Практика Shadowing: What is SMT (Surface Mount Technology)? PCB Assembly (Part 1) - Изучайте разговорный английский по видео
Создание урока...
1
Music Welcome to the next video in the series of PCBs.
2
Here we're going to be looking at what is an SMT.
3
So using a surface mount technology to assemble PCBs Part 1.
4
Surface Mount Technology Overview.
5
Now, Surface Mount Technology, which is the SMT, is a method for producing electrical circuits in which the components are mounted
6
or placed directly onto the surface of printed circuit boards or PCBs.
7
An electrical device that is soldered to the PCB is called a Surface Mount Device or an SMD for short.
8
By employing SMT, the production process speeds up
9
but the risk of defects also increases due to the component miniaturization and to the denser packing of boards.
10
In these conditions, detection of failures has become critical for any SMT manufacturing process.
11
Let's have a look at the PCBA production process.
12
So manufacturing PCBs with SMA techniques.
13
Manufacturing of printed circuit boards with an automated surface mount assembly,
14
or SMA line, consists of the following sequence of operations.
15
Solder paste application Component placement reflow soldering, cleaning and electrical test In this video,
16
we will concentrate on the first two steps in this process.
17
So we'll look at preassembly steps.
18
So the PCB design and manufacture.
19
Once the PCB has been designed and the components selected, it is time to get the PCB produced and the components ordered.
20
PCBs that are populated on a serviceman assembly line are normally produced in panel formats, as shown on the right hand side here.
21
The SMDs come packaged in different methods from trays for larger components and on tape bound on a reel for smaller components.
22
All the SMDs need to be sourced and made ready to load into the manufacturing line machines.
23
SodaPaste application Let's have a look at the solder paste application process.
24
So once the PCB is loaded into the machine, the stencil is positioned over the panels.
25
Solder paste is then added in front of the squeegee.
26
Let's have a look at that in a diagram format.
27
So we can see here the stencil is lowered onto the PCB, the squeegee is in position,
28
and the solder paste loaded just before the squeegee.
29
The squeegee lowers onto the stencil such that it is applying a very specific amount of pressure.
30
The squeegee moves along the length of the stencil while the solder paste is deposited into the stencil apertures.
31
And you can see that in this image here,
32
where the squeegee has completed its journey and left the solder deposits in the stencil apertures.
33
At the end of the travel, the squeegee raises up and the stencil is separated from the panels.
34
That is depicted here in this image.
35
You can see the stencil is raised leaving the soda paste on the correct positions on the pads.
36
Solder paste issues.
37
So this first one is the acceptable deposit onto a pad.
38
This is what it should be looking like.
39
Some of the issues that could follow are: Slumped deposit of solder paste onto the pad, which just looks like it's just dumped on.
40
Scavenged deposits of solder, and this is where the middle has been scooped out, and you can see that here.
41
Ridging is where a solid paste is connected between Two pads.
42
The last one we're going to look at is peaking or dog ears effect.
43
And you can see that depicted here.
44
So component placement process Let's have a look at that in the PCB design and manufacture.
45
So basic placement sequence generally includes board indexing,
46
board registration, fiducial vision alignment, component pickup component centering or vision inspection,
47
component placement and board indexing, and automated optical inspection, Component pickup.
48
component centering and vision inspection, component placement are repeated for each component.
49
And you can see an example of a component placed on the wet soda pads here.
50
Thank you.
51
Let's have a look at PCB positioning.
52
and the PCB positioning method.
53
Through the process of board indexing, The PCP is loaded to the appropriate position.
54
Fiducial marks provide common measurable points for all steps in the assembly process.
55
The three main types of fiduciary marks are: 1.
56
Panel.
57
This is a global fiducial mark on a multiple printed circuit board fabrication panel
58
that are located outside the parameters of the end product printed circuit boards.
59
You can see an example of that here.
60
2. Global.
61
These are fiduciary marks used to locate the position of all the features on an individual printed circuit port.
62
Again, this is shown here. And three, local.
63
These are fiduciary marks or marks used to locate the position of an individual allowance pattern
64
or component that may require more precision location such as a QFP.
65
and again you can see that here in this image Pick and place types.
66
Let's have a look at the chip shooter type.
67
Now chip shooters are generally fast.
68
They can range between 20 ,000 and 80 ,000 placements per hour
69
and can even range up to 100 ,000 placements per hour with relatively low accuracy, generally in a range of 70 microns.
70
As a result, chip shooters are not generally used for placing a active components which require better accuracy.
71
There are three major types of chip shooters Stationary turret overhead gantry and revolver head.
72
You can see an example of a chip shooter in this picture here.
73
Let's have a look at a flexible placer type Now comparing to chip shooters, these are flexible places are slow.
74
and they range between 6 ,000 to 40 ,000 placements per hour.
75
But they have a high accuracy, as low as 25 microns.
76
As a result, flexible placers are used to place complex and high I -O active components,
77
such as QFPs, as high -performance I -O components generally require higher accuracy.
78
There are three major types of flexible placer, Split axes.
79
Thank you.
80
Vacuum nozzles and grips.
81
Let's have a look at vacuum nozzles.
82
Vacuum nozzles are commonly used for handling all the components during the placement operations.
83
There are a variety of vacuum nozzle sizes for different component sizes.
84
For handling small components, positive pressure is often supplied in addition to vacuum at the moment of placement
85
so that the component will be completely released from the nozzle.
86
You can see a selection of vacuum nozzles in this image here.
87
You can see the different sizes for the vacuum pickup.
88
We also have mechanical grips.
89
Self -centering mechanical grippers allow simultaneous pickup and automatic centering without a need for vacuum.
90
A pair of tweezer type grippers would hold the part while centering it along one axis.
91
Vision inspection.
92
Upward facing vision system.
93
The vision inspection part of the process checks the critical components have been picked correctly.
94
their orientation and other features such as Pin 1 location.
95
All of this data is then fed into the machine to
96
ensure the device is placed into position with the highest accuracy possible.
97
Inline Automated Optical Inspection or AOI.
98
AOI is an automated visual inspection for printed circuit board manufacture
99
where a camera autonomously scans the device under test for both catastrophic failure, in other words missing component,
100
and quality defects such as fillet size or shape of component skew.
101
And this is what that looks like.
102
See the difference between these two.
103
One is up facing and the other is down facing or in this case, top and bottom vision.
104
Don't forget to check out our other videos in this PCB series
105
and you can contact us if you need any help with your projects in China.
106
So don't forget to like, share and subscribe to our channel.
107
And if you hit this little bell symbol that will notify you of every new content that we upload.
108
So thanks for listening, my name is Paul Adams and I shall see you in the next video.
📺 Тот же канал
C17
What is SMT (Surface Mount Technology)? PCB Assembly (Part 2)
Business EnglishWorking Adults
C1Sofeast PCB Video Series Introduction
Business EnglishUniversity StudentsWorking Adults
B22
DFM And DFA Explained
Business EnglishUniversity StudentsWorking Adults
C13
What is SMT (Surface Mount Technology)? PCB Assembly (Part 3)
Business EnglishUniversity StudentsWorking Adults
C14
PCB Inspection Methods & Common PCB Defects
Business EnglishUniversity StudentsWorking Adults
C13
NPI Process 1: Why A Pilot Run Before Mass Production Is Very Useful
Business EnglishUniversity StudentsWorking Adults
B2BONUS: Should we do PCB or enclosure design first? (Feat Andrew Amirnovin)
Business EnglishUniversity StudentsWorking Adults
B2What are PCBs and PCBAs? The 'PCB basics'
University StudentsWorking Adults
B1Don’t Approve a Product Until You’ve Lived With It
Business EnglishWorking Adults
B1The Product Passed the Safety Test, But Was Still Too Hot to Hold
Business EnglishWorking Adults
B2The Product Worked, But the Packaging Made It Look Dead
Business EnglishWorking Adults
B2Why User Experience Is Harder Than Engineering
Business EnglishUniversity StudentsWorking Adults
C14 NPI Tips Before You Move Into Mass Production
Business EnglishWorking Adults
C1The Production Validation Test (PVT) Phase of the NPI Process
Business EnglishWorking Adults
C1The Three NPI Phases Explained
Business EnglishUniversity StudentsWorking Adults
C1When Can The NPI Process Begin?
Business EnglishUniversity StudentsWorking Adults
C1NPI Process #3: Why A Feasibility Study With Suppliers Saves Time & Prevents Issues
Business EnglishWorking Adults
C1NPI Process 2: New Product Development Process (Why Planning Before Prototyping Saves Time)
Business EnglishUniversity StudentsWorking Adults
C1PCBs | Electronic Goods Reliability Testing
Business EnglishUniversity StudentsWorking Adults
✨ Рекомендуемое видео
C11
92 предложений
How Things Are Made | An Animated Introduction to Manufacturing Processes
Business EnglishUniversity StudentsWorking Adults
C11
64 предложений
What is SCADA?
Business EnglishUniversity StudentsWorking Adults
C12
153 предложений
S3 Speech1 short
Business EnglishUniversity StudentsWorking Adults
C12
32 предложений
PCB Assembly: Low Volume vs. High Volume
Business EnglishUniversity StudentsWorking Adults
C11
282 предложений
什麼是屏蔽罩(shielding can)？工程師對屏蔽罩的愛恨情仇
Business EnglishUniversity StudentsWorking Adults
C11
181 предложений
Aircraft General Knowledge | PPL Expert Online Ground School FREE Sample
TOEFL PrepWorking Adults
C11
4 предложений
Ambr®️ 250 High Throughput Perfusion Product Tutorial - Learn with Sartorius
Business EnglishUniversity StudentsWorking Adults
C1101 предложений
BGP Overview
Business EnglishUniversity StudentsWorking Adults
C11
150 предложений
Parallel Pump Operation
Business EnglishUniversity StudentsWorking Adults
C11
114 предложений
BAS Bootcamp: Day 6 Setting up IO Internally
Business EnglishUniversity StudentsWorking Adults
Лексика и советы по произношению к этому уроку
Этот урок разговорной практики уровня C1 построен на видео «What is SMT (Surface Mount Technology)? PCB Assembly». Чаще всего повторяются слова: component, Pcb, placement, board, solder. В этом видео 108 предложений и 1290 слов для шедоуинга. Речь длится 10:18. Говорящий держит ровный темп — около 125 слов в минуту, удобный для шедоуинга. Только 72% слов входят в 3000 самых частых слов английского языка, поэтому лексика сложная.
Ключевая лексика этого видео
Самые сложные слова из видео (15), с произношением и значением:
| Слово | Произношение | Значение |
|---|---|---|
| solder существительное | /ˈsɒl.də(ɹ)/ | припо́й |
| placement существительное | /ˈpleɪ̯smənt/ | размеще́ние |
| pasta существительное | /ˈpɑ.stə/ | макаро́ны, макаро́нные изде́лия |
| stencil существительное | /ˈstɛnsəl/ | трафаре́т, шабло́н |
| vacuum существительное | /ˈvæ.kjuːm/ | ва́куум |
| squeegee существительное | /ˈskwiˌd͡ʒi/ | ра́кель, рези́новая шва́бра |
| nozzle существительное | /ˈnɒzəl/ | наса́дка, наконе́чник |
| shooter существительное | /ˈʃuːtəː/ | стрело́к, стреле́ц |
| automate глагол | /ˈɔ.təˌmeɪt/ | автоматизи́ровать |
| fiducial прилагательное | /fəˈd(j)uːʃəl/ | базовый, реперный |
| fiduciary существительное | /fəˈduːʃ.i.eɹ.i/ | опеку́н, опеку́нша |
| locate глагол | /ˈloʊˌkeɪt/ | помести́ть |
| pad существительное | /pæd/ | подкла́дка, прокла́дка |
| aperture существительное | /ˈæp.ɚˌt͡ʃʊɹ/ | отве́рстие, проём |
| depict глагол | /dɪˈpɪkt/ | изобража́ть, изобрази́ть |
Фразовые глаголы, которые вы услышите
| Слово | Произношение | Значение |
|---|---|---|
| check out глагол | проверя́ть, прове́рить | |
| speed up глагол | /spiːdˈʌp/ | ускоря́ться, уско́риться |
Грамматика в этом видео
Конструкции, которые говорящий использует чаще всего, с точными словами из видео:
| Конструкция | В видео |
|---|---|
| «Used to» used to + глагол — прошлая привычка или состояние, которых больше нет | used to locate |
| Пассивный залог be + причастие прошедшего времени — важно, что происходит, а не кто это делает | are mounted · is soldered · has been designed |
| Present Perfect have/has + причастие прошедшего времени — прошлое действие, важное сейчас | has become · has been designed · has completed |
Произношение, на которое стоит обратить внимание
Говорящий использует 5 сокращённых и редуцированных форм, например don't, we're, we'll. Произносите их коротко, так, как слышите.
- Звуки «sh» и «zh»: shooter /ˈʃuːtəː/, fiducial /fəˈd(j)uːʃəl/, fiduciary /fəˈduːʃ.i.eɹ.i/, fabrication /fæbɹɪˈkeɪʃən/, measurable /ˈmɛʒəɹəbəl/
- Длинные слова — следите за ударением: fiduciary /fəˈduːʃ.i.eɹ.i/, fabrication /fæbɹɪˈkeɪʃən/, measurable /ˈmɛʒəɹəbəl/, simultaneous /ˌsaɪ̯.məlˈteɪ̯.ni.əs/, parameter /pəˈɹæm.ə.tɚ/
Звуки, трудные для русскоязычных:
- /w/ — губы округлены, это не /v/: squeegee /ˈskwiˌd͡ʒi/, upward /ˈʌpwɚd/
- Звонкие согласные в конце слова — не оглушайте их: pad /pæd/, scavenge /ˈskæv.ɪndʒ/, upward /ˈʌpwɚd/, bind /ˈbaɪ̯nd/, overhead /ˈəʊvəˌhɛd/
Как заниматься с этим видео
- Прослушайте всё видео один раз молча и выпишите незнакомые слова.
- Повторяйте предложение за предложением на обычной скорости, пока ваш ритм не совпадёт с ритмом говорящего.
- Запишите себя и сравните с оригиналом, обращая внимание на такие слова, как solder, placement, pasta.
Что такое техника Shadowing?
Shadowing — это научно обоснованная техника изучения языка, изначально разработанная для подготовки профессиональных переводчиков и популяризированная полиглотом доктором Александром Аргуэльесом. Метод прост, но эффективен: вы слушаете аудио на английском от носителей языка и немедленно повторяете вслух — как тень, следующая за говорящим с задержкой в 1–2 секунды. В отличие от пассивного прослушивания или грамматических упражнений, Shadowing заставляет мозг и мышцы рта одновременно обрабатывать и воспроизводить реальные речевые паттерны. Исследования показывают, что это значительно улучшает точность произношения, интонацию, ритм, связную речь, понимание на слух и беглость речи — что делает его одним из самых эффективных методов для подготовки к IELTS Speaking и реального общения на английском.