Basic working principle of wave soldering


S-WS450 Wave Soldering machine


一、Wave soldering machine

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.

wave soldering process
wave soldering 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.

wave soldering pot

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.

S-WS250 Wave Soldering machine
Megatrend_ Infotainment

Megatrend: Automotive Infotainment Microelectronics

Committing to growth

Megatrend: Automotive Infotainment Microelectronics

Is your SMT factory ready for the increasing electronic automotive demands? As consumer interest shifts from engine performance to interior infotainment, the automotove microelectronics manufacuturing demands will continue to rise. The latest and upcoming electronic technologies in vehicles, i.e. navigation technologies, sensor controls, smart technologies in vehicle and cellular communication is creating urgency now more than ever to evaluate your manufacturing process.

Considering the rising demands for the latest electronic gadgets and the predicted growth in Electronic Vehicles (EV) and autonomous cars makes you question how much production you should be doing in-house for the most growth, higher profits and most efficient productivity. Automotive Electronics and IoT are in the midst of growth, and there are many expected changes in the very near future fueling this growth. Design activity will remain strong and that this will ensure new products enter now and in the coming years. Miniaturization of device footprint fuels innovation in printed-circuit board (PCB) designs.

Outsourcing manufacturing is no longer as cost effective as it once was, as labor costs are continuing to rise, as well as importing and exporting costs. Companies are finally realizing in order for the highest productivity, quality, and monetary gains, considering domestic manufacturing is the solution.

The electronics industry is an ever fast-changing world, and we are here to help you keep up with your business advancements and needs. What trends are you noticing? Have questions on how you can keep up in your industry? Let us know.

Megatrend_ Infotainment

Is your SMT factory ready for the increasing electronic automotive demands?

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Southern Machinery Digital Catalog of Machines

Digital Catalog of AI/SMT Machines

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Thank you for watching our AI/SMT Video Catalog where we featured Pick & Place Machines, Axial Insertion Machines, Radial Insertion Machines, Printers, Wave Soldering Machines, Odd-Form Machines, SMT Stencil Cleaners, and much more. Did you see a SMT, THT, or other machine, spare part, or service you need? Request a quote and we will guide you through the rest.

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12 Common Errors that Cause FAI Rejection

First Article Inspection

12 Common Errors That Cause FAI Rejection

FAI First Article Inspection - 12 Common Mistakes that Cause FAI Rejection

First Article Inspection (FAI) is of vital importance to industries that are governed by strict guidelines and a high standard of quality assurance. These are the 12 common errors which cause FAI Rejection:

1. Typos, incorrect knowledge, revisions, numbers, and values are some of the most common causes for FAI rejection.

2. Missing or hidden requirements for detailed Commercial Off the shelf “COTS” parts, where dimensions are not included in the official drawings. Elements & hardware set up should be addressed in the document as specified.

3. All Dimensions and notes are not accounted for. Any notes that include a dimension shall have a bodily measurement recorded.

4. Incorrect or lacking course of action for supplier and buy order requirements.

Specific course of action for provider should be MEC accepted according to buy order necessities.Supplier shall be licensed to construct to RDD (Reduced Dimension Drawing) per buy order necessities.

5. Incorrect tolerances assigned to dimension leading to non-conformance.

Standard dimension tolerances akin to +/- .010 are discovered within the tolerance block.

Tolerances assigned to this dimension are outlined by the Feature Control Frame related to the Basic Dimension.

6. Adherence to Raw Materials Shelf Life. Proper use of expiration dates and labeling.Raw Material required to be indicated on type MEC-0293/AS9102 Form 2Parts for a meeting are required to be indicated on type MEC-0292/AS9102 Form

7. Incorrect Revision Degree

Ensure PO revision matches launched engineering specifications for merchandise(s) on FAI report.

Verify the required revision of MEC specs, like 79P050000. Indicate all revision ranges in block 6 of MEC-0293/AS9102 Form 2

8. Incorrect inspection gear used or not recognized on FAI report.

When inspection gear is listed, be sure that inspection gear has enough measurement accuracy for necessities being measured.

9. Wrong quantities listed on FAI type(s).

There shall be no typographical errors, lacking sprint numbers, and/or designators similar to Q1, D1,TPSS

Example: If the acquisition order requires K/I 7979797-003 Q1 the FAI type shall contain the complete G/I: 7979797-003 Q1

10. Missing Certificates of Conformance

Check & Review FAI types as a part of the FAI Package.

Ensure there isn't any missing or incomplete sub-tier provider information.

11. FAI type(s) not signed, authorized, or dated by applicable consultant.

Form(s) MEC-0293 & MEC -0294 should be signed by the preparer of the FAI.

12. Incomplete recording of a number of actuals.

A function that requires a number of locations also requires recording a number of actuals.

Example: FIN #6 needs to be put in 12 locations (point to those 12 locations or measurements as outlined by engineering).

The First Reed Switch Auto Insertion Machine in the World Hits the Market

The First Reed Switch Auto Insertion Machine in the World Hits the Market

Reed Switches, or Herkons, are extremely useful for many electronic applications. Reed Switches work by means of magnetism in reed relays and for electrical circuit control. In the presence of a magnetic field the reed will either open or close, depending on it’s original positioning and purpose. They are extremely useful as they are hermetically sealed and can operate in almost any environment.

Made for highly reliable switching, major advantages to Reed Switches include their capability for low contact resistance, do not require a supply current, offer non-touch switching, no minimum switching current necessary for them to function, except for Tungsten contact materials. In addition, Reed Switches are highly economical, suitable for many harsh environments, and deliver billions of operations throughout their lifetime.

Common applications for Reed Switches include gear speed and direction sensing, window and door sensors for security alarms, bridge operator controls in airplane docking, safety vane sensor applications, high voltage relays in the power industry, fuel pumping stations sensors, ferrous part detection, and hibernation mode sensing when laptops are closed. There are many more growing applications for the very useful Reed Switch.

Reed Switch insertion into PCBs have historically been conducted by means of manual labor, by hand. As Auto Insertion mechanisms have advanced, there are new technologies on the market that can accommodate these highly useful switches via automated machines. Through Hole Technologies (THT) have advanced to now offer mechanized equipment to automate an assembly line that requires Reed Switch insertion. The first ever Reed Switch Machine is now available on the market for production assembly and auto insertion uses. This will make electronic products requiring Reed Switches easier to produce, faster, and more affordable for an entire manufacturing production.

Contact Southern Machinery for more information or to get a quote!

Are You Finding the Odd Form Components Machine?


Learn how you can automate your odd-form component PCB Assembly

We designed and manufactured Auto Insertion machine in Shenzhen China, — Decreasing labor cost — Easier manufacturing and operations management — Predictable Product Quality – Less repairs — No wrong parts nor wrong polarity — Less risk of damage due to human contact (contamination, ESD, physical damage to components) — Better clinching, less risk of solder issues. — Smaller factory space required to produce same volume of product.

Odd-form components are the only remaining discrete components left to hand assessmbly of a Printed Circuit Board.

The reasons are many,but the fundamental reason is that there are no standards that govern the shape,lead count,packaging,etc.Therefore,most manufacturers are left to handle the components as a special request for proposal and address the problem with a very customized platform.

Our odd components machine is one of the best automation machine for the job can handle components ranging from a 0.01“single pin to a 12”square block if required and do it without tool change or at least an automatic tool change.

This machine also be equipped with vision to inspect the leads and the top of the device for orientation or even position correction.