The markings on SMD components have been always hard to read. Besides the fact that the numbers and letters in them are very small, the number coding used on them is different than what is used on traditional though-hole components (the reason is that there would not be enough space to print any long codes to those components). How to decipher those SMD resistor codes has been always a hard task. Pages like SMD Resistor Coding, The SMD Codebook, Marking SMD have tried to give some help on this.
Hackaday.com reports that it might be soon time that you can forget how to decipher those SMD resistor codes. Looks like surface mount resistors might be unmarked like their capacitor brethren. There are several reports (electronics-lab.com, dangerousprototypes.com and soselectronic.com) titled Will the SMD resistors marking become a history? that basically tell the same story: Company YAGEO announced its intention to remove marking of RC/AC 0603,0805,1206 SMD chip resistors from July, 1-st, 2013. The reason for this step is to reduce unnecessary chemical usages for environmental protections.
On EEVblog Electronics Community Forum there was discussion on will the rest of the manufacturers take the same decision. The clearest comment was: Sadly I’m sure they will. It’s not like any of their big customers are really going to care, and if they can eliminate an entire step of the production process the bean counters will ejaculate.
Everything seem to imply, that the situation with marking of chip resistors (0603/0805/1206) will soon be similar to chip capacitors (i.e. no marking on the top of the component, just component reels have the marking). A lot of SMD resistors already don’t have markings. But that should not be shocking news. You can put probes on your SMD component to verify there value is correct with your multimeter. It was not much of a problem with caps it wont be a real problem with resistors.
7 Comments
Online Dizi says:
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Tomi Engdahl says:
SMD resistor examples (EIA-96)
The following table lists all commonly used SMD resistors marked with the EIA-96 code from 1 ohm to 97.6 Mohms.
http://www.hobby-hour.com/electronics/eia96-smd-resistors.php
Tomi Engdahl says:
SMD resistor code calculator
http://www.hobby-hour.com/electronics/smdcalc.php
Tomi Engdahl says:
SMD Resistor Codes: How to Find the value of SMD Resistors
https://www.electricaltechnology.org/2013/07/how-to-calculate-or-find-value-of-smd.html
Tomi Engdahl says:
Decoding SMD Part Markings
https://hackaday.com/2021/10/06/decoding-smd-part-markings/
You’ve probably encountered this before — you have a circuit board that is poorly documented, and want to know the part number of a tiny SMD chip. Retro computer enthusiast [JohnK] recently tweeted about one such database that he recently found, entitled The Ultimate SMD Marking Codes Database. This data base is only a couple of years old judging from the Wayback Machine, but seems to be fairly exhaustive and can be found referenced in quite a few electronics forums.
The ultimate SMD marking codes database
https://smd.yooneed.one/
Tomi Engdahl says:
SMD Resistors: Surface Mount Resistor
https://www.electronics-notes.com/articles/electronic_components/resistors/surface-mount-smt-smd-resistor.php
Surface mount resistors, SMD resistors use surface mount technology, SMT to provide considerable advantages in terms of space saving and automated manufacture of printed circuit boards.
TYPICAL SMD RESISTOR POWER RATINGS
PACKAGE STYLE TYPICAL POWER RATING (W)
2512 0.50 (1/2)
2010 0.25 (1/4)
1210 0.25 (1/4)
1206 0.125 (1/8)
0805 0.1 (1/10)
0603 0.0625 (1/16)
0402 0.0625 – 0.031 (1/16 – 1/32)
0201 0.05
COMMON SURFACE MOUNT RESISTOR PACKAGE DETAILS
PACKAGE STYLE SIZE (MM) SIZE (INCHES)
2512 6.30 x 3.10 0.25 x 0.12
2010 5.00 x 2.60 0.20 x 0.10
1812 4.6 x 3.0 0.18 x 0.12
1210 3.20 x 2.60 0.12 x 0.10
1206 3.0 x 1.5 0.12 x 0.06
0805 2.0 x 1.3 0.08 x 0.05
0603 1.5 x 0.08 0.06 x 0.03
0402 1 x 0.5 0.04 x 0.02
0201 0.6 x 0.3 0.02 x 0.01
Tomi Engdahl says:
Online calculator – 4 digit SMD resistor
Resistors:
https://kiloohm.info/smd4-resistor/R007?fbclid=IwAR2B7xc1U8d1k4VG80vOa89BwZqiYvmxYEjUKuqP5EM9JUB8pW2_4FPUNEA#google_vignette