard. Installed on a 1.52 mm(0.060 in.) thick pc board, thelamp dome of a yoke leadcomponent will protrude out thesolder side about 0.38 mm(0.015 in.), and a Z- bendcomponent will be flush torecessed 0.38 mm (0.015 in.).

    Table 1. Lead Base Metal and Lead Finish for SMT LED Indicator Components.

    SMT LED Indicator Component Lead Base Metal Lead Finish

    HLMP-6XXX/-PXXX Copper/Iron Alloy, OLIN 194 Solder Plate, 85% Sn/15% Pb

    Chip LED and Flip Chip LED Copper on pc Board Substrate Gold over Nickel Alloy

  • 8

    Figure 6 shows the pc board padlayout for the Option 011 gullwing lead components. Figure 7shows the pc board pad layoutsfor Option 021 yoke lead andOption 031 Z-bend leadcomponents.

    A Type 2 pc board assemblycontains both surface mount andthrough hole components. ForOption 021 yoke lead andOption 031 Z-bend leadcomponents mounted on a Type2 board that will be wavesoldered, the clearance throughhole in the pc board should betemporarily closed off on thesolder side with a removablesolder resist cover, as shown inFigure 8. This removable solderresist cover prevents flux andsolder from flowing up throughthe clearance hole during wavesolder and being deposited onthe leads the LED device. Thisunwanted excess solder depositrestrains the component leadsfrom absorbing thermal stressesduring temperature cycling andwill inevitably lead tocatastrophic failure of the SMTLED component.

    Figure 2. Moisture Barrier Envelope Packaging for SMT LED Indicator Components.

    Figure 3. Recommended Orientation of SMT LED Components on PC Boards forMinimum Stress.

    REEL OF SMTLED DEVICES

    DESICCANTINSIDE

    MOISTURE BARRIERENVELOPE

    SEALEDENVELOPE

    IDENTIFICATION LABEL

    PC BOARDLONG DIMENSION

    AXIS OF SMT LED DEVICE

    SOLDER CONNECTIONS

    CL CL

  • 9

    Figure 4. PC Attachment Pad Design Considerations for SMT LED Components. Pad Dimensions should not exceed 0.25 mm (0.010) in.)Recommended Size.Figure 4. PC Attachment Pad Design Considerations for SMT LED Components.Pad Dimensions should not exceed 0.25 mm (0.010) in.) Recommended Size.

    9

    CORRECTPAD SIZE

    PADSTOO LONG

    PADS TOO WIDEPC BOARD ATTACHMENT PAD SHAPES

    SMT LED ISSELF CENTERED

    REFLOW SOLDERED SMT LED

    TOMBSTONINGSMT LED SKEWED SMT LED

    0.020 IN. MAX.

    GOOD DESIGN INFERIOR DESIGN

    PADS IN A SERIES CONNECTION

    GOOD SOLDERMASKING

    UNACCEPTABLESOLDER MASKING

    SOLDER MASKING

    SOLDER MIGRATION

    SOLDERMIGRATIONADDS A TORQUE

    POOR TRACECONNECTION

    GOOD TRACECONNECTION

    CIRCUIT TRACE-TO-PAD CONNECTIONS

  • 10

    Figure 5. Orientation of HLMP-6XXX/-PXXX SMT LED Component Options on a PC Board.

    Figure 6. PC Board Attachment Pad Layout for HLMP-6XXX/-PXXX Gull Wing Lead Option 011 Single Indicator and Option 013 Linear ArraySubminiature SMT LED Components. PC Board Solder Dipped, Hot Air Leveled.

    CLEARANCE0.13 mm (0.005 IN.) MAX.

    APPROXIMATE PROTRUSION1.52 mm (0.060 IN.)

    APPROXIMATELYFLUSH

    OPTION 011"GULL WING" LEAD

    OPTION 021"YOKE" LEAD

    OPTION 031"Z-BEND" LEAD

    0.89(0.035)

    3.56(0.140)

    0.45(0.018)

    0.89(0.035)

    0.45 (0.018)

    1.78(0.070)

    PAD SPACING ON 2.54 (.100) CENTERS

    TOLERANCE ISNON-CUMULATIVE

    "GULL WING" LEADOPTION 011

    DIMENSIONS ARE INMILLIMETERS (INCHES)

  • 11

    Figure 7. PC Board Attachment Pad Layout for HLMP-6XXX/-PXXX Yoke Lead Option 021 and Z-Bend Lead Subminiature SMT LEDComponents, Mounted Dome Down Through Clearance Hole in PC Board. PC Board Solder Dipped, Hot Air Leveled.

    Figure 8. Removable Solder Resist Cover to Close Off Through Hole in a Type 2 PC Board to Protect LED Component During a Wave SolderOperation.

    6.60 (0.260)

    3.30 (0.130)

    0.64(0.025)

    1.27(0.050) 0.45

    (0.018)

    0.89(0.035)

    #27 DRILL3.73 (0.147) DIA.CLEARANCE HOLETHROUGH PC BOARD

    DIMENSIONS ARE INMILLIMETERS (INCHES)

    "YOKE" LEAD OPTION 021

    0.89(0.035)

    0.45(0.018)

    1.27(0.050)

    3.30 (0.130)

    6.60 (0.260)

    #27 DRILL3.73 (0.147) DIA.CLEARANCE HOLETHROUGH PC BOARD

    SMT LED DEVICE MOUNTED DOMEDOWN THROUGH CLEARANCE

    HOLE IN PC BOARD

    "Z BEND" LEAD OPTION 031

    REMOVABLE SOLDERRESIST COVER

    OPTION 021"YOKE" LEAD

    OPTION 031"Z-BEND" LEAD

    0.60 IN.

    HLMP-6XXX/-PXXX

  • 12

    Chip LED Lamp ComponentsFigure 9 shows the pc boardattachment pad layouts for theChip LED and flip Chip LEDcomponents. These attachmentpad layouts may be used forboth reflow solder andconductive attachment. Thewidth of the attachment pads isabout 0.1 mm (0.004 in.) narrowwith respect to the width of therespective top emitting andreverse mount components toassure alignment of the devicewith respect to the pads. Note,the reflow solder pads are on apc board that has been solderdipped and hot air leveled; theepoxy attachment pads are cleanbare copper.

    Automatic Placement EquipmentConsiderationsThe subminiature Option 011gull wing lead components aremounted upright in theembossed cavities of the carriertape. A hole is located in thebottom of each embossed cavityto allow an automatic pick andplace machine to utilize a pushpin to assist in device removalfrom the carrier tape.

    The subminiature Option 021yoke lead and Option 031Zbend lead components aremounted top side down in thecarrier tape. Since the rounddomes of the device packagesare pointing down, the bottomsof the embossed cavities do nothave push-pin holes. Also, thecarrier tape for the chip LEDcomponents does not have push-pin holes in the bottom of theembossed cavities. Thus, thepush-pin action of the automaticpick and place machine must bedisabled when picking thesedevices from the carrier tape.

    The top side surfaces of SMTLED components, as they sit inthe embossed cavities of thecarrier tape, present to a pick-up tool either a surface that isnot perfectly flat or a rounddome. As a result, the typicalstainless steel vacuum pick-uptool may not form a vacuum sealwith the device package andthus may not be able to pick itout of the embossed cavity.Figure 10 shows a flat soft tippick-up tool for picking up chipLED components andsubminiature lamp Option 021yoke lead and Option 031 Z-bend lead components that aremounted upside down in theembossed cavities. The soft tippick-up tool is usually made ofnylon or other soft plastic. Forpicking up subminiature lampOption 011 gull wing domedcomponents, the end of the softtip should be contoured concaveto fit snugly over the dome ofthat particular SMT LED deviceto form a vacuum seal.

  • 13

    Figure 9. PC Board Attachment Pad Layouts for Chip LED and Flip Chip LED Components.

    1.25(0.049)

    1.25(0.049)

    1.10(0.043)

    1.10(0.043)

    1.50(0.059)

    1.75(0.069)

    1.75(0.069)

    2.00(0.079)

    1.1

    1.40 mm

    1.25 mm

    1.15 mm

    2.00(0.079)

    2.40(0.094)

    1.75(0.069)

    1.00(0.039)

    1.00(0.039)

    1.75(0.069)

    HSMX-C670, -H670 SERIESHSMX-S670 SERIES

    HSMX-C650HSMF-C655

    1.0 1.0

    0.8

    1.4

    HSMX-R661/R761 SERIES

    0.8 0.8

    0.8(0.031)

    0.85

    HSMX-H690/H790 SERIES

    3.4

    1.3

    0.8

    HSMX-S690 SERIES

    2.4

    0.8

    2.00 DIA. PCB HOLE

    0.9

    0.9

    0.2

    2.05.0

    1.5

    RWS CENTER

  • 14

    Figure 10. Soft Tip Vacuum Pick-up Tool for Extracting SMT LED Components from Embossed Carrier Tape.

    Solder PasteFor best results, an SN63eutectic solder paste, liquidus at+183 C (+361 F), should beused. SN62 solder pastecontaining 2% silver, liquidus at+189 C (+372 F), may be usedwith the chip LED devices, withthe advantage of obtainingstronger solder connections, buthigher cost. The solder pasteshould contain 85 to 95% byweight (38 to 67% by volume)solder ball powder, with the sizeof the spherical solder ballsscreened -200/+325 mesh. Thesolder paste should be stableover time after deposition on thepc board. After deposition, awell formulated paste will notdegrade or change reflowcharacteristics due to moistureabsorption and oxidation overtime period of 12 hours at roomtemperature. Refrigeratedstorage of unused solder pasteextends shelf life, typicallybeyond three months at 0 C(+32 F). The solder paste maybe deposited onto pc board padsby either screen printing, using astencil, or by syringe dispensing.

    The viscosity range of the solderpaste should be specified for thespecific deposition process to beused: between 500,000 and600,000 centipoise for screenprinting, between 700,000 and800,000 centipoise for stencilprinting, and between 350,000and 450,000 centipoise fordispensing. An 80 mesh screenwill provide a solder depositionthickness of 0.20 mm (0.008 in.).The solder paste should coverthe pad with a smooth, evencontour, without voids. Voids inthe deposited solder paste maybe due to contamination oroxidation on the pc board metalpads, improper solder pasteviscosity, clogged openings inthe screen mesh, or a dirtysyringe dispensing tool. Sincesolder paste will wick outwardby 0.004 to 0.005 inches, thedeposited paste should cover theattachment pad just short bythis amount.

    Convective IR Reflow SolderingAll SMT LED components maybe reflow soldered using aconvective IR process. Aconvective IR process usesmiddle to long infraredwavelengths (approximately4000 to 6200 nanometers).Approximately 65% of the energyis used to heat the air in thereflow chamber (convectiveheating) and 35% of the energydirectly heats the pc board andcomponents (radiative heating).Some systems are forced hot airsystems with a dual chamberdesign, where one chamber hasIR heaters to heat the air whichis then blown over the pc boardassemblies located in a secondchamber. In these systems,heating is 100% convective. Thepc board and components areuniformly heated to achievereliable solder connections. Thethermal stresses experienced bySMT LED components areminimized in a convectivethermal environment.

  • 15

    Figure 11 is a straight-linerepresentation of a nominaltemperature profile for aconvective IR reflow solderprocess. The temperature profileis divided into four processzones with four DT/Dtimetemperature change rates. TheDT/Dtime temperature changerates are detailed in Table 2. Thetemperatures are measured atthe component to pc boardconnections.

    Process Zone P1In process zone P1, the pc boardand SMT LED components areheated to a temperature of +125C to activate the flux in thesolder paste. The temperatureramp up rate, R1, is limited to +3C per second to allow for evenheating of both the pc board andthe SMT LED components.

    Process Zone P2Process zone P2 should be ofsufficient time duration to drythe solder paste. Thetemperature is raised to a leveljust below the liquidus point ofthe solder, usually +170 C (+338F) for leaded IR reflow solderprocess and [+217 C (+422.6F)] for lead free reflow solderprocess.

    Process Zone P3Process zone P3 is the solderreflow zone. In zone P3, thetemperature is quickly raisedabove the liquidus point ofsolder to +230 C (+446 F)[+260 C (+500 F)] for optimumresults. The dwell time above theliquidus point of solder shouldbe between 15 and 90 seconds. Itusually takes about 15 [60]seconds to assure propercoalescing of the solder balls

    into liquid solder and theformation of good solderconnections. Beyond a dwelltime of 90 [150] seconds, theintermetallic growth within thesolder connections becomesexcessive, resulting in theformation of weak andunreliable connections. Thetemperature is then rapidlyreduced to a point below thesolidus temperature of thesolder, usually +170 C (+338F) for leaded IR reflow solderprocess and [+217 C (+422.6F)] for lead free IR solderprocess, to allow the solderwithin the connections to freezesolid.

    Figure 11. The Temperature Profile for a Nominal Convective IR Reflow Solder Process. See Table 2 for Temperature (RX) Values.

    Table 2. Convective IR Reflow Process Zones. See Figure 11.

    enoZssecorP lobmyS DDDDDT DDDDD /T DDDDD emit

    pUtaeH 1R,1P C521+otC52+ XAMs/C3+

    yrDetsaPredloS 2R,2P C071+otC521+ XAMs/C5.0+

    wolfeRredloS 3R,3P4R

    )XAMC532+(C032+otC071+C071+otC032+

    PYTs/C5.4+PYTs/C5.4-

    nwoDlooC 5R,4P C52+otC071+ XAMs/C3-

    230

    200

    150

    100

    50

    25

    125

    170

    183

    0 15 30 45 60 75 90 105 120 135 150 165 180 195 210

    T-TE

    MPE

    RA

    TUR

    E (

    C)

    P1HEAT UP

    P2SOLDER PASTE DRY

    P3SOLDERREFLOW

    P4COOL DOWN

    R1

    R2

    R3 R4

    R5

    90s MAX.ABOVE183 C

    t-TIME (SECONDS)

    Note:Values shown in [] are for lead free IR reflow solder process.

  • 16

    [P1] Heat Up

    [P2] Solder Paste Dry

    [ P3] Solder Reflow

    [P4] Cool Down

    0255075

    100125150175200225250275

    0 20 40 60 80 100

    120

    140

    160

    180

    200

    220

    240

    260

    280

    300

    320

    340

    360

    380

    400

    420

    t-Time (Seconds)

    T-Te

    mper

    atur

    e (C

    )

    60 - 150 sec

    10 - 20 sec

    255 +5/-0C

    217C

    [R1]

    [R2]

    [R3] [R4]

    [R5]

    Process Zone P4Process zone P4 is the cool downafter solder freeze. The cooldown rate, R5, from the liquiduspoint the solder to +25 C (+77F) should not exceed -3 C(+26.6 F) [-6 C (+21.2 F)] persecond maximum. Thislimitation is necessary to allowthe pc board and SMT LEDdevices to change dimensionsevenly, putting minimal stresseson the SMT LED devicepackages.

    Figure 12: Recommended Sample Lead-Free Temperature Profile IR Reflow Solder Process. See Table 3 for Temperature [RX] Values.

    Table 3. Recommended Lead-Free IR Reflow Process Zones. See Figure 12.

    sessecorP lobmyS DDDDDT DDDDD /T DDDDD emit

    putaeH ]1R[,]1P[ C521+otC52+ A/N

    yrDetsaPredloS ]2R[,]2P[ C712+otC521+ A/N

    wolfeRredloS ]4R[,]3R[,]3P[ C552+otC712+C712+otC552+

    XAMs/C3+XAMs/C3-

    nwoDlooC ]5R[,]4P[ C52+otC712+ XAMces/C6-

    Note:Values shown in [] are for lead free IR reflow solder process.

  • 17

    Type 2 PC Board Processing WithLED ComponentsA Type 2 pc board assembly hasboth SMT LED and through holeLED components installed. Theprocessing sequence of Type 2pc boards is important to assurefinal assembly yield. Thefollowing suggested processingsequences assure high post-solder yields for both the SMTLED and through hole LEDcomponents. The processesdescribed are assumed to behigh volume, automatedprocesses with auto-insertion ofthrough hole LED components.The SMT LED components areplaced onto the top surface ofthe pc board with automatedplacement equipment.Attachment epoxy may be usedto hold the SMT LEDcomponents to the pc boarduntil the board is reflowsoldered. The automated solderpaste screen printer, SMTplacement equipment, auto-insertion machine, reflow andwave solder machines, and postsolder cleaning unit are all partof a continuous in-line processwith automated board handlingequipment.

    Preferred ProcessReflow solder SMT LEDcomponents prior to auto-insertion of through hole LEDcomponents. The reflow andwave solder operations areseparated by the auto-insertionoperation.

    1. Screen print the solder pasteand deposit the attachmentepoxy for the SMT LEDcomponents.

    2. Auto-place the SMT LEDcomponents.

    3. Cure the attachment epoxyand dry the solder paste.

    4. Reflow solder the SMT LEDcomponents.

    5. Auto-insert the through holeLED components.

    6. Wave solder the through holeLED components.

    7. Clean the pc board assembly.

    This process sequence has thefollowing advantages:

    1. The SMT LED components areattached to the pc board priorto auto-inserting the throughhole LED components.

    2. Since the SMT LEDcomponents are reflowsoldered, they are notdisplaced from the pc boardduring auto-insertion of thethrough hole LEDcomponents.

    3. Wave soldering the pc boardafter solder reflow does notremelt the SMT solderconnections.

    4. The through hole LEDcomponents are not exposedto the high temperatures ofthe reflow solder operation.

    Alternate ProcessAuto-insert the through holeLED components prior toplacing the SMT LEDcomponents, then reflow andwave solder in direct sequence.

    1. Screen print the solder pasteand deposit the attachmentepoxy for the SMT LEDcomponents.

    2. Auto-insert the through holeLED components.

    3. Auto-place the SMT LEDcomponents.

    4. Cure the attachment epoxyand dry the solder paste.

    5. Reflow solder the SMT LEDcomponents.

    6. Wave solder the through holeLED components.

    7. Clean the pc board assembly.

    This process sequence has thefollowing advantages:

    1. The through hole LEDcomponents are auto-insertedprior to attaching the SMTLED components.

    2. The SMT LED components arenot subject to displacementoff the pc board during auto-insertion of the through holeLED components.

    3. Since the through hole LEDcomponents are loose on thepc board (not soldered) theyare better able to withstandexposure to the hightemperatures of the reflowsolder operation.

    4. Wave soldering the pc boardafter solder reflow does notremelt the SMT solderconnections.

    Precautions When Handling HSMx-C540 and HSMx-C2201. Once the moisture barrier bag

    unsealed, the best method isto finish the reel. Otherwise, itis advisable to immediatelystore the unfinished parts inthe moisture barrier bag andseal

    2. For double-sided PCB withSMT components on bothsides, it advisable to subjectboth sides to one time reflowonly, meaning that thecomponents will be solderedduring the second reflow.

    3. Avoid rinsing before solderreflow. If this is unavoidable,then bake dry thecomponents/ board beforesolder reflow.

  • 18

    Through-The-Wave (TTW) SolderingNot all SMT LED componentscan be mounted on the solderside of a pc board. See Table 3for a list of Agilent TechnologiesSMT LED components which canbe processed by TTW soldering.Attaching SMT LED componentsto the solder side of a pc boardusing TTW processing can beaccomplished by carefullycontrolling the wave solderprocess. It is absolutelyimperative that the SMT LEDcomponents be free of absorbedmoisture before being exposedto TTW solder processing, seesection titled Moisture BarrierEnvelope Packaging forappropriate handling measures.If the SMT LED componentscontain absorbed moisture,there is a high probability thatthe absorbed moisture will beturned into superheated steamby the large thermal mass of asolder wave, causing devicepopcorning to occur.

    A nitrogen atmosphere solderwave machine is recommendedto achieve the highest possiblesolder connection yields. Theuse of a high quality no-cleanflux and SN63 eutectic solderare encouraged. Spraying the no-clean flux onto the solder side ofthe pc board is recommended.Coverage is superior to foamfluxing, and the amount of fluxdeposited onto the pc board canbe controlled to assure properfluxing of all SMT componentconnections.

    It is critical that the temperaturedifference between the preheattemperature and the solderwave temperature must notexceed the maximum of +100 C(+180 F), as measured at asolder connection on the solderside of the pc board. SMT LEDcomponents, like many SMTceramic chip capacitors, are notable to withstand aninstantaneous thermal shock

    temperature difference greaterthan +100 C. The followingtemperature, dwell timeAbsolute Maximum Ratings forTTW processing must beobserved to assure high yields.

    The following TTW dual wavesolder process is recommended:

    1. Establish the correct preheattemperature, measured at asolder connection on thesolder side of the pc board,required to properly activatethe no-clean flux, for example+135 C (+275 F). Thispreheat temperature shouldbe reached only during thelast 20% of the travel throughthe preheat chamber to assureproper flux activation.

    2. Set the solder wavetemperature to be less than+100 C (+180 F) above thepreheat temperatureestablished in Step 1, forexample, +135 C (+275 F)+100 C (+180 F) = +235 C(+455 F) maximum solderwave temperature.

    Table 4. TTW Processing Compatibility of SMT LED Components

    Absolute Maximum Ratings for TTW Processing of SMT LED Components

    3. Set the machine conveyorspeed to limit the combineddwell time of an SMT LEDcomponent in the two solderwaves to no more that 10seconds.

    4. Spray flux at roomtemperature.

    5. Wave solder the pc board.6. Allow the soldered pc board

    to cool to room temperaturebefore handling.

    7. Post solder cleaning isnormally not necessary withthe use of a no-clean flux.

    8. Should post solder cleaningbe included in the process,allow the soldered pc board tocool to either roomtemperature, for handcleaning, or to the processingtemperature of the in-linecleaning process.

    9. For post solder cleaning, anin-line water cleaning processis recommended with watertemperature and hot air drytemperature set between +60C (+140 F) and +71 C(+160 F).

    Product Series Approved for TTW (Yes/No)

    HLMx-xxxx Subminiature Lamps No

    HSMx-Cxxx Chip LEDs No

    HSMx-Sxxx Chip LEDs No

    HSMx-H670 Flip Chip LEDs Yes

    HSMx-H690 Flip Chip LEDs Yes

    HSMx-R661 Right Angle Chip LEDs and FlipChip LEDs

    Yes

    HSMx-Axxx-xxxxx PLCC SMT LED Yes

    Temperature Difference Between Preheat andSolder Wave:

    +100 C (+180 F)

    Preheat: +160 C

    Solder Wave: +250 C

    Dwell Time: 10 seconds

  • www.agilent.com/semiconductorsFor product information and a complete list ofdistributors, please go to our web site.

    For technical assistance call:Americas/Canada: +1 (800) 235-0312 or(916) 788-6763

    Europe: +49 (0) 6441 92460

    China: 10800 650 0017

    Hong Kong: (+65) 6756 2394

    India, Australia, New Zealand: (+65) 6755 1939

    Japan: (+81 3) 3335-8152(Domestic/International), or0120-61-1280(Domestic Only)

    Korea: (+65) 6755 1989

    Singapore, Malaysia, Vietnam, Thailand, Philippines,Indonesia: (+65) 6755 2044

    Taiwan: (+65) 6755 1843

    Data subject to change.Copyright 2003 Agilent Technologies, Inc.Obsoletes: 5988-7835EN

    July 24, 2003

    5988-9462EN

    ContentsSurface Mount LED IndicatorsStandard EIA Tape and Reel PackagingFigure 1a.Figure 1b.Figure 1c.Figure 1d.Figure 1e.Moisture Barrier Envelope PackagingFigure 2.SMT LED Device Lead MaterialTable 1.PC Board Pad DesignPC Board Pad Design Considerations and Device-to-Device Pad AlignmentFigure 3.Figure 4.Subminiature Lamp ComponentsFigure 5.Figure 6.Figure 7.Figure 8.Chip LED Lamp ComponentsFigure 9.Figure 10.Automatic Placement Equipment ConsiderationsSolder PasteConvective IR Reflow SolderingFigure 11.Table 2.Process Zone P1Process Zone P2Process Zone P3Process Zone P4Figure 12: Recommended Sample Lead-Free Temperature Profile IR Reflow Solder Process. See Table 3 for Temperature [RX] Values.Type 2 PC Board Processing With LED ComponentsPreferred ProcessAlternate ProcessPrecautions When Handling HSMx- C540 and HSMx-C220Through-The-Wave (TTW) SolderingTable 3.Table 4. TTW Processing Compatibility of SMT LED ComponentsAbsolute Maximum Ratings for TTW Processing of SMT LED Components