ED-7306_E - 第21页

JEITA ED-7306 - 19 - 6. Deliberation members The scheme of this standard was made by the S ubcommittee on Integrated Circuit Packag es and deliberated by the Task force of the package wa rpage measurement at elevated tem…

JEITA ED-7306

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5. Relation to the international standard

There is not any international standard (IEC) related to the warpage measurement method at elevated

temperature but the JESD22B112 published by JEDEC, USA. The comparisons between JESD22B112

and this specification are shown below:

Item

JESD22B112 This specification (JEITA)

Object Surface mount devices BGA, FBGA, FLGA, but excluding QFP

Warpage

direction

Convex warpage results in the package

corners being closer to the seating plane than

the center of the bottom surface of the

package. Concave warpage results in the

package corners being farther from the seating

plane than the center of the bottom surface of

the package.

Same as JESD22B112

Measuring

zone

Unspecified a) For the packages whose standoff height is

more than 0.1 mm, such as BGA and FBGA,

the measuring zone is the area where

terminals are located. This area is bordered

by the lines connecting the centers of the

outermost neighboring solder balls. If there

are thermal balls at the package center,

their area is also considered as a part of

measuring zones.

For the packages whose standoff height is

0.1 mm or less, such as FLGA, the

measuring area is the substrate surface

except certain edge margin. The width of

this margin L depends on the capability of

each measuring instrument (0.2 mm

recommended).

Package

warpage sign

Convex warpage is plus.

Concave warpage is minus.

Plus or minus sign of package warpage

determined by the sign of the sum of the

largest positive displacement and the largest

negative displacement of the package profile

on both measurement zone diagonals.

Package

warpage

“Deviation from planarity” is the difference in

height between the highest point and the

lowest point on the package body bottom

surface measured with respect to the seating

plane.

The difference of the largest positive and the

largest negative displacements of the package

warpage in the measuring zone with respect to

the reference plane, preceded by package

warpage sign. This reference plane is derived

using the least square method with the

measuring zone data.

Measuring

instrument

Shadow moiré only The measurement methods of the package

warpage are shadow moiré or laser reflection

method.

Calibration Concave or convex ground glass made of

ultra-low expansion material

Unspecified

Measurement

points

Warpage measurements should be viewed on

the substrate side without solder balls

attached.

The measurement points shall not be on the

crown of solder balls but on the substrate

surface of the package. Only when the

behavior of the package top surface (mostly

marking surface) is verified to coincide with

that of the substrate surface, the measurement

from the top surface is allowed.

JEITA ED-7306

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Item

JESD22B112 This specification (JEITA)

Solder ball

removal

• A simulated solder ball attachment process is

recommended to subject the test samples to

the same thermal exposure.

• Verification of the technique used to remove

the solder balls must be conducted.

• If the samples are prepared without solder

balls, they shall be subjected to the

simulated reflow profile.

• In the case of removal of the solder balls, it is

recommended to use mechanical removal

rather than hot reflow.

Peripheral lead

packages

For lead frame based packages, either the top

or bottom for the package body surface can be

measured.

Peripheral lead packages are excluded in the

scope of this specification.

Sample A minimum of 3 samples shall be measured to

determine variation within an assembly lot. It is

recommended that samples be measured in

both the moisture soaked and dry states.

If this test method is used for monitoring then

the package warpage may be measured in

only the dry state.

• Standard sample size is a minimum of 3

samples with pretreatment.

• The same sample shall not be subjected to

the repetition of the reflow profile cycles.

Pretreatment

of the samples

The minimum moisture soaked condition shall

be the rated moisture sensitivity level per

J-STD-020. It specifies that the waiting time

for the measurement after pretreatment shall

be 4 h or less.

Pretreatment conditions shall conform to

JEITA ED-4701/300 to measure the package

warpage.

Waiting time for measurement shall be no

longer than 5 hours after the pretreatment.

Thermocouple Thermocouple of gauge 30 or finer is

recommended. When polyimide tape is used,

it is recommended that a thermal paste should

be applied between the thermocouple bead

and the surface of the test sample. (Original

document quotes the commercial name for the

polyimide tape.)

A thermocouple of gauge 30 (φ0.25 mm) or flat

tip type is recommended.

When polyimide tape is used, a thermal sheet

is applied between the thermocouple bead and

the package surface.

Temperature

measurement

Ideally, a temperature ramp rate that can

closely match the reflow profile should be

used. The equipment should be configured to

achieve as fast a ramp rate as possible without

introducing significant delta temperature

differences between the top and bottom of the

package body.

The temperature profile of the warpage

measurement does not necessarily simulate

that for production. Higher priorities are placed

maintaining the temperature constant

during the measurement,

never exposing the samples unnecessary

duration to high temperature. Samples

shall be proceeded to the next

measurement as soon as possible,

avoiding temperature surge to prevent the

overshoot, and

minimizing the temperature difference

between the top surface and the substrate

surface.

Reflow oven Thermal chambers equipped with assisted

convective heating are highly recommended.

Unspecified

Data - A plot showing total warpage magnitude

versus temperature with the (+) and (-)

conventions assigned.

3-D contour plots of package shape as a

function of peak reflow temperature.

Diagonal line scans showing total warpage

magnitude across the diagonal of the

component.

• Temperature dependency of the package

warpage

• 3D plots of surface topography at each

temperature

• Diagonal profile of the package at each

temperature

Recommended

datasheet

Unspecified • Typical temperatures for measurement and

recommended datasheet are described.

Maximum

permissible

package

warpage

Unspecified • Maximum permissible package warpages for

BGA, FBGA, and FLGA are specified in this

specification.

JEITA ED-7306

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6. Deliberation members

The scheme of this standard was made by the Subcommittee on Integrated Circuit Packages and

deliberated by the Task force of the package warpage measurement at elevated temperature.

The participated members are:

TSC chair Chiaki Takubo Toshiba Corp.

SC chair Hiroyuki Shigeta Sony Corp.

Leader Hirofumi Nakajima NEC Electronics Corp.

Member Koujiro Shibuya NEC Electronics Corp.

Akio Nakamura Oki Electric Industry Co., Ltd.

Hiroyuki Shigeta Sony Corp.

Hitoshi Shibue Sony Corp.

Yasuhiro Koshio Toshiba Corp.

Tsuyoshi Kanazawa Toshiba Corp.

Daisuke Otani Toshiba Corp.

Takayuki Maeda Texas Instruments Japan Ltd.

Kazunari Kosakai Fujitsu Ltd.

Takahiro Nakano Matsushita Electric Industrial Co., Ltd.

Takanori Hashizume Renesas Technology Corp.

Hiroshi Kawakubo Renesas Technology Corp.

Special members Tomoya Kiga Sony EMCS Corp.

Takanori Miyata Cermatronics Boeki Co., Ltd.

Nobuhiko Takahashi Hitachi Technologies and Services, Ltd.

Yoshio Ichikawa Cores Corp.