GB/T 4937.35-2024 Semiconductor devices - Mechanical and climatic test methods - Part 35: Acoustic microscopy for plastic encapsulated electronic components
1 Scope
This document defines the procedures for performing acoustic microscopy on plastic encapsulated electronic components. This standard provides a guide to the use of acoustic microscopy for detecting anomalies (delamination, cracks, mould-compound voids, etc.) reproducibly and non-destructively in plastic packages.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
A-mode
acoustic data collected at the smallest X-Y-Z region defined by the limitations of the given
acoustic microscope
Note: An A-mode display contains amplitude and phase/polarity information as a function of time of flight at a single point in the X-Y plane. In this test method, A-mode is primarily used for focussing the acoustic microscope. See Figure 1.
Figure 1 - Example of A-mode display
3.2
B-mode
acoustic data collected along an X-Z or Y-Z plane versus depth using a reflective acoustic microscope. A B-mode scan contains amplitude and phase/polarity information as a function of time of flight at each point along the scan line
Note: A B-mode scan furnishes a two-dimensional (cross-sectional) description along a scan line (X or Y). In this test method B-mode is used to provide cross-sectional acoustic information. When scanned, B-mode can be used to track the depth of a defect. See Figure 2.
Figure 2 - Example of B-mode display (bottom half of picture on left)
3.3
back-side substrate view area
interface between the encapsulant and the back of the substrate within the outer edges of the substrate surface
Note: Refer to Annex A, type IV.
3.4
C-mode
acoustic data collected in an X-Y plane at depth (Z) using a reflective acoustic microscope
Note 1: A C-mode scan contains amplitude and phase/polarity information at each point in the scan plane. A C-mode scan furnishes a two-dimensional (area) image of echoes arising from reflections at a particular depth (Z). See Figure 3.
Note 2: C-mode is the preferred mode for scanning devices to determine compliance to the criteria of IEC 60749-20.
Figure 3 - Example of C-mode display
3.5
through transmission mode
acoustic data collected in an X-Y plane throughout the depth (Z) using a through transmission acoustic microscope
Note: A through transmission mode scan contains only amplitude information at each point in the scan plane. A through transmission scan furnishes a two-dimensional (area) image of transmitted ultrasound through the complete thickness/depth (Z) of the sample/component (see Annex C). Through transmission mode is used as a quick scan method to determine large defects in devices prior to investigation using C-mode. See Figure 4.
Figure 4 - Example of through transmission display
3.6
die attach view area
interface between the die and the die attach adhesive and/or the die attach adhesive and the die attach substrate
Note: Refer to Annex A, type II.
3.7
die surface view area
interface between the encapsulant and the active side of the die (refer to Annex A, type I)
3.8
focal length; FL
distance in water at which a transducer’s spot size is at a minimum
3.9
focus plane
X-Y plane at a depth (Z), at which the amplitude of the acoustic signal is maximized
3.10
leadframe view area
L/F
imaged area which extends from the outer L/F edges of the package to the L/F “tips” (wedge bond/stitch bond region of the innermost portion of the L/F)
Note: Refer to Annex A, type V.
3.11
reflective acoustic microscope
acoustic microscope that uses one transducer as both the pulser and receiver
Note 1: See Figure 5.
Note 2: This is also known as a pulse/echo system.
Standard
GB/T 4937.35-2024 Semiconductor devices—Mechanical and climatic test methods—Part 35: Acoustic microscopy for plastic encapsulated electronic components (English Version)
Standard No.
GB/T 4937.35-2024
Status
valid
Language
English
File Format
PDF
Word Count
11000 words
Price(USD)
330.0
Implemented on
2024-7-1
Delivery
via email in 1~3 business day
Detail of GB/T 4937.35-2024
Standard No.
GB/T 4937.35-2024
English Name
Semiconductor devices—Mechanical and climatic test methods—Part 35: Acoustic microscopy for plastic encapsulated electronic components
GB/T 4937.35-2024 Semiconductor devices - Mechanical and climatic test methods - Part 35: Acoustic microscopy for plastic encapsulated electronic components
1 Scope
This document defines the procedures for performing acoustic microscopy on plastic encapsulated electronic components. This standard provides a guide to the use of acoustic microscopy for detecting anomalies (delamination, cracks, mould-compound voids, etc.) reproducibly and non-destructively in plastic packages.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
A-mode
acoustic data collected at the smallest X-Y-Z region defined by the limitations of the given
acoustic microscope
Note: An A-mode display contains amplitude and phase/polarity information as a function of time of flight at a single point in the X-Y plane. In this test method, A-mode is primarily used for focussing the acoustic microscope. See Figure 1.
Figure 1 - Example of A-mode display
3.2
B-mode
acoustic data collected along an X-Z or Y-Z plane versus depth using a reflective acoustic microscope. A B-mode scan contains amplitude and phase/polarity information as a function of time of flight at each point along the scan line
Note: A B-mode scan furnishes a two-dimensional (cross-sectional) description along a scan line (X or Y). In this test method B-mode is used to provide cross-sectional acoustic information. When scanned, B-mode can be used to track the depth of a defect. See Figure 2.
Figure 2 - Example of B-mode display (bottom half of picture on left)
3.3
back-side substrate view area
interface between the encapsulant and the back of the substrate within the outer edges of the substrate surface
Note: Refer to Annex A, type IV.
3.4
C-mode
acoustic data collected in an X-Y plane at depth (Z) using a reflective acoustic microscope
Note 1: A C-mode scan contains amplitude and phase/polarity information at each point in the scan plane. A C-mode scan furnishes a two-dimensional (area) image of echoes arising from reflections at a particular depth (Z). See Figure 3.
Note 2: C-mode is the preferred mode for scanning devices to determine compliance to the criteria of IEC 60749-20.
Figure 3 - Example of C-mode display
3.5
through transmission mode
acoustic data collected in an X-Y plane throughout the depth (Z) using a through transmission acoustic microscope
Note: A through transmission mode scan contains only amplitude information at each point in the scan plane. A through transmission scan furnishes a two-dimensional (area) image of transmitted ultrasound through the complete thickness/depth (Z) of the sample/component (see Annex C). Through transmission mode is used as a quick scan method to determine large defects in devices prior to investigation using C-mode. See Figure 4.
Figure 4 - Example of through transmission display
3.6
die attach view area
interface between the die and the die attach adhesive and/or the die attach adhesive and the die attach substrate
Note: Refer to Annex A, type II.
3.7
die surface view area
interface between the encapsulant and the active side of the die (refer to Annex A, type I)
3.8
focal length; FL
distance in water at which a transducer’s spot size is at a minimum
3.9
focus plane
X-Y plane at a depth (Z), at which the amplitude of the acoustic signal is maximized
3.10
leadframe view area
L/F
imaged area which extends from the outer L/F edges of the package to the L/F “tips” (wedge bond/stitch bond region of the innermost portion of the L/F)
Note: Refer to Annex A, type V.
3.11
reflective acoustic microscope
acoustic microscope that uses one transducer as both the pulser and receiver
Note 1: See Figure 5.
Note 2: This is also known as a pulse/echo system.
