For the vast majority of electronic components, they have polarity, or the pins can not be soldered wrong. For example, once the electrolytic capacitor is welded reversely, it will explode when energized. Generally speaking, when using automatic feeding machinery to assemble circuit board components, there will be no problem of misplacing components. However, due to the limitations of manufacturers and the characteristics of components, not all components can be automatically pasted or inserted. Common manual placement is required for various surface mounted transformers, connectors, to encapsulated integrated circuits, etc. These devices may still have the problem of assembly error. Generally, the repair is carried out manually, and this link is also prone to the problem of reverse welding. Therefore, it is necessary to explain the positioning method of components and the corresponding relationship between component pads and silk screen printing on the circuit board.

1. Kapasitansi
Kanggo kapasitor elektrolitik sing dipasang ing aluminium liwat bolongan sing ditampilake ing gambar ing ngisor iki, kutub positif lan negatif umume diwakili dening sikil dawa lan cendhak lan tandha ing awak. Sikil dawa positif lan sikil cendhak negatif. Umumé, ana loreng putih utawa liyane podo karo pin ing Nihan sisih negatif.
Kapasitor elektrolitik ing papan sirkuit umume ditandhani kanthi polaritas kaya sing ditampilake ing gambar kasebut.
One method is to mark a “+” sign directly on the positive side. The advantage of this method is that it is convenient to check the polarity after welding. The disadvantage is that it occupies a large area of the circuit board. The second method is to fill the area where the negative electrode is located with silk screen. This polarity representation occupies a small area of the circuit board, but it is inconvenient to check the polarity after welding. It is common in occasions with high density of circuit board devices such as computer motherboard.
Tantalum capacitors installed through holes are generally marked with “+” on the body on the positive side, and some varieties are further distinguished by long and short feet.
Cara menehi tandha ing papan sirkuit kapasitor iki bisa ngarujuk marang kapasitor elektrolitik aluminium.
Kanggo lumahing dipasang aluminium kapasitor elektrolitik. Sisih sing dilapisi karo tinta yaiku kutub negatif, lan dasar ing sisih kutub positif umume chamfered.
Ing Papan Sirkuit Cetak, iku umume ditampilake ing tokoh ndhuwur
That is to use silk screen “+” on the circuit board to represent the positive pole, and draw the outline of the device at the same time. In this way, the chamfered side can also be used to identify the positive electrode.

Kapasitor tantalum ikatan permukaan

2. Dioda
Kanggo dioda pemancar cahya, pin dawa lan cendhak umume digunakake kanggo makili kutub positif lan negatif. Pin dawa positif lan pin cendhak negatif. Kadhangkala pabrikan bakal ngethok sethithik ing sisih siji LED, sing uga bisa digunakake kanggo makili elektroda negatif.

Layar sutra “+” umume digunakake ing papan sirkuit kanggo nunjukake elektroda positif.
For ordinary diodes

Ing gambar ing ndhuwur, sisih kiwa minangka kutub negatif lan sisih tengen minangka kutub positif, yaiku, sablon sutra utawa kaca patri digunakake kanggo makili polaritas positif lan negatif. Rong cara ing ngisor iki umume digunakake kanggo makili kutub positif lan negatif ing papan sirkuit.

Polaritas dioda dituduhake dening layar sutra ing papan sirkuit. Iki luwih cetha. Sing liyane yaiku nggambar simbol skematis dioda langsung ing layar sutra papan sirkuit cetak.
Perwakilan polaritas saka LED sing dipasang ing permukaan banget mbingungake. Kadhangkala ana macem-macem perwakilan ing antarane macem-macem jinis paket ing pabrikan. Nanging, umume nglukis bintik-bintik warna utawa jalur warna ing sisih katoda dioda pemancar cahya. Ana uga sudhut sing dipotong ing sisih katoda.
The polarity of the diode is indicated by the silk screen on the circuit board. This is more vivid. The other is to draw the schematic symbols of diodes directly on the silk screen printed circuit board.
Perwakilan polaritas saka LED sing dipasang ing permukaan banget mbingungake. Kadhangkala ana macem-macem perwakilan ing antarane macem-macem jinis paket ing pabrikan. Nanging, umume nglukis bintik-bintik warna utawa jalur warna ing sisih katoda dioda pemancar cahya. Ana uga sudhut sing dipotong ing sisih katoda.

Dioda dipasang ing permukaan biasa uga nggunakake percetakan layar sutra utawa kaca patri ing awak kanggo makili elektroda negatif.

Sirkuit terpadu
For dip and so packaged integrated circuits with pins distributed on both sides, the upper semicircular notch is generally used to indicate that this direction is above the chip, and the first pin on the upper left is the first pin of the chip. It is also indicated by a horizontal line on the top with silk screen printing or laser.

In addition, there are also silk screen dots directly on the body next to the first pin of the chip or pressing a pit directly during injection molding.
Sawetara sirkuit terpadu uga dituduhake kanthi nglereni pinggiran beveled ing awak pinggir wiwitan pin pisanan.

Simbol-simbol sirkuit terpadu iki ing papan sirkuit umume ditandhani karo celah ing sisih ndhuwur.
For QFP, PLCC and BGA in tetragonal package.
QFP rangkep sirkuit terpadu umume nggunakake titik cekung, titik layar sutra, utawa printing layar sutra miturut model kanggo ngadili arah ing awak cocog kanggo pin pisanan. Sawetara nggunakake cara nglereni sudut kanggo makili sikil pisanan. Ing wektu iki, arah counterclockwise yaiku sikil pisanan. Sampeyan kudu nyatet sing kadhangkala ana telung ngadu ing chip, supaya sudhut tanpa pit cocog karo sisih tengen ngisor chip.

Amarga awak paket PLCC relatif gedhe, iku umume dituduhake dening ngadu langsung ing awal pin pisanan. Sawetara uga ngethok sudhut ing sisih kiwa ndhuwur chip.

obyek paket BGA
packaging BGA ora mung nggunakake foil tembaga dilapisi emas ing sudhut kiwa ngisor makili pin pisanan, nanging uga nggunakake cara ilang sudhut, ngadu lan titik layar sutra kanggo makili arah pin pisanan.
Grafis ing papan sirkuit sing cocog yaiku kaya ing ngisor iki
Sikil pisanan diobati nganggo titik layar sutra lan sudhut sing ilang.

4. other devices

Ing obyek nyata, konektor umume ngontrol arah kanthi posisi kedudukan. Ana uga sing nulis 1 cedhak sikil pisanan utawa nggunakake segitiga kanggo makili sikil pisanan. Umumé, piranti liyane ngindhari sisipan sing salah kanthi nggambar layar sutra sing konsisten karo obyek nyata ing papan sirkuit cetak.
Kanggo mbusak resistance saka instalasi liwat-bolongan, iku umume ditulis dening mbungkus mburi umum karo layar sutra ing Papan sirkuit. Utawa nulis 1 cedhak sikil pisanan.
Supaya standar syarat pad, printing layar sutra lan resistance welding komponen ing Papan sirkuit, organisasi IPC wis ditanggepi loro standar related: ipc-7351 lan ipc-sm-840. Nanging, ing panggunaan nyata, simbol tandha arah piranti sing digawe kanthi cara perwakilan arah piranti sing ditetepake dening IPC asring diblokir dening awak piranti sawise welding, sing ora cocok kanggo inspeksi. Desain grafis pad komponen kudu diatur miturut kahanan sing nyata.
Singkatipun, ing obyek nyata, piranti diskrèt umume nggunakake cara sikil dawa lan cendhak, printing layar sutra utawa pewarnaan kanggo makili polaritas. Kanggo sirkuit terpadu, titik cekung, printing layar sutra, notches, sudhut ilang, pinggiran ilang utawa indikasi langsung asring digunakake kanggo tandha pin pisanan. Nalika nggawe grafis pad, umume nggambar miturut wangun piranti sabisa, lan nggambarake informasi sing gegandhengan karo posisi ing wangun piranti ing wangun layar sutra okehe, supaya minangka supaya kasalahan ing Déwan manual lan welding.