Difference between through hole and Surface mount components






As technology grows the demand for less weight and smaller size component increases. This leads to new improved technology known as surface mount technology (SMT). Surface mount components are similar to plated through hole as far as there electrical function is concerned but the key difference is in their size. The small size of surface mount components (SMC) provides better electrical performance. Surface mount components are placed or mount directly on Printed circuit board (PCB) which means they do not require hole for mounting the component. They can be directly soldered on track side. Surface mount components have different shape leads and they have little circular at bottom etc for soldering as shown in figure below.

SMD devices are mainly found in multi-layer PCB where size of device is major concern. They can also be used on boards or devices which contain both through hole and SMC because some components like transformer, heat sink are not suitable for SMC.
It depends on the requirement of an individual which technology is suitable between through hole or SMT. Like for beginners it is easy to solder the through hole components than SMC's, but when it goes in multilayer complicity increases and we have to chose SMT. There are some points that makes SMT different from Through hole which are summarized below.

Difference between Trough hole and Surface Mount Technology are as follows-
1. As SMC are small in size they take less space in comparison to through hole. As you can see from figure the difference between sizes of LED.

2. Pin count of component is increased greatly in SMT as compared to old through hole for example the micro process used today in computers PGA, FPGA etc.

3. SMC is leadless component and can be directly mounted on board surface while through hole components required drilling to mount the components. As shown in figure below.

4. The pads on the surface in SMT are not used for connection of layers on the printed wiring boards.

5. Size of through hole component is large in comparison to SMC there component density per unit area  is more in through hole component result in large size of Printed circuit board.

6. In SMT, components can be mounted on both side of PCB, this is not possible in through hole. Therefore SMC has made application possible which seems impossible with through hole.

7. SMT technology is used where large production is required which leads to low cost of unit assemblies.

8. With the help of SMC higher performance circuit can be made in small size which is prime requirement today.

9. Soldering of SMC is quite tough through manual soldering. Hence machines are required therefore big capital investment is required.

10. Designing, production, skills and technology required in SMT is very advance as compared to through hole technology.

11. Through hole technology is basically used in prototyping.

12. Soldering and de-soldering of through hole component is easy in comparison to SMT. Hence replacement of component is easy.

Happy Reading..

Thanks,
Ruby



Comments

Post a Comment

Popular posts from this blog

Do's and Don'ts for PCB Layer Stack-up

Image
Each day the electronic gadgets complexity increases with the miniaturization requirements, boards are becoming much denser. Multilayer PCB technology can satisfy today’s miniaturization board requirement. Multilayer PCBs has more than two layers of PCBs, arrangement of layer should be done with great care because inefficient layer arrangement will lead to the noisy board with unexpected performances. This article addresses the layer stack-up basics and the general layer stack-up considerations. 2 . Layer stack-up basics  Layer stack-up specifies the proper arrangement of circuit board layers for multilayer boards before starting board layout design.  Stack-up mainly defines which layers should be solid power and ground planes, the substrate (dielectric constant), and the spacing between layers.  While planning a layer stack-up, also compute the desired trace dimension and minimum trace spacing. SIDE VIEW    Multilayer boards are made up of one or mo
Read more

Types of Components Used in PCB and their explanations.

Image
In recent years, semiconductor packaging has evolved with an increased demand for greater functionality, smaller size, and added utility. A modern PCBA design has two main methods for mounting components onto a PCB:  Through-Hole Mounting  and  Surface Mounting.   Through-Hole Components Through-Hole Mounting (THM): Through-hole mounting is the process by which component leads are placed into drilled holes on a bare PCB. The process was standard practice until the rise of surface mount technology (SMT) in the 1980s, at which time it was expected to completely phase out through-hole. Yet, despite a severe drop in popularity over the years, through-hole technology has proven resilient in the age of SMT, offering a number of advantages and niche applications: namely, reliability.   Through-hole components are best used for high-reliability products that require stronger connections between layers. Whereas SMT components are secured only by solder
Read more

Difference Between Plated through Hole and Non Plated Through Hole

Image
During  PCB design  many issues come across and one of them is in the regard of non-plated and plated through holes. What is the difference between them and where should one use which one? is a commonly asked question. Here we will briefly discuss this issue.  Through hole components  have leads(straight or clinched) and these leads are put through holes available or made on the PCB insulating materials and soldered on the other side onto the copper tracks. The  difference between non plated through hole and plated through hole  is the presence of plated copper inside the insulating base material as shown in the pictures below. The presence of this plated through hole has in turn effect on electrical properties and mechanical stability. When component leads is soldered through plated holes then (1)the electrical resistance by the joint formed becomes less and (2) the mechanical stability increases. This is not the case with the non plated holes and hence plated through holes are more
Read more