Pratique du Shadowing: What is SMT (Surface Mount Technology)? PCB Assembly (Part 3) - Apprendre l'anglais à l'oral avec la vidéo

Création de la leçon...
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Welcome to this video.
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This is part 3 of using surface mount technology to assemble PCBs.
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Electrical testing process.
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This is the last section of the process as you can see here.
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So So physical testing of printed circuit boards can also be carried out within the SMT production line.
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This is known as inline testing.
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However, it is more common for physical testing to be carried out offline in a separate area or test station.
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This is known as in-circuit testing.
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Although the generic term in-circuit testing or ICT is widely used within the electronics manufacturing industry,
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there are actually several different types of tester that are available.
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The type of tester required is dependent upon the manufacturing test process used, the volume and the boards that are used.
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Let's have a look at the different types of in-circuit tester.
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Let's start with the flying probe tester.
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In view of the issues of developing and manufacturing complete bed of nail access fixtures,
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they are costly and difficult to change if any component positions or tracks are moved.
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Another approach is to use a roving or flying probe.
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This has a simple fixture to hold the board
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and contact is made via a few probes that can move around the board and make contact as required.
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These are moved under software control so any board updates can be accommodated with changes to the software program.
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Another reason to use flying probes is the shrinking component size and denser chip scale packaging technologies.
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Manufacturing Defect Analyzer or MDA.
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The tester makes contact to the board under test using a bed of nails fixture
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and this means that a different fixture is generally required for each board.
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It needs to make contact with specific points on the board where often there may be test point
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or a land area for the probe.
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This form of tester offers a basic in circuit test of resistance, continuity and insulation.
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As the name implies it is just used for detecting the manufacturing defects like short circuits across tracks and open circuit connections.
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Automated X-ray inspection.
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AXI as is known is a technology based on the same principles as automated optical inspection or AOI.
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It uses x-rays as its source instead of visible light to automatically inspect features which are typically hidden from view.
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Automated x-ray inspection equipment can not only check the solder joints under components,
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but also reveal any defects in solder joints that may not be visible with ordinary optical inspection equipment.
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First off, sample inspection.
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The inspection microscope is generally used in FAI or first article inspection,
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which is required to ensure that the first product produced is 100% correct.
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In the SME industry, there is a need to ensure
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that the first off from any SMT assembly line is perfect before running the rest of the batch.
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Functional testing.
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At the end of the line, there needs to be a functional test to establish if the PCB actually functions and conforms to specification.
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The key features of the functional test are Identify errors in all functional aspects of the PCB
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Identify failure thresholds in the PCB when both upper and lower voltages are applied Simulate the operating environment for the PCB
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Verify speed, frequency, oscillations and other onboard timing elements Verify all input and output features conform to specification
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and establish all communication features are operational.
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Burn-in testing.
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Burn-in is a technique used as part of the quality insurance
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procedures where assembled printed circuit boards are operated under both normal and accelerated environmental conditions prior to shipment.
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Theoretically, any weak components would fail during the burn-in time allowing those parts to be replaced.
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Replacing the weak components would prevent premature failure, infant mortality failure, or other latent defects.
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On the right-hand side here, we can see a typical burn-in bathtub graph.
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We can see that the decreasing failure rate shows the early infant mortality failures.
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The constant failure rate covers the constant or random failures, whereas the increasing failure rate shows the wearout failures.
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This graph is failure rate over time
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Don't forget to check out our other videos in this PCB series
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You can contact us if you need any help with your projects at all in China And don't forget to like, share and subscribe to our channel
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And you see this little bell symbol If you hit that you'll get a notification each time we upload new content
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So thanks for listening, my name is Paul Adams from SofEast and I shall see you in the next video

Vocabulaire et conseils d’expression pour cette leçon

Cette leçon d’expression orale de niveau C1 s’appuie sur la vidéo « What is SMT (Surface Mount Technology)? PCB Assembly ». Les mots qui reviennent le plus souvent : failure, board, circuit, testing, inspection. Cette vidéo contient 56 phrases et 769 mots à répéter en shadowing. La partie parlée dure 5:51. Le locuteur parle à un rythme régulier d’environ 131 mots par minute, confortable pour le shadowing. Seuls 77 % des mots font partie des 3 000 mots les plus courants en anglais, le vocabulaire est donc exigeant.

Vocabulaire clé de cette vidéo

Les 15 mots les plus avancés de la vidéo, avec leur prononciation et leur sens :

MotPrononciationSens
probe nom/pɹoʊb/sonde, explorateur
fixture nom/ˈfɪks.t͡ʃə/habitué
automate verbe/ˈɔ.təˌmeɪt/automatiser
defect nom/ˈdiːfɛkt/défaut
solder nom/ˈsɒl.də(ɹ)/soudure
conform verbe/kənˈfɔɹm/s'aligner
assemble verbe/əˈsɛm.bəl/assembler, rassembler
specification nomspécification
mortality nom/mɔɹˈtælɪti/mortalité, condition mortelle
infant nom/ˈɪn.fənt/nourrisson, enfant en bas âge
graph nom/ɡɹæf/graphique
optical adjectif/ˈɑptɪkəl/optique
bathtub nom/ˈbæθtʌb/baignoire
latent adjectif/ˈleɪ.tənt/latent
oscillation nom/ˌɒ.sɪˈleɪ.ʃən/oscillation

Les verbes à particule que vous entendrez

MotPrononciationSens
carry out verbe/ˈkæ.ɹi aʊt/sortir, transporter dehors
check out verbemater, regarder

Prononciation à surveiller

Le locuteur utilise 3 contractions et formes réduites, comme don't, you'll. Prononcez-les sous leur forme courte, telles que vous les entendez.

  • Les sons « th »: bathtub /ˈbæθtʌb/, threshold /ˈθɹɛʃ(h)oʊld/
  • Les sons « sh » et « zh »: oscillation /ˌɒ.sɪˈleɪ.ʃən/, insulation /ˌɪnsəˈleɪʃən/, shipment /ˈʃɪpmənt/, notification /ˌnoʊtɪfɪˈkeɪʃn̩/, threshold /ˈθɹɛʃ(h)oʊld/
  • Mots longs — placez bien l’accent: mortality /mɔɹˈtælɪti/, oscillation /ˌɒ.sɪˈleɪ.ʃən/, accelerate /ɪkˈsɛl.əˌɹeɪt/, insulation /ˌɪnsəˈleɪʃən/, continuity /ˌkɑn.tɪˈn(j)u.ə.ti/

Comment s’entraîner avec cette vidéo

  1. Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
  2. Répétez phrase par phrase à vitesse normale, en reprenant chacune jusqu’à ce que votre rythme corresponde à celui du locuteur.
  3. Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme probe, fixture, automate.

Qu'est-ce que la technique du Shadowing ?

Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.

Technique du shadowing : lire le guide complet étape par étape →