Productivity, flexibility, cost-effectiveness and performance when choosing to evaluate automated smt process equipment such as stencil printing systems

 

These are some aspects that need attention.

 

In addition to freeing people to do other work, the most fundamental advantage of automatic equipment is that it can target specific product lines

 

to set up each job to ensure optimal operating parameters are used. These advantages help to achieve the two most common in all SMT production processes

 

High goal: to shorten the production cycle and obtain the maximum first pass rate of products.

 

Although the current online automatic stencil printing machine can also shorten the production cycle and maximize the first pass rate of the outgoing line, but now a new kind of printing machine has been developed

 

A new standard called "dual pass" is being used to help increase productivity in the SMT assembly process.

 

In most cases, stencil printing will not be the longest step in the SMT production process, and many times it will take longer to complete the placement than silk printing

 

. Nevertheless, it makes sense to evaluate and implement new methods to reduce the actual printing process time, the savings in actual printing operations

 

Time can be used to complete other steps such as solder paste application, stencil wipe and post-press inspection. There are several factors that affect the printing process

 

The time required, these factors are equally important to shorten the process time.

 

Video registration is a key factor for fast stencil printing.

 

These factors include: the printing equipment itself; the speed of PCB transfer and the speed of PCB positioning adjustment by the vision system;

 

The speed of functions such as swabbing and postpress checking. The solder paste itself determines the ultimate speed that can be obtained, which is also a major influencing factor. Right now

 

Even the fastest printing machine in the world can only print any kind of solder paste at the printing speed for which the solder paste is designed.

 

Another major factor affecting printing speed is the ratio of component pad size to stencil opening size. In order to ensure the fastest printing speed, the template

 

The component pads on the printed circuit board must be closely attached or filled, so as to ensure that the solder paste will not be squeezed under the template during the printing process.

 

surface to cause moisture bridging. It can be considered that the pad of the component is half the pitch of the component plus 0.002 inches, and the opening of the template is on each side of the pad

 

Reduced by about 0.001 inches. For a component with a pitch of 0.020 inches, the component pad size is 0.012 inches, and the template opening is 0.010 inches.

 

A better choice.

 

Each automation feature has its own advantages.

 

Apply solder paste

 

A common problem with working with tinned solder paste is placing too much solder paste on the stencil at a time. This is generally due to the silk screen operator as

 

This is done to save time for other operations, usually for the replenishment of patch reels. Doing so will leave a lot of solder paste on the stencil

 

can dry out, cause printing defects, or excessive solder paste sticks to machines, supports, or cameras. Excessive use of solder paste can also cause the operator

 

Solder paste is used up quickly, thereby reducing normal rolling of paste on the stencil while increasing exposure of paste to the operator and to air

 

degree. Put the solder paste in a container, and use the automatic solder paste application system to ensure that the solder paste is added to the template in a timely and appropriate amount. Other

 

External use of containers with application systems also reduces the exposure of the solder paste to the operator and keeps equipment and other tools as safe as possible.

 

keep it clean.

 

wipe template

 

Even a PCB with flat component pads and a well-designed printing process still needs to wipe the bottom of the stencil regularly. template open

 

Appropriate shrinkage of the port relative to the component pad, and the use of a flat component pad, such as bare copper or Alpha Level (silver infiltration), will reduce

 

The amount of solder paste squeezed into the bottom of the stencil, but still doesn't eliminate the need for wiping. An automatic system can be set to execute at appropriate intervals

 

This operation ensures that the bottom of the template is clean without bridging. Modern stencil printing machines, such as Speedline MPM products, come with

 

There is an automatic wiping system, which can be used for dry wiping, solvent wiping or vacuum wiping. A dry or solvent-impregnated wipe, either to remove the stencil

 

The solder paste on the bottom is wiped off, eliminating bridging. Vacuum wiping can suck out the solder paste in each opening to ensure that the openings are clean and open, so that there is no

 

Insufficient amount of solder paste application may occur.

 

It can be set to do automatic stencil wiping regularly to ensure that the bottom of the stencil is clean without wet bridging.

 

Post-press inspection

 

With the increase in the use of array packages, such as Ball Grid Array (BGA), Chip Scale Package (CSP), Flip Chip, and others, the

 

The ability to "see" the applied solder paste before turning on the printing press is becoming more and more important. While array packaging offers many advantages,

 

It also brings with it the disadvantage that the actual solder joints can no longer be seen by conventional inspection methods. Using post-print inspection can leave the PCB

 

Make sure that the solder paste is applied to each component pad before the screen printer. New releases of software like Speedline MPM include custom BGA inspection capabilities

 

The force can be set to check the geometry of any practical package after 2D printing.

 

Using post-print inspection can ensure that every component pad is printed with solder paste before the PCB leaves the screen printing machine.

 

In addition to technical issues, long-term factors must also be considered, such as the return on plant and equipment assets. In this regard, there are many production

 

On the basis of traditional SMT production equipment such as printing machines, placement machines and reflow ovens, equipment suppliers have developed new ideas for complete production lines

 

, which is based on a new generation of equipment designed with two parallel conveyor belts. This idea is called "dual access".

 

dual channel thinking

 

The dual-channel idea can be described as follows: In SMT electronic assembly, each channel can be independently controlled in a logical sequence, thus forming a

 

Efficient board flow. This reduces the time lost in the board delivery process and extends the time that the SMT equipment can do its job. A two-channel module

 

Plate printers can print on a second plate while loading/unloading one plate, saving overall time.

 

Dual-channel SMT thinking can lead to higher yields in a given area.

 

The dual-channel thinking will also shorten the production line, thereby reducing the demand for plant area; in addition, many single pieces of equipment are cut off, so

 

It also reduces upfront investment, manpower requirements, facility overhead, and overall operating costs. From the equipment point of view, including the new type of screen printing machine

 

The new assembly system, including , can utilize two independent pathways to provide greater flexibility. Using this type of equipment, a two-lane line can

 

Process several boards at the same time.

 

In electronics and PCB manufacturing, many assembly tasks must be done efficiently to maximize yield and productivity. Carefully plan the assembly

 

The process is very critical, and all steps of the SMT process must be closely linked to its adjacent previous or next step. need to consider

 

There are various types of PCBs with different component densities, different layers, different sizes, and different shapes. In order to solve these assembly problems, the process

 

Engineers must plan the setup of the assembly equipment line to accommodate the type of PCB being processed. Some production lines may be set up to have

 

have the most flexibility (can be changed quickly), while others may be set to have a higher output, and more are set to combine the two extremes

 

The situation is considered together.

 

However, while setting up the SMT electronic product assembly line, other aspects other than output must also be considered. Although SMT continues to be used in packaging, manufacturing

 

Every aspect of technology and technology continues to evolve, but the idea of "lighter, smaller, faster, cheaper" is becoming more entrenched. including high density

 

The technology including high-degree internal interconnection will definitely affect the size of the product. As an electronic product assembly manufacturer, the goal is to achieve the best manufacturing process.

 

art. The result is that regardless of the number of productions involved or the difficulty of the product, productivity is definitely the most important factor in SMT manufacturing at present.

 

The most fundamental concern.

 

Therefore, one cannot simply add together printers, pick and place machines, reflow systems, cleaning machines, or other SMT assembly equipment without regard to the

 

Factors such as plant area and investor cost. Instead, it must be recognized that different machines or

 

The results of machine combinations can vary widely.

 

For this reason, manufacturing ideas such as the dual-pass approach can bring some obvious and tangible benefits in the silk-screen process. Dual-channel can shrink

 

Reducing the time required for loading and unloading panels that does not generate added value, while generating significant cost savings by bringing more manufacturing potential to a given area,

 

In other words, a higher yield can be obtained in a given area.

 

In PCB assembly like in the automotive industry, the production time per PCB component can be as low as 7 seconds, so the savings made by methods like dual pass

 

The saving percentage is very large. What's more, these time savings are achieved without compromising product quality. Moreover, by using this method

 

Cost advantages in terms of direct labor, maintenance and facilities can also be realized by reducing the need for equipment. In short, something like

 

Manufacturing ideas such as dual lanes lead to lower acquisition costs, lower operating costs, cost-effective production, and minimal production

 

production space.

 

Applying the automation advantages brought by today's advanced stencil printing machines, coupled with proper design of the printing process, can ensure the best

 

Short lead times and the best quality of the end product, especially when using the new dual channel idea seen in the SMT industry.