PCB element Encapsulation

Reprinted from: http://www.cnblogs.com/asus119/archive/2012/03/26/2418427.html

0805 encapsulation size/0402 encapsulation size/0603 encapsulation size/1206 encapsulation size

Relationship between package size and power:
0201 1/20 million
0402 1/16 million
0603 1/10 million
0805 1/8 million
1206 1/4 million
Correspondence between package size and Package

0402 = 1.0mm x 0.5mm
0603 = 1.6mm x 0.8mm
0805 = 2.0mm x 1.2mm
1206 = 3.2mm x 1.6mm
1210 = 3.2mm x 2.5mm
1812 = 4.5mm x 3.2mm
2225 = 5.6mm x 6.5mm

There are 9 common encapsulation methods for SMD resistor and capacitor (capacitance refers to stepless SMD), two representation methods are available: Imperial and metric. The Imperial representation is a four-digit EIA (American Association of electronics industry)CodeThe first two digits indicate the length of the resistor or capacitor, and the last two digits indicate the width, in inches. We often say that 0805 encapsulation refers to imperial code. In fact, the metric system is rarely used. The Metric code is also represented by four digits in millimeters, similar to the English system.

The following table lists the mappings between the package size and specifications:

Imperial (Inch)	Metric (Mm)	Length (L) (Mm)	Width (W) (Mm)	High (t) (Mm)
0201	0603	0.60 ± 0. 05	0.30 ± 0. 05	0.23 ± 0. 05
0402	1005	1.00 ± 0. 10	0.50 ± 0. 10	0.30 ± 0. 10
0603	1608	1.60 ± 0. 15	0.80 ± 0. 15	0.40 ± 0. 10
0805	2012	2.00 ± 0. 20	1.25 ± 0. 15	0.50 ± 0. 10
1206	3216	3.20 ± 0. 20	1.60 ± 0. 15	0.55 ± 0. 10
1210	3225	3.20 ± 0. 20	2.50 ± 0. 20	0.55 ± 0. 10
1812	4832	4.50 ± 0. 20	3.20 ± 0. 20	0.55 ± 0. 10
2010	5025	5.00 ± 0. 20	2.50 ± 0. 20	0.55 ± 0. 10
2512	6432	6.40 ± 0. 20	3.20 ± 0. 20	0.55 ± 0. 10

The encapsulation size is generally related to power:

imperial	power W
0201	1/20 W
0402	1/16 w
0603	1/10 W
0805	1/8 W
1206	1/4 W
1210	1/3 W
1812	1/2 W
2010	3/4 W
2512	1 W

On the capacitor encapsulation in addition to the above chip encapsulation, the non-polar capacitor, its encapsulation model also has rad type, such as "RAD-0.1" "RAD-0.2", etc, the suffix number indicates the distance between two pad in the encapsulation model, in inches. There is an excellent electrolytic capacitor encapsulation model for the RB Type, for example from "RB-.2 /. 4 "to" RB-.5 /. the first digit in the suffix represents the distance between the two pad in the encapsulation model, and the second digit represents the size of the capacitor shape, in the unit of inches.

 

Resistance: RES1, RES2, RES3, res4; Axial Series
Polar capacitance: CAP; encapsulation property is RAD-0.1 to rad-0.4
Electrolytic Capacitor: electroi; encapsulation attribute: rb.2/. 4 to rb.5/1.0
Potentiometer: pot1, pot2; encapsulation property is vr-1 to vr-5
Diode: encapsulation property: Diode-0.4 (Low Power) Diode-0.7 (high power)
Transistor: the common encapsulation attribute is to-18 (Common Transistor) to-22 (High-Power Transistor) to-3 (high-power dington tube)
The power supply regulator has 78 and 79 series; 78 series such as 7820, etc.
Series 79 includes 7920, etc.
Common encapsulation attributes include to126h and to126v.
Bridge: bridge1, bridge2: encapsulation properties for D series (D-44, D-37, D-46)
Resistance: AXIAL0.3-AXIAL0.7 where 0.4-0.7 refers to the length of the resistance, usually with axial0.4
Porcelain capacitor: RAD0.1-RAD0.3. Among them, 0.1-0.3 refers to the capacitance size, generally rad0.1
Electrolytic Capacitor: rb.1/. 2-rb.4/. 8 wherein. 1/. 2-.4/. 8 indicates the capacitor size. Generally, rb.1/. 2 is used for 100uf, rb.2/. 4 is used for 100uf-470uf, and rb.3/. 6 is used for 470uf.
Diode: DIODE0.4-DIODE0.7 of which 0.4-0.7 refers to the length of the diode, usually with diode0.4
Light Emitting Diode: rb.1/. 2
Integrated Block: DIP8-DIP40, where 8-40 refers to how many feet, 8 feet is the dip8 SMD Resistance

Part encapsulation refers to the appearance and solder joints indicated when the actual part is soldered to the circuit board. Is a pure concept of space, so different components can share the same part encapsulation, the same component can also have different parts encapsulation. Such as resistance, there is a traditional plug-in type, this component is large, the circuit board must be drilled to place the component, after the completion of the drill, insert the component, then over tin furnace or spray Tin (can also be manually welded ), the cost is relatively high. newer designs use small surface SMD components that do not need to be drilled, and use steel films to pour semi-fused solder paste into the circuit board, put the SMD component on, and then weld it to the circuit board.

We mentioned earlier about part encapsulation, except for device. components in the Lib library, other library components have fixed component encapsulation, because the components in this library have multiple forms: Take the transistor as an example to describe:

Transistor is one of our commonly used components in device. in the Lib library, there is only one simple distinction between the two n3055, but in fact, if it is 2n3055, it may be the iron shell to-3, if it is 2n3054, it may be Iron Shell to-66 or to-5, and learning to use cs9013, TO-92A, TO-92B, and to-5, to-46, to-52 and so on, ever-changing. The other one is resistance. In the device library, it also simply calls them RES1 and RES2, regardless of whether it is 100 Ω or 470k Ω. For the circuit board, it is unrelated to the Ohm number. It is determined by the power Number of the resistor. The resistance of 1/4 W or even 1/2 W can be encapsulated by axial0.3, axial0.4, axial0.5, and so on. The common components are encapsulated as follows:

Resistance and non-polar double-ended element AXIAL0.3-AXIAL1.0

Stepless capacitance RAD0.1-RAD0.4

Polar capacitor rb.2/. 4-rb.5/1.0

Diode diode0.4 and diode0.7

Z crystal oscillator xtal1

Transistor, Fet, UJT to-xxx (to-3, to-5)

Variable Resistance (pot1, pot2) VR1-VR5

Of course, you can also open the c: \ client98 \ Release 98 \ library \ advpcb. Lib library to find the corresponding encapsulation of the parts used.

We recommend that you back these commonly used component packages. You can split these components into two parts, for example, resistance axial0.3 can be split into axial and 0.3, axial is translated into Chinese, and 0.3 is the distance between the Solder Pad of the Resistance on the printed circuit board, that is, Mil (because in the field of motor, it is mainly based on the imperial unit. Similarly, for non-polar capacitors, The RAD0.1-RAD0.4 is also the same; for Polarity capacitors such as electrolytic capacitors, its encapsulation is rb.2 /. 4, rb.3 /. 6. 2 "is the Pad Spacing,". 4 "is the outer diameter of the capacitor cylinder.

For a transistor, you can directly look at its shape and power. For a high-power transistor, you can use the to-3, medium-Power Transistor. If it is flat, you can use the to-220, if it is a metal shell, with to-66, small power transistor, with to-5, to-46, TO-92A and so on can be, anyway, its pin is also long, you can also bend it.

For commonly used integrated IC circuits, there are dipxx, that is, dual-row direct plug-in component encapsulation, and dip8 is double-row, each row has four pins, the distance between the two rows is mil, the distance between the pad is 100mil. Sipxx is the encapsulation of a single row. And so on.

It is worth noting that the packaging of transistors and variable resistors is the most headache. the PINs may not be the same for the same packaging. For example, for packaging such as TO-92B, usually 1 foot is E (emission pole), and 2 feet may be B (base pole), or C (collector ); similarly, the three-legged device may be C or B. Specifically, only the component can be determined. Therefore, the circuit software does not dare to hard define the pad name (PIN name). Similarly, the FET and MOS tubes can be encapsulated in the same way as the transistor, which can be used in three pin components. Q1-B, in the PCB, when loading this network table, it will not find the node (not ). Similar problems also occur in the Variable Resistance. In the schematic diagram, the variable resistance pins are 1, W, and 2, respectively, it is 1, 2, and W. In the PCB, the pad is 1, 2, and 3. When these two components exist in the circuit, the fastest way to change the difference between the PCB and Sch is to change the transistor pins to 1, 2, 3 directly in the network table after the network table is generated; change the variable resistance to 1, 2, and 3 in the same shape as the circuit board component.

Http://hi.baidu.com/79165913/blog/item/6ddaab6120844b4ceaf8f8a4.html

For the use of the encapsulation library in PCB design, the mainstream resistance encapsulation is usually available in the Library, including the rad type. If you want to design your own encapsulation library, then we can design the conversion relationship according to 1 mil = 0.001 inch, 1 inch = 54cm. Do not design the silk screen on the outer ring. Otherwise, it is easy to overlap with other silk screens.