Surface Mount Technology (SMT) PCB Assembly Service
PTPCBA has been engaged in quick turn PCB manufacturing and quick turn PCB assembly services for 11 years; our quick turn PCB assembly factory is located in China. Our customers are all over the United States, Canada, Australia, Europe, etc.; we have become the most popular quick turn PCB assembly manufacturer and supplier.
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Advanced PCB Assembly Technology
Printed Circuit Boards (PCBs) have changed the concept of soldering components with wire and creating a complicated and unreliable circuit. PCBs are very compact and offer reliable performance for a very long time. They take up very little space and deliver the expected results.
Nowadays, PCBs are used in almost every industry. Every product that requires some components and their interconnection uses a PCB. PCBs have gone through many changes in the past few decades. There have been many advancements, improvements, and new technologies. One of the leading PCB technologies is surface mount technology. It has supreme importance because it has further reduced the size of PCBs. The components used in the surface mount technology are minimal; the smallest SMD (surface mount device) has a dimension of 0.6mm x 0.30mm. SMT technology has significantly impacted the PCB industry and is widely used nowadays.
Table of Contents
SMT PCB Assembly Supplier
What is SMT PCB Assembly?
Surface Mount Technology is a specific technology for PCB assembly service. The components in this technology are directly mounted on the surface of the PCB without any holes/drilling. There are special components used for this technology that are called Surface Mount Devices. The components are placed over the PCB that already has conduction paths, and finally, the components are soldered in a reflow oven. They are directly attached to the board and perform better than Through-hole Technology (THT).
SMT PCB assembly is an easy and quick technique to make reliable circuit boards. The components are very compact, so the PCB is very small. SMT PCB assembly is widely used because it is a quick and better alternative to THT.
SMT Assembly Capability of JHY
PTPCBA offers high-quality and highly reliable PCB assembly service. Our PCB assembly factory has 8 fully automatic high-speed surface mount production lines and uses the most advanced SMT PCB assembly equipment. Including automatic board loading machine, automatic solder paste printing machine, solder paste thickness detector (SPI, Solder Paste Inspection), multi-temperature zone reflow soldering machine, optical inspection equipment (Automatic Optical Inspection), X-ray inspection machine, baking machine, and PCB stencil cleaning machine, etc. To meet the SMT assembly requirements of customers to the greatest extent, JHY can accept precision electronic components mounting like 0201 components, 0.4mm Pitch BGA, and QFN.
Combining quality and cost-effectiveness, JHY has become the leader in SMT PCB assembly services. With our extensive experience in various PCB assembly fields, we have become a trusted partner for customers worldwide with unmatched turn-around times and flexible options.
SMT PCB Assembly Capabilities
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Low-to-high Volume Assembly
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Single and Double-sided Assembly
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Mixed Technology
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Smallest components 01005, 0201, 0402
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Assemble 0.25mm fine-pitch parts
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Leadless components, BGA, µBGA, LGA, package on package, etc.
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PCB Types: Rigid PCB, Flexible PCB, Rigid-flex PCB
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PCB Shape: Any
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Quality Grade: IPC Class 2 | IPC Class 3
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No MOQ
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Capacity: SMT SMD 5 Million Points/day, Plug-in Welding 500,000 Points/day, 50-100 Models/day
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Free DFM and DFA Check
SMT PCB Assembly Capabilities
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Automated Optical Inspection
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Solder Paste Inspection
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First Article Inspection
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X-ray Testing
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In-circuit Testing
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Functional Testing
Applications of SMT PCB Assembly Services
As the Surface Mount Technology picked up momentum, there has been a constant increase in the usage of this technique across many industries. The market share of SMT assembly services has been increasing by the day.
Some of the industries that utilize JHY for SMT PCB assembly are –
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Aerospace
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Consumer Electronics
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Defense
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LED components
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Medical and Health care
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Transport and Automotive Electronics
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Telecommunication & Mobile communications
What is the Difference Between SMT and SMD?
Quick Turn PCB Prototype Assembly Service
Often buyers get confused with these two terms: SMT and SMD. These terms are often used interchangeably, but they are different.
SMT stands for Surface Mount Technology, a technology or a method of placing components directly on the PCB. On the other hand, SMD stands for Surface Mount Devices that are components or devices used in the Surface Mount Technology. The devices are components, such as resistors, transistors, and LEDs. Both terms have a relationship, but they refer to different things. Long story short, SMT is a process while SMDs are the physical components.
What is the Difference Between SMT and THT?
SMT and THT are two different technologies for mounting electronic components on the PCB board. Both are different and have their distinct advantages and disadvantages.
Traditional through-hole Dual In-Line Package assemblies reached their limits in terms of cost, weight, volume, and reliability improvements. SMT allows more reliable assemblies with higher I/O, increased board density, and reduced weight, volume, and cost. The weight of printed circuit board assemblies (PBAs) using SMT is reduced because surface mount components (SMCs) can weigh up to 10 times less than their conventional counterparts and occupy about one-half to one-third of the space on the printed circuit board (PCB) surface. SMT also provides improved shock and vibration resistance due to the lower mass of components. The smaller lead lengths of surface mount components reduce parasitic losses and provide more effective decoupling.
THT is old technology and was widely used before SMT. THT components are a bit large as compared to their SMT counterparts. Thus, a THT PCB assembly is larger than an SMT PCB assembly. However, when the THT components are soldered, they can bear high mechanical and environmental stress. But SMT components cannot bear thermal and mechanical stress because they use less solder paste, which fails in the case of stress.
Advanced Learning: Solder Paste and Solder Paste Printing in SMT PCB Assembly
Nowadays, SMT is preferred over THT, but THT is still used where there is high heat and mechanical stress. There is also a Mixed technology that uses both SMT and THT. It is by far the best because the components suitable for SMT are placed via SMT and the others placed through THT. Such types of boards have the qualities of both technologies, making the PCB more reliable and cost-effective.
ADVANTAGES & DISADVANTAGES
Benefits of Surface Mounting Technology
Compact PCBA
Reliable Performance
Low Cost
Quick Production Process
Disadvantages of Surface Mounting Technology
Weak Solder Connections
Difficult to Troubleshoot
Requires Expertise and Expensive Machinery
Surface Mount Technology Types and Process Flow
Surface Mount Technology (SMT) replaces DIPs (or THT, Through-hole Technology) with surface mount components (SMCs). The assembly is soldered by reflow and/or wave soldering processes depending on the mix of surface mount and through-hole mount components. When attached to PCBs, both active and passive SMCs form three major types of SMT assemblies, commonly referred to as Type 1, Type II, and Type III (As shown on the right).
Type I is a full SMT PCB board with components on one or both sides of the circuit board.
Type II is probably the most common type of SMT board. It has a combination of through-hole components and SMT components. Often, surface mount chip components are located on the secondary side of the Printed Circuit Board (PCB). Active SMCs and DIPs are then found on the primary side. Multiple soldering processes are required.
Type III assemblies are similar to Type II. They also use passive chip SMCs on the secondary side, but on the primary side only DIPs are used.
Typical Process Flow for Underside Attachment (Type III SMT)
Leaded components are inserted, usually by automatic equipment. The assembly is turned over, and adhesive is applied. Next, passive SMCs are placed by a “pick-and-place” robot, the adhesive is cured, the assembly is turned over, and the wave-soldering process is used to solder both leaded and passive SMCs in a single operation. Finally, the assembly is cleaned (if needed), inspected, repaired if necessary, and tested. For this type of board, the surface mount components used are chip components and small pin count gull wing components.
Typical Process Flow for Total Surface Mount (Type I SMT)
For a single sided type I, solder paste is printed onto the board and components are placed The assembly is reflow soldered and cleaned (if needed). For double-sided Type I, the board is turned over, and the process sequence just described is repeated.
Type II assemblies go through the process sequence of Type I SMT followed by the sequence for Type III. In general practice, only passive chip components and low pin count gull wing components are exposed to solder wave immersion.
The process of surface mount technology involves some important steps. It starts all the way from PCB designing and ends at the final testing of PCBA.
Surface Mount Technology Assembly Process
1) PCB Designing
2) Design for Manufacturability (DFM) Inspection
3) Component Procurement
4) PCB Fabrication
5) Application of Solder Paste
6) Pick and Place
This is an automated process of picking and placing the SMDs on the PCB. The PCB is held in a machine, and the components are picked and placed in specific places. This automatic process makes the manufacturing process quicker. There is no need to place and solder the components manually. The process is done with the help of a robotic arm, so it can be carried out round the clock. It also reduces the probability of errors.
The components are placed where they should be. The XY coordinate of the components is provided using the Pick and Place file.
7) Reflow Soldering
In pick and place, the components are only placed in the right places. Then, they are soldered using reflow soldering. The PCB is passed through a reflow oven, which melts the solder paste and connects the SMDs to the board.
The PCB is placed over a conveyor belt and passed through the oven. So, there is no manual work needed. After passing through the hot oven, the PCB is cooled.
8) Inspection
Inspection is an important step to make sure the PCB is up to the mark and ready to provide the desired results. The problem can be with soldering. There could be short circuits or open circuits. Therefore, inspection is necessary to detect the flaws and errors.
First, the inspection is carried out manually. This is not necessary, but some errors can be detected by the naked eye. After manual inspection, AOI (Automatic Optical Inspection) or X-ray Inspection is carried out.
Automatic Optical Inspection (AOI) is a quick method of detecting errors. There are cameras that visualize the PCB. The visual image can also be seen on monitors. The cameras are placed at different angles to analyze every part of the PCB. But this method cannot analyze the connections under the components. It cannot be used for the inspection of a multilayer PCB.
X-ray Inspection is an advanced method. It can be used to see the connections under the components and the layers of the PCB. X-rays pass through the board and provide a picture on the screen. It can detect minor faults in the PCBA.
9) Final Test
SMT PCB Assembly FAQs
What does your quoted price include ?
The PCB assembly pricing includes setup fee, stencil fee, assembly fee and components cost. We do not charge any other labor fees.
What files are required for SMT assembly order?
Gerber file, it is used for PCB production.
BOM file(Bill of Materials).
CPL file(Component Placement List / Pick & Place File (PNP) file), it is used by our automated SMT Assembly machines to determine where each part should be located on the board.
