■ Soldering and Mounting

1.PCB Design

1. Notice for Pattern Forms

1-1. Unlike leaded components, chip components are susceptible to flexing stresses since they are mounted

directly on the substrate.

They are also more sensitive to mechanical and thermal stresses than leaded components.

Excess solder fillet height can multiply these stresses and cause chip cracking. When designing substrates,

take land patterns and dimensions into consideration to eliminate the possibility of excess solder fillet

height.

1-2.There is a possibility of chip crack caused by PCB expansion/contraction with heat.

Because stress for chip is different depend on PCB material and structure.Especially metal PCB

such as alumina has a greater risk of chip crack because of large difference of thermal expansion coefficient.

In case of chip below 0402 size, there is also the same possibility of crack with a single-layered glass epoxy

board.

Pattern Forms

Placing of Leaded

Components

after Chip Component

Lateral Mounting

Notice

Prohibited

Correct

Placing Close to Chassis

Placing of Chip

Components

and Leaded Components

Chassis

Solder (ground)

Electrode Pattern

Solder Resist

Lead Wire

Solder Resist

Lead Wire

Soldering Iron

Solder Resist

ｿﾙﾀﾞﾚｼﾞｽﾄ

Solder Resist

JEMCCC-0010Q

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