As we all know, the continuous progress of electronic equipment and circuit technology, the peak of engineering art in the design, development and manufacture of guddiga wareegsan oo daabacan (PCB) waxaa goob joog ka ahaa dad ku kala nool daafaha dunida. Our planet is full of highly intelligent machines, automated robots and scientific marvels, and of course, there are plenty of PCBS in every corner of the planet, no matter what country or city it is. Si kastaba ha ahaatee, PCBS -yadu waxay ku kala duwan yihiin shaqaynta, kakan, qiimaha wax -soo -saarka, tayada iyo isku halaynta. Maqaalkani wuxuu diiradda saarayaa labadii qodob ee ugu dambeeyay, tayada iyo isku halaynta PCBS.

Haa, macaamiisha iman karta waxay had iyo jeer rabaan elektiroonig tayo sare leh, laakiin tani aad bay qaali u tahay waxayna ku lug yeelan kartaa hababka wax soo saarka ee adag. In habka adag ee wax soo saarka PCB, ururinta iyo imtixaanka, waxaa jira hab aad u muhiim ah loo yaqaan “daahan conformal” ee PCB. Daboolkan iswaafaqsan ayaa aad muhiim ugu ah PCBS marka la eego tayada iyo isku halaynta.

Waa maxay dahaarka waafaqsan iyo muhiimada ay leedahay:

Conforming coating, an ultra-thin protective coating of polymer film, can be used in conjunction with assemblies mounted on assembly surfaces to protect assembly leads, solder joints, exposed wiring, and other metal points on the PCB surface from corrosion, dust, or chemicals due to various operating or environmental conditions.

Dahaarka iswaafaqsan wuxuu noqon karaa mid khafiif ah 25 microns wuxuuna “waafaqsan yahay” qaabka iyo qaabeynta qeybta guddiga wareegga. Sidaan kor ku soo sheegnay, sababta loogu dabaqayo dahaar waafaqsan dusha (kor iyo hoos) PCB -ga ayaa ah in laga ilaaliyo PCB -ga xaaladaha deegaanka ee dibedda ah, sidaasna lagu kordhiyo nolosha adeegga PCB -ga iyo qalabka elektaroonigga ah ee la xiriira.

Sida heerkulka sare ee laga helo warshadaha, warshadda, iyo korontada korontada sare leh, PCBS-yadaan leh dahaarka iswaafaqsan waxay u adkeysan karaan heerkulka ba’an. Sidoo kale, qalabka elektaroonigga ah ee lagu rakibay aagagga/aagagga u dhow badda ama badweynta waxaa laga yaabaa inuu saameeyo qoyaan badan, sida qalabka maraakiibta badda ee elektiroonigga ah waxaa laga yaabaa inuu ku dhaco daxalka/nabaad -guurka taasoo horseedi karta oksaydhka birta. Similarly, in microbiology laboratories and the medical industry, sensitive electronic equipment can be exposed to toxic chemicals, acidic and alkaline solvents that can accidentally spill onto a PCB, but the PCB’s “conformation coating” will protect the PCB and components from fatal injury.

Sida loo dalbado dahaarka waafaqsan?

In fact, the method of applying “conformal paint” in the right way is so important that careful consideration must be given to how conformal paint is applied. It is as important to choose suitable conformal coating materials.

Qodobbada ugu waaweyn ee go’aaminaya adeegsiga habboon ee dahaarka iswaafaqsan waa:

1- Dhumucda rinjiga

2- The level of coverage achieved

3- The degree of adhesion of paint to wood panels and their components.

There are five methods for applying conformal coatings:

1- Gacanta ku rinji burush

2- dahaarka Aerosol

3- Atomizing spray gun coating

4- Automatic dip coating

5- Automatic selection of coating

Habka daaweynta/qallajinta dahaarka caadiga ah:

Conformal coatings themselves can be classified according to the drying and curing methods used after conformal coatings are completed. These methods are:

1- Heat/heat curing: Conformal coating is dried at high temperature. Drying rate is much faster than normal room temperature drying/curing.

2- Daaweynta Uumiga: Daaha isku habboon ee PCB-ga waxaa lagu qalajiyaa heerkulka deegaanka, qoyaanka jawigu wuxuu hoos u dhigaa habka daaweynta ama qalajinta.

3- ULTRAVIOLET (UV) curing: Here PCB with conformal coating is exposed to UV radiation. The uv energy determines the curing speed of PCB conformal coating

4- Daaweynta Oxidation-ka: Qaabkan, conformers PCB waxay la kulmaan jawi furan oo leh tiro badan oo oksijiin ah, taas oo gacan ka geysan doonta qalajinta/daawaynta conformers ku salaysan dareeraha

5- Catalytic curing: This is the process of curing conformal coating in which two materials are fused together, one of which is conformal coating. Marka dahaarka la isku daro walxaha kale ee wax kiciya, habka dawaynta lama joojin karo ilaa laga dhammaystiro.

Classification of conformal coatings:

There are five main conformal coatings used: acrylic resin, epoxy resin, silicone, polyurethane (PU) and polyparaxylene coating.

L cusbi akril (AAR):

Acrylics are ideal for (low-cost and high-volume) common electronics because AAR is inexpensive and can be easily applied to PCB surfaces by brush, dip, and manual or automatic spraying, reducing turnaround time and producing cost-effective products.

Faa’iidooyinka:

1 – qiimo jaban

2- Easy for manual or automatic robot applications

3- Easy to rework

4- Excellent moisture protection

5- Good surface elasticity, can withstand static voltage discharge, and does not react with the atmosphere, therefore helps cure through solvent evaporation

Qasaaraha:

1- Due to the use of atmospheric curing/drying methods for this material, proper ventilation systems need to be ensured

2- Dayactirka nafsaaniga oo hooseeya

3- iska caabin xirashada oo yar iyo iska caabinta kiimikada

L Epoxy conformal coating (ER) :

Xirmooyinka iswaafaqsan ee ku salaysan xabagta epoxy waxaa lagu dhammayn karaa buraashka gacanta, buufin ama dahaadhka daloolka. Xereynta waxaa lagula talinayaa mugga weyn iyo mugga yar ama tusaalaha PCBS.

Faa’iidooyinka:

1- High moisture resistance and good dielectric resistance

2- Excellent chemical resistance, abrasion resistance, moisture resistance and high temperatures up to 150 O C

Qasaaraha:

1-epoxy conformal paint is very hard and rigid and can damage PCB and its components if attempted peeling or removal. Ka saar dahaarka adiga oo isticmaalaya dareeraha halista ah

2- Waxqabadka heerkulka oo hooseeya

3- Yaraynta daawaynta oo sareysa

4- Way adag tahay in dib loo sameeyo

L cusbi silikoon (OSR) daahan waafaqsan:

The softest of the above two types of conformal coatings is silicone resin (OSR) conformal coatings. They are widely used in LED lamp PCBS without reducing light intensity or color change. Ideal for PCB installation at high humidity and exposure to air. Suitable for PCB with high operating temperature and high power

Faa’iidooyinka:

1- Iska caabin kiimiko oo wanaagsan, iska caabin qoyaan, buufin milix iyo heerkul aad u sarreeya ilaa 200 OC

2- Good flexibility makes it resistant to vibration stress on PCB from external environment.

3- Ku habboon codsiyada dibadda ee PCB oo leh qoyaan badan

Dhibka xun:

1- Ha gashan dhar adkaysi u leh guryaha caagga ah awgood

2- Dib ayaa loo shaqeyn karaa, laakiin si fudud uma baahna, oo u baahan dareerayaal khaas ah, waqtiyo qooqan dheer iyo walaaq sida burush ama qubeys ultrasonic ah

3- Low mechanical strength, weak adhesion to PCB substrate

L Polyurethane (PU) daahan isku habboon:

Ku habboon codsiyada PCB ee baabuurta, warshadaha, qalabaynta iyo isgaarsiinta. Aerospace, gaar ahaan, uumiga shidaalka ayaa si joogto ah ula kulma jirka ugu weyn ee qalabka elektarooniga ah sidaasna ku gala gudaha wuxuuna saameeyaa guddiga PCB

Faa’iidooyinka:

1- High resistance to moisture, chemicals (acid and alkali) and wear

Qasaaraha:

1- Muddo dheer oo dhammaystiran ka dib markii la daweeyey, waxay u egtahay inay huruud isu beddesho heerkulka sare iyada oo ay ugu wacan tahay maadada VOC ee sare

2- Sida silikoon, ma sahlana in gabi ahaanba meesha laga saaro

L polyparaxylene conformal coating:

This type of coating is suitable for avionics, microelectronics, sensors, high-frequency circuits, and densely populated PCB-based components. It is applied by means of vapor deposition.

Faa’iidooyinka:

1- Excellent dielectric strength

2- High resistance to moisture, solvents, extreme temperatures and acid corrosion

3- Can be applied evenly with very thin paint.

Qasaaraha:

1- Kala-furid/dib-u-shaqayntu aad bay u adag tahay

2- Qiimaha badan waa cilladda ugu weyn.