When you look at smt vs through-hole, you notice big differences. The way you put parts on the board is not the same. SMT lets you put small parts right on the board. This saves space and makes building cheaper. THT, or through-hole, uses bigger parts with leads. These leads go through holes in the board. This makes them stronger for tough jobs.
Picking smt or through-hole is important. Each one changes your circuit’s size, cost, and how well it works. The table below shows how smt and tht are different in mounting, size, and best uses:
| Aspect | SMT | THT (Through-Hole) |
|---|---|---|
| Mounting | On board surface | Through drilled holes |
| Size | Smaller components | Larger components |
| Best Use | Compact, high-speed electronics | High-power, military, prototyping |
Key Takeaways
-
SMT parts are tiny and light. They help you make small and quick electronics. Machines can put them together fast, which saves time and money.
-
Through-hole parts are bigger and stronger. They work well in hard places. They are good for easy fixes and for things that need lots of power.
-
SMT assembly is best for making lots of things at once. It is also good when you need many parts in a small space. Through-hole is better for test models and things that need strong links.
-
SMT parts need special tools to fix. You also need to watch the heat. Through-hole parts are easier to fix by hand. They also handle shaking better.
-
You should pick SMT or through-hole based on your project. Think about size, cost, speed, and how tough it needs to be. Using both types can give you the best results.
SMT vs Through-Hole Overview
What Is SMT?
Surface mount technology puts parts right on the pcb surface. You do not need to make holes in the board. The parts sit on pads. Solder paste holds them in place. A reflow oven melts the solder to attach them. This way, you can put more parts on both sides of the pcb. Most new electronics use surface-mount technology. It lets you use smaller and lighter parts. You can also make high-density designs.
Here is a simple look at how smt and tht are different:
| Feature | Surface Mount Technology (SMT) | Through-Hole Technology (THT) |
|---|---|---|
| Mounting Method | Components placed on PCB surface pads | Leads inserted into drilled holes |
| Board Design | No holes needed; higher density possible | Requires holes; less dense placement |
| Assembly Process | Automated; uses solder paste and reflow | Manual or wave soldering |
| Component Size | Smaller, lighter surface-mounted devices | Larger components with leads |
People pick smt for pcb assembly when they want fast work. It is good for small and compact designs. Surface-mount technology saves space and money.
What Is Through-Hole?
Through-hole technology uses parts with leads that go through holes in the pcb. You solder the leads on the other side of the board. Tht makes strong bonds. You use it for parts that get pulled or pushed, like connectors or big capacitors. You see tht in old electronics, military items, and test boards.
Let’s see how smt and tht are different in how they look and are put together:
-
Tht needs holes in the printed circuit board. This makes the board thicker and less small.
-
Smt lets you put parts on both sides of the pcb. Tht usually only lets you use one side.
-
Smt uses machines to put parts on the pcb. Tht often needs people to do the work by hand.
Tip: If you want to fix things easily or try out different parts, tht is a good pick. If you want fast, tiny electronics, smt is better.
When you compare smt and through-hole, you see surface-mount technology is best for new, packed designs. Through-hole technology is better for strong, safe connections and for making test boards.
Advantages
SMT Advantages
When you pick smt, you get many good things for your pcb. Surface-mount technology helps you make electronics that are smaller and lighter. It also lets you build more advanced devices. Here are some main reasons why smt is helpful:
-
You can use much smaller parts. This makes your pcb up to 80% smaller and lighter.
-
Surface-mount technology lets you put parts on both sides of the pcb. You can fit more parts in a small space.
-
The small size of smt parts lets you make high-density circuits. You can add more wires and connections without making the board bigger.
-
You have more ways to design your board. Small smt parts let you try new ideas and features.
-
Smt is fast and uses machines to put parts on the board. Machines can place thousands of parts every hour. You do not need to drill holes, so you save time and money.
-
Smt works well for making just a few boards or many boards. You can make more boards quickly without slowing down.
Note: Smt parts are about 10% the size and weight of through-hole parts. This means your devices can be much lighter and easier to carry.
You also get better signals. Shorter paths between smt parts help signals stay strong. This is important for fast electronics.
| SMT Advantage | How It Helps You |
|---|---|
| Smaller components | Makes your pcb smaller and lighter |
| Double-sided placement | Lets you fit more parts on your board |
| High-speed automation | Makes building faster and cheaper |
| Flexible design | Lets you try new and small layouts |
| Improved signal integrity | Shorter paths help your device work better |
Through-Hole Advantages
Through-hole technology, or tht, gives you strong and safe connections. You should use tht when your parts need to handle stress or tough places. Here are the main reasons to pick tht:
-
Tht gives much stronger connections. The leads go through the pcb and get soldered on the other side. This makes the connection over 16 times stronger than smt.
-
You can use tht for big or heavy parts. It is good for connectors, big capacitors, and parts that get shaken or bumped.
-
Through-hole technology is best for high-power, high-voltage, or hot places. The bigger size helps with heat and power.
-
Tht is common in military, airplane, and factory equipment. These jobs need parts that work well in hard places.
-
You can easily fix or change tht parts by hand. This makes testing and repairs easier.
Tip: If you build things for cars, planes, or factories, tht gives you the strength you need. It is also good for test boards and projects where you want to change parts.
| Parameter/Aspect | Through-Hole Technology (THT) | Surface-Mount Technology (SMT) |
|---|---|---|
| Mechanical Strength | Stronger; better for shaking and bumps | Smaller; can break easier from shaking and bumps |
| Thermal Performance | Handles heat better because it is bigger | More sensitive to heat because it is smaller |
| Use Cases | Best for strong, powerful, and tough jobs | Good for small, packed designs and making lots of boards |
You get the best results from tht when your pcb needs to last in rough places. It is the best pick for connectors and power parts that must not break.
Disadvantages
SMT Disadvantages
SMT has some problems you need to think about. These can make building and fixing electronics harder.
-
SMT parts are very small. This makes them tough to pick up and fix. You often need special tools to repair them. Sometimes you need a microscope or even an X-ray machine. This makes repairs cost more and take longer.
-
SMT boards can get damaged by heat. If you do not watch the temperature, you can get problems. Solder paste might not work right. Heating can be uneven. Solder joints can be weak. These problems can break your device, especially if it gets hot or shaken.
-
SMT connections are not as strong as THT. If your device shakes or gets bumped, SMT joints can break. This means SMT is not great for rough jobs.
-
It is hard to check and test SMT boards. The parts are close together. It is hard to see or touch them. You may need special machines to inspect them. This costs more money.
-
SMT assembly has many steps that can go wrong. You might get solder bridges or tombstoning. Cold joints can happen too. These problems come from tiny parts and needing perfect placement.
Note: SMT is not good for high-power or high-heat parts. The solder joints can melt or break. THT handles heat better.
Here is a quick look at SMT’s main problems:
| Disadvantage | Impact on Your Project |
|---|---|
| Hard to repair | Needs special tools and skills, raising costs |
| Heat sensitivity | Can cause solder failures and device breakdowns |
| Weak mechanical strength | Not good for vibration or shock environments |
| Inspection difficulty | Makes testing and error detection harder |
| Assembly complexity | Increases risk of defects and slows down troubleshooting |
Through-Hole Disadvantages
THT has its own problems too. You should know these before you pick THT.
-
THT needs you to drill holes in the board. This takes more time and costs more money. If your board has many layers, every hole goes through all layers. This means you cannot fit as many parts.
-
THT parts are bigger. You cannot make your board as small or packed as with SMT. THT is not good for tiny or portable devices.
-
THT assembly is slow. You often need to solder both sides of the board. Most of the work is done by hand. This slows down making boards and costs more for workers.
-
THT parts have long leads. These can mess up fast circuits. The leads add things that hurt signals. This makes THT not good for fast or fancy electronics.
-
THT is not great for making lots of boards. Manual work and big parts make it hard to build many devices quickly.
Tip: If you want fast, small, or cheap electronics, THT is not the best. SMT works better for these jobs.
Here is a table that shows THT’s main problems:
| Disadvantage | How It Affects You |
|---|---|
| High manufacturing cost | Drilling and manual work increase expenses |
| Large component size | Limits board density and miniaturization |
| Slow assembly | Manual soldering slows down production |
| Poor high-frequency performance | Long leads degrade signal quality |
| Less suited for automation | Harder to scale for big projects |
Think about these problems when you choose between SMT and THT. Each one has limits that can change your project’s cost, size, speed, and how well it works.
Cost
SMT Cost
When you choose smt for your pcb, you often see lower costs in large production runs. Machines place smt parts quickly and accurately. This automation gives you better cost efficiency, especially if you need many boards. The setup and tooling fees for smt assembly usually range from $200 to $500, but these are one-time costs. After setup, the cost per pin or pad is about $0.07 to $0.08 in the US. In China, the cost per pad is even lower, around 0.33 cents. Smaller smt parts, like SOIC8, can cost as little as 3 cents each to assemble.
| Cost Metric | SMT Assembly Cost (US) |
|---|---|
| Cost per pin/pad | $0.07 to $0.08 |
| Cost per pad (China) | ~0.33 cents |
| Cost per component (SOIC8) | ~3 cents |
| Setup and tooling fees | $200 to $500 (one-time) |
You also save money because smt components are smaller and use less material. This means your printed circuit board can be more compact. The board material and thickness affect the price more than the choice between smt and tht. For most projects, smt gives you the best cost efficiency when you make many pcbs.
Through-Hole Cost
Tht costs more to assemble because it needs manual labor. Workers must place each part through holes in the pcb and solder them by hand. This process takes more time and raises the price per board. Tht is less suited for mass production, so you see higher costs if you need many boards.
-
Tht boards are often larger, which means you use more material.
-
Drilling holes adds to the setup time, but it is not the main cost.
-
Tht assembly is more labor-intensive, which increases the total cost.
-
You may pay more for repairs or changes because tht parts are easier to swap, but the process is slower.
| Aspect | Through-Hole Assembly |
|---|---|
| Suitability for Mass Production | Less suited, mostly manual |
| Material Costs | Higher due to larger size |
| Manufacturing Costs | Labor-intensive, slower process |
| Assembly Process | Manual, risk of component damage |
If you need strong connections or plan to build only a few boards, tht can work well. For most modern electronics, smt offers better cost efficiency and faster assembly for your pcb.
Space & Size
SMT for Compact Designs
You can make your devices much smaller when you use smt. This technology lets you place components right on the surface of the pcb. You do not need to drill holes for each part. Because of this, you can fit more parts in a small area. You can even use both sides of the board for your design. This helps you create thin and lightweight electronics.
SMT gives you more freedom with your layout. You can place tiny resistors, capacitors, and chips close together. This high-density placement is perfect for smartphones, tablets, and wearables. You save space and reduce the weight of your device. You also make your pcb easier to route because you have more room for traces.
Tip: If you want to build compact gadgets or pack more features into a small space, smt is the best choice.
Through-Hole for Larger Components
Tht uses parts with leads that go through the pcb. These leads need holes, which take up space on both sides of the board. You must leave room for the holes and the pads around them. This makes your board bigger and limits how close you can place other components.
Through-hole components come in different shapes. Axial leads stretch across the board and use more space. Radial leads stand up but still need holes. You must also make the pads larger to get a strong solder joint. All these rules mean tht takes up more board area and makes your layout more complex.
-
You need to drill holes for every lead, which increases the size of your pcb.
-
Pads for tht must be bigger, so you use more space for each part.
-
The holes block you from using the back side of the pcb in those spots.
-
You cannot place parts as close together as with smt.
If you use tht, your board will be larger and heavier. This method works best for big or heavy components that need strong support. You often see tht in power supplies, connectors, and test equipment.
Assembly Speed
SMT Automation
You can build electronic devices much faster with smt automation. Machines handle most of the work in smt pcb assembly. These machines pick up tiny parts and place them on the board with great speed and accuracy. A typical smt line uses pick and place machines, stencil printers, and reflow ovens. Each machine has a special job. The pick and place machine puts parts on the pcb. The stencil printer spreads solder paste. The reflow oven heats the board to attach the parts.
Automated smt assembly lines can produce thousands of boards every day. This speed is a big reason why smt is the top choice for high-volume production. You can expect machines to place between 2,000 and 5,000 parts per hour. This high speed means you finish large orders quickly and keep costs low.
| Assembly Method | Average Speed Range |
|---|---|
| SMT Automation | 2,000 to 5,000 parts per hour |
| Manual Through-Hole (Large PCB) | 100 to 200 parts per day |
| Manual Through-Hole (Small PCB) | 500 to 1,000 parts per day |
Note: Automation in smt pcb assembly lowers labor costs and reduces mistakes. You need skilled workers to set up and maintain the machines, but you need fewer people overall. This makes your process more efficient and helps you get a fast return on your investment.
Through-Hole Manual Process
With tht, you rely on people to place and solder each part by hand. This manual process takes much longer than smt automation. Workers must insert each lead through holes in the pcb and then solder them on the other side. For a large pcb, you might only finish 100 to 200 parts in a whole day. Even with a small pcb, you can only reach about 500 to 1,000 parts per day.
Manual tht assembly works best for small batches or special projects. You might choose this method for prototypes or when you need strong connections. However, it does not suit high-volume production. The slow speed and high labor needs make it hard to keep up with modern demands.
Tip: If you want to build many boards quickly, smt is the better choice. Use tht when you need strength or when you work on a unique pcb assembly project.
Reliability
SMT Reliability
You can count on smt for most electronics today. For 20 years, the military and space groups have used smt in many projects. These jobs need parts that work well all the time. Smt parts have lasted through hard tests, like strong shakes and many hot and cold cycles. Most devices now use smt because it works in normal and tough places.
Smt parts sit right on top of the board. This helps you make smaller and lighter gadgets. Usually, smt gives good results and does not break often. Problems can happen if your device shakes a lot or gets hit. Smt joints might come off if the board is not made well. But with smart design, smt can handle heat changes and daily use.
Note: Smt is the best pick for phones, computers, and most home devices. It works well unless you need extra strong parts.
Through-Hole Reliability
Tht gives you the strongest connections. The leads go through the board and get soldered underneath. This makes the bond very tough. You should use tht if your device gets bumped, shaken, or used roughly. Many engineers choose tht for connectors and power parts that must not break.
Tht works better when things get very hot or need lots of power. The bigger size and strong bonds help your device last longer in hard places. You see tht in cars, planes, and factory machines. These jobs need parts that can take stress and keep working.
Here is a simple comparison:
| Aspect | SMT Components | Through-Hole Components |
|---|---|---|
| Mechanical Robustness | Good, but not best for heavy stress | Excellent, stands up to shaking and bumps |
| Reliability in Harsh Settings | Works well most of the time | Best for very tough places |
| Failure Rates | Low, except when stressed a lot | Very low in hard conditions |
Tip: Pick tht if your device needs to survive drops or lots of power. Use smt for most other jobs where small size and speed matter.
Application Suitability
SMT in Electronics
You see smt in almost all new electronics today. This technology helps make devices smaller and faster. It also lets you build more powerful gadgets. Smt parts are used in many fields because they save space. You can fit more parts on a board with smt. Here is a table that shows where smt is used most:
| Sector | Common Electronic Applications Using SMT Components |
|---|---|
| Consumer Electronics | Smartphones, tablets, laptops, wearable devices, smart TVs, refrigerators |
| Automotive | Engine control units, ADAS, infotainment systems, electric vehicle parts |
| Medical Devices | MRI machines, patient monitors, pacemakers, portable medical tools |
| Aerospace & Defense | Avionics, satellites, military equipment, UAVs |
| Industrial | Automation, robotics, power electronics, test equipment |
| Telecommunications | Base stations, routers, fiber optic and satellite communications |
| Energy Sector | Solar inverters, wind turbines, smart grid systems |
Smt is great when you want small and strong devices. These parts make your gadgets lighter and more dependable. You also get faster building and lower costs for big projects.
Through-Hole in Harsh Environments
You should pick through-hole parts for tough places. These parts make strong bonds that last a long time. They work well under heat, shaking, and stress. Data shows through-hole parts fail less than 2% in vibration tests. Smt parts fail over 10% in the same tests. Through-hole parts can handle over 1,000 hot and cold cycles before wearing out. In cars, these parts often last more than 15 years.
You find through-hole parts in cars, planes, factories, and military gear. These places need parts that can take hits, high power, and very hot or cold weather. The leads go through the board, which helps stop damage from shaking or heat.
Tip: Pick through-hole parts if you need your device to be safe and last a long time.
Prototyping & Hobby Use
Through-hole parts are best for trying out new ideas. Many hobbyists and engineers use them because you can put them in by hand. You can use breadboards and perfboards, which makes testing easy. Here are some reasons why through-hole is good for making test boards:
-
You can put in and solder parts without trouble.
-
Fixing and checking parts is easy because they are bigger.
-
Breadboards and perfboards work well with through-hole parts.
-
You only need simple soldering skills.
Smt is getting more popular for small or quick projects. Still, through-hole is easiest if you want to change your design a lot.
| Aspect | Through-Hole Technology (THT) | Surface-Mount Technology (SMT) |
|---|---|---|
| Assembly | Easy manual assembly | Needs machines or careful hand work |
| Debugging & Repair | Simple to fix | Harder to repair |
| Prototyping Boards | Works with breadboards and perfboards | Needs special PCBs |
| Skill Requirement | Good for beginners | Needs more skill |
Choosing SMT or Through-Hole
Decision Factors
When you pick between smt and through-hole, you must think about a few key things. Each one is better for different jobs. The table below helps you see how they compare:
| Factor | SMT (Surface Mount Technology) | Through-Hole Technology (THT) |
|---|---|---|
| Size and Density | Smaller parts, boards can be tiny and packed | Bigger parts, boards are larger and less packed |
| Mechanical Strength | Not as tough, harder to fix | Very strong, good for rough use |
| Heat Dissipation | Needs careful planning, not much material for heat | Easier to cool, handles more heat |
| Electrical Performance | Great for fast, low-power circuits | Good for strong, high-power circuits |
| Manufacturability | Uses machines, quick, saves on work costs | Done by hand, slower, costs more for work |
| Production Volume | Best for making lots of boards | Good for testing or making a few boards |
| Repairability | Harder to check and fix | Easier to find and fix problems |
| Application Examples | Phones, computers, small chips | Power parts, connectors, switches |
Think about how big your device is, how many you want to make, and if you need to fix it later. SMT is great for small, fast gadgets. Through-hole is best if you want strong parts or only need a few boards.
Tip: Pick smt if you want to build fast and keep things small. Choose through-hole if you need strong parts or easy repairs.
Typical Use Cases
Most new electronics use smt. These parts help you make small and powerful gadgets. You see smt in phones, laptops, and even space tools. SMT is also good for LEDs because it helps with heat.
Through-hole parts are still important for special jobs. You use them in power supplies, connectors, and test tools. These parts are best for tough places like factories or cars where things get rough.
Here is a simple guide to help you choose:
-
Use smt for:
-
Gadgets for people to use every day
-
Fast circuits
-
Devices that must be small and light
-
Making lots of boards
-
-
Use through-hole for:
-
Testing and hobby projects
-
Parts that get hot or use lots of power
-
Strong or factory equipment
-
Easy fixing and testing
-
Remember: The best choice depends on what your project needs. Think about your design, where it will be used, and how many boards you need.
You know that SMT and through-hole parts are both useful. SMT helps you make small gadgets. It also lets machines build things quickly. If you make lots of boards, SMT saves money. Through-hole parts are strong and easy to fix. They work well in tough places and for testing new ideas.
| Key Factor | SMT Best For | Through-Hole Best For |
|---|---|---|
| Size & Speed | Small, high-speed devices | Large, durable components |
| Cost | Mass production | Low-volume, high-power builds |
| Repairability | Specialized tools needed | Simple manual repairs |
Pick SMT for new and fast electronics. Use through-hole if you want strong parts or easy testing. SMT will be used more in the future, but both ways are still important for different jobs.
FAQ
What is the main reason to choose SMT over through-hole?
You should pick SMT if you want smaller, lighter, and faster devices. SMT lets you fit more parts on your board. You can also use machines to build your boards quickly and save money on large projects.
Can I mix SMT and through-hole components on one PCB?
Yes, you can mix both types on one board. Many designs use SMT for most parts and through-hole for connectors or heavy components. This gives you the benefits of both methods.
Are through-hole components better for beginners?
Through-hole parts are easier for beginners. You can see and handle the parts easily. Soldering is simple, and you can fix mistakes without special tools. Many hobby kits use through-hole components for this reason.
Do SMT components need special tools for assembly?
You need special tools for SMT assembly. Machines place tiny parts on the board. For hand assembly, you use tweezers, a fine-tip soldering iron, and sometimes a magnifier. Repairs can be hard without the right equipment.
Which method is better for high-vibration environments?
Through-hole components work better in high-vibration places. The leads go through the board and make strong connections. You should use through-hole parts for cars, planes, or machines that shake or move a lot.
Written by Jack Elliott from AIChipLink.
AIChipLink, one of the fastest-growing global independent electronic components distributors in the world, offers millions of products from thousands of manufacturers, and many of our in-stock parts is available to ship same day.
We mainly source and distribute integrated circuit (IC) products of brands such as Broadcom, Microchip, Texas Instruments, Infineon, NXP, Analog Devices, Qualcomm, Intel, etc., which are widely used in communication & network, telecom, industrial control, new energy and automotive electronics.
Empowered by AI, Linked to the Future. Get started on AIChipLink.com and submit your RFQ online today!
