Nemco Electronics Full Catalog - Manual (Page 38)

3 38
Page
Cross Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Part Numbering System . . . . . . . . . . . . . . . . . . . . . . . . 5
Marking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Packaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Case Dimensions
for all Surface Mount Tantalums
. . . . . . . . . . 8
PCT
Surface Mount Tantalum Capacitors
Standard and Extended Range
. . . . . . . . . . . . . . . . . . 9
Low Profile
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
LSR
Low ESR Tantalum Capacitors
Standard and Extended Range
. . . . . . . . . . . . . . . . . 15
Low Profile
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
MCT
Miniature Surface Mount Tantalum Capacitors
. . . . . . . . . . . . 27
CGT
Consumer Grade Miniature Surface Mount Tantalum Capacitors
. . 29
TB
Dipped Tantalums
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Tips for Design and Use . . . . . . . . . . . . . . . . . . . . . . . 36
Table of Contents
There are several important general soldering considerations for tantalum capacitors.
• Soldering temperature and time should be the minimum for a good connection.
• Recommended soldering profiles are designed to insure that the temperature of the internal construction of the
capacitors does not exceed +220°C.
• Positioning capacitors near components radiating heat such as power transistors should be avoided.
• Allow for an increase to ESR ratings of 1.25 x catalog limit post PCB assembly.
Lead-free RoHS compliant, 100% Sn termination finish
Legislation is being developed worldwide to reduce the lead content and other hazardous substances in electronic products. This
will reduce the environmental impact when such products are discarded. Nemco products are lead-free devices which meet RoHS
requirements. Optional suffix codes have been added to our part numbering system so either 90/10 Sn/Pb or 100% Sn (lead-free)
can be specified. The following general information applies to lead-free surface mount devices.
IR and Convection reflow
Pre-heating: 150°C +/- 15°C / 60-90s
Maximum peak temperature: 240°C - 260°C, 250°C max recommended, 10 seconds maximum time at peak, 3 reflow cycles.
Ramp rate: 2-3°C/sec.
Maximum time (cumulative) above 230°C 40 seconds.
Cool down should not be forced. 6°C/sec. is recommended.
Wave soldering
PCT, LSR, MCT and CGT: Maximum peak temperature: 250°C - 260°C for 3-5 seconds max (250°C max recommended)
TB: Maximum peak temperature: 230°C - 250°C for 3-5 seconds max (240°C max recommended)
All other parameters remain the same as for IR reflow.
Hand soldering
Soldering iron tip diameter: select to fit application
Maximum tip temperature: +370°C
Maximum exposure time: 3 seconds
Apply heat to pad, not the terminations.
Recommended solder alloy for reflow: SnAgCu
lead-free (100% Sn) termination finish is compatible with all common lead-free solder pastes including SnCu, SnCuAgBi, etc.
Recommended solder alloy for wave soldering: SnCu
Recommended solder alloy for hand soldering: SnAgCu
Soldering conditions
Fluxes containing acids must not be used.
Cooling
After soldering, the assembly should preferably be allowed to cool naturally to room temperature. In the event that assisted cool-
ing is used, the rate of change in temperature should not exceed that used in reflow.
Forward compatibility
Parts with Sn/Pb can be used in a lead-free process depending on the solder and solder temperature.
Solders with Bi are not compatible.
Backward compatibility
Lead-free parts (100% Sn termination finish) can be used in a Sn/Pb process. The 100% Sn (Tin) termination finish is compatible
with existing Sn/Pb solder pastes / systems in use today.
RoHS
Nemco lead-free product complies with EU Directive 2002/95/EC on the Restriction of Hazardous Substances requirements.
JEDEC Standard JESD97
Nemco lead-free surface mount devices are in accordance with category e3 terminations.
MSL
PCT, LSR, MCT and TB series moisture sensitivity level per IPC/Jedec J-STD-020B is level 1.
CGT series moisture sensitivity level per IPC/Jedec J-STD-020B is level 3.
Visual standard
Lead-free solder joints are not as bright as tin-lead pastes and the fillet may not be as large.
Resin color
The encapsulant resin color may darken due to the increase in temperature required for the paste.
Self alignment
lead-free solder pastes do not allow the same self alignment as lead containing systems, Standard mounting pads are acceptable,
but machine set up may need to be modified.
Reliability
PCT, LSR, MCT and TB series are 1% per 1,000 hours at 85°C, Vr with 0.1Ω / V series impedance, 60% confidence level.
CGT series is 0.2% per 1,000 hours at 85°C, 0.5xVr with 0.1Ω / V series impedance, 60% confidence level.