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SMT PCB Assembly Supplier
LZJPCB is an SMT PCB assembly supplier from Shenzhen, China, offering full SMT PCB assembly with 8 million placements per day, 01005 fine pitch, and 8-hour rapid turnaround. We serve procurement teams and engineers with 1-on-1 engineer support, backed by IATF16949 and ISO13485 certification.
Senior Electronics Engineer
Most SMT assembly companies push you into a website form and leave you alone. We do the opposite. My name is Jayden, and I want to show you how our SMT PCB assembly line handles your board, your BOM, and your deadline. Keep reading to see the numbers, the process, and the reasons why medical equipment PCB customers have always chosen to work with us.
LZJPCB SMT Assembly Capabilities
| Capability | Specification |
|---|---|
| Daily SMT Capacity | 8 million placements/day |
| Monthly Output | 200M+ component placements |
| PCBA Factories | 3 factories, 100+ employees |
| EMS Experience | 10+ years |
| Min Package | 01005, 0.35mm pitch BGA |
| Placement Accuracy | ±0.04mm (chip) / ±0.03mm (IC) |
| PCB Size Range | 50×50mm ~ 774×710mm |
| Board Thickness | 0.3–6.5mm |
| Board Types | POP, rigid, FPC, rigid-flex, metal core |
| Lead Time | As fast as 8 hours |
| Kitted Material Online | Within 2 hours |
| Core Equipment | YAMAHA SMT machines, GKG solder paste printers, 3D SPI, inline AOI, X-Ray, BGA rework stations, JT reflow ovens, wave soldering |
| Certifications | ISO9001, ISO13485, IATF16949, UL |
What Is SMT Assembly
SMT assembly is a method of placing components directly onto the PCB surface rather than pushing leads through drilled holes. This surface-mount approach saves board space, supports higher component density, and lets machines place parts quickly. Most modern SMT circuit board products use it as the default.
SMT stands for surface mount technology. In SMT, parts sit right on the copper pads of an SMT printed circuit board. No long leads are going through the board. This is the core of PCB and SMT work today. The technology first appeared in the 1960s. By 1986, surface-mount parts made up at most 10% of the component market. By the late 1990s, most high-tech boards used SMT. That shift started in the 1980s and has not stopped since. It replaced through-hole because through-hole could no longer keep up with speed, size, and volume needs. SMT in PCB design gives you three big wins. First, fewer drilled holes, so lower drilling cost. Second, higher volume, so lower per-unit cost. Third, denser layouts, so smaller products. High-speed pick-and-place machines can place more than 136,000 parts per hour. A job that took 1–2 hours by through-hole now takes 10–15 minutes by SMT. That is the reason SMT sits at the heart of almost every consumer and industrial device.
Difference Between SMT and SMD Assembly
SMT is the process, and SMD is the part. SMT means “surface mount technology,” the method used to mount and solder parts. SMD means “surface-mount device,” the actual component that gets placed on the board. So when you order smd pcb assembly, you are asking us to run the SMT process using SMD parts on your SMD PCB board.
| Term | Meaning | Example |
|---|---|---|
| SMT | The assembly method | Pick-and-place, reflow soldering |
| SMD | The physical component | Chip resistor, QFN, BGA |
An SMD board is simply an SMD PCB built to hold surface-mount parts. These parts have no lead wires through holes. They have short pins, flat contacts, pinless bodies, or ball arrays. They are made for machines, not for hand work. That is why an SMD PCB manufacturer needs proper SMT lines to operate effectively.
SMD PCB Assembly Services
SMD PCB assembly services cover full PCB SMD assembly, from resistor and capacitor chips down to fine-pitch ICs. We place parts on one or both sides of your SMD PCB, run reflow soldering, and inspect every board. As an SMD PCB manufacturer, we handle SMD board assembly for prototype and volume runs.
When you send us an SMD PCB board, we treat the whole job as one flow. We prepare your parts, print solder paste, place components, reflow, and inspect. Our lines handle a wide range of SMD packages so your SMD board gets built right the first time.
Common SMD Packages We Handle
- Chip resistors and capacitors down to 01005
- QFN and QFP fine-pitch ICs
- SOIC and PLCC packages
- BGA and micro BGA
- Package-on-package (POP)
- Small chip packages with 0.2mm pitch
SMD parts give real electrical gains. Their connections have lower resistance and lower inductance than through-hole. That means fewer unted RF effects and better EMC. The smaller radiation loop area also cuts radiated emissions, so you may need less shielding. Smaller parts and shorter traces also help higher circuit speed. For a PCB procurement specialist, this PCB SMD assembly quality shows up as a stable, low-defect product he can sell into industrial automation. We support prototyping with no minimum order, so you can test a design before you commit to volume.
BGA and Fine Pitch PCB Assembly
We handle BGA and fine-pitch PCB assembly down to 0.35mm pitch BGA and 01005 chips. Our fine-pitch PCB assembly uses 3D SPI, inline AOI, and X-Ray to check hidden joints under each BGA PCB. This X-Ray step is the only way to verify BGA solder balls you cannot see.
BGA parts hide their solder balls under the body. You cannot inspect them with your eyes or with normal AOI. That is why PCB assembly BGA work needs X-Ray. We use X-Ray on every BGA, micro BGA, QFN, and POP joint. This catches voiding and bridging before the board ships.
BGA and Fine Pitch Control Points
| Control Step | What It Checks |
|---|---|
| 3D SPI | Solder paste volume, height, offset |
| Pick-and-place | ±0.03mm IC placement accuracy |
| Reflow profile | Ramp, soak, peak temperature |
| X-Ray | Hidden BGA joints, voiding |
| BGA rework station | Repair and reball |
Fine-pitch work needs strict control. A BGA PCB with 0.35mm pitch leaves little room for error. Our GKG solder paste printers and 3D SPI keep paste volume in spec. If paste is too low, you get open joints. If it is too high, you get bridging. We also store BGA parts in dry cabinets to control moisture, then bake when needed. This care is what makes fine-pitch PCB assembly reliable for medical and automotive boards. Our engineers review your BGA layout at the design stage, so problems get caught early, not on the line.
Double Sided SMT Assembly
Double-sided SMT assembly places components on both sides of your PCB to raise density and shrink the board. We assemble the heavier or denser side first, run reflow, then process the second side. Surface tension holds bottom-side parts during the second reflow, with adhesive used in rare cases.
Double-sided SMT assembly doubles the space you have for parts. This is how complex boards fit into small products. But it adds process steps that need careful control. We repeat the print, place, and reflow flow for the second side.
How We Run Double Sided Boards
- Assemble the heavier or denser side first
- Run the first reflow cycle
- Print paste and place parts on the second side
- Run the second reflow cycle
- Use adhesive on bottom-side parts only in rare cases
The main risk is bottom-side parts falling off during the second reflow. In most cases, the surface tension of molten solder holds them in place. In rare cases, we glue small parts before reflow to keep them secure. When a board mixes SMT and through-hole and uses wave soldering, we glue bottom-side SMT parts first, or we use selective soldering masks to protect them. Correct pad geometry also helps. Good pads let surface tension pull each part into place on its own. This self-alignment corrects small placement errors. For Michael’s industrial automation boards, double-sided assembly is the standard way we hit high density without growing the board size.
SMT and THT Mixed Assembly
SMT and THT assembly on one board combines surface-mount density with through-hole strength. We use PCB assembly smt tht when a board needs both small dense parts and rugged connectors, large transformers, or power semiconductors. This mixed build gives you the space savings of SMT and the mechanical hold of through-hole.
Some parts still work better as through-hole. Large transformers, heat-sinked power semiconductors, and connectors that get plugged and unplugged often need the extra grip of a through-hole joint. So we build many boards with both SMT and THT assembly on the same PCB.
When Mixed Assembly Makes Sense
- Connectors that are frequently attached and detached
- Large transformers and magnetic parts
- Heat-dissipating power semiconductors
- Boards that face heavy shock, vibration, or thermal stress
- Parts too large for standard SMT packages
Boards built only with SMT can face reliability risk under mechanical stress, humidity, dust, and thermal cycling. Mixing SMT and through-hole is a smart way to reduce that risk. You keep the density of SMT for most parts. You add through-hole for the few points that need a strong mechanical hold. Our PCB assembly SMT and THT flow handles this in one job. We run SMT first, then add through-hole parts by hand soldering, focused infrared, or selective wave soldering. For industrial equipment sold across many markets, this balance of density and durability matters. It is a common request from procurement teams who need boards that survive rough field conditions.
Rapid and Small Batch SMT Assembly
Our rapid SMT assembly ships in as fast as 8 hours, with single or double-sided prototypes in 24 hours and small batch SMT assembly in 48 hours. Kitted materials go online within 2 hours. Urgent orders get 7×24 response. This speed cuts the long supply chain lead times that slow down product launches.
Speed is a real pain point for buyers. Michael in Germany designs boards in-house, then needs them built and assembled fast so his local team can finish the product. Long lead times hurt his whole schedule. Our rapid SMT assembly is built to fix that.
Our Lead Time Options
| Order Type | Lead Time |
|---|---|
| Fastest turnaround | As fast as 8 hours |
| Single/double-sided prototype | 24 hours |
| Small batch | 48 hours |
| Standard orders | 2 days |
Small-batch SMT assembly is where flexibility counts most. You may need 5 boards to test, then 100 to launch, then more for volume. We keep tens of thousands of stock parts, and our supply team kits samples in as fast as 3 days. Kitted material goes online within 2 hours, so your job does not sit and wait. For urgent runs, our team answers 7×24. This matters when a client serves several markets and needs different builds fast. We do not force you through a rigid website order flow. A dedicated engineer stays with your job so changes get handled without delay.
SMT PCB Assembly Applications
- Communications equipment and 6-layer high-frequency boards
- Medical devices, including MRI control boards and ceramic boards
- Industrial control and smart building control boards
- Automotive electronics, such as T-BOX, gateway, and motor drive boards
- Instrumentation and data acquisition PCBA
- Smart wearables and consumer electronics
- Robotics, including smart robotic vacuum mainboards
- Self-service systems, such as checkout control boards
- Test and measurement, such as scanners and video capture boards
- Energy equipment, such as wind turbine vibrometer mainboards
SMT Assembly Quality and Certifications
| Certification / Control | Detail |
|---|---|
| ISO9001 | Quality management system |
| ISO13485 | Medical device quality |
| IATF16949 | Automotive quality standard |
| UL / CUL | Safety certification |
| RoHS / REACH | Material compliance with SVHC reports |
| 3D SPI | 100% solder paste inspection |
| Inline AOI | Real-time board inspection |
| Offline AOI | Batch and rework verification |
| X-Ray | Hidden BGA and QFN joint inspection |
| IQC | Incoming component inspection |
| First-article inspection | Intelligent verification before run |
Applications of High Frequency PCBs
- Wireless communications: GPS devices, Cell phones, and Wi-Fi routers with built-in antennas, amplifiers, and RF parts.
- 5G and telecom: Base station antennas and RF modules for sub-6GHz and mmWave bands. This is the largest and fastest-growing use.
- Radar systems: weather data, Airport traffic, and military radar signal processing.
- Automotive: 77GHz long-range and 24GHz short-range radar for ADAS and autonomous driving, plus LIDAR and vehicle networks.
- Satellite communications: Microwave and RF links that must survive vacuum and wide temperature swings.
- Medical electronics: patient monitors, MRI RF coils, RF ablation tools, and RF-enabled diagnostic devices.
- Aerospace and defense: Navigation, avionics, and electronic warfare systems working from −55°C to +125°C.
- Industrial and power: Precision automation and sensor systems that need clean high-frequency control signals.
High Frequency PCB Certifications and Quality Standards
| Certification | What It Covers |
|---|---|
| ISO9001 | Quality management system |
| ISO14001 | Environmental management |
| IATF16949 | Automotive quality, near-zero defect targets |
| ISO13485 | Medical device manufacturing |
| UL / CUL | Product safety (US and Canada) |
| RoHS / REACH | Hazardous substance compliance, with SVHC reports |
| IPC Class 2 & 3 | Commercial and high-reliability build standards |
| Others | 20+ patents, China National High-Tech Enterprise |
Why Choose Us for SMT PCB Assembly
- Dedicated 1-on-1 engineer support, not a website-only order form
- 8 million placements per day across 3 PCBA factories
- Fine pitch down to 01005 and 0.35mm pitch BGA
- Full inspection chain: 3D SPI, inline AOI, offline AOI, and X-Ray
- Rapid turnaround from 8 hours, with kitted material online in 2 hours
- Turnkey BOM sourcing with 100% genuine, traceable parts
- No minimum order quantity, so prototypes are welcome
- Certified for medical (ISO13485) and automotive (IATF16949) work
- Global export experience to USA, Europe, Brazil, and Russia
- 10+ years of EMS experience and 300+ managed projects
SMT PCB Assembly Process
Our SMT assembly process runs seven stages: board and stencil prep, solder paste printing, 3D SPI, pick-and-place, reflow soldering, AOI, and a repeat cycle for double-sided boards. Each stage on our smt assembly line uses dedicated smt assembly equipment to keep defects low and quality stable.
The PCB SMT assembly process follows a fixed order. Every step feeds the next, and we inspect early to catch problems before they cost more. Here is how our SMT PCBA assembly processes work on the floor, step by step.
- Prepare and inspect the PCB, SMD parts, and stencil. We check for warp, clogged apertures, and damaged parts.
- Print solder paste onto every pad. Our GKG printer uses a steel stencil, or a jet printer for low-volume, high-mix jobs.
- Run 3D SPI on every board. This checks paste volume, height, coverage, and shorts. 3D beats 2D because it measures volume, not just area.
- Pick-and-place. Our YAMAHA SMT machine for PCB assembly places parts at high speed with ±0.03mm IC accuracy. Parts arrive on reels, tubes, or trays.
- Reflow soldering. The board moves through preheat, soak, reflow, and cooling zones. Preheat rises slowly to avoid thermal shock. The peak melts the paste, then controlled cooling sets joint strength.
- AOI inspection. We check for missing parts, misaligned parts, and bridging. X-Ray checks hidden BGA joints.
- For double-sided boards, we repeat steps 2 to 5 on the second side.
Our SMT assembly equipment list is broad. It includes GKG solder paste printers, 3D SPI, YAMAHA high-speed machines, JT reflow ovens, inline AOI, X-Ray, BGA rework stations, and wave soldering. Any board that fails inspection goes to a rework station where a skilled operator repairs it, then re-inspects. This full PCB SMT assembly machine chain is what keeps our yield high and your product stable. Every SMT manufacturing process PDF we share follows this same flow.
SMT Assembly Cost
SMT assembly cost depends on board size, layer count, part count, package type, order volume, and BOM sourcing. Fine-pitch BGA and small batches cost more per board than high-volume runs. We use transparent markup and offer samples at wholesale prices, so you always see where your money goes.
SMT cost has a few clear drivers. In high volume, SMT is cheaper per joint than through-hole because machines run fast and setup cost spreads across many boards. In small volumes, stencil and setup costs can push the per-board price up. Package type matters too, since fine-pitch BGA needs more inspection.
How to Reduce SMT Assembly Cost
- Increase order volume so setup cost spreads across more boards
- Standardize part packages to cut feeder changes
- Let our BOM team suggest tested alternative parts when a part is costly or out of stock
- Design for manufacturability early, so no rework is needed
- Panelize boards to raise throughput and cut handling
- Send us a clean, complete BOM to avoid delays and re-quotes
Our supply chain team of 20+ people sources parts from original makers and tier-1 agents, all genuine and traceable. We price with transparent markup, not hidden fees. Because we run our own SMT lines and PCB factory, we control cost across the whole build. For a buyer with moderate price sensitivity and high quality needs, this mix gives fair pricing without cutting corners on quality. Our engineers also flag design choices that raise cost, so you can decide with full information before the order starts.
SMT Assembly FAQ
What is the minimum order quantity for SMT PCB assembly?
We have no minimum order quantity. We build single prototypes, small batches, and full-volume runs. Prototyping is fully supported, with samples kitted in as fast as 3 days.
How fast can you deliver SMT assembly?
Our SMT assembly ships in as fast as 8 hours. Single or double-sided prototypes take 24 hours, and small batches take 48 hours. Kitted material goes online within 2 hours.
What is the smallest component you can place?
We place parts down to 01005 chips and 0.35mm pitch BGA. Our placement accuracy is ±0.04mm for chip parts and ±0.03mm for ICs.
Do you inspect BGA solder joints?
Yes. We use X-Ray on every BGA, micro BGA, QFN, and POP joint. X-Ray is the only way to check solder balls hidden under the part body.
Can you source the components for me?
Yes. We offer turnkey BOM procurement from original makers and tier-1 agents. All parts are 100% genuine and traceable, with transparent pricing.
Do you handle both SMT and through-hole on one board?
Yes. We build mixed boards with SMT and through-hole together. This adds mechanical strength for connectors, transformers, and power parts while keeping SMT density.
Get an SMT PCB Assembly Quote
To get an SMT PCB assembly quote, send us your Gerber files and BOM at jayden@lzjpcb.com or call (86) 133-1654-3659. A dedicated engineer reviews your board, checks for DFM issues, and returns a clear quote fast. No website-only ordering, just real 1-on-1 support.
