ฝึกพูดภาษาอังกฤษด้วยเทคนิค Shadowing จากวิดีโอ: PCB Assembly: Low Volume vs. High Volume

กำลังสร้างบทเรียน...
1
One of the first questions to ask when evaluating a PCB assembly contract manufacturer is can they handle the expected production volume?
2
To answer that, we first have to understand what we mean by low, mid, and high volumes.
3
For this video, we'll leave aside very high -volume consumer electronics,
4
and consider more typical volumes done by US -based contract manufacturers like Z -Axis.
5
Buyers of SMT printed circuit boards often consider volume in terms of boards per year, but that doesn't tell us what we need to know.
6
A contract manufacturer thinks in terms of numbers of parts to be placed.
7
This is
8
because the speed of the SMT pick -and -place machines is
9
generally the limiting factor in how fast a job can be completed.
10
Consider this example.
11
For this job, we need to produce 50 boards.
12
For this job, we need to produce 1 ,000.
13
Which is higher volume?
14
This board has 1 ,800 parts, so that's a total of 90 ,000 parts in the job.
15
This one has 40 parts per board for a total of 40 ,000 parts.
16
We'd consider it to be a lower volume job even though it's 20 times more boards.
17
One reason the number of boards doesn't give you the true picture of volume is panelization.
18
For most PCB assemblies, the layout designer fits multiple boards in an array on a single substrate or panel.
19
The entire panel is populated at once, and then depaneled into individual boards.
20
So to produce 10 ,000 small boards, which sounds like a lot, we may need just 100 panels.
21
But again, what really matters is the total number of parts in the job job.
22
Now that we have a better understanding of volume, let's look at what a contract manufacturer needs in order to do low, mid, and high volumes in one factory.
23
First, you need SMT lines designed for both speed and flexibility.
24
These machines pick and place up to 45 ,000 parts per hour to complete high volume jobs fast, and are designed for fast changeover between jobs,
25
so you can do many different lower volume jobs in a week.
26
A contract manufacturer may also have a semi -automated line for lower -volume jobs, as well as new products.
27
For work other than SMT assembly, we may use manual processes for low volumes and switch to robotic systems for higher volumes.
28
For example, this robotic dispensing system for box builds.
29
For IC programming, we can process a low volume by hand or use a robotic system for higher volumes.
30
For through -hole PCB assembly and some mixed technology boards, the wave solder can handle any volume.
31
For mixed technology boards that can't be wave soldered, we can do hand soldering for low volumes or robotic soldering for higher volumes.
32
Visit our website to learn more about contract manufacturing of low, mid, or high volume electronic products in the USA.

Vocabulary and speaking notes for this lesson

This speaking lesson is built on the video “PCB Assembly: Low Volume vs. High Volume”. The speaker keeps coming back to these words: volume, board, parts, contract, manufacturer. This video has 32 sentences and 471 words to shadow. The speech runs for 3:00. The speaker talks at a natural 157 words per minute, close to everyday conversation. 82% of the words are among the 3,000 most common in English; the rest is worth studying before you start.

Key vocabulary in this video

15 words from the video worth learning, with pronunciation and meaning:

WordPronunciationMeaning
manufacturer noun/ˌmænjʊˈfæktʃəɹə/A person or company that manufactures.
robotic adjective/ɹoʊˈbɑtɪk/Of, relating to, or resembling a robot; mechanical, lacking emotion or personality, etc.
circuit noun/ˈsɝ.kɪt/The act of moving or revolving around, or as in a circle or orbit; a revolution
designer noun/dɪˈzaɪnɚ/A person who designs something, or who designs things as a profession.
manual noun/ˈmæn.j(u)əl/Synonym of handbook.
electronics noun/ɪˌlɛkˈtɹɑ.nɪks/The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles or by converting the flow of…
array noun/əˈɹeɪ/Clothing and ornamentation; raiment.
layout noun/ˈleɪ.aʊt/A structured arrangement of items within certain limits.
buyer noun/ˈbaɪ.əɹ/A person who makes one or more purchases.
flexibility noun/ˌflɛksɪˈbɪlɪti/The quality of being flexible, whether physically or metaphorically.
evaluate verb/ɪˈvaljʊeɪt/To draw conclusions from examining; to assess; to appraise.
substrate noun/ˈsʌbˌstɹeɪt/An underlying layer; a substratum.
solder noun/ˈsɒl.də(ɹ)/Any of various easily melted alloys, commonly of tin and lead, that are used to mend, coat, or join metal objects, usually small.
automate verb/ˈɔ.təˌmeɪt/To replace or enhance human labor with machines.
changeover nounA conversion or transition from one thing to another.

Phrasal verbs you will hear

WordMeaning
leave aside verbTo not talk about a topic so as to allow full consideration to something else.

Pronunciation to watch

The speaker uses 5 contractions and reduced forms, such as doesn't, can't, we'd. Say them the short way, as you hear them.

  • Long words — get the stress right: manufacturer /ˌmænjʊˈfæktʃəɹə/, electronics /ɪˌlɛkˈtɹɑ.nɪks/, flexibility /ˌflɛksɪˈbɪlɪti/

How to practise with this video

  1. Listen to the whole video once without speaking and note the words you do not know.
  2. Start at 0.75× speed, shadow it sentence by sentence, then go back to normal speed once it feels easy.
  3. Record yourself and compare with the original, paying attention to words like manufacturer, robotic, circuit.

เทคนิค Shadowing คืออะไร?

Shadowing เป็นเทคนิคการเรียนรู้ภาษาที่ได้รับการรับรองทางวิทยาศาสตร์ พัฒนาขึ้นสำหรับการฝึกนักแปลมืออาชีพ วิธีการนี้เรียบง่ายแต่ทรงพลัง: คุณฟังเสียงภาษาอังกฤษจากเจ้าของภาษาและพูดตามทันที — เหมือนเงาที่ตามผู้พูดด้วยช่วงเวลาห่าง 1-2 วินาที การวิจัยแสดงว่าเทคนิคนี้ปรับปรุงความแม่นยำในการออกเสียง ทำนองเสียง จังหวะ การเชื่อมเสียง การฟังเข้าใจ และความคล่องแคล่วในการพูดได้อย่างมีนัยสำคัญ

เทคนิค shadowing: อ่านคู่มือฉบับเต็มทีละขั้นตอน →