A PCB or tejede Circuit ọkọ n ṣe ooru nigbati ina mọnamọna n ṣàn nipasẹ rẹ. Laisi idabobo to dara, ooru yii le fa awọn iṣoro to ṣe pataki fun PCBS.

Kini idi ti PCBS nilo idabobo?

Ṣaaju ki o to ni oye idabobo PCB, o gbọdọ loye: Kini PCB?

PCBS, or printed circuit boards, are small green squares with copper sheets (but also in other colors). It can be found in almost any electronic device! Awọn igbimọ Circuit ti a tẹjade jẹ ki awọn ẹrọ itanna ṣiṣẹ ni deede, ṣiṣe wọn di apakan pataki ṣugbọn alaihan ti igbesi aye ojoojumọ. Laisi wọn, awọn kọnputa, tẹlifoonu, tẹlifisiọnu ati ẹrọ itanna kii yoo ṣiṣẹ tabi wa.

Itanna jẹ alagbara pupọ fun PCB. PCBS contain printed copper wires, so they naturally conduct electricity. Bibẹẹkọ, awọn paati itanna le ṣe eewu ti wọn ko ba wa ni titiipa ninu ile ti ko ṣe tabi di gbigbona pupọ. PCB gbọdọ wa ni sọtọ lati ṣe idiwọ ibajẹ epo ati dinku olubasọrọ lairotẹlẹ pẹlu awọn ohun elo ifọnọhan. Proper insulation can help prevent the PCB from overheating or exploding.

There are several ways to isolate a PCB. There are several common insulation materials, but the exact type of insulation usually depends on the application of the PCB design.

Photo source: pixabay

PCB insulating ohun elo

Awọn ohun elo idabobo PCB ti o wọpọ jẹ igbagbogbo bi awọn sobusitireti ti kii ṣe adaṣe ti o le dapọ papọ ni awọn fẹlẹfẹlẹ pupọ lati gba lọwọlọwọ laaye lati ṣàn daradara nipasẹ gbogbo igbimọ Circuit. PCBS ti o rọrun le jẹ apa kan tabi fẹlẹfẹlẹ kan. Complex PCBS, such as those used for high-speed digital communications, may contain more than two dozen layers.

PCB insulation calculator can help you determine creepage distance and electrical clearance, which will be the determining factor in the exact type and quantity of insulation material. Ijinna jijin jẹ aaye to kuru ju laarin awọn ẹya idari, ati imukuro jẹ ipin ti a yapa nipasẹ afẹfẹ dipo sobusitireti. Agbọye ijinna nrakò ati imukuro itanna jẹ pataki fun iṣiro iṣiro idabobo PCB.

Awọn aṣelọpọ PCB le yan lati lo ọpọlọpọ awọn oriṣiriṣi awọn ohun elo fun idabobo, lati awọn pilasitik ti ko gbowolori bi FR-2 si awọn irin ti ko ni iru bi aluminiomu. The insulating material of a PCB usually determines its use. Fun apẹẹrẹ, PCB ninu nkan isere itanna ti a ṣe ni ẹdinwo kii yoo nilo iru idabobo kanna bi PCB ninu satẹlaiti kan.

Lati ni oye daradara idabobo PCB ati awọn ohun elo idabobo, jẹ ki a ṣawari awọn ọna marun ti o wọpọ julọ ti idabobo PCB.

FR-2

Fr-2 jẹ aṣayan laminate ina kekere ti o ni ina. It is made from a composite of paper and plasticized phenolic resin, making it light and durable. Awọn igbimọ Circuit apa kan nigbagbogbo lo ohun elo yii. FR-2 jẹ halogen-ọfẹ ati hydrophobic ati pe o le ni rọọrun tẹ tabi milled. FR-2 jẹ ọkan ninu awọn aṣayan ti o gbowolori fun idabobo PCB ati pe o jẹ yiyan ti o wọpọ fun awọn ile-iṣẹ ṣiṣe ẹrọ itanna eleto isọnu.

FR-4

Fr-4 jẹ aṣayan laminate ina ti o ni ilọsiwaju ina. O jẹ ohun elo idapọmọra ti a ṣe ti fiberglass hun fabric ati pe o jẹ igbagbogbo lo ninu iṣelọpọ ti PCBS ni ilopo-meji ati ti ọpọlọpọ. FR-4 le farada awọn iwọn otutu ti o ga ati awọn igara ti ara ju FR-2. O tun jẹ ohun elo ti ifarada, ti o jẹ ki o jẹ yiyan ti o gbajumọ fun awọn aṣelọpọ ti itanna eleto giga. FR-4 kii ṣe ẹrọ ni iyara, to nilo milling, stamping tabi awọn irinṣẹ carbide tungsten ẹrọ.

Igbohunsafẹfẹ redio (rf)

Awọn sobusitireti RF jẹ apẹrẹ lati gba PCBS laaye lati ṣiṣẹ ninu awọn ohun elo nipa lilo RF giga ati makirowefu. Awọn sobusitireti RF jẹ igbagbogbo lo fun PCBS ti a fi sii ninu ẹrọ itanna ologun, avionics ati avionics. O ṣe pataki lati ṣe akiyesi, sibẹsibẹ, pe diẹ ninu awọn ọja itanna eleto ni iru iru sobusitireti. Awọn pilasitik ti o jẹ sobusitireti RF aṣoju ko ṣe agbejade idabobo pupọ ati ṣiṣẹ daradara fun iṣẹ ṣiṣe ti npese awọn ṣiṣan nla. RFBS ati makirowefu PCBS nigbagbogbo ni ọkan tabi meji fẹlẹfẹlẹ.

rọ

Botilẹjẹpe ọpọlọpọ awọn igbimọ Circuit ti a tẹjade jẹ alapin ati lile, diẹ ninu awọn PCBS imotuntun wa ti o le tẹ ni fere eyikeyi itọsọna laisi fifọ. Awọn iyika rirọ nilo iru kan ṣugbọn fọọmu alailẹgbẹ ti idabobo. Awọn iyika rirọ ni igbagbogbo ni aabo pẹlu A SPRAY ti idabobo PCB, ni afikun si fiimu ṣiṣu jẹ yiyan ti o gbajumọ. Awọn iyipo rirọ nilo tinrin, ti a bo ti idabobo PCB ti o lagbara ki wọn le gbe larọwọto ati baamu ni Awọn aaye to muna.

irin

Yiyan irin bi insulator le dabi ajeji. Awọn irin jẹ deede adaṣe ina mọnamọna, ati adaṣe lairotẹlẹ le fa ki PCB kan kuna, mu ina tabi yo. However, in some cases, a PCB with a metal substrate may be more advantageous. Irin jẹ adaṣe ti o dara julọ ti ooru ati pe o le koju awọn ṣiṣan nla laisi fifọ tabi sisun. PCBS ti a fi sii ninu ẹrọ itanna ti o gba agbara ti o jẹ agbara pupọ le nilo awọn sobusitireti irin lati ṣiṣẹ daradara.

Ipa ile -iṣẹ

Lati ṣe idiwọ PCB lati igbona pupọ, mimu ina, tabi mimu ina, o gbọdọ jẹ isunmọ to. The type of insulation corresponds to the type of use provided by the PCB.

PCBS itanna eleto-gbogbogbo jẹ o dara fun lilo pẹlu irọrun ati iye owo-doko FR-2 tabi awọn sobusitireti FR-4. Awọn sobusitireti RF dara julọ fun awọn ohun elo ti o kan RF agbara giga.

Awọn sobusitireti ti o rọ gẹgẹbi awọn pilasitik dara fun lati pade awọn ibeere idabobo ti awọn igbimọ Circuit ti o rọ. Awọn irin, ni apa keji, jẹ awọn oludari ti o dara julọ ti ooru lakoko ti o tọju awọn elekitironi agbara.