SURFACE MOUNT PRODUCTS Marking Because of the limited space available for part marking on some SMT packages, abbreviated marking codes are used to identify the device. These codes, if used, are identified in the individual SMT package data sheets. Lead Finish and Solderability Standard lead finish is electroplated 100% matte tin. LTC also offers electroplated PbSn (15% Pb/85% Sn) lead finish upon request. Both are electroplated with < 0.05% carbon content. Solderability meets the requirements of MIL-STD-883C, Method 2003. Recommended minimum solder pad dimensions are given with each package. (Note: Consideration should be given to your process and power requirements.) Wave and Reflow Soldering for Lead Frame Packages (QFN, DFN, CLCC, SOIC, SSOP, TSSOP, MSOP, PDIP, TO-220/DD-Pak, TSOT, SOT, SC70 and LQFP) Following are the recommended procedures for soldering surface mount packages to PC boards. 1.Wave Soldering • • • • • • • • • Use solder plating boards. Dispense adhesive to hold components on board. Place components on board. Cure adhesive per adhesive manufacturer’s specification. Preheat package temperature shall be between 100°C and 130°C. Foam flux using RMA (Rosin Mildly Activating) flux. Wave solder using a dual wave soldering system, see Figure 3 (Guideline for Dual-Wave Solder Profile), for details. Clean board. Wave soldering is not recommended for SOT-223, QFN and DFN packages. 2. Reflow Soldering Temperature Profile for SnPb and Matte Sn Lead Finishes Linear Technology offers products with either SnPb or matte Sn finishes for lead frame packages (QFN, DFN, CLCC, SOIC, SSOP, TSSOP, MSOP, PDIP, TO-220/DDPAK, TSOT, SOT, SC70, and LQFP) which are compatible with eutectic SnPb and SnAgCu/ SAC solder pastes for PCB assemblies. SMT reflow conditions per IPC/JEDEC J-STD-020 are recommended for SnPb finish and matte Sn finish products (see Figure 1 and Figure 2). It is recommended not to exceed a maximum three cycles of SMT reflow under the appropriate conditions. Table 1. SnPb Eutectic Process–Classification Temperatures (TP) PACKAGE THICKNESS VOLUME mm3 <350 VOLUME mm3 ≥350 <2.5mm 235°C 220°C ≥ 2.5mm 220°C 220°C Table 2. Pb-free Process–Classification Temperatures (TP) PACKAGE THICKNESS VOLUME mm3 <350 VOLUME mm3 350 to 2000 VOLUME mm3 >2000 <1.6mm 260°C 260°C 260°C 1.6mm to 2.5 mm 260°C 250°C 245°C > 2.5 mm 250 °C 245 °C 245 °C Table 3. Classification of Reflow Profiles Sn-Pb EUTECTIC ASSEMBLY Pb-FREE ASSEMBLY 100°C 150°C 60 to 120 Seconds 150°C 200°C 60 to 120 Seconds 3°C/Second Max 3°C/Second Max 183°C 60 to 150 seconds 217°C 60 to 150 seconds See Table 1 See Table 2 Time (tP) Within 5°C of the Specified Classification Temperature (TP) 20 Seconds Max 30 Seconds Max Average Ramp-Down Rate (TP to TSMAX) 6°C/Second Max 6°C/Second Max 6 Minutes Max 8 Minutes Max PROFILE FEATURE Preheat and Soak Temperature Min (TSMIN) Temperature Max (TSMAX) Time (TSMIN to TSMAX) (tS) Average Ramp-Up Rate (TSMAX to TP) Liquidous Temperature (TL) Time at Liquidous (tL) Peak Package Body Temperature (TP) Time 25°C to Peak Temperature Note: Reflow profiles in this document are for classification/ preconditioning and are not meant to specify board assembly profiles. Actual board assembly profiles should be developed based on specific process needs and board designs and should not exceed the parameters in Table 3. SURFACE MOUNT PRODUCTS Soldering: max 235°C (SnPb), 260°C (Pb free) Contact time: 10 sec max 130°C Solder joints formed at top by SMT reflow do not revert to liquid state Ramp up rate max: 3°C/sec Figure 1. SnPb Eutectic Process–Reflow Profile (J-STD-020D) Ramp down rate max: 5°C/sec Figure 3. Guideline for Dual-Wave Solder Profile temperature shall be carefully considered and simulated to ensure no damages to the components, PC boards and to achieve a good quality of solder joints. Dry Pack in Moisture Barrier Bags In the event of a requirement for Dry Pack, LTC employs as a guideline the methods of IPC-SM-786A, Procedures for Characterization of Moisture/Reflow Sensitive ICs. Figure 2. Pb Free Process–Reflow Profile (J-STD-020D) 3. Backward Compatibility Lead frame package finishes are backward compatible, meaning that the component can be soldered with SnPb solder using SnPb soldering process. Lead frame packages that use a matte Sn plating on the leads which is compatible with both Pb-free soldering alloys and SnPb soldering alloy. 4. Hand Soldering • Hand soldering of packages is not recommended for QFN, DFN, CLCC leadless packages. 5. Wave Solder Profile Non-surface mount pin through-hole IC packages, the recommendation is to follow IPC-7530-Guideline for Temperature Profiling for Massive Soldering Processes (See Figure 3) and IPC-9502-PWB Assembly Soldering Process Guideline for Electronic Components. The ramp up, thermal spike, dwell time and maximum topside Thermal Information Table 4 shows the range of junction-to-ambient thermal resistance of SO devices mounted on a PCB of FR4 material with copper traces, in still air at 25°C. θJA with a ceramic substrate is about 70% of the FR4 value. Maximum power dissipation may be calculated by the following formula: PDMAX ( TA ) = TJMAX – TA θ JA where, TJMAX = Maximum operating junction temperature. TA = Desired ambient operating temperature. θJA = Junction-to-ambient thermal resistance. Table 4. Typical Thermal Resistance Values SO-8 150°C/W to 200°C/W SO-18 70°C/W to 100°C/W SO-14 100°C/W to 140°C/W SO-20 70°C/W to 90°C/W SO-16 (0.150) 90°C/W to 130°C/W SO-24 60°C/W to 80°C/W SO-16 (0.300) 85°C/W to 100°C/W SO-28 55°C/W to 75°C/W Conditions: PCB mount on FR4 material, still air at 25°C, copper trace. SURFACE MOUNT PRODUCTS Thermal resistance for power packages (DD and SOT223) depends greatly on the individual device type. Please consult the device data sheets for thermal information. More current data, by device type, may be obtained by contacting LTC, Marketing Department. Tape and Reel Packing (See Tape and Reel Section) Plastic Tube Packing LTC’s Surface Mount products are packed in “antistatic” plastic tubes with the tube dimensions indicated in Figure 2. Unit quantities packaged per tube are listed below in Table 5. Table 5. Devices Per Tube LTC Package Code Designator LTC Package Type Actual Lead Count Number of Units DC LTC Package Code Designator LTC Package Type Actual Lead Count Number of Units DFN (2mm × 2mm) 3, 4, 6, 8 142 S8, S8E SO (0.150) 8 100 DCB DFN (2mm × 3mm) 6, 8 95 S SO (0.150) 14 55 DD DFN (3mm × 3mm) 8, 10, 12 121 S SO (0.150) 16 50 DDB DFN (3mm × 2mm) 5, 8, 10, 12 95 ST SOT-223 3 78 SO (0.300) 16 47 DE, UE DFN (4mm × 3mm) 12, 14, 16 91 SW DF DFN (4mm × 4mm) 12 91 SW SO (0.300) 18 40 SO (0.300) 20 38 SO (0.300) 24 32 DH DFN (5mm × 5mm) 16 73 SW DHC DFN (5mm × 3mm) 16 73 SW DHD DFN (5mm × 4mm) 16 73 SW SO (0.300) 28 27 QFN (3mm × 2mm) 10 95 DJC DFN (6mm × 3mm) 22 61 UDB DKD DFN (7mm × 4mm) 24, 32 52 UD QFN (3mm × 3mm) 12,16, 20 121 F, FE TSSOP (4.4mm) 20 74 UDC QFN (3mm × 4mm) 20, 24 91 QFN (3mm × 5mm) 24 73 F, FE TSSOP (4.4mm) 14, 16 95 UDD FE TSSOP (4.4mm) 24 62 UDE QFN (3mm × 6mm) 28 61 FE TSSOP (4.4mm) 28, 38 50 UF QFN (4mm × 4mm) 16, 20, 24, 28 91 QFN (4mm × 5mm) 20, 24, 28 73 FW TSSOP (6.1mm) 48 39 UFD FW TSSOP (6.1mm) 56 35 UFE QFN (4mm × 6mm) 26, 38 61 G SSOP (5.3mm) 16 77 UFF QFN (4mm × 7mm) 36, 34, 44 52 G SSOP (5.3mm) 20 66 UFH QFN (4mm × 9mm) 44 40 G SSOP (5.3mm) 24 59 UH QFN (5mm × 5mm) 20, 32, 40, 24 73 G SSOP (5.3mm) 28 47 UHE QFN (5mm × 6mm) 28, 36, 42 61 G SSOP (5.3mm) 36, 44, 48 37 UHF QFN (5mm × 7mm) 38 52 GN SSOP (0.150) 16 100 UHG QFN (5mm × 8mm) 39, 52 45 GN SSOP (0.150) 20, 24 55 UHH QFN (5mm × 9mm) 48, 56 40 GN SSOP (0.150) 28 49 UJ QFN (6mm × 6mm) 40 61 GW SSOP (7.62mm) 36 32 UK QFN (7mm × 7mm) 44, 48 52 GW QFN (7mm × 8mm) 52 45 SSOP (7.62mm) 44 27 UKG, WKG MS8, MS8E MSOP (0.118) 8 50 UKH, WKH QFN (7mm × 9mm) 64 40 MS, MSE MSOP (0.118) 10 50 UKJ QFN (7mm × 11mm) 64 33 MS, MSE MSOP (0.118) 12, 16 37 UKK QFN (7mm × 12mm) 64 30 DD 3, 5, 7 50 UP, WP QFN (9mm × 9mm) 64 40 M, Q, R SURFACE MOUNT PRODUCTS PLASTIC TUBE SPECIFICATIONS DD Pak M, Q, R Package Shipping Tube MSOP MS8 Package Shipping Tube 3.65 .274 .090 .040 ±0.005 .078 2.45 R0.4 .362 9.0 .709 .445 0.224 .050 .030 .360 .340 .080 ±.005 .015 0.035 ±0.005 +0.05 –0.05 3.6 1.5 REF 1.3 REF +0.10 1.35 –0.00 SMP 27 LENGTH: 171.5 ±0.50 DETAIL A .600 REF NOTE: ALL DIMENSIONS ARE IN MILLIMETERS, ±0.15 UNLESS OTHERWISE STATED. MATERIAL: POLYCARBONATE, ANTISTATIC TREATED SSOP G Package Shipping Tube SMP 43 R .025 TYP .354 +0.00 0.75 –0.10 1.339 .030 1.05 .050 “A” .030 3.15 ±0.1 LENGTH: 21.619 – 21.712 .080 ±.005 (NOTE 2) NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED .059 ±.005 .10 R MAX ALL CORNERS S (0.150) SO Package Shipping Tube .370 (NOTE 2) .220 ±.007 .205 .099 ±.007 .107 ±.005 .025 ± 0.005 WALL .170 REF .265 .315 REF .025 +.002 –.005 .163 ±.005 .024 ±.005 TYP WALL THICKNESS LENGTH: 20.0 ±.05 NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED .070 .155 +.063 LENGTH: 20.50 –.031 SMP 09 NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED SMP 45 SURFACE MOUNT PRODUCTS PLASTIC TUBE SPECIFICATIONS ST SOT-223 Package Shipping Tube .142 .026 .150 .140 SW (0.300) SO Package Shipping Tube .205 +.010 .048 –.005 .105 .060 .340 .375 ±.005 .020±.005 .280 .300 .310 .580 R .020 ×4, REF LENGTH: 21.288 – 21.381 SMP 11 NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED .063±.007 .055±.005 LENGTH: 20.75 +.031 –.063 NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED TSSOP F, FE Package Shipping Tube .080 .268 .020 ±.003 TYP WALL .025 R .160 SMP 44 .045 ±.005 LENGTH: 20.0 ±.050 NOTE: ALL DIMENSIONS ARE IN INCHES, ±.010 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED SMP 10 SURFACE MOUNT PRODUCTS PLASTIC TUBE SPECIFICATIONS DFN/QFN 0.80mm Thick Package Shipping Tube 1.27 A SMP50 MINIMUM PACKAGE WIDTH A DIMENSION 3mm 3.50 ±0.20 4mm 4.50 ±0.20 5mm 5.50 ±0.20 6mm 6.50 ±0.20 7mm 7.50 ±0.20 9mm 9.50 ±0.20 0.50 ±0.10 LENGTH: 379.86 – 382.14 NOTE: ALL DIMENSIONS ARE IN MILLIMETERS, ±0.25 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED UTDFN/UTQFN 0.60mm Thick Package Shipping Tube 0.76 +0.15 –0.10 A MINIMUM PACKAGE WIDTH A DIMENSION 3mm 3.50 ±0.20 4mm 4.50 ±0.20 5mm 5.50 ±0.20 7mm 7.50 ±0.20 SMP54 0.50 ±0.10 LENGTH: 379.86 – 382.14 NOTE: ALL DIMENSIONS ARE IN MILLIMETERS, ±0.25 UNLESS OTHERWISE STATED. MATERIAL: PVC, ANTISTATIC TREATED REV J 1015