SMT basic knowledge

SMT concept
SMT: surface mount technology, abbreviation of surface mount technology.
The components are mounted on the designated PCB pads that have been coated with solder paste or glue, and then reflow or wave soldering is used to establish reliable mechanical and electrical connections between the components and the PCB pads.
Product production process selection
There are mainly three types of PCB board assembly methods:
Product production process selection-PCB board assembly methods mainly include the following three categories:
Assembly method Schematic diagram Circuit board Soldering method Features
full surface assembly
Single-sided table assembly
Single sided PCB
Single side reflow soldering
Simple process, suitable for small, thin and simple circuits
Double-sided surface assembly
Double sided PCB
Double-sided reflow soldering
High-density assembly, thinner
Surface mount + through hole reflow soldering
Single-sided PCB single-sided reflow soldering High-density assembly, plug-in wave soldering moved forward, through-hole reflow soldering reduces manpower and increases efficiency
Single side mixed installation
SMD and THC are both on side A
Double sided PCB
Reflow solder the A side first, then wave solder the B side.
Generally, it is pasted first and then inserted, which is a simple process.
THC is on side A and SMD is on side B
Single sided PCB
First, surface A is flow soldered, then surface B is wave soldered.
PCB has low cost and simple process. It is pasted first and then inserted. If the method is to insert first and then stick, the process will be complicated.
Double-sided mixed installation
THC has SMD on both sides A and AB
Double sided PCB
First, surface A is flow soldered, then surface B is wave soldered.
Suitable for high-density assembly
AB has SMD and THC on both sides
Double sided PCB
First, surface A is flow soldered, then surface B is wave soldered.
The process is complex and rarely used
Summary of SMT IPC standards
IPC stands for Institute of Printed Circuits
Summary of SMT IPC standards
1
IPC-7525
Stencil Design Guide
2
IPC-7527
Solder paste printing requirements
3
IPC/EIA J-STD-004
Flux requirements
4
IPC/EIA J-STD-005
Solder paste requirements
5
IPC-A-600
Acceptability of printed boards
6
IPC-A-610
Acceptability of electronic components
7
IPC-7711/21
Rework and repair of electronic components
8
J-STD-020
Humidity/Reflow Sensitivity Classification of Non-Hermetic Packaged Solid State Surface Mount Devices
9
J-STD-033
MSD humidity sensor management specifications
10
IPC-9853
Hot air reflow soldering system characterization and verification specifications
11
IPC-7530
Group soldering process temperature profile guide (reflow soldering and wave soldering)
12
IPC-7351
General requirements for surface mount device and land pattern standards
Abbreviations and definitions of professional English terms Term&Definition
Abbreviations Abbreviations Full English name Full spelling
English full name Full spelling
ACF
Anisotropic conductive film
AOI
Automated Optical Inspection
BGA
Ball Grid Array
BOM
Bill of Material
CMI
Capability Machine Index
CPI
Process Capability Index
pk
Process Capability Index
CSP
Chip Size Package
CTE
Coefficient of Thermal Expansion
EMS
Electronic Manufacturing Services
ENIG
Electroless Nickel and Immersion Gold
EPA
Electrostatic discharge Protected
ESD
Electrostatic Discharge
FG
Fine Grain
FOV
Field of View
FPC
Flexible Printed Circuit
GR&R
Gauge Repeatability & Reproducibility
HIC
Humidity Indicator Card
led
Light Emitting Diode
LGA
Land Grid Array
LSL
Lower Specification Limit
MBB
Moisture Barrier Bag
MSDS
Material Safety Data Sheet
OSP
Organic Solderability Preservatives
PCB
Printed Circuit Board
PCBA
Printed Circuit Board Assembly
PCN
Process Correction Notification
POP
Package on package
QFN
Quad flat no-lead package
QFP
Quad Flat Package
RCV
Receiver
RH
Relative Humidity
SAC
SnAgCu
SPK
Speaker
SMT
Surface Mount Technology
SOP
Small Outline Package
SOT
Small Outline Transistor
SPC
Statistical Process Control
SPI
Solder Printing Inspection
TDS
Technical Data Sheet
Tg
Glass-transition Temperature
USL
Upper Specification Limit
WLCSP
Wafer Level Chip Size Package
Wafer-level chip size packaging, that is, bare die chips; the manufacturer’s naming description generally starts with “WL”, such as WLNSP and WLPSP, which also belong to this type of device.
1 PCB QR code laser engraving machine
2 SMT printing stencil
3 SMT printing stencil cleaning machine
4 SMT printing stencil inspection machine
5 SMT printing stencil wiper paper / wiper cloth
6 PCB cleaning machine
7 SMT solder paste printing machine
8 SPI solder paste inspection machine
9 Leaded solder paste/lead-free solder paste/solid crystal solder paste/high, medium and low temperature solder paste
10 Leaded tin wire/Lead-free tin wire/Medium, medium and low temperature tin wire
11 BGA solder balls/lead-free BGA solder balls
12 BGA Ball Planting Machine (FlipChip, Concave BGA, PoP, SiP)
13 solder paste mixer
14 Dispensing equipment
15 SMT glue (red glue, solid crystal glue)
16 DIP glue (UV, three-proof, Underfill, Sidefill)
17 Carrier Tape. Cover Tape
18 SMD parts taping machine
19 SMD tape peel strength measuring machine
20 SMD strip vacuum forming machine
21 SMD parts counter
22 PCB sending/receiving machine and temporary storage machine
23 Pick & Place M/C Multifunctional SMT Machine
24 Pick & Place M/C High Speed SMT Machine
25 Pick & Place M/C Ultra-high-speed placement machine
26 AOI optical inspection machine
27 Reflow reflow oven
28 N2 Reflow nitrogen reflow oven
29 Lead-Free Reflow Nitrogen reflow oven for lead-free process
30 Vacuum Reflow vacuum reflow oven
31 Nitrogen generator
32 Furnace temperature tester
33 Flux/no-clean flux
34 Flux spray equipment
35 Substrate cleaning equipment (DI washing machine)
36 Cleaning chemicals
37 x-ray related
38 SMT rework equipment
39 BGA/CSP/FLIP CHIP rework equipment
40 2.5/3 dimensional inspection machine
41 Electron Microscope
42 Metallographic microscope
43 Intelligent ESD System Suppliers
44 Slicing and grinding machines
45 dryer/constant temperature and humidity oven/baking oven/warm impulse cycle/aging acceleration equipment
46 Wire bonding equipment (WireBonding, DieBonding)
47 SMT desktop equipment
48 FEEDER/NOZZLE
49 SMT used equipment suppliers
50 SMT Equipment Accessories Suppliers
52
MES system supplier
53
Second hand materials buying and selling supplier
54
Electronics factory scrap recycling supplier
55
PCBA maintenance parts outsourcing supplier
LOADER
AUTO LOADING MACHINE
Marking 1
laser marking machine
Print barcode on PCB
Marking 2
Inkjet marking machine
Spray on PCB Print barcodes to facilitate traceability of product dynamics and product life cycle tracking
clean
Dust removal and static air gun Perform dust removal, static electricity removal, and board dust and foreign matter removal on the PCB board to be printed.
print
Solder paste printing Print solder paste on PCB pads.
Dispensing glue
Red glue dispensing Dot the red glue on the solder resist between the pads of the PCB.
SPI
Solder paste printing quality inspection Check the length, width, shape and volume of the printed solder paste.
High speed machine
High speed placement machine High-speed placement of chip components
General purpose machine
Multifunctional medium speed placement IC, BGA, medium speed placement of larger components
Special placement
Special special-shaped structural component patch Special placement machines for special-shaped devices, including straight pin types for through-hole reflow Other large special-shaped parts
AOI
Optical automatic inspection of patch quality before furnace Conduct placement quality inspection on completed components
Hot air reflow soldering
Hot air reflow soldering Solder paste reflow soldering Vapor phase reflow soldering
IR infrared reflow oven
Solder paste reflow soldering
AOI
Post-furnace welding quality optical automatic inspection performs placement quality inspection on completed PCBA components
X-Ray
X-ray optical inspection machine performs X-ray perspective placement inspection on the internal and bottom quality of electronic components
Unloader
After AOI inspection, differentiate between NG/OK and frame, temporarily store, waiting for confirmation.
Barcode collection
Scanner gun After electronic scanning, enter and track the entire process quality status of semi-finished products.
Splitting machine 1
Online milling cutter depaneling Milling cutter method, cutting the entire Panel into small Set parts
Splitting machine 2
v-cut hob plate splitting machine Hob method, cutting the entire Panel into small Set parts
Splitting machine 3
Laser depaneling machine Laser method, cutting the entire Panel into small Set parts, suitable for PCBs with a thickness of 1.4mm and below
First article inspection machine
Automatic LCR measurement and confirmation of the first product produced
LCR
Bridge
LCR
Bridge
picture
Measuring instrument for measuring specific values of capacitors, resistors and inductors
Steel mesh cleaning machine
According to the frequency, remove the steel mesh and clean it thoroughly offline.
Solder paste mixer
Solder paste, glue and bubbles to make the proportions even
ICT testing machine
Flying probe testing machine