PCBA Tech - MES system realizes SMT loading error prevention

Before the SMT equipment is mounted, the operator needs to place the feeder on the correct feeder, and then place the feeder on the appropriate SMT equipment station. In this process, the wrong material or the wrong feeder is often used. Since the SMT equipment runs continuously at high speed, if this error cannot be avoided in advance, it will cause rework or scrapping and cause huge losses to the enterprise. To avoid this situation, the best way is to wait during the feeding process. The corresponding relationship between the feeding tray, the feeder used, and the station to be fed is compared with the feeding station table.

To achieve the purpose of comparison, it is first necessary to establish the basic data of the material station table in the MES system. A complete material station table data basically includes product code [or work order code], material code, feeder specifications, production line code, equipment number, station number, and for double panels, it also includes board information [A/B [Face], for dual-table devices, there is also a table number. The material station table data is generally maintained by the craftsman and entered into the computer connected to the SMT equipment in advance. Before the material is compared, it is only necessary to import this information from the computer of the SMT equipment into the MES system.

Speaking of this, you may consider another question, that is, what if the material in the station table itself is wrong?

In the electronic assembly industry, a product is composed of hundreds of electronic devices, and these electronic devices have many alternative materials or designated materials. In order to reduce costs, the remaining materials in inventory may be used to the greatest extent. Changing the materials used naturally requires frequent changes to the material station table. Considering this situation, it is necessary to minimize the possibility of material station table data errors. There are generally two ways to achieve this goal: First, after changing the material station table, the system forces the user to include the product station table The material of the current work order is compared with the material issue list of the current work order. Only when the comparison results are consistent or the user recognizes the difference, the material station table is allowed to continue to be used; second, the material station table data entered into the MES system consists of two It is composed of parts, one part is the ingredient BOM of the work order (including material code, symbol number), and the other part is the process BOM data prepared by the craftsman. The process BOM data does not contain specific material information, only each symbol is given The location and feeder specification information of a corresponding SMT device. The process BOM data is basically fixed for each model. The only thing that changes is the work order ingredient BOM data, and the work order ingredient BOM data is often generated and adjusted in the ERP system, and the possibility of error is extremely small.

Once you have the material station table data, you need to consider how to implement error prevention during the loading scan process. Simply put, loading error prevention means that the system compares the material tags, feeder tags, station location tags scanned by the user during the loading process to see if they match the material station table data, and when inconsistencies are found, clear warning information is given to achieve inspection. And the purpose of the warning. The seemingly simple SMT loading operation has its own complexity. A complete and practical SMT loading error prevention system needs to provide at least the following functions: First, during the entire production process of the SMT workshop, the loading scan can be It is boiled down to four business types: loading, refueling/receiving, unloading, and QC sampling comparison. The loading error prevention system must first provide system functions that meet these types of business, and pay special consideration to the user's operating habits., To minimize the complexity of user operations; second, many electronic products produced by customers involve single-sided, double-sided, and mixed panels containing multiple products, and the error-proofing system must be able to support a variety of complex products Structure, and keep the coordination with the customer’s business habits to the greatest extent; Third, the loading error prevention system needs to collect the various label information scanned by the operator before comparing the material station table data, and the system must consider how to prevent The loss of operators allows the system to truly function, while at the same time reducing the complexity of system operation as much as possible and reducing the resistance of front-line personnel to the system.

There are many types of hardware to choose from to realize the error-proof function of SMT loading. The device with relatively minimal investment is to configure only an offline inventory machine, download the material station table data to the inventory machine, and then develop a simple comparison program To achieve simple comparison function, this kind of equipment is more suitable for customers with simple business and single functional requirements; secondly, a combination of wireless scanner + PC can be used. This equipment combination has a lower investment cost, and the loading error prevention software runs on the PC It can realize a variety of complex applications and is easy to expand the functions. The disadvantage is that the location of the scan collection may be far away from the computer, and the interaction is not very good; if the customer has high requirements in all aspects, you can also consider using the WinCE platform. The PDA device, which can be used to solve the problem of interactivity, does not occupy production line space and is easy to arrange. The disadvantage is that the software development cost is high, and the equipment investment is also high.