PCB flatness zviyero zvakakosha pakuita kwakanaka. Bow uye twist inzira dzakadhindwa redunhu bhodhi rinogona kukotama. Bow ndiyo iyo bhodhi inokombamira kureba kwayo. Twist inguva iyo makona ari pakukwirira kwakasiyana. Matambudziko aya anogona kuita kuti gungano riome uye kukuvadza kuti pcb inoshanda sei. IPC-6011 zviyero zvinoti maseketi anofanirwa kuve akaenzana uye akavakwa zvakafanana pamativi ese. Izvi zvinobatsira kumisa uta uye kumonyoroka. Kana huremu hwemhangura huri 3 oz/ft² kana kudarika, mitemo yakaoma inodiwa. Flatness kuzvidzora anochengeta pcb yakatsiga uye anomisa kudiwa kwokuwedzera rutsigiro zvikamu.
Bow uye monyorora chinja sei sandara pcb uye sarudza kana yakadhindwa redunhu bhodhi achapfuura yakaoma indasitiri mitemo.
Zvitsva Zvitsva
Bow uye twist inoita kuti maPCB akotama, izvo zvinogona kukuvadza mashandiro avanoita. Zvakakosha kudzora uta uye kumonyorora. -Kushandisa IPC-TM-650 maturusi anotarisa flatness kutanga. Izvi zvinobatsira kuwana matambudziko nekukurumidza uye inoita kuti mabhodhi ave nechokwadi anotevera mitemo. -Kugadzira maPCB ane kunyange mhangura uye akangwara chikamu mavara anobatsira kumisa uta uye kumonyoroka kana uchiagadzira. -Kutora zvinhu zvakanaka uye kukora chaiko kunoita kuti maPCB arambe akasimba. Izvi zvinoita kuti vasanyanya kukotama kubva pakupisa kana mvura. -Kutaura zvakanaka pakati pevagadziri nevatengi kunobatsira kugadzirisa matambudziko nekukurumidza uye kunoita kuti maPCB ave nani.
PCB Flatness Standards
Bow uye Twist
PCB flatness zvinoreva kutsetseka uye kunyange bhodhi iri. Bow uye twist ndiyo nzira huru bhodhi inogona kurasikirwa nayo. Uta hunoitika kana makona mana anobata tafura, asi yepakati inosimuka. Twist inguva apo makona matatu anobata, asi kona imwe iri pamusoro kana pasi. Aya matambudziko anogona kuratidza panguva yekugadzira bhodhi, kunyanya mushure mekupisa matanho. Bow inogona kuita 0.47 mm, uye inoshanduka nebhodhi zvinhu uye kupisa. Twist ndipo apo bhodhi rinotenderera pamwe chete nediagonal, saka imwe kona iri kumusoro kana pasi.
Bow uye twist hazviteveri zvakajairika. Zvinhu zvakasiyana uye kupisa panguva ye soldering zvinokonzera shanduko idzi. Vanhu vanoshandisa nzira dzakakosha dzekutarisa uta uye kumonyoroka. Vanotarisa pabhodhi, shandisa flatness maturusi, uye dzimwe nguva 3D scanning. Mitemo yakaita se IPC-TM-650 2.4.22 inotsanangura nzira yekuyera uye kubvuma mapuranga ehuta nekumonyorora.
Tafura iri pazasi inoratidza uta uye kumonyoroka kwakanyanya kunobvumidzwa kune yega bhodhi mhando:
Bhodhi Rudzi | Maximum Bow uye Twist (%) |
|---|---|
NeSurface Mount Devices | 0.75% |
Pasina SMD | 1.5% |
Iyi miganho inobva kuIPC 2422-1 uye IPC 2422-2 mitemo. Vanoita kuti mapuranga echokwadi ashande zvakanaka, kunyange kana akakotama zvishoma.
Sei Kufuratira Kunokosha
Kufuratira kwakakosha kwazvo kuti zvakanaka sei pcb inoshanda. Bow uye twist zvinogona kuita kuti zvive zvakaoma kuisa zvikamu pabhodhi. Kana bhodhi risina kutsetseka, zvikamu zvinogona kusakwana zvakanaka, uye solder inogona kusamira zvakanaka. Izvi zvinogona kukonzera maseketi akavhurika kana nzvimbo dzisina simba.
Zvidzidzo zvinoratidza flat pcbs inogara kwenguva refu uye inoshanda zvirinani. Kunyanya uta kana kumonyoroka kunoisa kushushikana pane masolder majoini. Masungiriro aunoita bhodhi, sepaunoisa mabhaudhi, anochinja kuti anokotama sei. Mabhoti ari kure nezvikamu zvakakosha anobatsira solder joints kugara kwenguva refu. Kana mabhaudhi akabatanidza pcb kune zvinhu zvinowedzera zvakasiyana nekupisa, majoini ekutengesa anogona kuputsa kusvika ku60% nekukurumidza. Miedzo uye mhando dzemakomputa dzinoratidza kuti zvirongwa zvekutsigira zvinoshanduka panotanga kutsemuka uye kuti majoini ekutengesa anogara kwenguva yakareba sei.
Vatsvagiri vakaona kuti flatter pcbs inopa mhedzisiro iri nani mukugadzira mabhodhi. Mabhodhi ane zvishoma coplanarity ane mashoma solder matambudziko. Semuenzaniso, pa 0.177 mm coplanarity, mukana wekuvhura solder inenge 1%. Mabhodhi anokunda bvunzo anowanzo kupfava pane anokundikana. Ipo bhodhi rinogara pane pani uye kuti rinoputika sei zvine basa, asi mhangura chiyero uye zvinhu hazvichinje zvinhu zvakanyanya.
Bow and twist control haisi yekungotevera mitemo. Inobatsira ese akadhindwa redunhu bhodhi kushanda zvakanaka uye kugara kwenguva refu muhupenyu chaihwo.
Nzira dzekuyera
IPC-TM-650
Mainjiniya anoshandisa nzira dzakasiyana dzekutarisa kuti flat rakadhindwa redunhu bhodhi rakaita sei. Iyo IPC-TM-650 yakajairwa inotsanangura maitiro ekuyedza uta uye kumonyoroka. Kuti uite izvi, iwe unoisa bhodhi panzvimbo yakadzika. Zvadaro unoyera nzvimbo dzakakwirira uye dzakaderera. Vanhu vanoshandisa maturusi kana akakosha makamera kune izvi. Mamwe maturusi akajairika mumvuri moiré, fringe fungidziro, uye confocal kuyerwa. Zvishandiso izvi zvinogona kuwana shanduko diki dzehurefu, dzimwe nguva idiki se5 micrometer. Vamwe vagadziri vanotoda mamwe macheki chaiwo, senge 1 kana 3 micrometer.
Kuyera flatness, unofanira kutevera mamwe matanho:
Bika bhodhi kutanga kubvisa mvura.
Penda bhodhi chena kuitira kuti makamera aone zviri nani.
Cheka bhodhi kuitira kuti ikwane muchoto.
Isa thermocouples pedyo, asi kwete mukati, nzvimbo yekuedza.
Shandisa kupisa kunokwira zvishoma nezvishoma, pakati pe0.5°C ne1.0°C sekondi yega yega.
Iyo IPC-TM-650 yakajairwa inotiwo kutarisa mapaneru makuru usati waacheka kuita mabhodhi madiki. Izvi zvinoita kuti mapuranga ese akanaka asati aabatanidza.
Miganhu Inogamuchirwa
Pane mitemo yakajeka yekuti bhodhi rinofanira kunge rakatsetseka sei. Nhamba dzakakodzera dzinoenderana nemhando yebhodhi uye kuti ichashandiswa sei. Tafura iri pazasi inoratidza miganho mikuru:
Bhodhi Rudzi | Bow and Twist Limit (%) |
|---|---|
Surface gomo rakadhindwa redunhu mabhodhi | 0.75 |
Mamwe marudzi ebhodhi | 1.5 |
Mabhodhi anofanirwawo kunge ari mukobvu chaimo uye ane mipendero yakatsetseka. Kana bhodhi rakakora kudarika 31 mils, rinofanira kunge riri mukati me ± 10% yeukobvu chaihwo. Mabhodhi matete anogona chete kudzimwa ne ± 3 mils. Kana bhodhi richikotama kupfuura 0.75%, hazvina kunaka kumabasa mazhinji. Mitemo iyi inobatsira kuita kuti mapuranga echokwadi ashande zvakanaka kana achigadzirwa uye achishandiswa.
Nekutevera aya euta uye twist bvunzo, makambani anogona kugadzira mabhodhi anosangana nemitemo uye haakundike zvakanyanya.
Kufurira Zvinhu zvePCB Flatness
Dhizaini uye Kurongeka
Magadzirirwo aunoita uye kuisa pcb inochinja kuti inogara sei. Mainjiniya anoedza kuchengeta mhangura kunyangwe kumativi ese. Kana rumwe rutivi rune mhangura yakawanda, bhodhi rinogona kukotama. Izvi zvinoitika kana bhodhi rinotonhora pasi. Iyo yakadzikama stack-up inobatsira kumisa dambudziko iri. Maronda nendege zvinoiswa kuparadzira kushushikana. Mahombe akachekwa kana anotsvedza anogona kugadzira nzvimbo dzisina simba. Aya mavara asina simba anoita kuti uta kana kumonyoroka zvakanyanya panguva yekuyamwisa. Kwaunoisa zvikamu nemakomba zvine basa zvakare. Sarudzo dzakanaka mukugadzira dzinobatsira kumisa kukotama. Izvi zvinoita kuti pcb ishande zvakanaka uye igare kwenguva refu.
Zano: Kuchengeta mhangura uye nekuisa zvikamu munzvimbo dzakangwara kunobatsira kumisa uta uye kumonyoroka kana kugadzira bhodhi redunhu.
Zvishandiso uye Ukobvu
Zvishandiso uye ukobvu zvaunotora sarudza kuti sandara sei pcb ichave. Zvinhu zvakasiyana-siyana zvinoshanda zvakasiyana nekupisa nemvura. FR4, Teflon, uye flexible substrates imwe neimwe ine yakakosha hunhu. FR4 ine yepakati CTE, asi Teflon's CTE yakakwira zvakanyanya. Flexible substrates inoda kutarisirwa kwakawedzerwa kuti igare yakapfava. Kana zvinhu izvi zvikapisa panguva yekuyamwisa, zvinokura nekuderera nekumhanya kwakasiyana. Izvi zvinogona kuita kuti bhodhi rikotamire kana kumonyoroka.
Kuti bhodhi rakakora sei zvakare zvine basa zvakanyanya. Mabhodhi matete anokotama kana kumonyoroka zviri nyore. Mapuranga akakora haakotame zvakanyanya asi anogona kunge akaomarara. Tafura iri pazasi inoratidza kuti zvinhu uye ukobvu zvinoshandura sei flatness uye kushivirira:
Parameter | tsananguro | Impact paPCB Flatness uye Kushivirira |
|---|---|---|
Material Type | FR4, Teflon, Flexible Substrates | MaCTE akasiyana-siyana anoita mapuranga akaputika kana kuderera; Teflon yakaoma kuchengeta yakati sandara, inochinjika substrates inoda kutarisirwa kwakakosha |
Hukobvu hukuru (mm) | 0.2-0.4 | ± 0.1mm kushivirira; mapuranga akakora anorasikirwa nekushanduka, matete haana simba |
Hukobvu hukuru (mm) | 0.5-1.0 | ± 0.2mm kushivirira; mapuranga makobvu anononoka masaini ekumhanya, matete haana kugadzikana |
Hukobvu hukuru (mm) | 1.0-1.5 | ± 0.3mm kushivirira; mapuranga akakora akaoma kukwira, matete anogona kuputsika |
Thermal Kuwedzera Migumisiro | FR4 (14-16 ppm/°C), Teflon (30-40 ppm/°C), Polyimide (10-20 ppm/°C) | Higher CTE inoreva kuwedzera kurwa, izvo zvinokuvadza flatness |
Environmental Factors | Tembiricha, Humidity | Kupisa uye mvura zvinoita kuti mapuranga akure, kupera, kana kuchinjika |
Manufacturing Processs | Reflow soldering thermal stress | Kutonhodza kusina kuenzana kunokotama mapuranga uye kunofambisa zvikamu |
Mainjiniya vanotora zvinhu uye ukobvu zvichibva pane izvo pcb inoda. Vanofungawo nezvekuti sarudzo idzi dzinoshandura sei uta uye kumonyoroka panguva yekugadzira nekushandisa bhodhi.
Layer Count
Nhamba yezvikamu mu pcb inoshandura kuti yakawanda sei inokotama. Mamwe akaturikidzana anoreva mamwe matanho e lamination. Nhanho imwe neimwe inoshandisa kupisa nekumanikidza. Aya matanho anogona kuita kuti bhodhi rikotame kana kumonyoroka kana isina kuenzana. Mamwe matinji anogona kureva kushushikana kwakawanda. Kana akaturikidzana asina kuenzana ukobvu kana mhando, bhodhi rinogona kukotama mushure mekucheka.
Vagadziri vanoshandisa kunyange stack-ups kubatsira neizvi. Vanofananidza mitsara kumusoro uye pasi pepakati. Izvi zvinoita kuti bhodhi rirambe rakadzikama panguva yekugadzira. Kana iyo stack-up isiri kunyange, bhodhi rinogona kukotama panguva yekuchera. Kuronga nhamba yezvikamu uye stack-up inobatsira kumisa uta uye kumonyoroka.
Manufacturing Process
Iyo pcb inogadzirwa sei inoshandura kuti sandara iri pakupera. Nhanho yega yega, senge lamination uye soldering, inogona kukonzera matambudziko. Lamination inoshandisa kupisa uye kumanikidza kunamatira zvidimbu pamwechete. Kana kupisa kana kudzvinyirira kusina kunyange, bhodhi rinogona kukotama. Kutonhodza kusiri kunyangwe mushure mekucheka kunokonzerawo kukotama. Munguva ye reflow soldering, bhodhi rinopisa zvakare. Kupisa uku kunogona kuita kuti bhodhi rikotame, kunyanya kana zvinhu zvichikura pamitengo yakasiyana.
Vagadziri vanoshandisa matanho akangwarira kumisa matambudziko aya. Vanotarisa kupisa uye kudzvinyirira panguva yelamination. Vanobika mapuranga vasati vanyudzwa kuti vaome. Aya matanho anobatsira kumisa uta uye kumonyoroka. Matimu anotarisa flatness kakawanda panguva yekugadzira. Cheki dzekutanga dzinowana matambudziko pamberi pedanho rinotevera. Kudzora zvakanaka muitiro anochengeta pcb sandara uye kunoderedza mukana matambudziko.
Cherechedza: Kuchengeta muitiro wakatsiga panguva kugadzira uye lamination kunokosha zvikuru kumisa uta uye monyorora mune ose pcb.
Kuverengera PCB Kutevedza
Maitiro Akanakisisa
Vagadziri vanoshandisa nzira dzakasiyana dzekuchengeta pcb flatness. Vanosarudza pamusoro inopera senge ENIG kana ENEPIG. Aya mapeji anobatsira mapedhi kuti agare akagadzikana uye akasimba. Dry film solder masks anogona kugadzira mabhodhi akanyanya kupfava, kusvika ku5-7 micrometer. Mainjiniya vanogadzira stack-ups akafanana pamativi ese. Vanoenzanisa mhangura kumisa uta uye kumonyoroka. Empty copper spots anozadzwa kuti arambe achipepetwa. Panguva yelamination, vanotarisa kupisa uye kumanikidzwa kuti vamise kurwisana. Tafura iri pasi apa inoronga dzimwe nhamba dzakakosha:
Kuonekwa | Details / Numerical Benchmarks |
|---|---|
IPC Warpage Limits | 0.1% yeClass 3 mabhodhi; 0.05% yeKirasi 4; 0.2% yeKirasi 1 |
Core Hukuru | 1.6 mm inobatsira mapaneru makuru kugara akaomarara kana anopfuura 400 mm |
Copper Distribution | Yakaenzana mhangura inodzikisa njodzi yehondo ne15-20% |
Kusarudzwa Kwezvinhu | High-Tg FR-4 (> 170°C) kana polyimide (kusvika 260°C) inocheka kuwedzera nezvikamu makumi maviri kubva muzana. |
Zano: Kushanda nevagadziri vekugadzira nekukurumidza uye kugadzira mabhodhi ekuyedza nekukurumidza unogona kuwana anosvika makumi masere muzana ematambudziko ekufuratira usati wagadzira akawanda mabhodhi.
Mugadziri-Mutengi Kukurukurirana
Kukurukurirana kwakanaka pakati pevagadziri nevatengi kunobatsira pcb kutevedzera. Mativi ese ari maviri anofanira kubvumirana pamitemo yeflatness asati agadzira mapuranga. Kugovera zvirongwa zvekurongedza, zvinhu zvinotora, uye nhanho dzelamination zvinomisa zvinoshamisa. Vagadziri vanogona kuratidza bvunzo dzekombuta kutsanangura kuti pcb ichaita sei panguva yekuungana. Vatengi vanofanirwa kuudza vagadziri nezve chero matambudziko anowanikwa mukuyedzwa. Kubatana uku kunobatsira kuvandudza zvese kugadzira nekuita matanho.
Misangano yenguva dzose inoita kuti munhu wose agadziridzwe.
Kugovera mhinduro dzebvunzo uye masampuli kunobatsira kugadzirisa zvinhu nekukurumidza.
Kutaura nezvematambudziko mukugadzira kunotungamira kugadzirisa nekukurumidza.
Kugadzirisa Nyaya
Kana matambudziko eflatness aonekwa, zvikwata zvinotevera matanho ekuzvigadzirisa. Chekutanga, vanotarisa kana mhangura yakaenzana uye stack-up yakaenzana. Zvadaro, vanoona kana zvinhu zvakakodzera uye gobvu zvakashandiswa. Kana lamination kana soldering yakakonzera dambudziko, vanochinja maitiro ekugadzirisa. Dzimwe nguva, vanoshandisa mabatiro chaiwo panguva yekuungana kuti mapuranga asakotama. Zvidzidzo zvenyaya zvinoratidza kuti kuedza zvigadziriso zvitsva kana kushandura mabatirwo ezvikamu zvinogona kugadzirisa matambudziko akaomarara. Semuyenzaniso, European sensor project yakawana zvirinani flatness nekuyedza matatu matsva madhizaini. Izvi zvakavabatsira kugadzira mamwe mapuranga. Mumidziyo yekurapa, kugadzira mabhodhi ebvunzo akawanda uye kuwana rubatsiro rwekugadzira zvinounza mhedzisiro iri nani uye mabhodhi akasimba.
Matimu anowana matambudziko nekukurumidza uye anonatsiridza maitiro avo ane mashoma flatness nyaya uye nani pcb kuita.
Kuziva zviyero zvePCB uye zvinokanganisa kunaka kunobatsira mainjiniya kugadzira zvigadzirwa zvakanaka. Dhizaini yakanaka, kutora zvinhu zvakanaka, uye nhanho dzakangwarira dzinomisa mapuranga kubva pakukotama. Izvi zvinobatsirawo kuisa zvikamu pabhodhi zviri nani. Tafura iri pasi apa inoratidza nzira mbiri dzekucheka mapuranga akaparadzana. Inotaurira kuti nzira imwe neimwe inoshandura sei mupendero uye kushushikana:
Kuonekwa | Stamp Hole Depaneling | V-Scoring Depaneling |
|---|---|---|
Kugadzirisa Mutengo | Cheap uye nyore kuita | Inodhura uye inoda rimwe basa |
Depaneling Quality | Micheto yakaoma uye inoda kuchekwa | Mipendero yakatsetseka uye inotaridzika zvakanaka |
Depaneling Stress | Kwete kushushikana kwakawanda, kwakanakira nhengo dzisina kusimba | Kushushikana kwakawanda, saka zvikamu zvinoda kuchengetedzwa |
Dhizaina Shanduko | Inoshanda kune akawanda maumbirwo uye magadzirirwo | Inoshanda chete kune akareruka, akajairika maumbirwo |
Yakakodzera Scenarios | Zvakanaka kumabasa maduku uye mabhodhi ekuedza | Zvakanakisa pakugadzira mapuranga akawanda anofanira kunge akati sandara |
Kuti uwane rumwe rubatsiro, tarisa IPC-6012 uye IPC-2221 mitemo. Kuongorora mabhodhi kazhinji uye kushanda pamwe chete kunobatsira munhu wese kuwana mhedzisiro iri nani.
FAQ
Chii chinokonzera PCB kurasikirwa flatness?
Zvinhu zvakawanda zvinogona kuita kuti PCB isafuratike. Kana mhangura isina kupararira zvakafanana, bhodhi rinogona kukotama. Kunhonga zvinhu zvisiri izvo kunoitawo matambudziko. Kupisa panguva yekugadzira bhodhi kunogona kukonzera uta kana kushandura. Vagadziri uye vagadziri vanofanirwa kutarisa zvinhu izvi kuchengetedza bhodhi rakati sandara.
Mainjiniya anoyera sei PCB flatness?
Mainjiniya anoshandisa maturusi akakosha kutarisa flatness. Mamwe maturusi mumvuri moiré, fringe fungidziro, uye confocal kuyerwa. Vanotevera mitemo kubva kuIPC-TM-650. Bhodhi rinoenda patafura yakati sandara. Zvadaro vanotarisa nzvimbo dzakakwirira uye dzakaderera. Izvi zvinobatsira kuve nechokwadi chekuti bhodhi rakakwana kuti rishandiswe.
Chii chinoitika kana PCB ikatadza flatness zviyero?
Kana PCB isina kufuratira zvakakwana, inogona kukonzera dambudziko. Zvikamu zvinogona kusakwana pabhodhi. Solder majoini anogona kupera simba uye kuputsika. Izvi zvinogona kuita kuti bhodhi rirege kushanda kana kusagara kwenguva refu. Vagadziri vanofanira kugadzirisa dambudziko vasati vashandisa bhodhi.
Ko dhizaini shanduko inogona kuvandudza PCB flatness?
Hongu, shanduko yekugadzira inogona kubatsira kuchengetedza mapuranga. Mainjiniya anoyera mhangura akaturikidzana uye anotora zvinhu zvakanaka. Vanoronga kuti stack-up ive yakaenzana. Ivo havashandise mahombe cutouts uye vanoisa zvikamu munzvimbo dzakangwara. Aya matanho anobatsira kumisa uta uye kumonyoroka paunenge uchigadzira bhodhi.
