What Are The Types Of PCB Soldering? PCB Soldering Process 2024

What is PCB Soldering?

PCB stands for a printed circuit board. PCB soldering is an alternative method of patching electrical sheets.

This sort of soldering is one of the foremost essential methods that anybody wishing to work with.

While there are numerous distinctive ways you can achieve the patching method, the most important clarification of the fastening handle is that it’s the method of linking two little pieces together on the surface of the printed circuit board.

In other words, patching could be a way of interfacing two or more distinctive electronic components on your circuit board.

What are the Different Types of Soldering?

Three types of PCB soldering utilize progressively higher temperatures, which in turn create continuously more grounded joints.

What is Brazing?

This type of fastening employments a metal with a much higher softening point than those utilized in difficult and delicate patching. The melting point of the metal in this type of soldering is above 4500C. In any case, so also too difficult fastening, the metal being fortified is warmed as contradicted to being dissolved.

After warming both the materials adequately, you’ll be able at that point to place the patching material between them which softens and works as a holding specialist.

What is Soft Soldering?

This handle has the least filler metal dissolving point of all the fastening sorts at less than around 4000C. These filler metals are as a rule amalgams, frequently having led with liquid temperature beneath 3500C.

PCB Soldering

PCB Soldering

Since the moo temperature utilization is delicate patching it thermally stresses parts the slightest but doesn’t create solid joints and is at that point hence unacceptable for mechanical load-bearing practices.

Additionally, it is not suitable for tall temperature use as this sort of loses quality, and durability as well as softens.

What is Hard Silver Soldering?

Brass or silver is the holding metal utilized in this handle. It needs a blowtorch to realize the temperatures at which the patch melts.

The temperature for this type of soldering is approximately above 4500C.

These all are the types of PCB soldering and all have great importance in daily life.

We are dependent on PCBs because they have implementations in almost all sorts of businesses, computer works, etc.

Which Type of PCB is Correct for Soldering?

When characterizing what is the top side of your printed circuit board, subsequently the inverse side will be called the bottom side.

The foot side of the printed circuit board is more often than not the side without components as well as the side that touches the patch wave amid get-together.

That’s why sometimes it is additionally called patch side. In any case, more regularly, printed circuit boards have a connection on both sides, and the assembly handle does not require wave patching. However, the bottom side is best for PCB soldering.

Can a PCB be Repaired?

Not every printed circuit board is a result of comparative conditions. With the variety in the natural push that might cause harm, it is basic to get which thing is causing the issue so that you can discover an arrangement to that issue.

PCB Repair

PCB Repair

What Causes Damage to PCB?

For the most part with fire, most printed circuit boards will not be easy to repair.

Additionally, it depends on the degree of harm caused by fire. You’ll discover it exceptionally troublesome to reestablish such harms.

On the other hand, the inactive power supply can also cause damage to PCB.

Consequently, it is fundamental to switch off your gadgets amid electrical surges.

A few physical harms might happen to a printed circuit board when uncovered to stretch, might cause a break, and wear or tear.

What is PCB Repairing Rules?

Simple PCB soldering harms one cannot repair effectively. Depending on the printed circuit board’s usefulness issues, does repairing the printed circuit board fathom the issue or not. For occasion, short-circuiting or open circuit. A few electronic printed circuit boards are difficult to repair. In conclusion, you cannot repair all the base of PCBs also it depends upon the damage.

Can You Solder without Flux?

Yes, you can patch without using flux. Whereas it is accommodating within the method of soldering as the flux helps break down the oxides on the metal. Additionally, most patches these days come with a rosin center which does the work of flux making a difference by breaking down oxides and other atoms. It depends on numerous factors.

What are the Types of Flux?

Flux implies a nonexistent line through which a physical amount can travel. The word flux has origin from the Latin word Fluxus meaning stream. Fluxes play an important role in PCB soldering. Isaac Newton to begin with the utilization of this term as fluxion into different calculus. In science, flux has fundamental use all over the world.

Here are the types of fluxes.

  • Magnetic flux
  • Acoustic flux
  • Luminous flux and Heat flux
  • Radiant flux or Energy flux
  • Mass flux and Momentum flux

What is the Strongest Solder?

The most grounded of the patches contain direct sums of silver and likely to be called silver solder.

While the genuine ductile quality will never be as tall as the steel itself. It has utilization in creating the joints that are each bit as slid as the steel.

It is joined by utilizing lungs with the patch being drawn into the joint by capillary action.

Custom, as well as other tall end bikes, are manufactured this way and when completed legitimately the joints last longer than steel itself.

Which Metals are Used in Soldering?

Filler metals that have an implementation in patching were once lead-based like lead patch, be that as it may, owing to directions, lead base filler metals are progressively supplanting with lead-free fastens. These may consist of the following metals.

  • Brass
  • Copper
  • Antimony
  • Tin
  • Indium
  • Silver or bismuth

Which Soldering Wire is Best?

Off all other PCB soldering wires, KESTLER SOLDER is the leading wire and one can buy this online. It encompasses a better than average 0.031 inches distance across 60/40 tin-lead portion, moo dissolving point, and exceptionally solid cement control making solid joints as well.

Besides, it’s enormously checking on and profound elevation, US military had utilized this, which makes a better choice for buying.

What is Meant by Desoldering?

In electronics, it is the evacuation of patches and parts from a circuit board for investigating, repairing, substitution and rescue. It is opposite to PCB soldering.

Tools in desoldering

Desoldering devices incorporate the following things.

  1. It includes solder wick.
  2. Heat guns, with the help of this you’ll be able to dissolve the solder.
  3. Desoldering pump
  4. Removal of alloys to remove different alloys that are already there.
  5. Removal fluxes are to vanish fluxes over there.
  6. Heated soldering tweezers
  7. Different tweezers and pick for assignments such as holding, evacuating, scratching, and pulling components.
  8. Vacuum and weight pumps with specialized radiator tips
  9. Rework stations, which have utilization in repairing PCB soldering.

What is the Difference between Soldering Paste and Flux?

Solder has its use in assembling components onto your PCB. While the flux is utilized earlier to assembly to plan and offer assistance to your board through the PCB soldering handle. The unsecure metal on your printed circuit board can be gotten to be sullied with debasements from dealing with, as well as from oxides and other atoms that shape due to metal’s introduction to air.

This defilement can avoid the fastening handle from making great strong joints between the circuit board metal and leads of the components that are going to join with it. In arrange to expel this defilement, the board must be clean with flux earlier to fastening.

How does Solder Work with Flux?

The patch is a cement fabric that has utilization in the joining of two metals. Such as parts of lead and their comparing cushions or gaps on a printed circuit board. The patch has implementation as a metal filler between the joining metals and heats it until softens.

Since the liquid patch contains a lower dissolving point than the metal it is joining, so it gives a solid metal to the metal joint without giving rise to any damage to the board or the parts after cooling. Thus, solder and flux work together in creating a solid joint and have a lot of importance in PCB soldering.

In the electronics area there is a wide choice of connectors and terminals for printed circuit boards. These components can be welded in different ways, in order to facilitate their handling or to make better use of the space on the board.

In general, there are 3 types of mounting on the PCI, each with its advantages and disadvantages. The type of assembly must be determined in the initial stage of the project, so that the chosen products work efficiently and safely.

Next, see how each of these processes is carried out.

Wave Soldering

The solder wave is the classic welding process for the manufacture of electronic modules. It is the oldest and most common method to be found on the market. It is characterized by using components with terminals that cross the printed circuit board (known as PTH – pin through hole) and the welding takes place at the bottom of the PCI.

It consists of making the plate go over a welding wave. Air is pumped from the bottom of a melted solder vessel and this wave is created. Once preheated, the PCI passes on a conveyor over the wave in such a way that the weld is applied and fixed to the islands. The areas on the plate that are not to be welded are covered by a protective mask, in order to prevent the welding from joining unwanted parts.

solder wave

Solder wave


  • Allows serial fabrication.
  • Equipment is still the least expensive compared to other welding technologies.


  • It requires constant maintenance of the equipment, in order to guarantee the quality of the weld.
  • It does not allow the use of plates with multiple layers.
  • Components take up more space on the PCI.
  • It is necessary to maintain control over temperature, belt speed, weld purity and other variables to prevent damage to the PCI or to more sensitive components, such as semiconductors, for example.
  • It allows only one type of assembly technology in the welding process.

solder wave reflow

Solder wave reflow

THR Soldering

In THR (Through Hole Reflow) weld, a solder paste is used to position a large number of components on their respective islands. Considering that the solder paste contains a resin that only changes its state at temperatures above + 100ºC, it remains, without drying, on the surface of the terminal until the welding process. The assembly is subjected to a controlled heat source, which melts the solder paste, permanently fixing it on the component terminals.

The heating is carried out through a reflux chamber, which in order to avoid material damage caused by different expansion coefficients of each component, the complete module is slowly heated up to approximately + 150ºC. Thereafter, rapid heating occurs at a temperature higher than the specific melting temperature of the weld.

The solder melts, runs through the terminal surface until it reaches the island and completely fills the PCI perforations. When the module cools down completely, secure and permanent connections are formed between the terminals and the islands.

THR solder

THR soldering


  • Process quality with high production capacity, thanks to a high level of automation.
  • The technology of passing through the islands in the plate ensures a high mechanical stability of the connection components.
  • The equipment used accepts both THR and SMD components in a single process.


  • Equipment with high costs.
  • It does not justify small-scale manufacturing.

SMT Solder

The components for surface mounting ( SMD – Surface Mount Device ) are welded directly on the top or bottom of the printed circuit board by means of weldable contact surfaces. Since the construction elements do not need to have wire connections that are passed or welded through holes in the PCI, the surface mount technology (SMT – Surface Mount Technology) allows the production of a compact electronic device using both sides of the board.

Before applying the SMD components, the metallized pads on the plate are covered with a solder paste using a deposition method by screen printing, matrix or dispenser.


  • High level of productivity and quality, thanks to a high degree of automation.
  • High density of components in the device: plates usable on both sides thanks to surface mounting and miniaturization of components, saving space occupied in the PCI and reducing its proportions.
  • Allows processing of THR and SMD components in a single device.


  • Equipment with high costs.
  • It does not justify small-scale manufacturing.

Currently, printed circuit boards use two types of solder to fix electronic components, Pb-Sn (lead-tin) and Lead-Free (lead-free) solders, which contain several types of alloys. Lead-Free welds also present problems of reliability, price / material cost stability, high melting temperature.

Thus, alternatives are sought, where other studies that are being developed reduce or completely remove the solder in the process of making a printed circuit board, but using resins as a means of fixation or not completely eliminating the solder.

This invention consists of a process of manufacturing a printed circuit board without the use of solder as a way of joining the electronic components. These components are fixed using mechanical elements and pressure as the only way of joining, eliminating any type of welding.

Problem that PCB Soldering Solves

The main innovation of the invention is the possibility of not using solder to fix the electronic components on a printed circuit board. The plate is manufactured in the same current way until the process of fixing the components, where they are fixed using pressure through mechanical elements.

the finished plate

Circuit drawing (A) and the finished plate (B)

Technology Differentials

  • Printed circuit boards manufactured without using solder as a means of fixing electronic components
  • No use of toxic materials for fixing the components
  • Fixing of components using mechanical elements and pressure as the only way of joining
  • Easy disassembly of the base plate components, for later reuse and / or recycling of the components
  • Reducing environmental impact
  • Maintenance of the plate in an easy way – disassembly and component replacement does not cause damage to the plate
  • Reduction of usual problems of the plates related to welding as fixation, such as the formation of “whiskers”, among others.

Industrial Application

This invention focuses on products in the class 1 product reliability category, standard IPC-A-600G (IPC, 2004) , which are electronic products in general, including consumer products, the main requirement being the function of the printed circuit board, where aesthetic imperfections are not important.

This class of product application represents the largest production volume, with the products of greatest use and thus of greatest consumption, generally having a short useful life, generating major environmental problems.

If you are looking for reliable pcb assembly solutions in China at best price, we can support your all kind of future assembly needs.

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