Sida side ee qaybaha kala duwan iyo xudunta gudbinta calaamadaha wareegga, PCB wuxuu noqday qaybta ugu muhiimsan uguna muhiimsan ee alaabta macluumaadka elektiroonigga ah, tayada iyo heerka isku hallaynta ayaa go’aamisa tayada iyo isku halaynta qalabka oo dhan. Si kastaba ha ahaatee, sababo la xiriira kharash iyo farsamo awgood, waxaa jira dhibaatooyin badan oo guuldaro ah soo saarista PCB -ga iyo dalabkiisa.

Dhibaatada noocan oo kale ah, waxaan u baahanahay inaan isticmaalno qaar ka mid ah farsamooyinka falanqaynta guuldarrada ee inta badan la isticmaalo si loo hubiyo heerka tayada iyo isku -halaynta PCB ee wax -soo -saarka. Qoraalkani wuxuu soo koobayaa toban farsamadood oo falanqaynta guuldarada ah si loo tixraaco.

Farsamaynta iyo sababta falanqaynta fashilka PCB

1. Kormeer muuqaal ah

Kormeerka muuqaalka ayaa ah in si muuqaal ah loo baaro ama loo isticmaalo qalab fudud, sida microscope stereoscopic, microscope metallographic ama xitaa muraayadda weyneynta, si loo hubiyo muuqaalka PCB -ga oo loo helo qeybihii fashilmay iyo caddeymaha jir ahaaneed ee habboon. Shaqada ugu weyni waa in la helo guuldarrada oo si hordhac ah loo xukumo habka fashilka ee PCB. Kormeerka muuqaalka ayaa inta badan hubiya wasakheynta PCB, daxalka, meesha qaraxa boodhka, fiilooyinka wareegga iyo joogtaynta fashilka, haddii ay tahay dufcad ama shaqsi, haddii ay mar walba ku urursan tahay meel gaar ah, iwm. In addition, the failure of many PCBS was discovered after the assembly of PCBA. Whether the failure was caused by the influence of the assembly process and materials used in the process also requires careful examination of the characteristics of the failure area.

2. X-ray fluoroscopy

Qaybaha qaarkood oo aan lagu baari karin muuqaalka, iyo sidoo kale gudaha PCB-ga dalool iyo cillado kale oo gudaha ah, waa inaan u isticmaalnaa nidaamka fluoroscopy-ka raajada si aan u hubinno. Nidaamka fluoroscopy-ka ee X-ray waa adeegsiga dhumuc maado oo kala duwan ama cufnaanta maaddada kala duwan ee raajada hygroscopicity ama gudbinta mabaadii’da kala duwan ee sawirka. Farsamadan ayaa aad loo isticmaalaa si loo hubiyo meesha cilladaha ku jira kala -goysyada iibiyaha PCBA, iyada oo loo marayo cilladaha godadka iyo cilladaha ku jira aaladda BGA ama CSP oo leh baakad cufnaanta sare. At present, the resolution of industrial X-ray fluoroscopy equipment can reach less than one micron, and is changing from two dimensional to three dimensional imaging equipment. There are even five dimensional (5D) equipment used for packaging inspection, but this 5D X-ray fluoroscopy system is very expensive, and rarely has practical application in the industry.

3. Falanqaynta qaybta

Falanqaynta jeexdu waa geedi socodka helitaanka qaab -dhismeedka qaybta PCB iyada oo loo marayo sambal -qaadista, Muuse, jeex, nadiifinta, daxalka, fiirinta iyo habab iyo tallaabooyin taxane ah. Abundant information about the microstructure of PCB (through hole, coating, etc.) can be obtained by slice analysis, which provides a good basis for the next quality improvement. However, this method is destructive, once the slice is carried out, the sample will inevitably be destroyed; Isla mar ahaantaana, habka shuruudaha tusaalaha ayaa sarreeya, waqtiga diyaarinta muunadku sidoo kale waa dheer yahay, baahida loo qabo shaqaale farsamo oo tababaran si ay u dhammaystiraan. For detailed slicing procedures, please refer to IPC standards IPC-TM-650 2.1.1 and IPC-MS-810.

4. Baadhitaanka microscope -ka dhawaaqa

At present, c-mode ultrasonic scanning acoustic microscope is mainly used for electronic packaging or assembly analysis. It makes use of the amplitude, phase and polarity changes generated by the reflection of high-frequency ultrasound on the discontinuous interface of materials to image, and its scanning mode is to scan the information in the X-Y plane along the Z-axis. Therefore, scanning acoustic microscopy can be used to detect various defects, including cracks, delamination, inclusions, and voids, in components, materials, and PCB and PCBA. Internal defects of solder joints can also be directly detected if the frequency width of scanning acoustics is sufficient. Of a typical scanning acoustic image in color red alert said defects exist, because a large amount of plastic packaging components used in SMT process, by a lead into the process of lead-free technology, a large number of moisture reflow sensitive problem, namely the moisture absorption of powder coating devices will be at a higher temperature reflow lead-free process occurs within or substrate layer cracking phenomenon, Under the high temperature of lead-free process, common PCB will often burst board phenomenon. Waqtigan xaadirka ah, iskaanka microscope-ka acoustic-gu wuxuu muujinayaa faa’iidadiisa gaarka ah ee ogaanshaha aan fiicnayn ee PCB-ga cufnaanta sare leh. The general obvious bursting plate can be detected by visual inspection.

5. Falanqaynta microinfrared

Falanqaynta infrared -ka microscope -ka waa in lagu shubo shucaaca infrared oo ay weheliso habka falanqaynta mikroskoob, waxay u adeegsataa waxyaabo kala duwan (inta badan maaddo dabiici ah) mabda’a nuugista nuurka infrared, falanqaynta ka kooban walxaha, oo ay weheliso mikroskoobku waxay samayn kartaa iftiin muuqda iyo iftiin infrared oo leh waddada iftiinka, illaa iyo inta ka hooseysa goobta muuqaalka, waxay raadin kartaa falanqaynta raad -raacyada sunta dabiiciga ah. Maqnaanshaha microscope -ka, spectroscopy infrared ayaa badiyaa falanqeyn kara shaybaarro waaweyn oo keliya. In many cases, trace pollution in electronic process can lead to poor weldability of PCB pad or lead pin. It can be imagined that it is difficult to solve the process problem without the matching infrared spectrum of microscope. The main use of microscopic infrared analysis is to analyze the organic pollutants on the welding surface or solder spot surface, and analyze the causes of corrosion or poor solderability.

6. Baadhitaanka falanqaynta mikroskoobka elektarooniga ah

Baadhitaanka microscope electron (SEM) waa mid ka mid ah hababka imaging microscopic electron ee baaxadda leh ee baaxadda leh ee falanqaynta guuldarrada. Mabda’a shaqayntu waa in la sameeyo laydh elektaroonig ah oo leh dhexroor tobanaan ilaa kumanaan angstroms ah (A) iyada oo diiradda la saarayo laydhka elektaroonigga ah ee ka soo baxa cathode -ka ay dardar gelisay anode. Iyada oo la raacayo ficilka leexashada gariiradda iskaanka, Ilayska elektaroonigga ah wuxuu baaray dusha dhibicda tusaalaha dhibic ahaan waqti go’an iyo meel bannaan. Iftiinka elektaroonigga ah ee tamarta sare leh ayaa duqeeya dusha muunadda wuxuuna soo saaraa macluumaad kala duwan, kuwaas oo la ururin karo lana xoojin karo si loo helo sawirro kala duwan oo u dhigma shaashadda bandhigga. The excited secondary electrons are generated within the range of 5 ~ 10nm on the surface of the sample. Therefore, the secondary electrons can better reflect the surface topography of the sample, so they are most commonly used for morphology observation. Elektaroonnada gadaal -ka -laabashada leh ee xiisaha leh ayaa laga soo saaraa inta u dhexeysa 100 ~ 1000nm dusha muunadda, waxayna soo saaraan astaamo kala duwan oo leh farqiga tirada atomka ee walaxda. Sidaa darteed, sawirka elektaroonigga ah ee gadaal -ka -duubmay wuxuu leeyahay astaamo maansoor ahaan iyo karti takoor nambarka tirada, sidaas darteed, sawirka elektaroonigga ee gadaal ka muuqda wuxuu ka tarjumayaa qaybinta walxaha kiimikada. Mikroskoob -ka korantada ee korontada ee imminka wuxuu ahaa mid aad u awood badan, qaab dhismeed kasta oo wanaagsan ama astaamaha dusha ayaa lagu weyneyn karaa boqolaal kun oo jeer si loo fiiriyo loona falanqeeyo.

In PCB or solder joint failure analysis, SEM is mainly used for failure mechanism analysis, specifically, is used to observe the surface morphology structure of the pad, solder joint metallographic structure, measurement of intermetallic compounds, solderable coating analysis and tin must be analyzed and measured. Different from the optical microscope, the scanning electron microscope produces electronic images, so it has only black and white colors. Moreover, the sample of the scanning electron microscope is required to conduct electricity, and the non-conductor and part of the semiconductor need to be sprayed with gold or carbon, otherwise the charge will gather on the surface of the sample and affect the sample observation. Intaa waxaa dheer, qoto -dheeraanta goobta sawirka sawirka microscope -ka elektaroonigga ayaa aad uga weyn tan microscope -ka indhaha, taas oo ah hab muhiim u ah falanqaynta qaab -dhismeedka biraha, jajabka microscopic -ka iyo xamuurada daasadda.

7. X-ray energy spectrum analysis

Baadhitaanka kor ku xusan ee microscopy electron waxaa sida caadiga ah lagu qalabeeyaa raajada raajada raajada. When the high-energy electron beam hit the surface, the surface material of the inner electrons in the atoms are bombarded escape, outer electrons to low energy level transition will inspire characteristic X ray, atomic energy level difference of different elements from different characteristic X ray is different, therefore, can send sample of the characteristics of X-ray as chemical composition analysis. Isla mar ahaantaana, aaladaha u dhigma waxaa loogu yeeraa siday u kala horreeyaan loo yaqaan spectrumeter dispersion spectrum (WDS for short) iyo spectrometer firdhinta tamarta (EDS oo gaaban) marka loo eego mowjadda dabeecadda ama tamarta dabeecadda ee ogaanshaha signalada raajada. Xallinta cabbiraadda ayaa ka sarreysa tan mitirka tamarta, iyo xawaaraha falanqaynta cabbirka tamarta ayaa ka dhaqso badan kan tamarta tamarta. Sababtoo ah xawaaraha sare iyo qiimaha jaban ee cabbirayaasha tamarta, guud ahaan SCANNING microscopy electron microscopy wuxuu ku qalabaysan yahay qiyaasaha tamarta.

Iyada oo leh habka iskaanka ee kala duwan ee dogobka elektaroonigga ah, shaashadda tamarta ayaa falanqayn karta barta, xarriiqda iyo diyaaradda dushiisa, waxayna heli kartaa macluumaadka qaybinta kala duwan ee walxaha.Point analysis yields all elements of a point; Falanqaynta xariijinta Hal falanqayn oo halbeeg ayaa lagu sameeyaa khad cayiman mar kasta, iyo qaybinta xariiqa dhammaan walxaha waxaa lagu helaa iskaan badan. Falanqaynta dusha Falanqaynta dhammaan walxaha ku jira dusha sare ee la siiyay. Maaddada curiye ee la cabiray waa celceliska cabirka dusha sare.

In the analysis of PCB, energy dispersive spectrometer is mainly used for the composition analysis of pad surface, and the elemental analysis of contaminants on the surface of pad and lead pin with poor solderability. Xaqiijinta falanqaynta tirada ee spectrometer -ka tamarta ayaa xaddidan, iyo waxa ka yar 0.1% guud ahaan ma sahlana in la ogaado. Isku -darka tamarta tamarta iyo SEM waxay isku mar heli karaan macluumaadka qaab -dhismeedka dusha sare iyo halabuurka, taas oo ah sababta keentay in si weyn loo isticmaalo.

8. Falanqaynta Photoelectron spectroscopy (XPS)

Muunadaha ka soo baxa shucaaca shucaaca, dusha korantada qolofka gudaha ee atomka ayaa ka baxsan doona addoonsiga bu’da iyo dusha adag ee samayska, cabiraya tamartiisa kinetiga ah ee Ex, electrons -ka qolofka gudaha ee atamka waxaa laga heli karaa tamarta ku xidhnaan karta Eb, Eb waxay ku kala duwanaayeen walxo kala duwan iyo qolof elektiroonig ah oo kala duwan, waa “faraha” ee xuduudaha aqoonsiga atomka, sameynta xariiqa isha waa sawir -qaade sawir -qaade (XPS). XPS waxaa loo adeegsan karaa falanqayn tayo iyo tiro leh oo ku saabsan walxaha ku yaal dusha hoose (dhowr nanometer) ee dusha muunadda. Intaa waxaa dheer, macluumaadka ku saabsan dawladaha qiimayaasha kiimikada ee canaasiirta waxaa laga heli karaa isbeddellada kiimikada ee tamarta wax -qabadka. Waxay bixin kartaa macluumaadka xiriirka ka dhexeeya heerka qiimaynta ee lakabka dushiisa iyo walxaha ku xeeran. The incident beam is X-ray photon beam, so insulation sample analysis can be carried out, without damaging the analyzed sample rapid multi-element analysis; Soo -saareyaal badan ayaa sidoo kale lagu falan -qayn karaa dhererka argon ion stripping (eeg kiiska hoose) oo leh xasaasiyad aad uga fog tan tamarta tamarta (EDS). XPS waxaa inta badan loo adeegsadaa falanqaynta falanqaynta tayada dahaarka PCB, falanqaynta wasakhda iyo falanqaynta heerka oksaydhka, si loo go’aamiyo sababta qoto dheer ee alxanka liita.

9. Differential Scanning Calorim-etry

Habka lagu qiyaaso farqiga udhaxgalka awooda u dhexeysa walax iyo walax tixraac ah sida heerkulka (ama waqtiga) ee hoos yimaada kontoroolka heerkulka barnaamijka. DSC is equipped with two groups of compensation heating wire under the sample and reference container, when the sample in the heating process due to the thermal effect and reference temperature difference δ T, through the differential heat amplifier circuit and differential heat compensation amplifier, so that the current flowing into the compensation heating wire changes.

The temperature difference δ T disappears, and the relationship between the difference of the thermal power of the two electrically compensated samples and the reference material with temperature (or time) is recorded. According to this relationship, the physicochemical and thermodynamic properties of the material can be studied and analyzed. DSC is widely used in PCB analysis, but is mainly used to measure the curing degree of various polymer materials used in PCB and glass state transformation temperature, these two parameters determine the reliability of PCB in the subsequent process.

10. Thermomechanical analyzer (TMA)

Thermal Mechanical Analysis is used to measure the deformation properties of solids, liquids and gels under Thermal or Mechanical forces under programmed temperature control. Commonly used load methods include compression, pin insertion, stretching, bending, etc. Baadhitaanku wuxuu ka kooban yahay go’an on dogobka cantilever iyo taageerada guga helical, iyada oo loo marayo mashiinka culeyska la adeegsaday, marka isbeddelka muunaddu dhacdo, isbeddel -kala -duwan si loo ogaado isbeddelka, iyo wada -shaqaynta xogta, sida heerkulka, cadaadiska iyo cadaadiska ka dib alaabta waxaa lagu heli karaa iyadoo hoos loo eegayo xiriirka cilladda culayska dayacan ee heerkulka (ama waqtiga). Marka loo eego xiriirka ka dhexeeya kala -beddelidda iyo heer -kulka (ama waqtiga), astaamaha fiisiko -fikemiyeerka iyo heer -kulmeynta qalabka ayaa la baran karaa lana falanqeyn karaa. TMA si baaxad leh ayaa loogu adeegsadaa falanqaynta PCB waxaana inta badan loo adeegsadaa cabiraadda labada cabbir ee ugu muhimsan PCB: isbarbar -dhigga toosan iyo heerkulka kala -guurka galaaska. PCB -ga oo leh is -weydaarsi ballaarineed oo aad u ballaaran wuxuu inta badan horseedaa jabka jabka godadka birta ka sameysan ka dib alxanka iyo isu -imaatinka.