SMT零件识别

　　一 电阻(Resistor):

　　SMT 电阻一般而言, 其常用之外型尺寸有以下数种规格:

　　Generally, the SMT resistor dimension of common using is following 3 types:

　　注:公制与英制间之单位换算会有些许误差, 且各家厂商之产品间亦有少许差异, 因此上述之尺寸数据为概略值。There will be little of bias when we converse mm to inch. Different vendor will make little of dimension. Above table is estimate dimension.

　　SMT 电阻的阻值可直接由电阻上之数字计算出来:

　　The resistor value can be read by marking on resistor surface:

　　(1) 一般电阻: 其阻值以3码标示。单位为奥姆(ohm; Ω), 以下为例:

　　Normal resistor: Using 3 digital to represent resistor value:

　　*若电阻标示为203, 则其阻值之计算方式为

　　If the digital is “203”, then the resistor value is:

　　20x103 = 20000 ohm = 20K ohm

　　*若电阻标示为351, 则其阻值之计算方式为

　　If the digital is “351”, then the resistor value is:

　　35x101 = 35 ohm

　　*若电阻标示为050, 则其阻值之计算方式为

　　If the digital is “050”, then the resistor value is:

　　05x100 = 5 ohm

　　(2)精密电阻: 其阻值以4码标示。单位为奥姆(ohm; Ω), 以下为例:

　　Precise resistor: Using 4 digital to represent resistor value:

　　若电阻标示为1203, 则其阻值之计算方式为:

　　If the digital is “1203”, then the resistor value is:

　　120x103 = 120000 ohm = 120K ohm

　　若电阻标示为1301, 则其阻值之计算方式为:

　　If the digital is “1301”, then the resistor value is:

　　130x101 = 130 ohm

　　若电阻标示为0500, 则其阻值之计算方式为:

　　If the digital is “0050”, then the resistor value is:

　　050x100 = 50 ohm

　　(3) 0 奥姆电阻, 其阻值之标示为0:

　　0 ohm is represented as below:

　　(4) 电阻标示中若有”R”, 表示阻值中有小数点:

　　Letter “R” means dot as below:

　　5R6 = 5.6 ohm

　　二 电容 (Capacitor):

　　SMT 电容之外型尺寸与电阻相同, 常用之外型尺寸有以下数种规格:

　　SMT capacitor dimension is same as resistor, the dimension of common using is as below:
 

　　SMT 电容在外观上无法辨别其电容值, 需以电容表量测。

　　Capacity value can’t show on the capacitor surface, it should be measured by meter.

　　三 IC:

　　(1) 名词解释(Definition):

　　Pin: IC 脚 (又称lead)。

　　Pin: IC lead.

　　Pitch: Pin的中心点到相邻Pin的中心点之距离。

　　Pitch: Distance between pin center to next pin center.

　　(2) 外观分类(IC package type):

　　2.1 SOP(Small Outline Package): IC脚位于本体两侧, 呈L型向外延伸。

　　SOP(Small Outline Package): IC leads are L-shape and locate in 2 side of body.