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 bolodi losindikizidwa (PCB) yawonetsedwa ndi anthu padziko lonse lapansi. 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. Komabe, ma PCBS awa amasiyana pamachitidwe, zovuta, mtengo wopanga, mtundu komanso kudalirika. Nkhaniyi ikuyang’ana kwambiri mfundo ziwiri zapitazi, mtundu ndi kudalirika kwa PCBS.

Inde, makasitomala omwe angathe kukhala nawo nthawi zonse amafuna zamagetsi apamwamba, koma izi ndiokwera mtengo kwambiri ndipo zitha kuphatikizira njira zopangira zovuta. Muzovuta kupanga kwa PCB, msonkhano ndi kuyesa, pali njira yofunikira kwambiri yotchedwa “conformal coating” ya PCB. Kuphimba kwofananaku ndikofunikira kwambiri mu PCBS potengera mtundu ndi kudalirika.

What is conformal coating and its importance:

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.

Chovala chofananira chimatha kukhala chowonda ngati ma microns a 25 ndipo “chimafanana” ndi kapangidwe kake ndi kapangidwe kake ka board. Monga tafotokozera pamwambapa, chifukwa chogwiritsira ntchito zokutira pamwamba (pamwamba ndi pansi) za PCB ndikuteteza PCB ku zovuta zakunja, potero ndikuwonjezera moyo wa PCB ndi zida zamagetsi zogwirizana nazo.

Monga kutentha kwakukulu komwe kumapezeka m’mafakitale, m’mafakitale, ndi zamagetsi zamagetsi, ma PCBS awa okhala ndi zokutira mofananira amatha kupirira kutentha kwakukulu. Mofananamo, zida zamagetsi zomwe zimayikidwa m’malo / madera oyandikira nyanja kapena nyanja zitha kukhudzidwa ndi chinyezi chambiri, monga kuyendetsa zida zamagetsi zamagetsi zitha kukhala ndi dzimbiri / kukokoloka komwe kumatha kuyambitsa makutidwe azitsulo. 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.

Momwe mungagwiritsire ntchito zokutira zofananira?

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.

Zinthu zazikuluzikulu zomwe zimatsimikizira kugwiritsidwa ntchito koyenera kwa zokutira ndi:

1- Makulidwe a utoto

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- Jambulani pamanja ndi burashi

2- Kuphimba kwa aerosol

3- Atomizing spray gun coating

4- Automatic dip coating

5- Automatic selection of coating

Njira yodziwikiratu yochiritsa / kuyanika:

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- Kutsekemera kwamadzimadzi: Kuphika kofanana kwa PCB kumawuma kutentha kozungulira, chinyezi mumlengalenga chimachepetsa kuchiritsa kapena kuyanika.

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- Kuchiritsa makutidwe ndi okosijeni: Mwa njirayi, opanga ma PCB amakumana ndi malo ampweya wokhala ndi mpweya wambiri wamlengalenga, womwe ungathandize pakuumitsa / kuchiritsa kwama conformers ofikira zosungunulira

5- Catalytic curing: This is the process of curing conformal coating in which two materials are fused together, one of which is conformal coating. Chovalacho chikangosakanikirana ndi zida zina zothandizira, njira yakuchiritsa siyimitsidwa mpaka itatha.

Classification of conformal coatings:

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

L akiliriki utomoni (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.

ubwino:

1 – mtengo wotsika

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

kuipa:

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

2- Kukonza mamasukidwe akayendedwe

3- Kutsika kochepa komanso kukana mankhwala

L Epoxy conformal coating (ER) :

Conformal coatings based on epoxy resins can be completed by hand brush, spray or dip coating. Kupopera kumalimbikitsidwa pamitundu yayikulu komanso pamitundu yaying’ono kapena PCBS.

ubwino:

1- High moisture resistance and good dielectric resistance

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

kuipa:

1-epoxy conformal paint is very hard and rigid and can damage PCB and its components if attempted peeling or removal. Chotsani chovalacho pogwiritsa ntchito zosungunulira zoopsa

2- Kutentha kochepa

3- Kutsitsa kochepera

4- Ndizovuta kuyambiranso

L silikoni utomoni (OSR) conformal coating kuyanika:

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

ubwino:

1- Kukana kwamankhwala, kukaniza chinyezi, kutsitsi mchere komanso kutentha mpaka 200 OC

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

3- Oyenera PCB panja ntchito ndi chinyezi mkulu

Zoipa:

1- Osati kuvala kugonjetsedwa chifukwa cha katundu wa mphira

2- Itha kugwiritsidwanso ntchito, koma osati mosavuta, yofuna zosungunulira zapadera, nthawi yayitali yozungulirazungulira ndikuyambitsa ngati burashi kapena kusamba kopanga

3- Low mechanical strength, weak adhesion to PCB substrate

L Polyurethane (PU) yokutira koyenera:

Oyenera ntchito PCB mu magalimoto, mafakitale, zipangizo ndi kutumiza mauthenga. Mlengalenga, makamaka, nthunzi zamafuta zimawombana nthawi zonse ndi zida zazikulu zamagetsi motero zimalowa mkatikati ndikukhudza bolodi la PCB

ubwino:

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

kuipa:

1- Pakatha nthawi yayitali akuchiritsa, imayamba kusanduka chikasu kutentha kwambiri chifukwa cha kuchuluka kwa VOC

2- Monga silicon, sikophweka kuchotsa kwathunthu

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.

ubwino:

1- Excellent dielectric strength

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

3- Can be applied evenly with very thin paint.

kuipa:

1- Disassembly/rework is very difficult

2- High cost is the biggest drawback.