Amin’ny maha-mpitondra singa samihafa sy foiben’ny fampitana signal circuit, PCB nanjary ny ampahany manan-danja indrindra sy manan-danja indrindra amin’ny vokatra fampahalalana elektronika, ny kalitao sy ny haavony azo antoka dia mamaritra ny kalitao sy ny fahamendrehan’ny fitaovana iray manontolo. Na izany aza, noho ny antony lafo sy ara-teknika dia betsaka ny olana tsy fahombiazan’ny famokarana sy ny fampiharana PCB.

Ho an’ity karazana olana tsy fahombiazana ity dia mila mampiasa teknika famakafakana tsy fahombiazana mahazatra izahay mba hiantohana ny kalitao sy ny haavon’ny PCB amin’ny famokarana. Ity taratasy ity dia mamintina teknika famakafakana tsy fahombiazana folo ho fanovozan-kevitra.

Mekanisma ary mahatonga ny famakafakana ny tsy fahombiazan’ny PCB

1. Fanaraha-maso amin’ny maso

Ny fisavana ny bika dia ny fizahana maso na fampiasana fitaovana tsotra sasantsasany, toy ny mikraoskaopy stereoskopika, mikraoskaopy metallographic na koa fitaratra manitatra, hijerena ny fisehon’ny PCB ary hahitana ireo ampahany tsy nahomby sy porofo ara-batana mifandraika amin’izany. Ny tena lahasa dia ny mahita ny tsy fahombiazana ary mitsara mialoha ny fomba tsy fahombiazan’ny PCB. Ny fisavana ny endrika dia manamarina indrindra ny fandotoan’ny PCB, ny harafesina, ny toerana misy ny fipoahan’ny birao, ny tariby tariby ary ny tsy fahombiazan’ny tsy fahombiazana, raha andiany na olona io, na mifantoka amin’ny faritra iray sns, 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. Fluoroscopy amin’ny taratra X

Ho an’ny faritra sasany izay tsy afaka jerena amin’ny fisehoany, ary koa ny atin’ny PCB amin’ny alàlan’ny lavaka sy ireo lesoka anatiny hafa, dia mila mampiasa rafitra fluoroscopy X-ray isika hanamarinana. Ny rafitra fluoroscopy X-ray dia ny fampiasana ny hatevin’ny fitaovana samihafa na ny hakitroky ny fahasamihafana amin’ny X-ray na ny fandefasana ireo fotokevitra samihafa amin’ny sary. Ity teknolojia ity dia ampiasaina bebe kokoa hijerena ny toerana misy ny kilema amin’ny tonon-tsolika solosaina PCBA, amin’ny alàlan’ny lesoka sy lesoka amin’ny lavaka ao amin’ny fitaovana BGA na CSP misy fonosana avo lenta. 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. Fizahana fizarana

Ny famakafakana ny slice dia ny dingan’ny fahazoana ny firafitry ny fizarana PCB amin’ny alàlan’ny santionany, mozika, slice, polishing, harafesina, fandinihana ary fomba sy dingana maromaro. Ny fampahalalana marobe momba ny microstructure an’ny PCB (amin’ny alàlan’ny lavaka, fonosana sns.) Dia azo atao amin’ny famakafakana ny slice, izay manome fototra tsara ho an’ny fanatsarana kalitao manaraka. However, this method is destructive, once the slice is carried out, the sample will inevitably be destroyed; Mandritra izany fotoana izany, ny fomba fitakiana santionany dia avo, ny fotoana fanomanana santionany dia lava ihany koa, ny filàna mpiasa teknika voaofana mba hamitana. For detailed slicing procedures, please refer to IPC standards IPC-TM-650 2.1.1 and IPC-MS-810.

4. Mikaroka mikraoskaopy akustika

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. Amin’izao fotoana izao, ny mikraoskaopy akustika fitiliana dia mampiseho ny tombony manokana ananany amin’ny famaritana tsy misy fotony ny PCB avo lenta avo lenta. The general obvious bursting plate can be detected by visual inspection.

5. Fanadihadiana mikraoba

Ny famakafakana micro infrared dia ny spectroscopy infrared miaraka amin’ny fomba fandalinana mikraoskaopy, mampiasa fitaovana hafa izy io (akora biolojika indrindra) amin’ny fitsipiky ny fitrandrahana spektrra infrared, ny famakafakana ny fitambaran’ireo akora, miaraka amin’ny mikraoskaopy dia afaka manome hazavana hita sy hazavana infrared miaraka amin’ny lalan-jiro, raha mbola eo ambanin’ny sehatra hita maso, dia afaka mitady ny famakafakana ireo loto mandoto organika. Raha tsy misy mikraoskaopy, ny spectroscopy infrared dia mazàna mandinika santionany lehibe ihany. 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. Fanadihadiana momba ny fanadihadiana mikraoskaopy elektronika

Ny mikaroka mikraoskaopy elektronika (SEM) dia iray amin’ireo rafitra mpaka sary mikraoskaopy lehibe indrindra amin’ny famakafakana ny tsy fahombiazana. Ny fitsipika iasany dia ny mamorona andry elektrôna misy savaivony folo ka hatramin’ny an’arivony angstroms (A) amin’ny alàlan’ny fifantohana ny andry elektronika navoaka avy amin’ny katôdra haingan’ny anoda. Eo ambanin’ny hetsiky ny fihodinan’ny coil scanning, Ny andry elektronika dia manara-maso ny tampon’ny teboka santionany isaky ny teboka ao anatin’ny filaharana ora sy fotoana voafaritra. Ny tariby elektronika matanjaka be dia manafika ny tampon’ny santionany ary mamorona vaovao marobe, izay azo angonina sy hohamafisina mba hahazoana sary mifanentana isan-karazany amin’ny efijery fampisehoana. 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. Ireo elektronika miverina mihetsiketsika dia azo avy amin’ny 100 ~ 1000nm eo ambonin’ny santionany, ary mamoaka toetra samy hafa izy ireo miaraka amin’ny tsy fitovian’ny isa atomika ao amin’ilay akora. Noho izany, ny sary elektronika miverimberina dia manana toetra mampiavaka ny morphologic sy fahaizan’ny fanavakavahana isa atomika, ary noho izany, ny sary elektronika miverina dia afaka maneho ny fizarana singa simika. Ny mikraoskaopy elektronika fanovana ankehitriny dia natanjaka tokoa, ny firafitra tsara rehetra na ny fisehoana ambonin-javatra dia azo avoaka in’arivony heny ho an’ny fandinihana sy ny famakafakana.

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. Ho fanampin’izany, ny halalin’ny sehatry ny sary mikraoskaopy elektronika dia lehibe lavitra noho ny an’ny mikraoskaopy optika, izay fomba iray manan-danja amin’ny famakafakana ny rafitra metallographic, ny vaky mikroskopika ary ny volombava tin.

7. X-ray energy spectrum analysis

Ireto voalaza etsy ambony ireto ny mikraoskaopy elektronika fitiliana etsy ambony dia matetika mazàna amin’ny spectrometer angovo X-ray. 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. Mandritra izany fotoana izany, ny fitaovana mifandraika amin’izany dia antsoina hoe spectrometer dispersion spektrum (WDS ho an’ny fohy) sy spectrometer fanaparitahana angovo (EDS raha fohy) arakaraka ny halavan’ny halavan’ny toetr’andro na angovo mampiavaka ny fahitana ny taratra X-ray. Ny famahana ny spectrométer dia ambony kokoa noho ny an’ny spectrometer angovo, ary ny hafainganam-pandalinan’ny spectrometer angovo dia haingana kokoa noho ny an’ny spectrometer angovo. Noho ny hafainganam-pandeha haingam-pandeha sy ambany vidin’ny spektrometro angovo, ny mikraoskaopy elektronika SCANNING ankapobeny dia miaraka amin’ny spectrometre angovo.

Miaraka amin’ny fomba fitiliana samihafa amin’ny taratra electron, ny spectrometer angovo dia afaka mamakafaka ny teboka, ny tsipika ary ny fiaramanidina amboniny, ary mahazo ny mombamomba ny fizarana singa samihafa.Point analysis yields all elements of a point; Famakafakana andalana Ny famakafakana singa iray dia tanterahina amin’ny tsipika voatondro isaky ny mandeha, ary ny fizarana tsipika ny singa rehetra dia azo amin’ny alàlan’ny scanning maromaro. Famakafakana ambonimbony Ny famakafakana ireo singa rehetra ao anaty sehatra iray. Ny atin’ny singa refesina dia ny salan’isan’ny fandrefesana ambonin’ny tany.

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. Ny famaritana habetsahan’ny spectrometer angovo dia voafetra, ary ny atiny latsaky ny 0.1% amin’ny ankapobeny dia tsy mora ny mamantatra. Ny fampifangaroana ny angovo angovo sy ny SEM dia afaka mahazo ny mombamomba ny morphology ambony sy ny firafitra miaraka, izay no antony ampiasana azy ireo betsaka.

8. Fanadihadiana momba ny spectroscopy Photoelectron (XPS)

Ny santionany amin’ny fitrandrahana taratra X, ny atin’ny atin’ny atin’ny atin’ny atin’ny atôma dia ho afa-mandositra ny fatorana ny atin’ny atiny sy ny endrika matevina miorina, ny fandrefesana ny angovo kinetika ny Ex, ny elektrôna akorandriaka anatiny an’ny atoma dia azo angovo mamatotra. Ny Eb, ny Eb dia miovaova amin’ny singa samihafa sy ny akorandriaka elektronika isan-karazany, io no “dian-tànana” an’ny masontsivana famantarana ny atoma, ny fananganana tsipika spectral dia ny spectroscopy photoelectron (XPS). XPS dia azo ampiasaina amin’ny famakafakana kalitao sy habetsaky ny singa eo amin’ny faritra marivo (nanometera maromaro) misy ny santionany. Ho fanampin’izany, ny mombamomba ny fanjakana valence simika misy ny singa dia azo alaina amin’ny fiovan’ny simika ny hery mamatotra. Izy io dia afaka manome ny mombamomba ny fifamatorana eo amin’ny fanjakana valence ny sosona ambonin’ireo sy ireo singa manodidina. 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; Multilayers dia azo atao ihany koa ny mamakafaka lava amin’ny alàlan’ny fanesorana ny argon ion (jereo ny tranga etsy ambany) miaraka amin’ny fahatsapana be lavitra noho ny angovo angovo (EDS). XPS dia ampiasaina amin’ny famakafakana ny famakafakana kalitao PCB, ny fandalinana ny fandotoana ary ny fandalinana ny diplaoman’ny oksidasiana, mba hamaritana ny antony lalina mahatonga ny tsy fahombiazan’ny welding.

9. Differential Scanning Calorim-etry

Fomba fandrefesana ny fahasamihafana eo amin’ny fahan’ny herinaratra eo amin’ny akora sy ny votoatin’ny fanovozan-kevitra ho toy ny fiasan’ny maripana (na fotoana) eo ambanin’ny fanaraha-maso ny mari-pana. 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)

Ny famakafakana mekanika mafana dia ampiasaina handrefesana ny toetra mampiavaka ny solida, ranoka ary gels eo ambanin’ny hery Thermal na mekanika eo ambany fifehezana ny mari-pana. Ny fomba enta-mavesatra ampiasaina matetika dia misy faneriterena, fampidirana pin, fanitarana, famoritana, sns. Ny fisedrana andrana dia miraikitra amin’ny andry cantilever sy ny lohataona helika amin’ny alàlan’ny môtô ny enta-mavesatra apetraka, rehefa misy ny fiovan’ny endrika, ny mpanova samihafa mba hahitana ny fiovana, ary miaraka amin’ny fanodinana data, toy ny maripana, ny adin-tsaina ary ny fantsona aorian’ny ny fitaovana dia azo raisina eo ambanin’ny fifandraisan’ny fihenan’ny enta-mavesatra amin’ny hafanana (na fotoana). Raha ny fifandraisana misy eo amin’ny deformation sy ny mari-pana (na ny fotoana), ny fizicochemical sy ny thermodynamic fananana dia azo zahana sy fakafakaina. TMA dia be mpampiasa amin’ny famakafakana PCB ary ampiasaina indrindra amin’ny fandrefesana ireo mason-tsivana roa lehibe indrindra amin’ny PCB: coefficient fanitarana tsipika sy ny mari-pana amin’ny tetezamita fitaratra. PCB miaraka amin’ny coefficient fanitarana be loatra dia matetika mitarika amin’ny tsy fahombiazan’ny loaka vita amin’ny metaly rehefa vita ny welding sy ny fivondronana.