SMT SPI Manufacturer in China

Replace Your Best Solder Paste Inspection Machine Today

CNSMT provides you the best quality and best price SMT SPI machine in China, including online or offline, 2D/3D SPI solder paste inspection machines.

CNSMT has over 10 years of experience in developing SMT SPI and AOI machines, so our machine working very stable and no worry about the after-sale problems, we have a professional engineer team to support your business!

Fast response
We provide you the fastest response. We are available 24/7 to respond to you. Enjoy our quick response.
Free technical support
We offer the best free technical support for your cause. We serve you at your ease.
On-time delivery
We make sure the delivery of the order in time without any damage prospect.


Send Your Inquiry

Your Best SMT SPI Machine Supplier

CNSMT supply both new and used SMT SPI Solder paste inspection machines in China, with competitive prices and the best quality. The SMT SPI is used to inspecting solder paste thickness or other PCB solder paste problems. Such as solder paste open solder, floating solder, inveracious, solder bridge. etc. The solder paste inspection machine can help you find these solder problems before mounting, So it will greatly reduce your defective products.

Your Reliable SMT SPI Machine Supplier

CNSMT Provide the bellow related machines


Online SPI also called Inline SPI, is a full automatic PCB solder paste inspection equipment, with automatic conveyor transport function, and high precision vision camera.

You just need to make a program, rest of the work this online SPI machine will work all out for you.


Offline SPI is a semi-automatic or manual PCB solder paste inspection machine.By this offline or desktop SPI, you only need spend half or less cost than online SPI, so if you dont have too much budget, offline SPI will be your best option.


2D offline SPI is the cheapest model SPI in the market, CNSMT is a professional SMT SPI manufacturer in China, with over 10 years of experience of producing SMT equipments.


3D offline SPI is using 3D vision camera solder paste inspection machine, its more higher precision than 2D, so if you request higher accuracy about SMT SPI, this 3D will be your best choice.

Contact Our Support Team


SMT SPI – Solder Paste Inspection – The Ultimate FAQ Guide

Here is a complete guide on the SMT SPI systems.

All the queries that you may have about the SMT SPI systems are answered below in this guide.

So before you invest in the stock of SPI systems, read this guide for detailed understanding.

  1. What is SMT SPI – solder paste inspection
  2. How does the SMT SPI – solder paste inspection work?
  3. The use case of SMT and SPI:
  4. The top manufacturers of SMT SPI:
  5. Is the SMT SPI reliable?
  6. Benefits of a 3D SMT SPI:
  7. What is a SMT SPI – solder paste inspection machine made up of?
  8. Are solder flux and solder paste similar for SMT SPI?
  9. Benefits of a solder paste inspection:
  10. What is the solder paste inspection machine price?
  11. The different solder paste inspection parameters:
  12. How do you perform solder paste printing?
  13. What is a SMT SPI screen printer machine?
  14. What defects do SMT SPI systems examine?
  15. Method to calculate the solder paste volume for solder paste inspection:
  16. The solder paste inspection height specifications:
  17. What is the use of image capture in the SMT SPI system?
  18. Life of a solder paste inspection:
  19. Different techniques used in SMT SPI:
  20. Where to buy SMT SPI?

desktop-spi1.     What is SMT SPI – Solder Paste Inspection?

SMT SPI or solder paste inspection is a system. This system is used to measure the height, volume, and area of the paste deposits.

The SMT SPI system is also used to compute the stencil offsets and detect various defects.

Simply put, the SMT SPI is used to manufacture and test the PCBs.

Figure 1: SMT SPI

SPI machines are an efficient investment option for businesses and companies. They can serve in inspecting the solder paste of electronic printed circuit boards.

You can experience a fast and more accurate inspection with these machines.

2.     How does the SMT SPI – Solder Paste Inspection Work?

Using the SMT SPI machine, a fast and accurate inspection of the PCBs are conducted.

This inspection ensures that the solder paste on PCBs has no faults.

To ensure this quality of the paste, the SPI machines usually scan the PCB board’s surface.

Figure 2: SPI Working

To scan, the board is lighted with various lighting equipment along with a high definition camera. In this way, the SMT SPI machine captures an image of the PCB.

This picture is processed and then compared with the machine’s knowledge of a high-quality solder paste on the board.

In this way, the defects or suspected areas on the board are highlighted.

2D-SPI3.     The Use Case of SMT SPI:

The use case of an SMT SPI system allows you to understand how you will control and manage the system for analyzing the defects in the PCBs.

By following the step by step instructions, you can better understand how to use the SPI system in your business.

It also helps to figure out the use of each of the features present on an SPI system. You can follow the use case of SPI shown in the above link.

4.     The Top Manufacturers of SMT SPI:

Different brands/manufacturers offer the production of SMT SPI machines.

These machines are helpful tools, both for small scale as well as large-scale business.

The SMT SPI machines are usually sold in bulk amounts. You can also purchase a bulk amount of SPI machines for high-quality PCB inspection.

There are various manufacturers of SMT SPI. The top ones that you can buy your SPI machine from include:

  • KongYONG
  • VCTA
  • DWX
  • HNY
  • Yamaha

CNSMTLine offers you a wide variety of brands offering SMT SPI machines in bulk quantity for your business.

5.     Is the SMT SPI Reliable?

An SMT SPI technique is used to ensure that the PCBs quality and its solder paste are accurate.

This technique highlights all types of faults and defects in a PCB.

As a result, companies are better able to manufacture high-quality electric printed circuit boards with the help of SPI machines.

This quality guarantee makes SMT SPI machines highly reliable and essential for high-quality PCB manufacturing.

Smt-Stencil-Printer-manufacturer6.     Benefits of 3D SMT SPI:

A 3D SMT SPI works differently from a normal SMT SPI machine. Its 3D inspection verifies the height and footprint of solder paste targets.


This verification takes place before the parts are inserted for soldering in their place.

The consumed data from the 3D inspection helps in placing the parts in the right position.

It also benefits in reducing warpage after pats placement.

You can consider the 3D SPI machine for an advanced understanding of the problems and their progression.

It helps to track the origin point of the PCBs and eliminate the root causes of the problem.

7.     Is the Use of Solder Paste Inspection Systems Essential?

With the improvement of SPI technology and its systems, more defects are now easy to accurately predict on the PCBs.

In this way, SPI systems have successfully been able to form useful elements in all types of manufacturing environments of solder print.

8.     Are Solder Flux and Solder Paste Similar for SMT SPI?

Both solder and flux are an essential part of the PCB’s soldering and manufacturing process.

Figure 4: Difference Between Solder Flux and Solder Paste

Where solder is used to assemble the components of printed circuit boards, flux is utilized before this assembly.

Usage of flux works in preparing the board to undergo its soldering process.

This means that flux is an essential part of the PCB’s soldering.

Yet, both solder flux and solder paste are different materials, having different roles.

There are different types of flux like liquid, paste, and solid. Each of these flux types is used in different cases.

9.     Benefits of a Solder Paste Inspection:

With the increased complexity of the PCBs, manual inspection of these boards is not a reliable option.

Now markets require more accurate, high-quality, and reliable products for purchasing and supplying.

To make this possible, a reliable and faster method of solder paste inspection ensures that the manufactured complex PCBs quality is high.

This inspection tool is used in the production of the PCBs, right after they complete the solder printing process. With this advanced management of producing complex PCBs that can fulfill market demands, multiple benefits of SPI machines come along. These benefits include:

  • Instant Problem Recognition:

Since the SPI tools are used during the production process of the PCBs, the problems in the solder and board’s assembly can be recognized earlier.

It helps to gather feedback and take action against the faults in the earlier stages of production.

As a result, with the of an SMT SPI machine, the problems present in the PCBs are identified early.

This early recognition helps to rectify the faults before plenty of other boards are manufactured in the same way.

  • Less fault Fixing Costs:

Another benefit of using SMT SPI during the production process of PCBs includes reduced costs for fixing these boards.

Since the usage of these machines helps to analyze and rectify the PCB faults earlier, less investment is needed to fix these problems.

After all, the production process is the optimum stage to fix any faults present in the manufacturing of PCBs.

10.What is the Solder Paste Inspection Machine Price?

A solder paste inspection or SPI machine is available at different prices.

You can choose the price range of the solder paste inspection machine according to the manufacturing brand you choose.

CNSMTLine offers you reasonable rates on bulk SPI machines for your business.

So you can choose your desired brand of SMT SPI machine and consider CNSMTLine for delivering your bulk amount of SPI machines at reasonable rates, and on time.

11.Is the SMT SPI Lighting Source an Important Element of the System?

The lighting source in the SPI system is a highly important element of the system, along with the image capture system.

The usage of these lighting systems helps to capture clearer and better images of the PCB with the SPI system.


So an SPI system can’t perform efficiently without the essential lighting sources.

Various types of lightings used in this system include:

  • LED lighting
  • Fluorescent lighting
  • Infra-red/Ultra-violet lighting

12.Is a Solder Paste Inspection Different from Solder Paste Printing?

Yes, a solder paste inspection is a process of inspecting the PCBs thoroughly while and until their placement is performed.


It is more of a correction machine that looks into the faults of the PCBs so that they can be fixed on time.

Alternatively, the solder paste printer is simply a part of the PCB placement process.

This method takes place before the usage of solder paste inspection systems on the printed circuit boards.

13.What is an SMT SPI Screen Printer Machine?

The process of solder paste printing is performed before the use of SMT SPI machines.


In this process, solder paste is deposited on the printed wiring boards for creating electrical connections.

After this, the component placement process is performed.

This process is performed with specific tools including; a stencil, a printer, and solder paste.

14.What Defects do SMT SPI Systems Examine?

Usage of an SMT SPI helps to analyze and find different types of defects in a PCB.

With the help of an SPI machine, all the defects and faults in a PCB can be found and fixed on time.

Figure 8: PCB Defects

Some of the common defects that this machine examines include:

  • Nodules
  • Scratches
  • Stains

The SMT SPI also helps to determine various PCB dimensional defects including:

  • Height
  • Shape
  • Volume
  • Shift
  • Area
  • Bridge
  • Overflow

15.Method to Calculate the Solder Paste Volume for Solder Paste Inspection:

Before the solder paste inspection process is performed, the solder paste is applied to the printed circuit boards.

Figure 9: Solder Paste Volume Measurement

This solder paste is applied according to a specific volume calculation so that it can efficiently play its role in the PCBs placement while limiting the faults on the PCBs.

Businesses and manufacturers can easily calculate the right volume of solder paste with the help of the below method.

  • By calculating the theoretical volume of the solder paste. It can be calculated using the Greely Formula and simple volume calculation of each board.
  • To go further, it preferred to generalize the Specific Gravity of the flux vehicle with 1.
  • Also, the Solder Paste Specific Gravity should be 4.14
  • Now you can calculate the volume for this aperture using the formula: Length x Width x Height.

16.Different Cameras and their Accuracy in The SPI Systems:

Different types of cameras are used in the SPI systems for the accurate monitoring and analysis of the PCBs and their faults.

Figure 10: SPI Inspection Camera Equipment

These cameras include:

  • Video Streaming Camera:

One major type of camera used in the SPI system is the streaming video camera.

This camera helps to take the complete frames of the PCB.

These captured frames are used to create a still image to perform signal processing.

The use of this process may not be as accurate as of the still image systems, but they have a fast speed.

  • Still Image Camera:

This camera is placed close to the target PCB.

For accurate and clear still images to be taken with this camera, a good lighting system is required.

While the image is being taken, the operator might also need to move the camera following the software control.

Figure 11: SPI Camera Working

17.What is the Use of Image Capture in The SMT SPI System?

The image capture system is another key element of an SPI system.

This system captures an image of the PCB board and its assembly.

Figure 12: Inspection Equipment Capturing PCB Image

This image is then used to analyze with the help of the processing software that is present in the PSI system.

18. Advanced Benefits Enjoyed by Business with the Help of a Reliable Solder Paste Inspection:

Unlike the common previous benefits of using an SMT SPI system, there are a lot more benefits that are offered with these systems.

By investing in the PSI systems for your businesses PCB placement processes, you can enjoy advantages like:

  • Improved printed circuit boards quality
  • Better control of the process and the efficient operations
  • Enhanced yield and uptime for PCB placement
  • Less need for training time and extra resources
  • Decreased costs for work
  • Reliable establishment of both repeatable and verifiable standards

19.Different Techniques Used in SMT SPI:

The SMT SPI machine uses various techniques for analyzing if the PCBs are decent or have any defects.

Figure 13: SPI Working

These techniques include:

  • Matching the Template: 

In this process, the SMT SPI (Solder Paste Inspection system) uses the captured image of the board in its system to compare it with the templates of the ‘golden board’.

  • Matching the Pattern:

In this technique, the SPI system stores the image of both good and bad PCB board assemblies.

Using both these images, the SPI system matches the obtained image to evaluate the perfect pattern of a PCB.

  • Statistical matching of the Patterns:

Lastly, the SPI systems perform the statistical pattern matching technique.

This technique is quite similar to the previous one.

However, here the SPI system uses a statistically-based method to address the PCBs problems.

It stores the results of various boards and a variety of failure problems so that it can easily accept the minor changes.

These more changes can be accepted easily without causing any huge alarming errors.

20.Where to Buy SMT SPI?

With a wide range of manufacturing brands and rates of SPI machines, CNSMTLine delivers you a reliable and authentic stock of SPI machines.

So you can buy a bulk quantity of SMT SPI of any type or brand and at reasonable bulk rates.


I hope you have all the information you need on the SMT SPI systems.

Yet, if there’s anything more you need to ask, please feel free to contact us.

If you can’t find the device you want on our website, please email or contact us online for more information

Send Your Inquiry
Scroll to Top