SMD capacitors most extensively used for capacitor requirements on the PCB which are perfect for large scale manufacturing. SMD capacitor one of the derivatives of SMT (surface mount technology) having small and easy to place components which enhances the manufacturing speed.
Ceramic, tantalum, electrolytic capacitors are few of the available options when it comes to SMD capacitor. ceramic capacitors are easy and cost-effective to manufacture and thus most widely used.
If you want to go through the detail of the capacitor and their types along with its working then click here!
What is an SMD capacitor?
SMD capacitor is nothing but a capacitor with compact size and no long lead. It is developed in such a way that it offers an advantage for mass production of electronic devices and equipment, along with some technical advantage in the operation of high-frequency devices.
Advantage of SMD capacitor:
- SMD capacitor has no leads or very short lead, the inductive effect of leads are avoided ( its importance comes into the picture when we are working on high-frequency circuits and radio circuits ‘RF range’).
Eg. while designing a tank circuit using LC, if the leads of the capacitor are not kept short then it will oscillate at different frequencies than that we have designed. - The size of the surface mount capacitor is smaller than the traditional capacitor space and the device can be confined in a smaller area, useful in portable devices.
- An increase in the manufacturing speed, therefore, reduction in cost is possible.
- Due to the standard size, it is much easier to handle and place on PCB using the robotic assembly process.
Disadvantage of SMD capacitor:
Its advantages have an upper hand than that of disadvantages. Why we are saying its disadvantages are very few and can be neglected.
- One disadvantage is its size when it comes to repairing. Suppose you’re considering to replace it then it is a little bit arduous work.
- Lower heat capacity of a smaller capacitor can damage it if proper cooling ventilation is not given. Surface mount components lower operating temperatures than the traditional one.
Common capacitor value with codes in a chart:
Common capacitor value for SMD capacitor is almost same as ceramic and electrolytic capacitors. Below table have all the common capacitor values listed that are useful for you.
For code “104″
The two figures 10 indicate the significant figures and the 4 indicates the multiplier , i.e. 10^4 = 10000.
Therefore, the value comes out to be 100000 pf = 0.1 uf
There is a certain range of capacitors which is very commonly used with PCB and in the circuits. The common capacitor code is given below so that it is easier to remind it whenever required while studying or designing the circuits:
| Capacitor (104) | Capacitor (108) |
| 100 nF | 0.1 pF |
| Capacitor (154) | Capacitor (158) |
| 150 nF | 0.15 pF |
| Capacitor (224) | Capacitor (228) |
| 220 nF | 0.22 pF |
| Capacitor (334) | Capacitor (338) |
| 330 nF | 0.33 pF |
| Capacitor (474) | Capacitor (478) |
| 470 nF | 0.47 pF |
| Capacitor (684) | Capacitor (688) |
| 680 nF | 0.68 pF |
| Capacitor (105) | Capacitor (109) |
| 1.0 μF | 1.0 pF |
| Capacitor (155) | Capacitor (159) |
| 1.5 μF | 1.5 pF |
| Capacitor (479) | Capacitor (229) |
| 4.7 pF | 2.2 pF |
| Capacitor (689) | Capacitor (339) |
| 6.8 pF | 3.3 pF |
| Capacitor (100) | Capacitor (103) |
| 10 pF | 10 nF |
| Capacitor (150) | Capacitor (153) |
| 15 pF | 15 nF |
| Capacitor (220) | Capacitor (223) |
| 22 pF | 22 nF |
| Capacitor (330) | Capacitor (333) |
| 33 pF | 33 nF |
| Capacitor (470) | Capacitor (473) |
| 47 pF | 47 nF |
| Capacitor (680) | Capacitor (683) |
| 68 pF | 68 nF |
| Capacitor (101) | Capacitor (681) |
| 100 pF | 680 pF |
| Capacitor (151) | Capacitor (102) |
| 150 pF | 1000 pF [1.0 nF] |
| Capacitor (221) | Capacitor (152) |
| 220 pF | 1500 pF [1.5 nF] |
| Capacitor (331) | Capacitor (222) |
| 330 pF | 2200 pF [2.2 nF] |
| Capacitor (471) | Capacitor (682) |
| 470 pF | 6800 pF [6.8 nF] |
| Capacitor (332) | Capacitor (472) |
| 3300 pF [3.3 nF] | 4700 pF [4.7 nF] |
| Capacitor (225) | Capacitor (335) |
| 2.2 μF [2200 nF] | 3.3 μF [3300 nF] |
| Capacitor (475) | Capacitor (685) |
| 4.7 μF [4700 nF] | 6.8 μF [6800 nF] |
SMD capacitor size:
SMD capacitor’s size certainly depends on their types, their size a different for electrolyte capacitor and ceramic capacitor. Below are some SMD capacitor size standards for different types of SMD capacitor:
| Size Code (mm) | Size (in mm) | Size Code (inches) | Size (in inches) |
|---|---|---|---|
| 1005 | 1.0 × 0.5 | 0402 | 0.04 × 0.02 |
| 1608 | 1.6 × 0.8 | 0603 | 0.06 × 0.03 |
| 2012 | 2.0 × 1.2 | 0805 | 0.08 × 0.05 |
| 3216 | 3.2 × 1.6 | 1206 | 0.126 × 0.063 |
| 3225 | 3.2 × 2.5 | 1210 | 0.12 × 0.10 |
| 4520 | 4.5 × 2.0 | 1808 | 0.18 × 0.08 |
| 4532 | 4.5 × 3.2 | 1812 | 1.8 × 0.12 |
| 5750 | 5.7 × 5.0 | 2220 | 0.22 × 0.20 |
Are SMD capacitor polarized?
YES, SMD capacitors are polarized but not all SMD capacitors are polarized. The electrolytic SMD capacitor compulsorily comes with the polarity and has its dedicated applications.
They are normally yellow and black color with markings on it.
How to identify SMD capacitor polarity?
The polarity of surface mount capacitors is marked by a white or black line at one of the ends of the device. Note that on a rounded surface mount capacitor the small black corner indicates the negative side. This line/bar indicates the positive terminal of the capacitors as shown in the figure above.
How do you know the capacitor is nonpolar?
If no indication like a bar or colored dash is present on the capacitor then it is a nonpolar capacitor. This nonpolar ceramic capacitor generally brown, yellowish-brown or grey in color.
SMD resistors are generally black in color.
How to test a SMD capacitor?
If your surface mount capacitor does not have a code written on it then follow the following steps:
Step1 – Remove your capacitor from the PCB ( it is not possible to test the component without removing it from the board)
Step2 -Put your multimeter to the Mega-ohm range. And connect the positive of multimeter to the positive of a capacitor and negative to the negative of a capacitor (if it is polarised capacitor). If your capacitor is non-polarized then no issue of polarity.
Step3 – Now observe the value Of the component,
- If it is showing few Megaohms and decreasing slowly then your capacitor is faulty.
- If it is showing few Megaohms, increasing slowly and becomes steady (or not showing any value due to out of range), then the capacitor is good. There is no need to replace it.