MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第401页

MIL-STD-883F METHOD 2030 29 May 1987 1 METHOD 2030 ULTRASONIC INSPECTION OF DI E ATTACH 1. PURPOSE . The purpos e of thi s examination i s to nondes tr ucti vely detect unbonded regions and voids in the die attac h mater…

MIL-STD-883F

METHOD 2029

29 May 1987

c. Insert test post into test hole. The contact of the test post to the ceramic chip carrier shall be made without

appreciable impact (<

0.1 inch/minute). With the stressing element of the test equipment traveling at a constant

rate of 0.02 ±1 percent inch/second, apply sufficient force to chip carrier (through test post) to break all chip carrier

to substrate bonds on at least three edges of chip carrier under test. When failure occurs, the force at the time of

failure and the failure category shall be recorded. Any test resulting in the fracturing of either the chip carrier or test

substrate shall be considered unacceptable. The data from the test shall be discarded, and the test performed

again.

3.3 Failure criteria

. Any push test which results in separation with a bond strength of less than 30 kg-force per linear inch

(1180 g-force per linear mm) of solder pad width shall constitute a failure. The bond strength shall be determined by dividing

the separating force by the total of the solder pad widths as measured on the substrate at the package edge, in a direction

parallel to the package edge.

3.3.1 Failure category

. Failure categories are as follows. When specified, the stress required to achieve separation and

the predominant category of separation shall be recorded.

a. Device fracture.

b. Failure in package-bond interface.

c. Terminal break at point not affected by bonding process.

d. Failure in bond-substrate conductor interface.

e. Conductor lifted from board or substrate.

f. Fracture within board or substrate.

4. SUMMARY

. The following details shall be specified in the applicable acquisition document.

a. Minimum bond strength if other than specified in 3.3 or details of required strength distributions if applicable.

b. Sample size number and accept number and selection and number of devices to be tested on each substrate, if

other than 4.

c. Requirement for reporting of separation forces and failure categories, when applicable (see 3.3.1).

MIL-STD-883F

METHOD 2030

29 May 1987

METHOD 2030

ULTRASONIC INSPECTION OF DIE ATTACH

1. PURPOSE

. The purpose of this examination is to nondestructively detect unbonded regions and voids in the die

attach material of semiconductor devices through the measure of acoustic continuity. It establishes methods and criteria for

ultrasonic inspection of semiconductor devices.

a. For certain die attach materials, a dramatic distinction between well-bonded and poorly bonded conditions may be

difficult to achieve. This factor should be considered in relation to the design of each device when application of

this test method is specified.

b. The term "die attach interface" as used in this document refers to the entire area between the silicon die and the

substrate to which it is bonded. This includes the interface between the die attach material and the die, the

interface between the die attach material and the substrate, plus the die attach material itself.

c. The term ultrasonic inspection as used in this document refers to high frequency ultrasonic visualization (imaging)

which produces a gray scale output such as may be provided by ultrasonic scanning (US) or C-SCAN, scanning

laser acoustic microscopy (SLAM), or C-mode scanning acoustic microscopy (C-SAM).

2. APPARATUS

. The apparatus and materials for this test shall include:

a. Ultrasonic imaging equipment with a test frequency sufficient to penetrate to the die attach interface. The test

frequency and focal distance shall be adequate to detect voids as small as 0.0254 mm (0.001 inch) in diameter.

b. Output device: A hard copy grey scale recording unit or other direct recording device (computer storage) shall be

used to produce an image for analysis (manual or automated). The dynamic range of the output image shall be at

least sixteen discernible colors or levels of grey. The image shall be large enough to be viewed at 10X or lower

magnification.

c. Ultrasonic detector: Shall be capable of detecting an acoustic signal which enters the back or bottom of the

package and is reflected by or transmitted through the die attach interface. The reflected mode of imaging shall be

used where the opening of a sealed, hermetic device is undesirable.

3. PROCEDURE

. The ultrasonic generator, receiver, and line scan recorder settings (when used) shall be selected or

adjusted as necessary to obtain satisfactory images and achieve maximum image details within the sensitivity requirements

for the device or defect features the test is directed toward. In the case of reflection mode or transmission mode images,

care must be exercised to insure that the ultrasound penetrates and is sensitive to the entire die attach interface.

3.1 Mounting and views

. The devices shall be mounted in the holding tank so that the devices are not damaged or

contaminated and are in the proper plane as specified. The devices may be mounted in any type of fixture provided the

fixtures do not block the view from the ultrasonic transducer to any portion of the body of the device. The coupling fluid in

the holding tank shall be distilled water or other suitable noncorrosive liquid. The devices shall remain in the coupling fluid

for as short a time as possible. Subsequent to the ultrasound inspection, proper cleaning and drying of the samples are

required.

3.1.1 Views

. All devices, shall have one view made with the acoustic signal penetrating the device in a direction

perpendicular to the plane of the die attach, and for which there is acoustic continuity from the case exterior surface to the

die attach interface (generally, the Y1 direction with the die attach parallel to the XZ plane). For devices with no sealed air

gap above the active surface of the semiconductor element (unlidded devices), a view made with the acoustic signal

directed from or through the active surface of the semiconductor element to the die attach interface may be specified.

MIL-STD-883F

METHOD 2030

29 May 1987

3.2 Recording and marking. The acoustic image shall be printed by equipment using dry electrosensitive paper and with

a resolution of 150 data elements per inch nominal. The image shall be identified by unambiguously marking the paper on

which the image is printed with the following information:

a. Device manufacturer's name or code identification number.

b. Device type or part number.

c. Production lot number or date code or inspection lot number.

d. Ultrasonic image view number and date.

e. Device serial or cross reference numbers, where applicable.

f. Ultrasonic laboratory identification, if other than device manufacturer.

3.2.1 Nonprint techniques, when specified

. The use of other than paper recording techniques is permitted if permanent

records are not required and the equipment is capable of producing results of equal quality when compared to printed

recording techniques, and all requirements of this method are complied with, except those pertaining to the actual recording.

3.2.2 Serialized devices

. When device serialization is required, each device shall be readily identified by a serial number.

They shall be imaged in consecutive, increasing serial order. When a device is missing, the blank space shall contain the

serial number or other marking to readily identify and correlate ultrasonic image data. When large skips occur within

serialized devices, the serial number of the last device before the skip and the first device after the skip may be used in

place of large physical spacing of the devices.

3.2.3 Calibration

. When specified, at least one open lid device of the same type and construction should be available to

set up the visualization instruments. The device may be a scrap, nonoperational device which will be used to identify

internal landmarks and insure the equipment is properly operating.

3.3 Tests

. Acoustic frequency gate settings, receiver attenuation, and other equipment settings shall be selected to

achieve resolution of 0.0254 mm (0.001 inch) in major dimension, optimize the signal reflected from the die attach interface,

and to demark image features with as great a contrast as possible. Ultrasonic images shall be made for each view required.

3.4 Operating personnel

. Personnel who will perform ultrasonic inspection shall have training in ultrasonic imaging

procedures and techniques so that defects revealed by this method can be validly interpreted and compared with applicable

standards. The following minimum vision requirements shall apply for visual acuity of personnel inspecting images:

a. Distant vision shall equal at least 20/30 in both eyes, corrected or uncorrected.

b. Near vision shall be such that the operator can read Jaeger type number 2 at a distance of 16 inches, corrected or

uncorrected.

c. Vision tests shall be performed by an oculist, optometrist, or other professionally recognized personnel at least

once a year. Personnel authorized to conduct ultrasonic imaging tests shall be required to pass the vision tests

specified in 3.4a and 3.4b.

3.5 Interpretation of ultrasonic images

. Ultrasonic images shall be inspected to determine that each device conforms to

this standard and defective devices shall be rejected. Interpretation of the image shall be made under moderate light level

conditions without a glare on the recording paper's surface. The image shall be viewed at a magnification between 1X and

10X.