Frequently quality problems of SMT maching process.

Frequently quality problems of SMT maching process.

1, leading to leakage of patch main factors
1.1, SMT placement process, medium component feeding rack (feeder) feeding is not in place
1.2, SMT placement process, components suction nozzle gas road plug, suction nozzle damage, 

       suction nozzle height is not correct

1.3, the equipment vacuum, gas road failure, congestion
1.4, the circuit board purchase bad, produce deformation
1.5, there is no solder paste or solder paste on the circuit board
1.6, components quality problems, the thickness of the same species inconsistent
1.7, the patch machine calling program has errors or leaks, or programming, the choice of the 

      thickness parameters of components is wrong

1.8, because the operation is not standard, such as factors accidentally touch.

2, leading to the SMC resistor chip, flip side, side pieces of the main factors
2.1, components feeding rack (feeder) feeding abnormal
2.2 、 the height of the nozzle is not right
2.3 、 the height of the head is not right
2.4. The size of the loading hole of the component braid is too large, and the component is 

       turned over by vibration

2.5 the direction of the loose material into the braid is reversed

3, leading to the main component bias
3.1, patch machine programming, components of the X-Y axis coordinates is not correct
3.2, chip suction nozzle reason, so that the suction instability

4, leading to the main components of the patch damage

4.1, the positioning pin is too high, so that the position of the circuit board is too high,

 the components are pressed when mounted

4.2, patch machine programming, components of the Z axis coordinates is not correct
4.3. The suction head spring of the mounting head is jammed

How Many Feeder Slots Will You Need?

How Many Feeder Slots Will You Need?

Feeder slots can be one of the most confusing aspects of pick and place machines. A machine that has 64 
feeder slots won’t necessarily hold 64 feeders. Feeder slots are designed for 8-mm tape feeders. If you 
have larger tape feeders and/or sticks and waffle trays, each feeder will take up two or more feeder slots.

To determine whether a machine has enough capacity for your requirements, you will need to calculate 
just how many 8-mm feeder slots you’ll need.

Tape Feeders Slot Requirements
To calculate your feeder slot requirements, first list how many of each tape feeder size you will need. 
Then multiply each of those by the number of feeder slots the pick & place manufacturer says each will require.

Tape Feeder Example
For example, if you need 44 8-mm tape feeders and the manufacturer specifications say that each 8-mm 
tape feeder requires one feeder slot, you will need 44 feeder slots for your 8-mm tape feeders.
If you also need two 12-mm feeders, and the manufacturer’s specs say that 12-mm tape feeders require 
two slots each, you will need an additional four 8-mm tape slots (2 feeders x 2 slots/feeder) for your 
12-mm feeders, bringing your total slot requirement to 48.



Stick/Tube Feeder Slot Requirements
Generally, each manufacturer’s stick feeder will hold multiple sticks or tubes, so you’ll first figure 
out how many sticks or tubes of components you’ll have, then figure out how many stick feeders you’ll 
need in order to accommodate them, based on the number of lanes a stick feeder from that manufacturer 
holds. Finally, calculate out how many slots in the feeder base your stick feeder(s) will take up.

Stick Feeder Example
If you have 4 sticks and the available stick feeder holds 10 sticks, you would need one stick feeder. If 
the stick feeder requires 9 slots, your total slot requirement, building on the tape feeder example 
above, is now 57.

Matrix Trays and Cut Strip Tape Holders
Matrix tray holders and cut strip tape holders are sometimes mounted in feeder slots and sometimes 
placed in the board area. If the tray holder for the machine you’re looking at takes up feeder slots, 
you’ll need to find out how many and add that your requirement.
If, on the other hand, the matrix tray holder goes in the placement area, this will affect the size of 
the PCB/panel that the machine can handle, so be sure to keep that in mind. 

What Will Your SMT Production Require?

What Will Your SMT Production Require?

The following steps will help you identify your minimum equipment requirements based on the job(s) you 
will be running.

1. What parts do you need?
For this step, you’ll need your bill of materials (BOM) for each product you’ll be assembling on the 
pick and place machine. Your BOM provides information critical to helping you calculate placement rate 
requirement, feeder type and number requirements, and the component placement capabilities your new 
machine will need to have.

Take a look at your BOM to find the following four items:
Total placements on the PCB. You’ll need this in step four.
Component package sizes. In step two, you’ll use this to information to identify the feeder sizes, 

types and slots you’ll require.
Total amount of unique components. Each component type will require its own feeder. The number of unique 
components will give you an idea of how many feeders your job will require—and will help you determine 

the feeder slots you’ll need available on a machine, in step two.
Largest component, smallest component and fine pitch requirement.

While you’re there, are there any special components your machine will need to have capabilities for? 

Odd form? BGA? CSP?
If you have more than one product to spec, you should create a spreadsheet for this step that tells you 
all of the above information for each product. Make a master list of component types that are used 
throughout all of your products so that you know the total amount of unique components for your 
workload.

2. What feeders will you need?
Using the component package sizes from the BOM, mark down how each package will be delivered: tape? 
stick or tube? waffle or matrix tray?

If components are delivered on tape, what is the tape width? Make a note of how many tape feeders 
you’ll need of each width.
How many stick/tubes will you have?
How many waffle/matrix trays?
You’ll use this information to determine how many feeder slots you’ll need available on your machine, 
based on how many feeder slots the manufacturer says each feeder type will use up.

3. How much board room do you need?

This one is easy. For each product, note the board or panel dimensions: length, width and thickness. You’ll 

need to know the minimum and maximum board area your job(s) requires.

4. What kind of speed do you need?
To determine your throughput requirement in components per hour (CPH), first figure out how many boards 
you will need to produce per hour while your line is running. Now check your BOM to see how many 
placements your boards will require. (If you will be doing multiple products, use the board that has the 
highest number of placements.) Multiple these two numbers together to get your minimum speed requirement 
(CPH). 

How Pick & Place Manufacturers Specify Equipment？

How Pick & Place Manufacturers Specify Equipment？

Understanding how equipment manufacturers specify their equipment is the first step in finding the right 
equipment for your production requirements.

Placement Speed
Placement speed for pick and place machines is measured in terms of "components per hour," or CPH 
(sometimes also referred to as PPH for "parts per hour"). This is the rate at which components are picked 
up, inspected and placed onto a PCB.

Many equipment manufactures use the IPC 9850 standard to determine CPH rates for their machines. This 
ensures that they are using the same part mix and PCB placement arrays, making it easier for buyers to 
compare one machine—and one manufacturer's machine—against another's. Other manufacturers will design 
their own PCB for their speed rating and use more accessible pickup locations to get a "faster" rating.
To determine a more "real world" production speed of a machine, de-rate the manufacturer's stated IPC 9850 
CPH rating by 20%. If the manufacturer's CPH is not IPC 9850, de-rate it by 30%.



Feeder Slots
Feeder capacity means the number of 8 mm tape feeders that can be loaded onto the machine at one time. 
Larger components will require larger feeders. You'll need to find out from the manufacturer how many slots 
each of the larger tape feeder types—12 mm, 16 mm, 24 mm and up—take up.
Matrix or waffle trays and tube (or stick) feeders will also take up valuable feeder slot real estate. If 
you'll need to use trays or tubes, you'll need to find out the capacity of the available feeders and how 
many 8 mm spaces they'll require.

Feeder slots can be one of the most confusing aspects of pick and place machine. A machine that has 64 
feeder slots won't necessarily hold 64 feeders. Feeder slots are designed for 8-mm tape feeders. If you 
have larger tape feeders and/or sticks and waffle trays, each feeder will take up two or more feeder slots.
To determine whether a machine has enough capacity for your requirements, you will need to calculate just 

how many 8-mm feeder slots you'll need.
To calculate your feeder slot requirements, first list how many of each tape feeder size you will need. 
Then multiply each of those by the number of feeder slots the pick & place manufacturer says each will 
require.

For example, if you need 44 8-mm tape feeders and the manufacturer specifications say that each 8-mm tape 
feeder requires one feeder slot, you will need 44 feeder slots for your 8-mm tape feeders. 
If you also need two 12-mm feeders, and the manufacturer's specs say that 12-mm tape feeders require two 

slots each, you will need an additional four 8-mm tape slots (2 feeders x 2 slots/feeder) for your 12-mm 
feeders, bringing your total slot requirement to 48.
Stick feeders and matrix tray holders are treated differently. Each of the manufacturer's stick feeders 
will hold multiple sticks or tubes, so first figure out how many sticks you have, then figure out how many 
stick feeders you'll need, and then find out how many slots that feeder(s) will take up.
For example, if you have 4 sticks and the available stick feeder holds 10 sticks, you would need one stick 
feeder. If the stick feeder requires 9 slots, your total slot requirement, building on the tape feeder 

example above, is now 57.
Matrix tray holders are sometimes mounted in feeder slots and sometimes placed in the board area. If the 
tray holder for the machine you're looking at takes up feeder slots, you'll need to find out how many and 
add that your requirement.

If, on the other hand, the matrix tray holder goes in the placement area, this will affect the size of the 
PCB/panel that the machine can handle. You'll take that into consideration in the next step.
Part Size
Equipment manufacturers will give you the maximum and minimum component dimensions that the machine will 

handle.
In many cases you'll see multiple component size specs given for a single machine. This happens when there 
are multiple alignment methods installed on the machine. One method may be faster or more precise, but 

because it only handles a narrow range of part sizes, an alternate alignment system is included to cover a 
wider component range. The machine's software will automatically switch methods as needed.
One thing you'll want to know is not just the largest size the machine can place, but what's the largest it 
can inspect? Some equipment has the ability to handle larger parts than they can inspect.
You'll also need to know the maximum part height the machine can handle.
On the small end of the spectrum, you'll want to know the minimum size the equipment can pick, index and 
place. Most machines are capable of handling 0402 or even 0201 chips. 01005 placement capability is out 
there, too. In any case, keep in mind that anything 0402 or smaller may require a special nozzle and/or 
feeder. Check with the manufacturer.

Component Lead Pitch
0.012" fine pitch is fairly standard for today's pick and place equipment. If fine pitch capability is 
required, do not be fooled by manufacturers referencing motor specification or motor accuracy. There is 
more to fine pitch placement than motor accuracy. It does not matter how accurate a motor is if the machine 
(system) cannot pick up, inspect, and place fine pitch leaded and ball grid components.

Other important considerations
Maximum and minimum PCB or panel size and thickness can be critical for some electronics manufacturers. 

Don't take the maximum values on their face: feeder racks and waffle trays can reduce available space.
You'll also want to make note of placement accuracy.
If you're not looking at benchtop machines, the PCB loading method could be important.
Fiducial recognition, coordinate correction and bad mark detection should be standard for automatic pick 

and place machines—check to make sure the equipment you're looking at has these features.
If you're looking at automatic machines, how are they programmed? CAD download, teaching camera, bar code 
readers, MIS and optimization functions and off-line programming can all make the operator's job easier and 

your production more efficient.
Some machines can be optionally fitted with a dispense head for depositing adhesive on the board. If you 
require this feature, note what the dispense method is, along with dot size and dispense speed.

How to select pick and place equipment?

For most purposes, selecting pick and place machine can be broken down into three simple steps:

Understanding how equipment is specified by manufacturers.
Calculating your product requirements:


Speed/capacity
Maximum and minimum component sizes
Precision and accuracy
Board or panel size
Number and types of component feeders
Benchmarking machines from various manufacturers against your requirements.
There are special considerations that differ based on the type of manufacturing you'll be doing. 
Are you an original equipment manufacturer (OEM)—in other words, are you manufacturing your own 
product?—or are you a contract or custom manufacturer, where you either manufacture someone's 
else's products or you custom manufacture your line of products based on your customer's needs. 
Perhaps you do a mix of both.

Contract assemblers and custom manufacturers need more flexibility in their placement 
capabilities and faster, easier job changeovers while OEMs doing some or all of their production 
in-house are looking for accuracy, speed and ease of use.
If this is your first pick and place machine, the availability of onsite installation, training 
and support from experienced, factory-trained technicians may be a big factor in determining 

which machine you purchase. Having someone help ensure you get your production off on the right 
foot can make all the difference for a young or growing company.
You may also have specific production needs—perhaps you're doing prototyping, or LED components 
are part of your assembly mix.

How to select pick and place equipment?
Much  more refer to Joy Technology Co.,Limited

What is SMT production line？

SMT is the traditional electronic components compressed into a volume of only a few tenths of the device directly to the surface assembly components paste, printed on the printed circuit board surface location of the assembly technology. Compared with the traditional process, SMT has high density, high reliability, low cost, miniaturization, sound field automation and other five characteristics.

Types of SMT production lines
SMT production line can be divided into two types, according to the degree of automation can be divided into automatic production lines and semi-automatic production lines; in accordance with the size of the production line can be divided into large, medium and small production lines.
Automatic production line refers to the entire production line equipment are fully automatic equipment, through the automatic board machine, buffer cable and unloading machine all the production equipment with a production line;
Semi-automatic production line is the main production equipment is not connected or not fully connected, the press is semi-automatic, the need for manual printing or manual loading and unloading PCB.

SMT production line of the main components are: by the surface assembly components, circuit boards, assembly design, assembly process;
The main production equipment, including printing presses, dispensers, placement machines, reflow soldering furnace and wave soldering machine. Auxiliary equipment, testing equipment, repair equipment, cleaning equipment, drying equipment and materials storage equipment.


The importance of SMT testing
SMT inspection is an important step in improving the quality of SMT products, it can improve product quality, and strive to achieve "zero defect."
The cost of assembling to the instrument and finding the fault is several times the cost of finding the fault when assembling the printed circuit board;
And the cost of finding the product after the product is put into the market will be hundreds of times the cost of finding the fault when assembling the printed circuit board.


In order to ensure the quality of SMT products, it is necessary to carry out effective testing, timely detection of defects and failures and repair, thereby effectively reducing the manufacture of products and failures caused by the cost of repair.

ICT tester
ICT is In Circuit Tester English abbreviation, the Chinese meaning is the online tester, is the modern electronic enterprise essential PCBA (Printed Circuit Board Assembly, printed circuit board assembly) production of test equipment.
ICT use, high accuracy of the measurement, the detection of the problem clear, even if the general level of electronic technology workers to deal with the problem of PCBA is also very easy.

The most basic instrument used for electrical testing is the On-Line Tester (ICT), which uses a component-level test method to test each component on the assembled circuit board.
ICT can be divided into needle bed ICT and flying needle ICT.
Flying needle ICT basically only static test, the advantage is no need to make fixture, the program development time is short.
Needle-type ICT can be simulator function and digital device logic function test, high failure rate.

In the SMT production line, the time on behalf of the efficiency.
The use of ICT can greatly improve production efficiency and reduce production costs, online tester detection failure coverage of up to 95%, its reasonable configuration in the production line can be found as soon as possible manufacturing failure and timely maintenance, or timely adjustment of the production process, Effectively reducing the cost of manufacturing defective products and repairing.

BGA REWORK|SMT Technology

Since the late 1990s ball grid array (BGA) packages have been gaining as a preferred package style for several reasons. Their IO density compared with the previous high density ultra fine pith quad flat packs (QFPs) is such that they have shrunk the necessary footprint on the PCB by a factor of 50%. If we lump the BGA style of package, a high density IO with solder balls for the interconnection in with its stacked version counterpart the POP then this increase in density approaches nearly 100%. The ability to get more done in less space along with shorter trace spacing and length requirements for board layouts using this package style have allowed boards to be clocked at much higher rates

thereby increasing processing speed. In addition the reliability of the placement of BGAs has been high as initially the tin lead solder balls “self centered” on the pads during reflow. Lastly the reliability

of BGA packages has been increased with the use of underfills, the use of specialty flex solder balls and even solder columns with integrated springs.

The increased use of BGAs and the underlying trend of ever-smaller package sizes, finer pitches and their placement on to ever denser printed circuit boards has led to greater and greater challenges in BGA rework. In addition to these challenges there are many others that have made the job of BGA rework technicians more and more difficult. One of the trends in making BGA rework more difficult is their ever-increasing usage in handheld device. Due to the drop test requirements of these products

in many cases the BGAs and other higher density devices need to be underfilled. Underfilled BGAs have the challenge of the tacky material “squirt out” causing solder shorts underneath the BGA. In

addition, the tacky nature of this material tends to lift pads as well as destroying the underlying solder mask underneath he BGA. This makes the BGA rework even more challenging. The ever-thinning device packages of BGAs cause the packages to warp. This too makes BGA rework difficult.

While large packages with large-sized pitches placed on sparsely populated printed circuit boards made BGAs simple to remove and replace, BGA rework today requires a greater level of machine sophistication. With pitches down in to the 0.3mm areas and package sizes routinely under 10 x

10mm placement with a vision system using a highly precise and repeatable XY motion system is required. Placement accuracies for today’s BGA rework need to be in the less than a 1mil tolerance

range. In addition with the lead free packages the rework system now require sophisticated temperature control with programmable multi zone bottom heaters, nitrogen capability and low flow rates at the air nozzle. In addition to the rework equipment set the inspection equipment needs to be of a higher capability. X-ray inspection equipment with very small spot sizes is a requirement for BGA inspection post BGA rework. The ability to measure the sphericity of the solder balls, the solder ball diameter, the ability to shoot through RF shields as well as higher density ground planes is now a necessity for the x-ray equipment requirements for BGA rework. Also the endoscope is a necessity for checking the ball collapse, the surface of the BGA ball post reflow, the wetting action as well as other attributes is important in BGA rework.

In addition to the equipment requirements for modern day BGA rework, the skill level, dexterity and process knowledge of the rework technicians working on BGA rework is even more demanding today. The BGA rework technician needs to understand reflow profiles in order to deal with printed circuit boards with a high density of ground planes. The BGA rework technician must also understand flux chemistries and how this impacts the kind of cleaning which can be done underneath the device. The BGA rework technician must also be able to understand how a variety of conformal coatings can be removed from the PCB as well as underneath the BGA. BGA rework technicians must also understand how device which neighbor the BGA to be reworked can or could be impacted by the BGA rework process profile.

As BGA packages have become more widely-accepted the BGA rework process has become more difficult. This has meant that both the equipment used in BGA rework as well as the technicians doing the rework have had to become more sophisticated.