Nyocha zuru ezu nke SMT patch na TTHT site na oghere nkwụnye PCBA atọ mgbochi agba mkpuchi usoro na isi teknụzụ!
Dị ka size nke PCBA components na-aghọ nta na nta, njupụta na-adị elu na elu;Ogologo nkwado dị n'etiti ngwaọrụ na ngwaọrụ (ọpụpụ dị n'etiti PCB na nkwụsị ala) na-adịwanye ntakịrị na mmetụta nke ihe gburugburu ebe obibi na PCBA na-abawanye.Ya mere, anyị na-etinye n'ihu elu chọrọ na ntụkwasị obi nke PCBA nke electronic ngwaahịa.
1.Environmental ihe na mmetụta ha
Ihe gburugburu ebe obibi nkịtị dị ka iru mmiri, uzuzu, ịgba nnu, ebu, wdg, nwere ike ịkpata nsogbu ọdịda dị iche iche nke PCBA
iru mmiri
Ihe fọrọ nke nta ka ọ bụrụ ihe niile PCB eletrọnịkị na mpaghara mpụga nọ n'ihe ize ndụ nke corrosion, n'ime nke mmiri bụ ihe kachasị mkpa maka corrosion.Mkpụrụ ndụ mmiri dị ntakịrị iji banye n'ime oghere molekul ntupu nke ụfọdụ ihe polymer wee banye n'ime ime ma ọ bụ rute n'okpuru ígwè site na pinhole nke mkpuchi iji mee ka corrosion.Mgbe ikuku ruru ụfọdụ iru mmiri, ọ nwere ike ime ka PCB electrochemical mgagharị, ntapu ugbu a na mgbagha mgbaama na sekit ugboro dị elu.
Uzuoku / iru mmiri + ionic contaminants (nnu, flux activation agents) = conductive electrolytes + stress voltaji = Mbugharị electrochemical
Mgbe RH dị na mbara igwe ruru 80%, a ga-enwe ihe nkiri mmiri nke nwere ọkpụrụkpụ nke 5 ~ 20 molecules, na ụdị mkpụrụ ndụ niile nwere ike ịkwaga n'efu.Mgbe carbon dị, mmeghachi omume electrochemical nwere ike ime.
Mgbe RH ruru 60%, elu oyi akwa nke akụrụngwa ga-etolite 2 ~ 4 mmiri molekul oké mmiri film, mgbe e nwere pollutants igbari na, a ga-enwe chemical Jeremaya mere;
Mgbe RH <20% nọ n'ikuku, ihe fọrọ nke nta ka ọ bụrụ ihe niile corrosion na-akwụsị.
Ya mere, mgbochi mmiri bụ akụkụ dị mkpa nke nchebe ngwaahịa.
Maka ngwaọrụ eletrọnịkị, mmiri na-abịa n'ụdị atọ: mmiri ozuzo, condensation na vapor mmiri.Mmiri bụ electrolyte na-agbaze nnukwu ion na-emebi emebi na-emebi ọla.Mgbe okpomọkụ nke akụkụ ụfọdụ nke akụrụngwa dị n'okpuru "igirigi" (okpomọkụ), a ga-enwe condensation n'elu: akụkụ nhazi ma ọ bụ PCBA.
Uzuzu
E nwere uzuzu na ikuku, uzuzu adsorbed ion pollutants na-adaba n'ime ime ngwá electronic na-akpata ọdịda.Nke a bụ nsogbu a na-ahụkarị na ọdịda eletrọnịkị n'ọhịa.
A na-ekewa uzuzu ụzọ abụọ: uzuzu uzuzu bụ dayameta nke 2.5 ~ 15 microns nke ihe ndị na-adịghị mma, n'ozuzu agaghị eme ka mmejọ, arc na nsogbu ndị ọzọ, ma na-emetụta kọntaktị njikọ;Uzuzu dị mma bụ ụmụ irighiri ihe na-adịghị mma nke nwere dayameta na-erughị 2.5 microns.Uzuzu dị mma nwere ụfọdụ nrapado na PCBA (veneer), nke enwere ike wepu ya naanị site na ahịhịa mgbochi static.
Ihe ize ndụ nke uzuzu: a.N'ihi uzuzu na-edozi n'elu PCBA, a na-emepụta corrosion electrochemical, na ọnụ ọgụgụ ọdịda na-abawanye;b.Uzuzu uzuzu + iru mmiri + ikuku nnu kpatara mmebi PCBA kachasị, na ọdịda akụrụngwa elektrọnik bụ nke kachasị na ụlọ ọrụ kemịkalụ na mpaghara Ngwuputa dị nso n'ụsọ osimiri, ọzara (ala saline-alkali) na ndịda nke Osimiri Huaihe n'oge mildew na oge mmiri ozuzo.
Ya mere, nchedo uzuzu bụ akụkụ dị mkpa nke ngwaahịa ahụ.
Mgbasa nnu
Nhazi nke nnu nnu:A na-ebute ịgba nnu n'ihi ihe ndị sitere n'okike dị ka ebili mmiri nke oke osimiri, ebili mmiri, ikuku ikuku (ụnwụ) nrụgide, anwụ na ihe ndị ọzọ.Ọ ga-eji ifufe fegharịa n'ime ala, na itinye uche ya ga-ebelata site n'ebe dị anya site n'ụsọ oké osimiri.Ọtụtụ mgbe, ntinye nke nnu nnu bụ 1% nke ụsọ oké osimiri mgbe ọ dị 1Km site n'ụsọ oké osimiri (mana ọ ga-afụ n'ihu n'oge typhoon).
Imerụ nnu nnu:a.mebie mkpuchi nke akụkụ nhazi ígwè;b.Osooso nke electrochemical corrosion ọsọ na-eduga mgbaji nke metal wires na ọdịda nke components.
Isi mmalite nke corrosion yiri ya:a.Ọsụsọ aka nwere nnu, urea, lactic acid na kemịkalụ ndị ọzọ, nke nwere otu mmetụta na-emebi emebi na akụrụngwa eletrọnịkị dị ka ịgbasa nnu.Ya mere, a ga-eyi uwe aka n'oge mgbakọ ma ọ bụ eji ya eme ihe, na mkpuchi ekwesịghị iji aka efu metụ ya;b.Enwere halogens na acids na ntugharị ahụ, nke a ga-ehicha ma na-achịkwa itinye uche ha fọdụrụnụ.
Ya mere, mgbochi nnu nnu bụ akụkụ dị mkpa nke nchebe ngwaahịa.
Akpụkpọ anụ
Mildew, aha a na-akpọkarị fungi filamentous, pụtara " fungi na-akpụ akpụ," na-etolite mycelium mara mma, mana anaghị amịpụta nnukwu mkpụrụ dị ka olu.N'ebe mmiri na-ekpo ọkụ na-ekpo ọkụ, ọtụtụ ihe na-eto n'anya gba ọtọ ụfọdụ n'ime obodo ndị na-enweghị isi, ndị na-efegharị efegharị ma ọ bụ ndị na-eme ihe n'ụra, ya bụ ebu.
FIG.5: PCB mildew onu
Mmebi nke ebu: a.ebu phagocytosis na mgbasa na-eme ka mkpuchi nke ihe ndị dị ndụ na-adaba, mmebi na ọdịda;b.Metabolites nke ebu bụ organic acids, nke na-emetụta mkpuchi na ike eletriki ma na-emepụta arc eletrik.
Ya mere, mgbochi ebu bụ akụkụ dị mkpa nke ngwaahịa nchebe.
N'iburu n'uche akụkụ ndị dị n'elu, a ghaghị ijide n'aka na ntụkwasị obi nke ngwaahịa ahụ dị mma, ọ ghaghị ịdịpụrụ adịpụ site na gburugburu ebe dịpụrụ adịpụ dị ka o kwere mee, ya mere a na-ebute usoro mkpuchi ọdịdị ahụ.
Mkpuchi PCB mgbe usoro mkpuchi, n'okpuru mmetụta agbapụ ọkụ na-acha odo odo, mkpuchi mbụ nwere ike mara mma nke ukwuu!
Atọ mgbochi agba mkpuchina-ezo aka ikpuchi oyi akwa mkpuchi mkpuchi n'elu PCB.Ọ bụ usoro mkpuchi ịgbado ọkụ a na-ejikarị eme ihe ugbu a, mgbe ụfọdụ a na-akpọ mkpuchi elu na mkpuchi conformal (aha bekee: mkpuchi, mkpuchi conformal).Ọ ga-ekewapụ ihe elektrọnik nwere mmetụta na gburugburu ebe ọjọọ, nwere ike melite nchekwa na ntụkwasị obi nke ngwaahịa eletrọnịkị yana ịgbatị ndụ ngwaahịa.Ihe mkpuchi mgbochi atọ nwere ike ichebe sekit / ihe ndị dị na gburugburu ebe obibi dị ka mmiri, ihe ndị na-emetọ ihe, corrosion, nchekasị, ujo, vibration mechanical na thermal okirikiri, na-emeziwanye ike ígwè na mkpuchi mkpuchi nke ngwaahịa ahụ.
Mgbe mkpuchi usoro nke PCB, na-etolite a transperent nchebe film n'elu, nwere ike n'ụzọ dị irè gbochie mmiri na mmiri intrusion, zere ntapu na obere sekit.
2. Isi ihe nke usoro mkpuchi
Dị ka ihe achọrọ nke IPC-A-610E(Electronic Assembly Testing Standard), a na-egosipụta ya na akụkụ ndị a:
Mpaghara
1. Ebe enweghị ike mkpuchi:
Mpaghara chọrọ njikọ eletriki, dị ka paịlị ọla edo, mkpịsị aka ọla edo, ọla site na oghere, oghere ule;
Batrị na ihe ndozi batrị;
Njikọ;
Fuse na casing;
Ngwa ikposa ọkụ;
waya jumper;
The oghere nke ngwa anya ngwaọrụ;
Potentiometer;
Ihe mmetụta;
Enweghị mgba ọkụ emechiri emechi;
Ebe ndị ọzọ mkpuchi nwere ike imetụta arụmọrụ ma ọ bụ ọrụ.
2. Ebe a ga-ekpuchiri: niile solder nkwonkwo, atụdo, components na conductors.
3. Nhọrọ ebe
Ọkpụrụkpụ
A na-atụle ịdị arọ n'elu ihe dị larịị, nke na-enweghị ihe mgbochi, nke a gwọchara nke akụkụ sekit a na-ebipụta ma ọ bụ na efere agbakwunyere nke na-eme usoro ahụ na mpaghara ahụ.Mpempe akwụkwọ agbakwunyere nwere ike ịbụ otu ihe dị ka bọọdụ ebipụtara ma ọ bụ ihe ndị ọzọ na-adịghị agbapụta, dị ka igwe ma ọ bụ iko.Enwere ike iji nha nha ihe nkiri mmiri mmiri dị ka usoro nhọrọ mkpuchi nha nha nha, ọ bụrụhaala na enwere mmekọrịta ngbanwe edeputara n'etiti ọkpụrụkpụ ihe nkiri mmiri na kpọrọ nkụ.
Tebụl 1: ọkọlọtọ oke nha maka ụdị ihe mkpuchi ọ bụla
Usoro nnwale nke ọkpụrụkpụ:
1. Ngwá ọrụ nha nha ihe nkiri akọrọ: micrometer (IPC-CC-830B);b ihe nlere ọkpụrụkpụ ihe nkiri kpọrọ nkụ (isi igwe)
Ọgụgụ 9. Micrometer akọrọ ihe nkiri ngwa
2. Wet film ọkpụrụkpụ nha: ọkpụrụkpụ nke mmiri film nwere ike nweta site mmiri film ọkpụrụkpụ mmesho ngwá, na mgbe ahụ gbakọọ site nkezi nke gluu siri ike ọdịnaya.
Ọkpụrụkpụ nke ihe nkiri akọrọ
Na FIG.10, a na-enweta ọkpụrụkpụ ihe nkiri mmiri mmiri site na onye na-enyocha ihe nkiri mmiri mmiri, wee gbakọọ ọkpụrụkpụ ihe nkiri akọrọ.
Mkpebi ihu
Nkọwa: N'okpuru ọnọdụ nkịtị, ịgbasa valvụ ịgbasa n'akụkụ eriri ahịrị agaghị adị ogologo, a ga-enwe ụfọdụ burr.Anyị na-akọwa obosara nke burr dị ka mkpebi ihu.Dị ka egosiri n'okpuru, nha d bụ uru nke mkpebi ihu.
Rịba ama: Mkpebi ihu bụ n'ezie nke nta ka ọ dị mma, mana ihe dị iche iche ndị ahịa chọrọ abụghị otu, ya mere mkpebi nke mkpuchi mkpuchi kpọmkwem ma ọ bụrụhaala na ọ ga-egbo mkpa ndị ahịa.
Ọgụgụ 11: Ntụle mkpebi ihu
Ịdị n'otu
Glue kwesịrị ịdị ka akwa akwa na ihe nkiri dị nro na nke transperent kpuchie na ngwaahịa ahụ, a na-ekwusi ike na ịdị n'otu nke gluu kpuchie na ngwaahịa dị n'elu ebe ahụ, mgbe ahụ, ọ ghaghị ịbụ otu ọkpụrụkpụ ahụ, ọ dịghị nsogbu usoro: cracks, stratification, ahịrị oroma, mmetọ, capillary phenomenon, egosipụta.
Onyonyo 12: Axial akpaka AC usoro akpaka mkpuchi igwe mkpuchi mmetụta, uniformity dị nnọọ agbanwe agbanwe
3. Nghọta nke usoro mkpuchi
Usoro mkpuchi
1 Kwadebe
Kwadebe ngwaahịa na gluu na ihe ndị ọzọ dị mkpa;
Kpebie ebe nchekwa mpaghara;
Kpebie nkọwa usoro igodo
2: saa
Kwesịrị kpochara na obere oge mgbe ịgbado ọkụ, iji gbochie ịgbado ọkụ unyi siri ike ọcha;
Kpebisie ike ma isi ihe na-emetọ ya bụ pola, ma ọ bụ na-abụghị polar, ka ịhọrọ onye na-ehicha ihe kwesịrị ekwesị;
Ọ bụrụ na a na-eji ihe na-ehicha mmanya na-aba n'anya eme ihe, a ghaghị ilebara ihe nchebe anya: a ghaghị inwe ezigbo ventilashion na oyi na ihicha usoro iwu mgbe ịsachara, iji gbochie nkwụsịtụ ihe mgbaze nke ihe mgbaze na-akpata site na mgbawa na oven;
Mmiri na-ehicha mmiri, na mmiri mmiri na-ehicha alkaline (emulsion) iji sachaa mmiri ahụ, wee kpochaa ya na mmiri dị ọcha iji kpochapụ mmiri mmiri na-ehicha ihe, izute ụkpụrụ nhicha;
3. Nkpuchi mkpuchi (ma ọ bụrụ na ọ dịghị ngwá ọrụ mkpuchi nhọrọ), ya bụ, nkpuchi;
Kwesịrị ịhọrọ ihe nkiri na-adịghị mma agaghị ebufe teepu akwụkwọ;
Ekwesịrị iji teepu akwụkwọ mgbochi static mee ihe maka nchekwa IC;
Dị ka ihe ndị a chọrọ maka eserese maka ụfọdụ ngwaọrụ iji chebe nchebe;
4. Wepu mmiri
Mgbe ihichachara, PCBA (mpaghara) nke echedoro ga-ebu ụzọ kpoo ma mee ka ọ ghara ikpochapụ tupu mkpuchi;
Kpebisie ike na ọnọdụ okpomọkụ/oge tupu ihicha dị ka okpomọkụ nke PCBA (akụkụ akụkụ);
Enwere ike ịhapụ PCBA (mpaghara) iji chọpụta ọnọdụ okpomọkụ/oge tebụl tupu ihicha
5 Uwe
Usoro mkpuchi udi dabere na ihe nchekwa PCBA chọrọ, akụrụngwa usoro dị ugbu a yana nchekwa teknụzụ dị adị, nke a na-enwetakarị n'ụzọ ndị a:
a.Jiri aka na-asa ahịhịa
Ọgụgụ 13: Usoro ịsa aka
Ihe mkpuchi ahịhịa bụ usoro a na-ejikarị eme ihe, kwesịrị ekwesị maka mmepụta obere ogbe, ihe owuwu PCBA dị mgbagwoju anya na oke, ọ dị mkpa iji chebe ihe nchebe nke ngwaahịa siri ike.N'ihi na mkpuchi mkpuchi nwere ike ịchịkwa n'efu, nke mere na akụkụ ndị na-adịghị ekwe ka agba ghara imetọ;
Ihe mkpuchi ahịhịa na-eri ihe kacha nta, dabara maka ọnụ ahịa dị elu nke agba agba abụọ;
Usoro eserese nwere ihe dị elu chọrọ na onye ọrụ.Tupu e wuo ya, a ga-eji nlezianya gbarie ihe osise na mkpuchi ihe, a ga-amata aha PCBA components, na akụkụ ndị a na-agaghị ekwe ka a na-ekpuchi ya kwesịrị ka ejiri akara anya;
A naghị ekwe ka ndị na-arụ ọrụ jiri aka ha metụ nkwụnye e biri ebi aka n'oge ọ bụla iji zere mmetọ;
b.Tinye aka
Ọgụgụ 14: Usoro mkpuchi itinye aka
Usoro mkpuchi dip na-enye nsonaazụ mkpuchi kachasị mma.Enwere ike itinye akwa akwa, mkpuchi na-aga n'ihu n'akụkụ ọ bụla nke PCBA.Usoro mkpuchi itinye mmiri adịghị mma maka PCbas nwere ikike ndị na-agbanwe agbanwe, cores magnetik dị mma, potentiometers, cores magnetik nwere iko na akụkụ ụfọdụ nwere akara adịghị mma.
Isi paramita nke usoro mkpuchi itinye mmiri:
Gbanwee viscosity kwesịrị ekwesị;
Jikwaa ọsọ a na-ebuli PCBA ka ọ ghara ịpụta afụ.Ọtụtụ mgbe, ọ bụghị ihe karịrị 1 mita kwa nkeji;
c.Ịfesa
Ịfesa bụ nke a na-ejikarị eme ihe, dị mfe ịnakwere usoro a, kewara n'ime ụzọ abụọ a:
① Ịfesa akwụkwọ ntuziaka
Ọgụgụ 15: Usoro ịgbasa akwụkwọ ntuziaka
Kwesịrị ekwesị maka workpiece bụ ihe mgbagwoju anya, siri ike ịdabere na akpaaka akụrụngwa uka mmepụta ọnọdụ, dịkwa mma maka ngwaahịa ahịrị dịgasị iche iche ma obere ọnọdụ, nwere ike sprayed ka a pụrụ iche ọnọdụ.
Rịba ama na spraying ntuziaka: alụlụ agba ga-emerụ ụfọdụ ngwaọrụ, dị ka nkwụnye PCB, oghere IC, ụfọdụ kọntaktị nwere mmetụta na ụfọdụ akụkụ ala, akụkụ ndị a kwesịrị ịṅa ntị na ntụkwasị obi nke nchebe ụlọ.Isi ihe ọzọ bụ na onye ọrụ ekwesịghị iji aka ya metụ plọg e biri ebi aka n'oge ọ bụla iji gbochie mmetọ nke elu kọntaktị plọg.
② Ịfesa akpaaka
Ọ na-ezokarị aka na spraying akpaka na ngwá ọrụ mkpuchi nhọrọ.Kwesịrị ekwesị maka mmepụta oke, ịdị mma na-agbanwe agbanwe, nkenke dị elu, obere mmetọ gburugburu ebe obibi.Site na nkwalite nke ụlọ ọrụ, mmụba nke ụgwọ ọrụ na ihe siri ike nke nchebe gburugburu ebe obibi, ngwá ọrụ ịgbasa akpaaka na-eji nwayọọ nwayọọ dochie ụzọ mkpuchi ndị ọzọ.
N'ịbawanye mkpa akpaaka nke ụlọ ọrụ 4.0, a na-elekwasị anya na ụlọ ọrụ ahụ site n'inye ngwá ọrụ mkpuchi kwesịrị ekwesị iji dozie nsogbu nke usoro mkpuchi dum.Igwe mkpuchi nhọrọ akpaaka - mkpuchi ziri ezi na enweghị ihe mkpofu, dabara maka nnukwu mkpuchi mkpuchi, nke kachasị mma maka nnukwu mkpuchi mkpuchi mkpuchi atọ.
Ntụle nkeigwe mkpuchi akpakanausoro mkpuchi omenala
Omenala PCBA mkpuchi agba atọ:
1) mkpuchi ahịhịa: enwere egosipụta, ebili mmiri, iwepụ ntutu isi;
2) Ide: oke ngwa ngwa, nkenke enweghị ike ịchịkwa;
3) Ịkwasa akụkụ ahụ dum: agba na-efunahụ oke, ngwa ngwa ngwa ngwa;
4) Ịfesa egbe fesa: iji chekwaa nchekwa, kpafuo nke ukwuu
Ihe mkpuchi igwe mkpuchi:
1) A na-edobe ihe osise ịgba, ọnọdụ ịgba agba na mpaghara nke ọma, ọ dịghịkwa mkpa ịgbakwunye ndị mmadụ na-ehichapụ osisi ahụ mgbe eserese ịgbasa.
2) Ụfọdụ ihe nkwụnye nkwụnye nwere nnukwu oghere site na nsọtụ efere ahụ nwere ike ịse ya ozugbo na-etinyeghị ihe nkwụnye ahụ, na-echekwa ndị ọrụ ntinye efere efere.
3) Enweghị mgbanwe gas, iji hụ na ebe ọrụ dị ọcha.
4) All substrate adịghị mkpa iji ihe ndozi na-ekpuchi ihe nkiri carbon, na-ewepụ ohere nke nkukota.
5) atọ mgbochi agba mkpuchi ọkpụrụkpụ edo, na-emeziwanye nrụpụta mmepụta na àgwà ngwaahịa, mana zerekwa ihe mkpofu agba.
PCBA akpaka atọ mgbochi agba mkpuchi igwe, a pụrụ iche maka spraying atọ mgbochi agba nwere ọgụgụ isi spraying akụrụngwa.N'ihi na ihe a ga-efesa na mmiri mmiri na-agbanye mmiri dị iche iche, igwe mkpuchi na-arụ ọrụ nke nhọrọ akụrụngwa akụrụngwa dịkwa iche, igwe mkpuchi mkpuchi atọ na-anabata usoro njikwa kọmputa kachasị ọhụrụ, nwere ike ịghọta njikọ njikọ atọ axis, n'otu oge a kwadebere na igwefoto n'ọnọdu na nsochi usoro, nwere ike n'ụzọ ziri ezi ịchịkwa spraying ebe.
Igwe ihe mkpuchi agba atọ, nke a makwaara dị ka igwe mgbochi agba atọ, igwe agba agba atọ, igwe ịgba mmanụ atọ, igwe ịgba agba atọ, bụ nke pụrụ iche maka njikwa mmiri, n'elu PCB. kpuchie na oyi akwa nke mgbochi agba atọ, dị ka impregnation, spraying ma ọ bụ usoro mkpuchi mkpuchi n'elu PCB kpuchie na oyi akwa nke photoresist.
Olee otú dozie ọhụrụ oge nke atọ mgbochi agba mkpuchi ina, aghọwo ihe ngwa ngwa nsogbu a ga-edozi na ụlọ ọrụ.Ngwá ọrụ mkpuchi akpaka nke igwe mkpuchi na-ahọrọ nke ọma na-eweta ụzọ ọrụ ọhụrụ,mkpuchi ziri ezi na enweghị ihe mkpofu nke ihe, nke kachasị mma maka ọnụ ọgụgụ buru ibu nke mkpuchi mkpuchi atọ.