08055C datasheet(18/20 Pages) AVX

18 / 20 page

Surface Mounting Guide

MLC Chip Capacitors

APPLICATION NOTES

Storage

Good solderability is maintained for at least twelve months,

provided the components are stored in their “as received”

packaging at less than 40°C and 70% RH.

Solderability

Terminations to be well soldered after immersion in a 60/40

tin/lead solder bath at 235 ± 5°C for 2 ± 1 seconds.

Leaching

Terminations will resist leaching for at least the immersion

times and conditions shown below.

Recommended Soldering Profiles

General

Surface mounting chip multilayer ceramic capacitors

are designed for soldering to printed circuit boards or other

substrates. The construction of the components is such that

they will withstand the time/temperature profiles used in both

wave and reflow soldering methods.

Handling

Chip multilayer ceramic capacitors should be handled with

care to avoid damage or contamination from perspiration

and skin oils. The use of tweezers or vacuum pick ups

is strongly recommended for individual components. Bulk

handling should ensure that abrasion and mechanical shock

are minimized. Taped and reeled components provides the

ideal medium for direct presentation to the placement

machine. Any mechanical shock should be minimized during

handling chip multilayer ceramic capacitors.

Preheat

It is important to avoid the possibility of thermal shock during

soldering and carefully controlled preheat is therefore

required. The rate of preheat should not exceed 4°C/second

and a target figure 2°C/second is recommended. Although

an 80°C to 120°C temperature differential is preferred,

recent developments allow a temperature differential

between the component surface and the soldering temper-

ature of 150°C (Maximum) for capacitors of 1210 size and

below with a maximum thickness of 1.25mm. The user is

cautioned that the risk of thermal shock increases as chip

size or temperature differential increases.

Soldering

Mildly activated rosin fluxes are preferred. The minimum

amount of solder to give a good joint should be used.

Excessive solder can lead to damage from the stresses

caused by the difference in coefficients of expansion

between solder, chip and substrate. AVX terminations are

suitable for all wave and reflow soldering systems. If hand

soldering cannot be avoided, the preferred technique is the

utilization of hot air soldering tools.

Cooling

Natural cooling in air is preferred, as this minimizes stresses

within the soldered joint. When forced air cooling is used,

cooling rate should not exceed 4°C/second. Quenching

is not recommended but if used, maximum temperature

differentials should be observed according to the preheat

conditions above.

Cleaning

Flux residues may be hygroscopic or acidic and must be

removed. AVX MLC capacitors are acceptable for use with

all of the solvents described in the specifications MIL-STD-

202 and EIA-RS-198. Alcohol based solvents are acceptable

and properly controlled water cleaning systems are also

acceptable. Many other solvents have been proven successful,

and most solvents that are acceptable to other components

on circuit assemblies are equally acceptable for use with

ceramic capacitors.

Termination Type

Solder

Immersion Time

Tin/Lead/Silver Temp. °C

Seconds

Nickel Barrier

60/40/0

260 ± 5

30 ± 1

Reflow

300

250

200

150

100

10 sec. max

1min

(Minimize soldering time)

Natural

Cooling

220

°C

250

°C

Preheat

Wave

300

250

200

150

100

(Preheat chips before soldering)

T/maximum 150

°C

3 sec. max

1 to 2 min

Preheat

Natural

Cooling

230

°C

250

°C

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