4

ã 2000 Semtech Corp.

www.semtech.com

PRELIMINARY

PROTECTION PRODUCTS

SFC05-4

PRELIMINARY

Device Connection Options

The SFC05-4 has solder bumps located in a 3 x 2

matrix layout on the active side of the device. The

bumps are designated by the numbers 1 - 3 along the

horizontal axis and letters A - B along the vertical axis.

The lines to be protected are connected at bumps A1,

B1, A3, and B3. Bumps A2 & B2 are connected to

ground. All path lengths should be kept as short as

possible to minimize the effects of parasitic inductance

in the board traces.

Wafer Level CSP TVS

CSP TVS devices are wafer level chip scale packages.

They eliminate external plastic packages and leads and

thus result in a significant board space savings. Manu-

facturing costs are minimized since they do not require

an intermediate level interconnect or interposer layer

for reliable operation. They are compatible with cur-

rent pick and place equipment further reducing manu-

facturing costs. Certain precautions and design

considerations have to be observed however for

maximum solder joint reliability. These include solder

pad definition, board finish, and assembly parameters.

Printed Circuit Board Mounting

Non-solder mask defined (NSMD) land patterns are

recommended for mounting the SFC05-4. Solder

mask defined (SMD) pads produce stress points near

the solder mask on the PCB side that can result in

solder joint cracking when exposed to extreme fatigue

conditions. The recommended pad size is 0.200 ± 10

mm with a solder mask opening of 0.350 ± 0.025 mm.

Grid Courtyard

The recommended grid placement courtyard is 1.3 x

1.8 mm. The grid courtyard is intended to encompass

the land pattern and the component body that is

centered in the land pattern. When placing parts on a

PCB, the highest recommended density is when one

courtyard touches another.

Applications Information

Device Schematic & Pin Configuration

Layout Example

NSMD Package Footprint

A

B

1

23

To Protected IC

To Protected IC

To Connector

Ground