1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58methods Part 35: Acoustic microscopy for plastic encapsulated electronic componentsThe European Sta
2、ndard EN 60749-35:2006 has the status of a British StandardICS 31.080.01Semiconductor devices Mechanical and climatic test BRITISH STANDARDBS EN 60749-35:2006BS EN 60749-35:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2006
3、BSI 2006ISBN 0 580 49739 9Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK im
4、plementation of EN 60749-35:2006. It is identical with IEC 60749-35:2006. The UK participation in its preparation was entrusted to Technical Committee EPL/47, Semiconductors.A list of organizations represented on EPL/47 can be obtained on request to its secretary.This publication does not purport to
5、 include all the necessary provisions of a EUROPEAN STANDARD EN 60749-35 NORME EUROPENNE EUROPISCHE NORM September 2006 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat
6、: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60749-35:2006 E ICS 31.080.01 English version Semiconductor devices - Mechanical and climatic test methods Part 35: Acoustic microscopy f
7、or plastic encapsulated electronic components (IEC 60749-35:2006) Dispositifs semiconducteurs - Mthodes dessais mcaniques et climatiques Partie 35: Microscopie acoustique pour composants lectroniques botier plastique (CEI 60749-35:2006) Halbleiterbauelemente - Mechanische und klimatische Prfverfahre
8、n Teil 35: Ultraschallmikroskopie fr kunststoffverkappte Bauelemente der Elektronik (IEC 60749-35:2006) This European Standard was approved by CENELEC on 2006-09-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
9、Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English,
10、 French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belg
11、ium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of
12、 document 47/1863/FDIS, future edition 1 of IEC 60749-35, prepared by IEC TC 47, Semiconductor devices, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60749-35 on 2006-09-01. The following dates were fixed: latest date by which the EN has to be implemented at nation
13、al level by publication of an identical national standard or by endorsement (dop) 2007-06-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2009-09-01 _ Endorsement notice The text of the International Standard IEC 60749-35:2006 was approved by CENELEC
14、 as a European Standard without any modification. _ EN 60749-35:2006 2 CONTENTS 1 Scope.4 2 Terms and definitions .4 3 Test apparatus .8 3.1 Reflective acoustic microscope system8 3.2 Through transmission acoustic microscope system8 3.3 Reference packages or standards .8 3.4 Sample holder .8 4 Proce
15、dure 9 4.1 General .9 4.2 Equipment setup .9 4.3 Performance of acoustic scans9 Annex A (informative) Acoustic microscopy check sheet (example only not a mandatory template) .11 Annex B (informative) Potential image pitfalls 16 Annex C (informative) Some limitations of acoustic microscopy .17 Annex
16、D (informative) Reference checklist for presenting applicable scanned data18 Bibliography20 Figure 1 Example of A-mode display4 Figure 2 Example of B-mode display (bottom half of picture on left) .5 Figure 3 Example of C-mode display5 Figure 4 Example of through transmission display6 Figure 5 Diagra
17、m of a reflective acoustic microscope system.7 Figure 6 Diagram of a through transmission acoustic microscope system 7 EN 60749-35:2006 3 SEMICONDUCTOR DEVICES MECHANICAL AND CLIMATIC TEST METHODS Part 35: Acoustic microscopy for plastic encapsulated electronic components 1 Scope This part of IEC 60
18、749 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 packa
19、ges. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 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 informat
20、ion 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. Time Amplitude IEC 1333/06 Figure 1 Example of A-mode display 2.2 B-mode acoustic data collected along an X-Z or Y-Z plane versus
21、 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 metho
22、d 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. EN 60749-35:2006 4 C-mode display Line of B-mode scan B-mode display IEC 1334/06 Figure 2 Example of B-mode display (bottom half of picture on left) 2.3 ba
23、ck-side substrate view area interface between the encapsulant and the back of the substrate within the outer edges of the substrate surface (refer to Annex A, type IV) 2.4 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
24、 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 criter
25、ia of IEC 60749-20. Figure 3 Example of C-mode display IEC 1335/06 EN 60749-35:2006 5 2.5 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 informat
26、ion 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 d
27、evices prior to investigation using C-mode. See Figure 4. Figure 4 Example of through transmission display 2.6 die attach view area interface between the die and the die attach adhesive and/or the die attach adhesive and the die attach substrate (refer to Annex A, type II) 2.7 die surface view area
28、interface between the encapsulant and the active side of the die (refer to Annex A, type I) 2.8 focal length FL distance in water at which a transducers spot size is at a minimum 2.9 focus plane X-Y plane at a depth (Z), at which the amplitude of the acoustic signal is maximized 2.10 leadframe view
29、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) (refer to Annex A, type V) IEC 1336/06 EN 60749-35:2006 6 2.11 reflective acoustic microscope acoustic microscope that uses one transducer
30、as both the pulser and receiver (see Figure 5) NOTE This is also known as a pulse/echo system. X-Y-Z scanning system Pulser/receiver Transducer Fluid medium bath A-mode display Computer controller IEC 1337/06 Figure 5 Diagram of a reflective acoustic microscope system 2.12 through transmission acous
31、tic microscope acoustic microscope that transmits ultrasound completely through the sample from a sending transducer to a receiver on the opposite side (see Figure 6) X-Y-Z scanning system Pulser/receiver Transducer 1 Fluid medium bath A-mode display Computer controller Transducer 2 IEC 1338/06 Figu
32、re 6 Diagram of a through transmission acoustic microscope system 2.13 time-of-flight TOF a) in reflective mode, the time it takes for the acoustic pulse to travel from a single transducer/receiver to the interface of interest and back b) in through transmission mode, the time it takes for the acous
33、tic pulse to travel from the sending transducer through the sample to the receiving transducer EN 60749-35:2006 7 2.14 top-side die attach substrate view area interface between the encapsulant and the die side of the die attach substrate surrounding the die (refer to Annex A, type III) 2.15 top-side
34、 underfill/undermould area for flip chip type devices interface between the active side of the die and the underfill/undermould and/or the underfill/undermould on the substrate (refer to Annex A, type VIII) 3 Test apparatus 3.1 Reflective acoustic microscope system This shall comprise (see Figure 5)
35、 a) ultrasonic pulser/receiver, b) a display of the echo amplitude and phase/polarity versus time (A-mode display), c) a computer-controlled display system for image display (B-mode and C-mode), storage, retrieval, printing and analysis, d) an electromechanical X-Y-Z (typically computer-controlled)
36、scanning system for moving the acoustic probe over the sample and for setting the focus plane within the sample, e) a fluid medium bath, such as deionised water, to provide acoustic coupling between the sample and the transducer, f) a broad band acoustic transducer with a centre frequency in the ran
37、ge of 10 MHz to 200 MHz for subsurface imaging. 3.2 Through transmission acoustic microscope system This shall comprise (see Figure 6) a) items listed in 3.1 above, b) ultrasonic pulser (can be a pulser/receiver as in 3.1 a), c) separate receiving transducer or ultrasonic detection system. 3.3 Refer
38、ence packages or standards These include packages with delamination and packages without delamination, for use during equipment setup. 3.4 Sample holder The holder should position the samples in the proper place, keep the samples from moving during the scan, and maintain planarity. EN 60749-35:2006
39、8 4 Procedure 4.1 General This procedure is generic to all acoustic microscopes. For operational details related to this procedure that apply to a specific model of acoustic microscope, consult the manufacturers operational manual. 4.2 Equipment setup 4.2.1 Transducer selection Select the transducer
40、 with the highest useable ultrasonic frequency, subject to the limitations imposed by the media thickness and acoustic characteristics, package configuration, and transducer availability, to analyze the interfaces of interest. The transducer selected should have a low enough frequency to provide a c
41、lear signal from the interface of interest. The transducer should have a high enough frequency to delineate the interface of interest. NOTE Through transmission mode may require a lower frequency and/or longer focal length than reflective mode. Through transmission is effective for the initial inspe
42、ction of components to determine if defects are present. 4.2.2 Setup verification Verify setup with the reference packages or standards (see 3.3 above) and settings that are appropriate for the transducer chosen in 4.2.1 to ensure that the critical parameters at the interface of interest correlate t
43、o the reference standard utilized. 4.2.3 Placement of units in the sample holder Place units in the sample holder in the coupling medium such that the upper surface of each unit is parallel with the scanning plane of the acoustic transducer. Sweep air bubbles away from the unit surface and from the
44、bottom of the transducer head. 4.2.4 Transducer alignment At a fixed distance (Z), align the transducer and/or stage for the maximum reflected amplitude from the top surface of the sample. The transducer must be perpendicular to the sample surface. 4.2.5 Focus Focus by maximizing the amplitude, in t
45、he A-mode display, of the reflection from the interface designated for imaging. This is done by adjusting the Z-axis distance between the transducer and the sample. 4.3 Performance of acoustic scans 4.3.1 Inspection for anomalies Inspect the acoustic image(s) for any anomalies, verify that the anoma
46、ly is a package defect or an artefact of the imaging process, and record the results. (See Annex A for an example of a check sheet that may be used.) EN 60749-35:2006 9 To determine if an anomaly is a package defect or an artifact of the imaging process it is recommended to analyze the A-mode displa
47、y at the location of the anomaly. Physical analysis of the package may also be required to confirm the nature of the anomaly. 4.3.2 Potential pitfalls Consider potential pitfalls in image interpretation listed in, but not limited to, Annex B and some of the limitations of acoustic microscopy listed
48、in, but not limited to, Annex C. If necessary, make adjustments to the equipment setup to optimize the results and rescan. 4.3.3 Evaluation Evaluate the acoustic images using the failure criteria detailed in the relevant specification. 4.3.4 Records Record the images and the final instrument setup p
49、arameters for documentation purposes. An example checklist is shown in Annex D. EN 60749-35:2006 10 Annex A (informative) Acoustic microscopy check sheet (example only not a mandatory template) Types of delamination Circuit side scan Non-circuit side scan Type I delamination: Encapsulant/die surface Type II delamination: Die attach region Type III delamination: Encapsulant/substrate (die side) Type IV delamination: Substrate/encapsulant (backside) Type
