How to remove the misprinted solder paste on the PCB surface?
Prepared by Ming
email@example.com This article describes that paying attention to some details can often prevent common problems in assembly processes and equipment selection.
Question: Can I use a small spatula to remove misprinted solder paste from the board? Will this get the solder paste and small tin beads into the holes and small gaps?
Answer: Using a small spatula to remove the solder paste from the misprinted board may cause some problems. It is generally practicable to immerse the misprinted board in a compatible solvent, such as water with an additive, and then remove the small tin beads from the board with a soft brush. I prefer to soak and wash repeatedly instead of violent dry brush or shovel. After the solder paste is printed, the longer the operator waits to clean the misprint, the harder it is to remove the solder paste. Misprinted boards should be placed in the soaking solvent immediately after the problem is discovered, as the solder paste is easily removed before it is dried.
Avoid wiping with a strip of cloth to prevent solder paste and other contaminants from smearing on the surface of the board. After soaking, brushing with a gentle spray can often help remove unwanted tins. It is also recommended to dry with hot air. If a horizontal stencil cleaner is used, the side to be cleaned should face down to allow the solder paste to fall off the board.
As usual, note that some details can eliminate undesirable conditions, such as misprinting of the solder paste and removal of the solder paste from the board. It is our goal to deposit the right amount of solder paste at the desired location. Stained tools, dry solder paste, and misalignment of the stencils and plates can cause undesirable solder paste on the underside of the stencil or even the assembly. During the printing process, the template is wiped with a certain pattern between printing cycles. Ensure that the template is seated on the pad, not on the solder mask, to ensure a clean solder paste printing process. On-line, real-time solder paste inspection and inspection prior to reflow after component placement are process steps that reduce process defects prior to soldering.
For fine-pitch stencils, if damage is caused between pins due to thin stencil cross-section bending, it can cause solder paste to deposit between the pins, causing printing defects and/or short circuits. Low viscosity solder paste can also cause printing defects. For example, high operating temperatures or high blade speeds can reduce the stickiness of the solder paste during use, resulting in printing defects and bridging due to excessive solder paste deposition.
In general, the lack of adequate control of materials, solder paste deposition methods and equipment are the main causes of defects in the reflow soldering process.
Question: What type of assembly board depaneling equipment provides the best results?
Answer: There are several sub-board systems that offer a variety of techniques for slab assembly boards. As a rule, there are many factors that should be considered when selecting such a device. Regardless of whether there is routing, sawing or blanking to separate individual panels from the composite panel, stable support during the splitting process is the most important factor. Without support, the resulting stress can damage the substrate and solder joints. Distorting the plate, or stressing the assembly during the splitting, can result in hidden or significant defects. While sawing often provides minimal clearance, shearing or die cutting with tools can provide cleaner, more controlled results.
In order to avoid component damage, many assemblers attempt to maintain component solder joints at least 5.08 mm from the edge of the board when the splitter is required. Sensitive ceramic capacitors or diodes may require extra care and consideration.
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0201 assembly, from difficult to conventional placement
This article explains and discusses the guiding principles governing 0201 placement in both high-volume and high-mix assembly operations.
By Ming Gan, firstname.lastname@example.org
Although generally considered to be a relatively recent development, printed circuit boards (PCBs) have been available since the early 1950s. Since then, the demand for smaller, lighter, and faster electronic products has driven electronic components, PCB, and assembly equipment technology toward SMT.
The earliest general acceptance of SMT occurred in the early 1980s, when machines such as the Dynapert MPS-500 and FUJI CP-2 entered the market. At that time, 1206 (3216) resistors and capacitors were the most popular placement components. However, in one or two years, 1206 gave way to 0805 (2125) as the most common component package for SMT placement.
During this time, both machines and components evolved rapidly. As the machine became faster and more flexible, the 0603 (1608) component began to evolve. At this point, many assembly machine manufacturers went back to the R&D, research and development lab to re-evaluate the technology used to accommodate these newer, smaller components. Higher resolution cameras and smaller vacuum nozzles are among the variations that these components bring to the assembly equipment.
The emergence of 0402 (1608) packaging poses further challenges in all aspects of PCB assembly. In terms of machine development, vacuum nozzles have become smaller and more fragile. A new focus is placed on the component’s feeder, which acts as a unit for improvement, giving the machine more accurate parts.
With the advent of 0402 components, process challenges have increased to those that need to be addressed for successful component placement. Solder paste printing becomes even more critical – stencil thickness and solder paste mesh are increasingly important process considerations. The technology required for such placement also involves significant new costs.
The combination of these factors creates a new form of packaging that is the slowest to adopt in the history of the electronics industry. In total, for almost five years, 0402 packaging was widely accepted in the industry – and many assembly plants today never put a 0402 sheet.
Now, I entered 0201.
Over the past year and a half, 0201 placement has been a key topic of discussion throughout the industry. Due to the size, weight and power consumption requirements, many OEM board assemblers need to incorporate even smaller components and technologies into their products. Contract manufacturers (CM, contract manufacturer) must also have new technologies to keep the assembly process up to date and provide customers with a complete range of services. For machine builders, the challenge is to develop more resistant to obsolete assembly equipment in an era of dynamic technological change.
0201 placement challenge
The placement of the 0201 component is more challenging than the component intervention in front of it. The main reason is that the 0201 package is approximately one-third of the corresponding 0402 size.
The previously acceptable machine placement accuracy immediately became a limitation of the introduction of 0201. In addition, the traditional industrial tapeding specification allows for too much movement for reliable 0201 placement, and the level of process control must be increased to make the 0201 placement a production reality.
Although these obstacles are very large, they are far from insurmountable. Of course, they need all the determination, because the technology necessary for the 0201 placement requires a lot of money and top management’s promise of research and development (R&D).
The key to reliable 0201 placement
At FUJI, the aggressive R&D program has produced the ability to make all circuit assembly machines compatible with 0201 at 100% speed, with a minimum suction reliability of 99.90%, a target suction reliability of 99.95%, and minimal placement reliability. It is 99.99%. In the beginning, every aspect of the design was evaluated for its ability to work on a complete 0201 program, and the combination of single elements of closely related machine component parameters proved critical to success. These parameters include:
Figure 1 Component feeder table. The R&D program concluded that the ability to precisely position the carriage table – and make minimal adjustments to compensate for the inaccuracy of the tape – is a key factor in achieving component pickup reliability above 99.95%.
To achieve this, the feeder table must be precision machined to ensure repeatable positioning of the individual feeders and combined with a high-resolution semi-closed-cycle servo system using a two-track linear moving guide. This design allows for minor adjustments – based on the results of the suction accuracy as judged by the vision system. This ensures that the component is as close as possible to the center. Component feeder. The feeder must be manufactured to extremely tight tolerances to ensure repeatability of the suction position, regardless of component height and a large number of possible component positions. The mechanism used to position and lock the feeder in position must be durable and precise, yet be user friendly. In addition, the materials used to make the feeder must be high in strength and light in weight to allow for ergonomic operation while ensuring precise, repeatable delivery of the carrier tape. The feeder drives the sprocket. The drive sprocket plays a key role in the ability of the machine to position the component tape. The shape, taper and length of the drive sprocket teeth significantly affect the ability of the feeder to position the tape. Other factors have also been investigated, such as the diameter of the drive sprocket and the number of belts in contact with the sprocket. Changes to the basic sprocket design resulted in improved positioning accuracy, with earlier designs increasing by 20% in the X direction and 50% in the Y direction.
Figure 2 sucks the head. After properly feeding the component, the next step is to draw the component onto the vacuum nozzle and bring it to the board. Vacuum nozzles are compliant to absorb shock during pick-and-place components, compensate for small variations in solder paste height, and reduce the risk of component breakage. For these reasons, the nozzle must be able to move within its fixture.
Material selection, material hardness, machining tolerances, and thermal characteristics must all be understood to construct a reliable suction head. The nozzle must move freely within its holder without sacrificing accuracy (Figure 1). The nozzle shaft is assembled. The nozzle shaft is also a key design element – eliminating overdrive by keeping the entire nozzle in direct alignment with the shaft assembly. Overpressure is caused by the inertia generated when the head is moved up and down. If the nozzle and the shaft are not in a straight line, there is a little whip – or overpressure. Overpressure causes a change in positioning accuracy, which is determined by the speed of movement, the weight of the nozzle, and the weight of the component. By eliminating overpressure, direct alignment reduces the number of negative factors associated with component pick-and-place placement (Figure 2). Figure 3 nozzle design. Variations in the design of the nozzle are an important factor in allowing the 0201 component to be received. In order to draw a 0.6×0.3 mm component, the nozzle must have an outer diameter of no more than 0.40 mm. This forms a long, thin nozzle shaft that is fragile but must also maintain precision to maintain high reliability of suction. Changes from the linear axis to the tapered design increase the nozzle strength and allow the nozzle to resist bending (Figure 3). Matrix structure. All machines generate vibrations during operation. The base frame design is a key first step in reducing the speed and motion effects of vibration and harmonic resonance. By using a cast iron base frame and state-of-the-art structural technology, vibration and harmonic resonance can be reduced to a controllable level within the machine, so that negative effects can be dealt with. Up to standard Through all six key factors, the obstacles to reliable 0201 placement have been eliminated. As a result, R&D’s focus has shifted to newer, smaller components, and 0201 is no longer considered a leading edge component packaging technology. For 0201 component placement, the accepted process window is approximately 75 μm X and 75 μm Y at 3 。. To achieve 6 贴 placement reliability, the X and Y tolerances must be reduced to 50 μm. The latest high-speed placement equipment has a rating of 66μm with an actual standard deviation of approximately 35~45μm. As the 0201 component becomes more widely used and the manufacturing process becomes tighter, improved accuracy can be achieved. The difference in component size between suppliers poses a challenge to 0201 feeding and placement. Bulk feeding is being opened and should be available in 2001. Although the machine now has this capability, only a small percentage of users will be ready to take the 0201 placement in the next 12 to 24 months. This is similar to the introduction of a ball grid array (BGA) and 0402 components, in which the machine’s capabilities are ahead of the process state.
While the placement of 0201 components is now a standard feature of new placement equipment, additional work is needed to improve the overall process for the end user. The relationship between machine builders, component suppliers, board manufacturers, formwork factories, and solder paste manufacturers needs to be strengthened to create a more seamless development process. The end result will be a unified understanding of the process and a better working relationship that will benefit end users, especially by making new production technologies faster and more efficient.
Wave solderingis a kind of solder wave with a specific shape formed on the surface of molten liquid solder by means of pump pressure. When mounted components pass through the solder wave at a fixed angle, solder joints are formed in the lead solder zone. The component is preheated in the preheating zone of the welding machine (the preheating of the component and the temperature to be reached are still controlled by the predetermined temperature curve) in the process of conveyor belt conveyor. In actual welding, the preheating temperature of the assembly surface is usually controlled, so many devices have added corresponding temperature detection devices (such as infrared detectors). After preheating, the components enter the lead slot for welding. Tin trough contains molten liquid solder. The nozzle at the bottom of the trough determines the shape of the solder. Thus, the solder wave is heated when the welding surface of the component passes through the wave. At the same time, the solder wave wets the welding zone and expands and fills the welding process.
二、Basic working principle
Wave soldering is based on the principle of convection heat transfer to the welding area heating. The molten solder wave acts as a source of heat. On the one hand, it flows to wash out the pin welding area, on the other hand, it acts as a heat conduction. The pin welding area is heated under this effect. When the silver lead solder is used, the melting solder temperature is usually controlled at about 245 degrees Celsius. In order to ensure the temperature of the welding zone, the solder wave usually has a fixed width, so that when the welding surface of the component passes through the wave, there is sufficient time for heating and wetting. In traditional wave soldering, a wave is adopted and the wave is relatively flat. With the use of lead solder, double wave mode is adopted at present.
三、The welding spot
The pin of the component provides a way to immerse the liquid solder into the metal through hole. When the pin contacts the solder wave, the liquid solder climbs up along the pin and the hole wall with the help of the surface tension. The capillary action of metallized through-hole improves the climb of solder. When the solder reaches the PcB part, the surface tension of the pad is expanded. The rising solder discharges flux gas and air from the through hole, filling the through hole and forming a solder joint after cooling.
四、What’s the difference between wave soldering and reflow oven?
The mainly different are in heating source and solder supply mode. In wave soldering, the solder is pre-heated and melted in the trough. The solder wave pumped by the pump plays a dual role of heat source and solder supply. The solder wave of solder solder solder causes the through holes, pads and component pins of the PcB to be heated, and also provides the solder needed to form solder joints. In reflow soldering, solder paste is pre-quantitatively assigned to the solder zone of PCB. The role of heat source in reflow is to re-melt the solder.
五、Main components and working principle of wave soldering
A wave soldering machine is mainly composed of conveyor belt, heater, tin trough, pump, flux foaming (or spraying) device, etc. It is mainly divided into flux adding area, preheating zone and welding area.
The solder in the solder tank, heated by a heater, gradually melts, and the molten liquid solder, under the action of a mechanical pump (or electromagnetic pump), forms a specific shape of solder wave on the surface of the solder tank, which becomes a wave. The PCB with mounted elements is placed on the conveyor and solder joints are welded by passing through the solder wave at a certain angle and at a certain immersion depth, so it is called wave soldering.
For a single wave, there is only one wave, called the advection wave. For double waves, the first wave is called the disturbing wave, and the second wave is called the advection wave (Ping Huabo).
The role of spoiler: SMT element welding and prevent leakage welding, it ensures the proper distribution of solder through the circuit board. The solder is penetrated through the slit at a relatively high speed, thus leading to narrow gap. The direction of the jet is the same as that of the circuit board. For SMT components, the disturbance wave can basically be welded. But for through-hole components, the spoiler wave itself can not properly weld the components, it leaves the weld unevenness and excess solder, so the need for a second wave – advection wave.
The role of advection wave is to eliminate burr and weld bridge generated by the disturbance wave. Advection wave is actually the wave used by the single wave soldering machine. Therefore, when the traditional through-hole components are welded on the dual-wave machine, the disturbing wave can be turned off and the soldering can be completed by advection wave. The entire wavefront of the advection wave is basically horizontal, like a mirror. At first glance, it looks as if the tin wave is static, but in fact the solder is flowing continuously, but the wave is very smooth.
六、Wave soldering machine welding spot molding
Solder Joint Forming: When PCB enters the front end of the wave, the substrate and pin are heated, and before leaving the wave, the whole PCB is immersed in the solder, that is, bridged by the solder, but at the moment of leaving the wave end, a small amount of solder is attached to the pad due to the effect of wetting force, and due to surface tension, it will come out. At present, the shrinkage of the lead wire is small, and the wetting force between the solder and the pad is greater than the cohesion of the solder between the two pads. Therefore, a full, round solder joint will be formed, leaving the excess solder at the end of the wave, and due to gravity, it will fall back into the tin bath.
Bulk material handle method and process on SMT production line
SMT patch bulk material problems have plagued many SMT people, as we all know, once the placement machine starts, there will definitely be a problem in the SMT production line. For a variety of reasons, many bulk materials are produced, thrown, or are originally bulk materials, or other reasons. Some bulk materials, such as resistors, capacitors, inductors, etc., are not easily distinguishable and have little value in themselves, and there is no value for reuse. However, for large devices, especially some imported chip components, they are of high value and can be distinguished and distinguished, so they are generally reused. However, for scattered components, if the original package is a tray or a suitable tray, the problem may be solved better. Otherwise, it may be more difficult to handle. Southern Machinery today will talk about the handling of bulk material in the SMT production line. Method and process. First, the bulk material handle process
Collecting materials – material personnel sorting materials – using electrostatic bags to pack – paste material specifications – technicians based on bulk material springboard – hand paste bulk material – QC confirmation
Second, the definition
Bulk material: refers to the components that are separated from the original packaging during the production process due to machine throwing, or loading and unloading materials.
Third, job responsibilities
Material staff: responsible for the collection, classification, identification, storage, placement, and placement information of bulk materials, and the material loss rate is calculated according to the order.
QC in front of the furnace: responsible for the manual placement of bulk materials, the front back grain and material code confirmation, PCBA mark, and the classification of bulk materials.
Technician: Responsible for programming, patch production, monitoring patch quality distribution and timely improvement.
QC after the furnace: It is responsible for checking and checking the first piece of all the machines, and the quality is abnormal. Immediate feedback is provided to the front station to improve and track.
Fourth, the work content
In the production process, the material may be thrown due to equipment and other factors, so the operator should check the material step before the patch and after the shift, and check the throwing box and the trash can each time the garbage is dumped. Collect the bulk material and report to the supervisor about excessive bulk material anomalies.
According to the shape of the components, the bulk material is classified according to the shape of the components, and the back code of the components is checked to determine the material code. Then, the checked bulk materials are packed in anti-static bulk box or bulk bag, and the material code identification is performed to confirm the signature of the person. .
When using machine mounting, the operator should first check whether the components are consistent with the normal materials, confirm the material number, and then load the FEEDER tape.
The first piece of material feeding / mid-way refueling, the technician firstly inspects the materials that will be short of materials in the machine half-hour in advance, and collects the materials of the same item number in the component preparation area, and check them correctly, and submit them to the quality department QC/materials. The staff will check again and confirm the total signature of the refueling sheet.
How SMT workshop planning? It turned out to be so useful.
How SMT workshop planning!
And only after the plant began production found that some areas have not planned beforehand, need to be adjusted, resulting in a waste of human and financial resources and valuable production time.
Therefore, it is important to check in advance SMT factory layout, especially for new SMT factory business, because there is no experience in SMT plant layout, the need to pay attention to the elements is not very clear, if we find a problem in the layout after production point, will cause some unnecessary losses.
So, when doing layout SMT plant, what to pay attention to what matters in advance to do to prepare? Here actual cases where we work to and we explore this problem.
planning SMT line configure
the client recent planning new on two identical SMT production line, specific device configuration (see FIG. 1) and the size of the apparatus is as follows: According to Figure 1 can be seen, the maximum width of the production line equipment is 1.71 m, the length of all devices sum is 13.6 meters, will add future planning a production line (line bulk on equipment configuration).
Workshop length 36 m, width of 12 m, an area of 432 m2, on the ground floor of the factory. Currently common ground for the shop floor, and no established anti-static system, can not meet the requirements of SMT antistatic workshop, but two conductive ground terminals, can establish subsequent workshops antistatic SMT system. Further, there is no air conditioning workshop and humidifiers, can not meet the requirements of SMT workshop temperature and humidity control. There workshop ventilation system, back to meet the requirements of the reflow furnace equipment. Workshop sufficient power to meet the electricity needs of all equipment in the workshop. There are two entrances whole plant, as are required to meet the equipment, raw materials and semi-finished channel. Special materials warehouse in another workshop, the need for planning. Good lighting conditions in the workshop, to meet the brightness of the SMT shop lighting requirements all stations. Whole plant layout situation shown in Figure 2.
1, the current new move into production lines and related aids, regional positioning;
2, the whole plant to meet future erection and production requirements three production lines, without planning zone realignment;
3, each production line starting position as consistent as possible, so that the whole plant orderly arranged in three lines.
analysisthe customer’s request, we first analyzed how the production line positioning; and before locating the production line, we consider the following points:
1, SMT equipment should avoid column and they maintain a certain distance, the distance is equipment installed at least after a good feed material by a vehicle;
2, SMT crossing equipment required for frame division pitch, and the crossing equipment to extend outwardly after the device installed above the material 50 cm;
3, optimal spacing of the two lines spaced more than 1.2 meters between the outer frame;
4, check the wire tail is generally a repair plan area, quality control personnel can perform sampling line tail region.
Based on the above considerations, the length of each line should be at least 13.6 meters (without regard to the maintenance area and the tail, the case where the sampling area and the thread area kanban), the width should be 2.7 meters (SMT feeding both surfaces), specifically as shown in Figure 3.
Therefore, the production line is positioned in substantially considering plant shown in FIG. 4.
Some details of the requirements of SMT plant layout
after determining the approximate location of the production line, when the need to consider some details of SMT production line requirements, and then to determine the exact location and the location of other auxiliary equipment SMT line.
First, we analyzed the SMT line position and aids required for each area requirements: 1, fire extinguisher drop zone;
fire extinguishers to be placed around the side of the post and SMT plant, placed according to the requirements of fire regulations.
2, the car rack placement region; car rack replacement for SMT production line models and switching material, in order to facilitate production and to improve the efficiency of replacement materials, preferably the vehicle is placed near the rack placement machine.
3, stock units rest area;
stock table mainly used in the production process and dryer materials stock preparation before switching, therefore, to be placed near the preparation station placement machine, and the best car rack together, Preparation facilitates directly on the car frame after a good feed material.
4, the shelf rest area printing station;
printing station for positioning the shelf aids in the production of printing presses, such as wipes, paste, alcohol, etc., to be placed in the vicinity of the printing press to facilitate removal use, improve Productivity.
region comprising placing solder paste storage refrigerator, solder paste mixer, paste warmed cabinets, can be placed next to the plant as required or uprights placed around a fixed area of the plant, However, to facilitate the operator to take place.
6, visual inspection after the furnace area, maintenance area;
in order to facilitate visual inspection after reflow and rework semifinished product, a shelf generally placed in the furnace, designed for the visual inspection of the furnace and rework.
7, screen placement area;
drop zone comprises a mesh screen plate was placed cabinet, stencil cleaningmachine, inspection tools, screen, stencil for storing, cleaning and inspection screen tension, etc., while in the region as much as possible to facilitate the production screen to take place.
8, garbage drop zone;
Production waste mainly from two parts, wipes and the like used in one printing operation, the second is to replace the waste tray and waste material produced with the like. Garbage two parts is generated to be placed separately, specialized recycling, in particular waste presses used. Thus, waste area may be placed next to the press machine or patch, or set beside the column region refuse placed separately placed.
9, kanban placement region;
kanban including the SMT billboards and other signage quality management, may be centrally located on the entrance into the shop, and also set up the production line Kanban state in which each head of the line, in order to view the producers and managers, promptly understand the current state of production status and quality SMT workshop and so on.
10, product placement area;
include products produced finished products in two parts, to separate the two partial regions divided out, strictly distinguished, in order to avoid confusion.
11, SMT placement of spare areas;
Nozzle including the SMT spare parts, a motor, a belt, cylinder or the like, to be placed in a special area, to facilitate the production of access.
12, location area temperature and humidity;
temperature and humidity conditions in order to better understand the SMT plant, depending on the size of the workshop area, several appropriately set the temperature and humidity measurement area, generally placed on the production line next to the column or wall.
13, SMT workshop office area;
let engineers and technicians and management personnel in office SMT shop floor, which can solve the problem on technology and management encountered in the production, to ensure the smooth operation of the SMT production lines.
14, anti-static protection area;
entry into SMT workshop area must have good anti-static measures. You may delineate the area in front of the plant, including the replacement of static clothing, shoes, hats and so on each employee’s locker. Also, the establishment of regional designed to test the static ring in SMT workshop at the entrance, so that each employee to do static loop testing and record test results before going to work. Based on the above analysis, the results of this SMT plant layout is shown in Figure 5.
In addition, SMT workshop also meet other requirements: 1, anti-static processing;
shop floor must be anti-static treatment, a common anti-static conductive flooring and paint and other ordinary places, customers can choose according to the actual situation. In addition, anti-static system must be set up in the workshop, to meet the requirements of the entire anti-static SMT workshop.
2, air-conditioning and a humidifier; SMT workshop to meet the requirements of temperature and humidity control.
3, the material management requirements;
in the warehouse, with particular attention to the way the material is stored, reel packaging methods, the use of hook-type place, wetting elements employed Cabinets for placement shelves to be treated with anti-static manner.
4, patch equipment gas and electrical circuitry;
preferably introduced directly from the production line at the down side of the roof, is arranged below the gas passage in the device and circuit wrapped with wire groove.
5, the ventilation system requirements;
needs to be installed to meet the requirements of the three power lines of the blower, and the third exhaust port reserved line.
1, according to the size of production line and the size of the entire plant SMT, completed the reasonable position of the production line; and
2, for aids, regions, etc. SMT production lines need to make the corresponding position location; 3, according to the SMT the characteristics of the plant, some of the necessary factors to consider in planning, in particular, anti-static; 4, in accordance with the requirements of the current situation and future development of the factory has been take into consideration, unified planning.
For SMT plant layout, but also requires a combination of size and product requirements and other plants to consider a number of factors, but to stimulate here.
Use of PCB Pallets in Wave Soldering
Patch components are used more and more on the circuit board, but there are still some perforated components between them. For this kind of board, selective soldering is the best solution, but not every company has enough funds to purchase selective soldering equipment, or the number of this type of circuit board is too small, specifically to buy selective soldering equipment is not Cost-effective. Manual welding is prohibited in certain industries such as the automotive industry
Therefore, in PCB wave soldering, using trays to block those patch components is a good method: reliable, fast production, and adaptability to high-capacity requirements.
The benefits of using trays:
Lead-free soldering requires higher soldering temperatures. Therefore, the circuit board is more easily bent during welding. The tray provides maximum protection of the circuit board during soldering and prevents bending.
Similarly, in the automotive and consumer electronics industries, many special-shaped circuit boards have emerged for the needs of applications. It is sometimes difficult to transport these shaped plates with conventional chain rails and mesh belts, and placing the circuit board plates in trays allows any type of circuit board to be shipped.
By soldering some of the bottom components through the tray, it is also possible to use PCB wave soldering equipment for selective soldering of the product.
Since most trays are thick (sometimes 15 mm), solder certainly does not flow to the top of the board. The oxide layer on the solder surface will also be washed away by the edge of the tray before the board reaches the peak, so that when the solder starts, the tin is relatively clean.
By adding some stiffening strips to the tray, it can increase its hardness to withstand high-strength welding. It is also possible to install heat-absorbing blocks, component fixing devices and some other auxiliary devices on the upper part.
The use of pallets also helps standardize the width of the product line, soldering different circuit boards on the same production line, and can use bar code readers and other identification tools to quickly change process programs for different boards.
Although there are many advantages to using trays in lead-free soldering, it can also cause solder balls.
Requirements for pallet materials:
In order to maximize the service life of the trays, the trays must be made of materials that can withstand high temperatures and harsh process conditions, especially for lead-free soldering.
To meet these requirements, the material used to make the tray must meet the following characteristics:
• High dimensional stability
• Good thermal shock resistance
• Can remain flat after repeated use
• Corrosion resistance (flux and cleaning agent)
• Does not absorb moisture
The use of the tray brings the process problems:
The flux system must be able to spray the circuit board completely with flux. Poor tray designs can lead to “shadow effects” in flux spraying: Some parts of the board have insufficient flux or no flux at all. The flux must be sprayed onto the board and spread through the capillary action.
Before the tray touches the crest, it must be heated in the preheating unit. A typical preheating configuration is a combination of heat pipes and hot air forced convection. If the temperature drops before contact with the peak, the tray will have an endothermic effect, making the welding process difficult to control.
The use of trays requires a wave height of up to 0.5 inches (12.5 mm). In the case of such a high pump speed, the use of nitrogen can help reduce dross. When using pallets in lead-free soldering, Vitronics Soltec’s perturbed “smart wave” can also promote tinning of the perforated component.
In addition, we must pay special attention to keeping the circuit board in the pallet flat. If there is a gap between the circuit board and the tray, the flux will flow into the gap, and the solder will flow to the board when passing through the peak. This will cause solder residue on the board.
The gap between the circuit board and the tray may cause solder residue on the circuit board
Circuit board and tray design recommendations:
Avoid placing larger components near the piercing element as this can cause shadowing effects and tin difficulties.
Leave proper clearance around the pins and edges of the through-hole components so that solder can flow. These tin guides will guide the solder to the seat of the tray opening, while also greatly improving the solder flowability.
The tin slot at the tail of the tray allows the solder to flow smoothly back to the tin tank
The opening of the tray should be as large as possible to facilitate the flow of solder. This will reduce some of the welding defects, such as: short circuit and solder balls. At the same time, it is also beneficial to the solder filling of the through hole, because the large opening also means that there is more energy to enter the welding area.
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.
1, using the next vacuum mode, in line with the theory of free fall, good dust collection effect.
2, special jig fixed more solid, to avoid the poor positioning caused by the cutting accuracy error.
3, the system automatically fixes according to the product installation location, to ensure high-precision product cutting requirements.
4, the static eliminator is installed in addition to electricity, dust blower continued to work to eliminate static electricity generated when cutting high-speed spindle to avoid damage caused by static electricity parts to avoid accumulation of dust due to static electricity.
5, the use of safety doors, reduce noise and dust, improve safety.
Vacuum cleaner with vacuum collection box (according to production capacity or cutting dust collection time scheduled maintenance)
PCB Separator also called PWB Depaneling machine. Rotate router bit to cut high-density component PCB panel to single products v-groove or perforated line. Utilize all of our accumulated technology to help minimize dust attach on PCB. Router machine has following features.
The number of milling cutters (0-5 section)Break Detection断刀检测无(none)Cutter Life Control刀具寿命控制程序控制(controlled by Program)Table NumberTable数量1个Spindle Speed主轴转速60000rpmSpindle Cooling System主轴冷却系统气冷方式Air cooling modeCleaner Mode集尘方式下集尘(collect dust downside)Working Power工作电源220V ，50HZAir press空压供给0.4MpaSafety Device安全装置采用安全防护门加门锁感应器Safety door and door lock sensorMode机型模式离线机型，手工装载卸载PCBA(offline, load and unload PCBA by hand)Auto failure test and repair mode故障自动检知维修模式系统具有自我诊断功能，实时错误信息显示，能直观地查询设备各个IO端口状态，易于排除故障。
Self-diagnosis，display failure information in real time, query IO state visually, easy for troubleshootingComputer & Operation system电脑和操作系统工控机、Windows 7
IPC, Windows 7Program Backup程式备份USBSoftware access control软件权限管理密码保护，依权限进入对应操作界面，保护系统重要参数。(Password protection，the operator enter corresponding interface according to authority to protect important parameters.)Programming编程可视化界面，单个程序切割点容量无限制，切割路径动态模拟。(Visual interface, the cutting point capacity for a single program should be over 400, dynamic simulation of cutting schedule.)Auto correction of the mark pointMark点自动校准功能具备Mark点自动校准功能(Yes)Fixture 治具万用治具可供选择(universal fixture)Voice control噪音控制运行时，噪声小于60分贝（离设备一米距离测量）
≦78 dB（measured in 1M’s distance ）Maintenance Period保修周期整机1年或以上，主轴2年或主轴3000小时保养服务。
1 years or more, spindle for 2 years or spindle maintenance service for 3000 hours.Technology Support技术支持及培训提供设备操作、编程，硬件保养，维修培训服务；程序永久免费升级。(Offer service of operation, programming, hardware caring and maintenance training; free upgrade of application. )
1, vacuum cleaner built-in vacuum mode, in line with the theory of free fall, dust collection effect is good.
2, the equipment adopts automatic loading and unloading products, can be directly on the wiring body or on the board machine.
3, using a special fixture with products (pcb), to avoid poor placement caused by cutting error.
4, the system automatically fixes the installation error, to ensure product precision cutting requirements.
5.It is equipped with static eliminator. When dividing, the dust remover will work continuously to eliminate the static electricity generated when the high-speed spindle cut. It can avoid the damage caused by the static electricity and avoid the accumulation of dust due to static electricity.
6, the use of safety doors, reduce noise and dust, improve safety.
7, there are follow-up vacuuming function, dust collector attached to the dust collection box (according to capacity cutting needs or dust collection time scheduled maintenance).
8, touch the display as a display, setting, control, can display more content, the operation directly through the touch screen operation, easy to operate.
9, can be directly docking the next equipment, sub-plate processing.
10, in the cutting process, if broken knife, equipment with automatic tool change function, without manual to change the knife.
11, Equipment using Mes system, the factory can control the machine everywhere, equipped with WIFI function can be controlled.
0-100mm/sX,Y,Z axis Driving SpeedX、Y、Z轴驱动速度X、Y轴至少1000mm/s(min)，Z轴至少750mm/s(min)，伺服马达方式驱动(driven by servo motor)Repeatability Accuracy机台重复精度±0.02mmMechanical hand X, Z stroke机械手X、Z行程X：420mm、I：60mmManipulator X, Z running speed机械手X、Z运行速度200mm/sMechanical hand grasp mode机械手抓取方式真空吸附Precision of repeated positioning of manipulator机械手重复定位精度±0.04mmMechanical hand grab products (PCB) dimensions机械手抓取产品（PCB）尺寸350mm*350mmPCB feeding trackPCB上料轨道皮带输送；宽度60~360mm可调Split plate product分板产品下料皮带输送；宽度420mmWorking Area工作区域（可加工行程）X:300mm，Y：350mm，Z：0-50mmPCB Thickness切割PCB厚度范围0.5-2mm(or thicker)，或范围更大 Router Bit Diameter铣刀直径0.8-2.0mmCutting Precision切割精度±0.01mmCutting Ability切割能力具有切割直线、圆弧、圆、L型和U型的能力
Smart to set the no. of knife section(0-3)Break Detection断刀检测有（have）Cutter Life Control刀具寿命控制程序控制(controlled by Program)Product testing产品检测有（have）Table NumberTable数量1个Table FunctionTable功能并行Table运行方式；设备能实现1个Table联动功能(1 tables run in parallel)Spindle Speed主轴转速60000rpmSpindle Cooling System主轴冷却系统风冷方式(air cooling)Cleaner Mode集尘方式下集尘(collect dust downside)Working Power工作电源220V ，50HZAir press空压供给0.5Mpa以上(above)Safety Device安全装置采用安全防护门或感应器(security door or sensor)Mode机型模式在线机型，全自动装载卸载PCBA(offline, load and unload PCBA by hand)Auto failure test and repair mode故障自动检知维修模式系统具有自我诊断功能，实时错误信息显示，能直观地查询设备各个IO端口状态，易于排除故障。
Self-diagnosis，display failure information in real time, query IO state visually, easy for troubleshootingComputer & Operation system电脑和操作系统工控机、Windows 7或以上版本。
PIC、Windows 7 or more advanced versionProgram Backup程式备份USBSoftware access control软件权限管理密码保护，依权限进入对应操作界面，保护系统重要参数。(Password protection，the operator enter corresponding interface according to authority to protect important parameters.)Programming编程可视化界面，单个程序切割点容量无限制，切割路径动态模拟。(Visual interface, the cutting point capacity for a single program should be over 400, dynamic simulation of cutting schedule.)Auto correction of the mark pointMark点自动校准功能具备Mark点自动校准功能(Yes)Fixture 治具ASC-3500S专用治具ASC-3500S special fixtureVoice control噪音控制运行时，噪声小于60分贝（离设备一米距离测量）
≦78 dB（measured in 1M’s distance ）Maintenance Period保修周期整机1年或以上，主轴建议2年以上并在保内提供主轴3000小时保养服务。
Over 1 year for the whole machine, and over 2 years for the spindle, and the spindle enjoys 3000 hours’ maintenance during the periodTechnology Support技术支持及培训提供设备操作、编程，硬件保养，维修培训服务；程序永久免费升级。(Offer service of operation, programming, hardware caring and maintenance training; free upgrade of application. )
1, the use of multiple sets of upper and lower knife while cutting
2, the bottom of the device with adjustable foot castors, easy to move equipment, non-moving need to be stable and fixed; feet Cup adjustable height 50MM or more;
3, equipped with SMEMA interface communication with other devices can be linked, with reserved network interface, the follow-up factory aspects of networking;
4, the device uses power: AC230V gas source: 4-6KGF / cm2
5, the necessary safety devices;
6, the equipment needs to operate smoothly, the necessary test components;
7, according to the normal production capacity needs to reach 1500PCS / H or more
8, there are data monitoring statistics output: boot time monitoring, capacity monitoring, equipment failure information and automatic rejection system
9, using multiple groups simultaneously cut down on the knife
10, the distance between the knife can be accurately adjusted, sub-board thickness to be met: 0.6MM-3.5MM up and down the distance between the knife can be accurately adjusted, sub-board thickness to be met: 0.6MM-3.5MM
11, the knife and the knife gap can be adjusted according to the PCB board V-CUT spacing, precision control in the 0.1MM
12, the distance between two adjacent blades can be adjusted between 8MM-25MM, can quickly adjust the required width;
SMT filter cotton is usually replaced in three months, otherwise it will be blocked, affecting the use effect.
Filter has the following characteristics.
1.Is a high performance and high efficiency filter cotton non-woven processing using organic hot-melt synthetic fiber and;
2, increasing structure, using gradually encrypted multi-layer technology, that is, the fiber density in the direction of pure air will increase gradually, and the higher filtration efficiency can be blocked at different levels of density according to the size of dust, which will more effectively accommodate more dust.
3, efficient filter cotton sticky treatment, filter material after full dipping, because the adhesive penetrated the media completely, so that the dust particles can not pass through, so that the overall filtered air flow evenly diffused, forming laminar flow state, to achieve the best spraying effect.
Does anyone need SMT filter cotton? Factory price.