1. Obtain the proper shop packet and check order for build information. Pull all parts if any parts are missing, fill out a shortage sheet and give a copy to the appropriate material coordinator.
2. Pull the latest Electrical and Mechanical prints.
3. The following procedure is for a 29″ Destacker. Attach leg and control box to main beam. Leg should be flush to left side of main beam. Control box should be 3″ from right side of main beam. Attach width units to main beam, 4-3/8″ from either end square to main beam and Parallel to each other.
4. The following procedure is for the 44″ and 58″ Destackers Attach leg and control box to main beam. Leg 7-5/8″ from left end control box 7-5/8″ from right end. Attach width units to main beam 8.975″ from either end. Square to main beam and parallel to each other.
5. Attach rear rail to width supports parallel to main beam 3/8″ overhand from either end of main beam.
6. Level conveyor from side to side and front to back, off rear rail
7. Attach front rail to width supports. Match level to rear rail, especially front to back. Make parallel to rear rail. Make ends even with rear rail.
8. Install motors, pulleys, UHMW and belts on rails.
For the last 20 years any odd-form components that did not come pre-packaged have been assembled BY HAND. Any PCB Assembly in today’s market can gain quick advantages by automating their assembly line. Huge costs are spent unnecessarily on labor and import fees.
If you are considering automation of odd-form components in your PCBA, consider these questions:
Does your desired component come available in a package?
Is your lead to hole ratio appropriate for automating?
Is the quality and repeatability of the component suitable for automation?
Does your component require lead preparation prior to insertion?
Does your process require that the component is clinched?
Need help with these questions? Let us know and we will help design your Odd-Form Assembly tailored to your needs!
The following procedures explain how to properly clean and test an ESD surface.
Clean an ESD Surface
Do not use abrasive or highly alkaline cleaners on polycarbonate. Never scrape polycarbonate with squeegees, razor blades, or other sharp instruments. Benzene, gasoline, acetone, or carbon tetra chloride should never be used on polycarbonate. Do not clean polycarbonate in the hot sun or at elevated temperatures.
Using a sponge or soft cloth, wash the ESD-protected surface with either a mild detergent or Windex product and lukewarm water.
After washing, rinse with water and dry thoroughly with a chamois or moist cellulose sponge to prevent water spots.
To protect the ESD surface after rinsing and drying, recommends applying Kleenmaster Brillianize®. This application helps to maintain the static dissipative coating and reduce the accumulation of dust.
Test Static Dissipative Covers
Periodically and after maintenance, check the machine covers to determine if the dissipative qualities of the cover have changed. The following procedure ensures that static dissipative covers are in fact dissipative.
Surface resistance meter (such as 3M 701 Surface Resistance meter and probe).
The surface resistance should be less than 109 ohms in all areas. If the cover package is no longer dissipative, contact you Universal Instruments Corporation sales representative.
Clean the static dissipative covers using the Clean ESD Surface procedure to ensure the accuracy of the test.
Using the surface resistance meter, follow the instructions provided by the manufacturer to measure the surface resistance of both the inside and outside of the covers. Measure the resistance at all four corners and at several areas in the middle of the cover. This test checks the integrity of the ESD coating.
Connect the ground path resistance probe to the meter and chassis ground.
The path to the ground should not be higher than the surface resistance. If it is, clean the frame connections, repair loose or corroded fasteners and ground straps, and check tracks for dirt and/or corrosion.
4. Measure the ground path from the covers to the chassis ground. Take this measurement from both surfaces and all four corners of each cover.
Applies to tubes used in Generation 8 clinch units.
The expected life span of a Continuity Tube is dependent upon a number of factors including:
A Continuity Tube that is subjected to steel leaded components will cause more stress between the cutter, the cutter Bushing, and the continuity Tube. Expect to experience a higher wear rate on a continuity tube that is subjected to stiffer lead material than a continuity tube that is subjected to softer leaded material.
A larger lead diameter will cause more stress between the cutter, the cutter bushing, and the continuity tube. Larger leads being cut will accelerate the wear of a Continuity Tube.
Worn Tooling (cutters and cutter bushings) will cause the scrap lead to ‘tear’ instead of cut with a sharp clean cut. This ‘tear’ in the lead will accelerate continuity tube on both the metal tube and the plastic surrounding the metal tube. The tooling should be changed at recommended intervals, sooner if tearing of leads is noticed.
Working Environment (dust, humidity, temperature, etc.)
The continuity tube should be kept as clean as possible. Dust buildup caused as a result of the cut/form process and clinching process will grind into the metal tube and the plastic surrounding the metal tube possibly causing accelerated wear of the continuity tube.
There are too many variables associated with the performance of a continuity tube to allow Universal to list it as ‘consumable tooling’ and publish an estimated life span. The greatest life span will be generated by keeping the continuity tube as clean as possible, keeping the lead length within the middle of acceptable lead length range, and changing the cutters and cutter bushings on a regular basis.
Continuity Tubes and False Insertion Errors
Proper continuity lead sense is dependent upon the relationship between:
the continuity tube
the angle of the lead being cut
the lead length as the leads are cut.
It is important the lead is bent and touches the continuity tube before the cut takes place, making the position where the lead enters the cut and clinch assembly very important.
As the cutter moves across to the cut position, the lead begins to bend in the direction of the continuity tube.However, once the lead is pinched between the cutter and the cutter bushing, the scrap portion of the lead will no longer be pushed toward the continuity tube.At this point the scrap portion of the lead will actually be forced in the opposite direction of the continuity tube as the cutter shears through the lead.
The following scenario describes what happens if the lead length is set too short.In other words, the lead entrance to the cutter bushing set so the lead is very close the cutter bushing shear point.
By setting the lead length too short, (the lead too close to the cut point of the cutter bushing), the scrap portion of the lead will not be bent far enough to reach the continuity tube as the cutter bends the lead, resulting in a false insertion error.In other words, if the lead reaches the cut point before it has been bent far enough to touch the continuity tube, a false continuity error may occur.
On the other hand, having the lead length too long may cause accelerated wear and damage to the continuity tubes.Forcing the lead into the continuity tube with too much force will cause denting of the continuity tube and wear of the plastic insulation, resulting in premature failure and false continuity errors over time.
Cutter Stroke Speed and false Continuity Errors
The length of time necessary to drive the Cutter from the home position, to the extended ‘cut’ position, can affect continuity sensing.If the cutter speed is set too slow, the cutter air pressure is insufficient, or a mechanical assembly used in the operation of the cutter stroke binds, the cutter will not reach the component lead in the ‘window’ of time necessary for continuity to be sensed.This will result in a false continuity error.Examples of cutter stroke speed problems:
Pneumatic flow control for the cutters not properly set
Poor air flow from the valve to the cutter
Binding in the mechanical linkage from the cutter piston to the cutter
Lack of sufficient lubrication in the mechanical linkage from the cutter piston to the cutter
Incorrectly set cutter backstroke (the starting position for the cutter)
A torn O-ring on the cutter piston which causes a bind in the cylinder
Lack of sufficient lubrication on the O-ring for the cutter piston
Automatic Insertion Equipment Manufacturer for PCB Assembly
Stop Importing Cell Phones, Automate Them!
Times have officially changed. Where once there was no reason to invest in your homegrown cell phone manufacturing, now, with equipment that is more affordable than ever before, it makes sense to invest at home. Cell phone suppliers don’t have to rely on other countries to import cell phones any longer with new Smart Factories that are more efficient and affordable than labored hands. Now, businesses can incorporate manufacturing into their business model, and finally stop importing from China.
The SMT, pick and place Industry has revolutionized the way we used to look at manufacturing. The reasons for importing cell phones from China, namely cost and labor, are being reduced with the advancement of PCB AI Assembly equipment. Now you can home-grow your cell phone manufacturing with equipment that is smarter, faster, efficient, and more affordable than human labor force.
These huge changes will affect all companies that rely on electronics manufactured abroad. These imported items that have been historically low in cost, will no longer have the same low price tag. Intelligent companies are staying ahead of the curve and beginning to create their own reliable manufacturing processes, IN-HOUSE.
The good news is that there are companies that have planned ahead. It is now easier than ever to begin or improve your own manufacturing capabilities. It is not the huge undertaking it once was to establish and expand your own manufacturing equipment. PCB AI Assembly equipment is smarter, faster, efficient, and more affordable than ever before. Now is the time to get on board!
Assemblers surveyed report that cleaning misprinted circuit assemblies is a production gap that has not been adequately addressed. Traditionally, the industry has used stencil cleaning agents and equipment to address this rework need. One of the benefits of cleaning misprinted assemblies with the stencil cleaning process is the ability to collect and filter wet solder paste. The major short coming of cleaning misprints within stencil cleaning processes is the inability to remove B-side reflow flux residues from both the surface and under bottom termination components.
REWORKING/CLEANING MISPRINTED ASSEMBLIES
Stencil printing is a highly automated process. During machine setup, a small group of boards are misprinted. During production stencil printing, circuit boards are periodically misprinted due to clogged apertures, stencil out of alignment, solder paste rheology shifts and other issues. Stencil misprints are defined as A-Side (Initial print out of alignment with no components previously placed) and B-Side (A-Side was successfully printed and components placed and soldered. The subsequent process of printing the B-Side results in the solder paste being out of alignment resulting in a B-Side misprint).
Printed Circuit Board misprints are a costly problem with no easy rework methodology. Production cleaning processes are normally not used to clean misprint assemblies. Potential quality issues such as:
Solder balls collecting into the wash tank and being transferred back onto the assembly
Solder balls migrating into the rinse streams resulting in hazardous waste from metals in the wash and rinse holding tanks
These complexities potentially compromise repeatability and reliability standards. Due to these complex issues, most assembly houses do not allow misprints to be cleaned within their production cleaning process.
Assemblers commonly address the misprint cleaning need by either hand wiping the misprinted side of the circuit card and/or clean the misprint in a stencil cleaning machine. Both methods create the potential for quality issues. First, when wiping solder paste from the misprinted side of the board, solder paste can be trapped in solder mask defined channels, through-hole vias, and other board geometries (Figure 1). Numerous quality problems can result due to lack of control and definition.
Figure 1: Solder Balls Wedged into No Solder Mask Defined Channels and Via Holes
Second, stencil cleaning machines are designed to remove wet solder paste from stencils. Most stencil cleaning processes do not rinse the stencil with water. For those that use a water rinse, the water is reused since trace levels of metals in water prevent disposal to local treatment works. Cleaning a production board in a machine designed to clean stencils fails to meet ionic cleanliness standards required for a production assembly. Additionally, on B-Side misprints, the stencil cleaning agent is typically not adequate for cleaning reflowed flux residues on the A-Side of the board. In most cases, the stencil cleaning agent partially removes the reflowed no-clean flux residue resulting in white residue and an ionically dirty assembly.
Cleaning the misprinted circuit board within an electronic assembly production cleaning process has the potential to achieve cleaning of wet solder paste and reflowed flux residues as well as meet quality and yield objectives. The problem with cleaning a misprinted circuit board in a production cleaning process is the deposits of solder spheres collected into the wash holding tank. Free solder spheres within the wash holding tank can be picked up by the inlet of the pump and sprayed onto production assemblies. There is also the potential that the solder spheres can be dragged into the rinse sections. Both quality and waste treatment issues result from this practice.
To resolve the quality and water treatment issues, collection and filtration method systems are needed to trap and filter solder spheres. Filtration systems designed tocontain the solder spheres and capture them prevents spraying solder balls through the pump and spray manifolds. The mechanical and filtration systems resolve the issues of redepositing solder balls onto production assemblies and the potential to contaminate rinse streams. The overriding quality advantages in using production cleaning equipment, which is designed for repeatedly removing all solder spheres from the assembly, remove reflowed flux residues and render an ionically clean printed circuit board provide a reproducible and repeatable product.
Inline Cleaning Equipment
Two types of aqueous production machines are used to clean electronic assemblies, inline and batch. For the inline machine, the pre-wash section of the cleaning machine is designed to wet, elevate the circuit board to wash temperature, and soften reflowed flux residues from production circuit assemblies. On option for containing solder balls is to equip the pre-wash sectionwith deflectors that contain the raw solder paste as it is being displaced from the circuit assembly. The deflectors close in the pre-wash spray manifolds using two trays and plates to prevent solder spheres from escaping the housing of the pre-wash section. As the boards enter the pre-wash section, the displaced solder balls and wash fluid drain into the catch trays. By capturing and containing the pre-wash liquid, the majority of the solder balls can be channeled into a series of sluice boxes. This important design feature contains the bulk of the solder balls with a minimal amount escaping to the wash holding tank.
A series of Sluice Boxes can be designed to capture the heavy raw solder spheres similar to the techniques used in mining precious metals from water streams (Figure 5). Three separate sluice boxes capture the majority of the solder paste. Each sluice box is equipped with a wire mesh. The weight of the solder balls drop through the wire mesh and collect into the sluice box trays. The first sluice box captures the majority of the solder spheres with the remaining two sluice boxes used to collect the residual solder spheres.
Figure 3: Sluice Box Collection Boxes courtesy of Speedline Technologies
Solder balls that are not collected within the sluice boxes will drain into the wash fluid holding tank. To prevent these stray solder balls from being sprayed onto circuit boards, three pump intake strainers prevent large spheres from entering the pump (Figure 6). The smaller solder spheres that pass through the strainers will be captured in a bag filter from wash liquid pumped through the outlet of the pump.
Figure 4: Strainers in Suction Inlet of the Wash Holding Tank courtesy of Speedline Technologies
Following the suction strainers, the wash solution is pumped through a filtration system designed to collect any remaining solder spheres before reaching the spray manifolds. The wash outlet enters the top side of the filtration canister, exits the clean side of the filter and then goes to the spray jets.
Figure 7: Filtration Canister
Within the canister, there are internal bars that prevent the bag filter from getting next to the exit side of the filter housing. This design feature prevents back flow or resistance as the liquid pumps through the filter canister. The 10/5 bag filter cartridge (ten microns on the inside and 5 microns on the outside of the filter cartridge) provides double redundancy to contain any solder balls from escaping the filter (Figure 9). The 10 micron side captures the heavy particles and the fine 5 micron side of the filter assures no solder spheres are sprayed onto circuit cards. The filtration design removes solder balls as small as Type 5 Solder Paste while preventing solder balls going to the manifolds. Pressure drops are minimal due to the solder paste being captured within the bag filter. Should the pressure drop, the machine is equipped with a user defined interface, which sends an alarm to the operator. The design is such that thousands of misprint boards could be cleaned before having an impact on the bath integrity, pressure and cleaning performance.
Batch Cleaning Equipment
One main difference between batch cleaning machines versus an in-line type cleaner is the ability to program the type of wash cycle, the sequence, and cycle times within the cleaning process. It is therefore critical that the ability to effectively trap and collect wet solder paste be integrated into the batch cleaner wash cycles.
The design objective is to provide the board assembler the flexibility to deflux their normal production runs (A/ B side), deflux an A-side with B-side misprint, clean A/B side misprint, plus the ability to completely rinse and dry the product within the same batch type cleaner.
Similar to the design for the in-line cleaning system, the same equipment manufacturer used the multi-stage filtration approach to effectively collect solder spheres and to prevent the spheres from being sprayed onto the board assembly. A pre-wash type cycle in the batch cleaning process will wet, elevate the circuit board to wash temperature, and soften the reflowed flux residues from the production circuit assemblies. The flux composition with the raw solder paste is easier to remove than the reflowed paste. An internal bag type filter is used to capture the raw solder paste that is removed during the Flood Wash cycle . The main purpose of the internal bag filter is to minimize the amount of solder paste that would be drained into the wash fluid holding tank.
Figure 8: Bag Filter in Wash Holding Tank
Solder spheres that are not collected in the bag filter will collect in the wash fluid holding tank. To prevent large particles from entering into the wash pumps, two intake strainers are located in the wash holding tank.
Figure 9: Batch Intake Strainers
Following the suction strainers, the wash solution is pumped through a filtration system that is designed to capture the smallest of solder spheres before being sprayed through the wash fluid spray delivery system. The filtration system is designed to capture solder paste as low as type 5 paste (Figure 10).
Figure 10: Batch Filtration Design
Cleaning both A-Side and B-Side misprints has been a complex problem for assemblers. Using a stencil cleaner to clean misprints has numerous flaws. Two key issues is the inability to remove reflowed flux residues with stencil cleaning agents and poor rinsing. Notwithstanding, most assembly houses do not allow misprints to be cleaned in production cleaning machines due to the risk of contaminating product boards with stray solder balls and due to waste water metal contamination issues.
Collection and filtration systems designed into inline and batch production cleaning equipment safely captures and contains solder spheres from being sprayed onto production assemblies. Additionally, the containment and filtration systems prevent raw solder paste from entering the rinse water streams.
Using a production cleaning machine provides numerous benefits to the assembler.
Recovery and rework of expensive hardware
Removal of wet solder paste
Containment of solder spheres
Removal of reflowed flux residues
Ionically clean assemblies
Wiping wet solder paste from production assemblies is a bad practice. When wiping wet solder paste, solder spheres can be wedged into no solder mask defined troughs, vias and other offsets. When these solder balls become wedged, high levels of energized sprays may not be sufficient in displacing a wedged solder ball.
After the PCB is completed, the electric elements ought to be attached in order that a functional PCB assembly is formed. There are two construction processes which can be utilized to be able to type the PCB assembly. One could be the through-hole building in which the component leads are inserted within the holes although the other one may be the surface-mount building wherein the components are situated on pads positioned around the external surfaces on the PCB. Each sorts of construction have element leads that are fixed mechanically also as electrically towards the board through a metal solder which has melted.
Additionally, you’ll find a variety of soldering solutions to become utilized as a way to connect the PCB elements to ensure that PCB assembly could be achievable.
Production that is definitely of higher volume have to be carried out by means of machine placement and bulk wave sort of soldering. Having said that, expert technicians possess the capability to solder incredibly minute parts by the hand beneath a microscope. This is typically completed together with the use of tweezers and a soldering iron with a fine tip which is made for compact volume prototypes. Yet, there are parts that are impossible to solder together with the hands just like the ball grid array.
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PCB’s which would make up the PCB assembly have conformal coating that is certainly applied by way of dipping or spraying once the elements are carried out soldering. This coat will generally protect against corrosion plus the leaking of present or achievable shorting because of condensation. PCB assembly is static sensitive, thereby; it should be placed inside antistatic bags although it can be becoming transported. Improper techniques in handling could transmit static charge by way of the board and because of this may well damage the elements.