ʻO ka pilina ma waena o ka laula o ka trace a me ka manawa i loko PCB manao

He pilikia kēia i nui ai ka poʻe i ke poʻo. Ua loaʻa iaʻu kekahi ʻike mai ka Pūnaewele a hoʻokaʻawale ʻia e like me kēia. Pono mākou e ʻike he 0.5oz (ma kahi o 18μm) ka mānoanoa o ke keleawe keleawe, 1oz (ma kahi o 35μm), 2oz (ma kahi o 70μm) keleawe, 3oz (ma kahi o 105μm) a ma luna.

1. Nā palapala pūnaewele

ʻO ka waiwai lawe ukana i helu ʻia ma ka ʻikepili papa ʻo ia ka nui o ka lawe ʻana i kēia manawa ma kahi mahana maʻamau o 25 degere. No laila, pono e noʻonoʻo ʻia nā ʻano mea like ʻole e like me nā kaiapuni like ʻole, nā kaʻina hana, nā kaʻina papa, a me ka maikaʻi o ka pā i ka hoʻolālā maoli. No laila, hāʻawi ʻia ka pākaukau ma ke ʻano he kumu kuhikuhi.

2. Hōʻike ʻia ka hiki ke lawe i kēia manawa o ka pahu keleawe o nā mānoanoa like ʻole a me ka laula ma ka papa aʻe.

‘Ōlelo Aʻo: I ka hoʻohana ʻana i ke keleawe ma ke ʻano he alakaʻi e hoʻohele i nā au nui, pono e hoʻemi ʻia ka nui o ka lawe ʻana o ka laula keleawe i kēia manawa e 50% e pili ana i ka waiwai ma ka papa no ka noʻonoʻo ʻana.

3. ʻO ka pilina ma waena o ka mānoanoa keleawe, ka laula a me kēia manawa i ka hoʻolālā PCB

Pono e ʻike i ka mea i kapa ʻia ʻo ka piʻi ʻana o ka mahana: hana ʻia ka hopena wela o kēia manawa ma hope o ke kahe ʻana o ka conductor. Ke hele nei ka manawa, hoʻomau ka piʻi ʻana o ka mahana o ka ʻili o ka conductor a hiki i ka paʻa ʻana. ʻO ke kūlana kūpaʻa ʻo ka ʻokoʻa o ka mahana ma mua a ma hope o 3 mau hola ʻaʻole i ʻoi aku ma mua o 2°C. I kēia manawa, ʻo ke ana wela o ka ʻili o ka conductor ka wela hope o ka conductor, a ʻo ka ʻāpana o ka mahana he degere (°C). ʻO ka ʻāpana o ka piʻi ʻana o ka wela i ʻoi aku ma mua o ka wela o ka ea a puni (ka wela ambient) ua kapa ʻia ka piʻi ʻana o ka mahana, a ʻo ka ʻāpana o ka piʻi ʻana o ka mahana ʻo Kelvin (K). Ma kekahi mau ʻatikala a me nā hōʻike hoʻāʻo a me nā nīnau hoʻāʻo e pili ana i ka piʻi ʻana o ka wela, ua kākau pinepine ʻia ka ʻāpana o ka piʻi ʻana o ka mahana e like me (℃), a ʻaʻole kūpono ke hoʻohana ʻana i nā degere (℃) e hōʻike i ka piʻi ʻana o ka wela.

ʻO nā mea hoʻohana maʻamau PCB he mau mea FR-4. ʻO ka ikaika adhesion a me ka mahana hana o ka pahu keleawe he kiʻekiʻe. ʻO ka maʻamau, ʻo ka mahana ʻae ʻia o ka PCB ʻo 260 ℃, akā ʻaʻole pono ka mahana PCB maoli ma mua o 150 ℃, no ka mea inā ʻoi aku ia ma mua o kēia mahana Ua kokoke loa ia i ka helu heheʻe o ka solder (183 ° C). I ka manawa like, pono e noʻonoʻo ʻia ka mahana i ʻae ʻia o nā mea ma luna o ka papa. ʻO ka mea maʻamau, hiki i nā IC kūlana kiwila ke kū i kahi kiʻekiʻe loa o 70°C, ʻo 85°C nā IC kūlana kiʻekiʻe, a hiki i nā IC kūlana koa ke kū i kahi kiʻekiʻe o 125°C. No laila, pono e hoʻomaluʻia ka mahana o ka pahu keleawe kokoke i ka IC ma ka PCB me nā IC kīwila ma kahi haʻahaʻa. ʻO nā mea mana kiʻekiʻe wale nō me ke kūpaʻa wela kiʻekiʻe (125 ℃～175 ℃) hiki ke ʻae ʻia ke kiʻekiʻe. ʻO ka mahana PCB, akā pono e noʻonoʻo ʻia ka hopena o ka mahana PCB kiʻekiʻe i ka hoʻopau ʻana o ka wela o nā mana mana.