Dị ka onye na -ebu ihe dị iche iche na ebe mgbaama mgbama sekit, PCB aghọọla akụkụ kacha mkpa na ngwaahịa ngwaahịa elektrọnikị, ogo ya na ọkwa ntụkwasị obi ya na -ekpebi ogo na ntụkwasị obi nke ngwa ahụ niile. Agbanyeghị, n’ihi ọnụ ahịa na ebumnuche ọrụ, enwere ọtụtụ nsogbu ọdịda na nrụpụta na ngwa PCB.

Maka ụdị nsogbu ọdịda a, anyị kwesịrị iji ụfọdụ usoro nyocha ọdịda na -ejikarị eme ihe iji hụ na ogo PCB dị mma na ntụkwasị obi n’ichepụta. Akwụkwọ a chịkọtara usoro nyocha nyocha ọdịda iri maka ntụnye aka.

Usoro na akpata nyocha nke ọdịda PCB

1. Nnyocha anya

Nnyocha anya bụ ilele anya ma ọ bụ jiri ụfọdụ ngwa dị mfe, dị ka microscope stereoscopic, microscope microscope ma ọ bụ ọbụna iko na -ebuli elu, iji lelee ọdịdị PCB wee chọta akụkụ ndị dara ada yana ihe akaebe anụ ahụ dị mkpa. Isi ọrụ bụ ịchọta ọdịda ma buru ụzọ kpebie ọnọdụ ọdịda PCB. Nnyocha ọhụhụ na -enyochakarị mmetọ PCB, corrosion, ebe mgbawa bọọdụ, eriri sekit na oge ọdịda, ọ bụrụ na ọ bụ ogbe ma ọ bụ n’otu n’otu, ma ọ na -etinyekarị ya n’otu mpaghara, wdg. 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

Maka akụkụ ụfọdụ na-enweghị ike inyocha site n’ọdịdị, yana n’ime PCB site na oghere na ntụpọ ndị ọzọ dị n’ime, anyị ga-eji sistemụ fluoroscopy X-ray nyochaa. Sistemụ X-ray fluoroscopy bụ iji ọkpụrụkpụ ihe dị iche iche ma ọ bụ njupụta dị iche iche nke X-ray hygroscopicity ma ọ bụ nnyefe nke ụkpụrụ dị iche iche na onyonyo. A na -eji teknụzụ a elele ebe ntụpọ dị na nkwonkwo PCBA solder, site na ntụpọ oghere na ntụpọ na ngwaọrụ BGA ma ọ bụ CSP nwere nnukwu nkwakọ ngwaahịa. 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. Nyocha ngalaba

Ntụle iberi bụ usoro nke ịnweta usoro akụkụ PCB site na nlele, Mozis, iberi, ịchacha, corrosion, nleba anya na usoro na usoro dị iche iche. Enwere ike nweta ozi buru ibu gbasara microstructure nke PCB (site na oghere, mkpuchi, wdg) site na nyocha iberibe, nke na -enye ezigbo ntọala maka mmelite mma ọzọ. However, this method is destructive, once the slice is carried out, the sample will inevitably be destroyed; N’otu oge ahụ, usoro ihe nlele chọrọ dị elu, oge nkwadebe nlele dịkwa ogologo, mkpa maka ndị ọrụ nka zụrụ azụ ka ha mezue. For detailed slicing procedures, please refer to IPC standards IPC-TM-650 2.1.1 and IPC-MS-810.

4. Igwe nyocha microscope

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. N’oge a, igwe onyonyo onyonyo na-enyocha na-egosi uru pụrụ iche ya na nchọpụta na-adịghị emebi emebi nke PCB nwere oke nwere ọtụtụ. The general obvious bursting plate can be detected by visual inspection.

5. Nyocha microinfrared

Nnyocha infrared micro bụ ihe nlele infrared jikọtara ya na usoro nyocha microscope, ọ na -eji ihe dị iche iche (ọkachasị ihe ndị dị ndụ) na ụkpụrụ nke mmịpụta infrared spectrum, na -enyocha ihe mejupụtara ihe ndị ahụ, yana mikroskopu nwere ike ime ọkụ na -ahụ anya na ìhè infrared. na ụzọ ọkụ, ọ bụrụhaala n’okpuru oghere a na -ahụ anya, nwere ike chọọ nyocha nke ihe ndị na -emerụ emerụ. Na enweghị microscope, spectroscopy infrared nwere ike nyochaa naanị nnukwu nlele. 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. Nyocha nyocha microscopy elektrọn

Nnyocha microscope elektrọn (SEM) bụ otu n’ime sistemụ onyonyo elektrọn elektrọnik kacha baa uru maka nyocha ọdịda. Ụkpụrụ ya na -arụ ọrụ bụ imepụta ọkụ elektrọn nke nwere dayameta nke iri puku ruo puku puku angstroms (A) site n’ilekwasị anya na ọkụ elektrọn nke na -esi na cathode nke anode mere ngwa ngwa. N’okpuru mmegharị nke ịgbagharị eriri igwe nyocha, Osisi elektrọn na -enyocha elu isi ihe nlele site n’otu isi n’otu oge na usoro ohere. Igwe ọkụ elektrọn nke nwere ume dị elu na-akụda elu nlele ahụ wee mepụta ozi dị iche iche, nke enwere ike ikpokọta ma gbasaa iji nweta eserese dị iche iche kwekọrọ na ihuenyo ngosi. 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. A na -ewepụta elektrọnịkịgharị obi ụtọ dị elu nke ihe nlele 100 ~ 1000nm, ha na -ewepụta njiri mara dị iche iche na ọnụọgụ atọm nke ihe ahụ. Ya mere, onyonyo elektrọnik nke nwere azụ nwere njirimara morphologic na ikike ịkpa oke ọnụọgụ atọm, yabụ, onyonyo elektrọnik nwere ike gosipụta nkesa kemịkal. Igwe onyonyo elektrọnik dị ugbu a dị ike nke ukwuu, ụdị ọ bụla dị mma ma ọ bụ atụmatụ elu nwere ike bulie ya elu ruo narị puku ugboro maka nlele na nyocha.

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. Na mgbakwunye, ịdị omimi nke onyonyo onyonyo elektrọnik na -enyocha buru ibu karịa nke microscope ngwa anya, nke bụ ụzọ dị mkpa maka nyocha nke ihe eji arụpụta metallographic, mgbawa microscopic na ajị ajị tin.

7. X-ray energy spectrum analysis

Igwe onyonyo elektrọnikọnụ a kpọtụrụ aha n’elu na-enwekarị ihe nlele ike 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. N’otu oge ahụ, a na-akpọ ngwa ndị kwekọrọ na ya spectrometer dispersion spectrum (WDS maka mkpụmkpụ) na ike ịgbasa spectrometer (EDS maka mkpụmkpụ) dabere na ebili mmiri njiri mara ma ọ bụ ike njiri mara nchọpụta X-ray. Mkpebi nke spectrometer dị elu karịa nke ike spectrometer, yana nyocha nyocha nke ike spectrometer dị ngwa karịa nke ike ọkụ. N’ihi oke ọsọ na ọnụ ala nke ihe nlele elele ike, igwe onyonyo elektrọnik SCANNING nwere ngwa elele ike.

Site na usoro nyocha dị iche iche nke ọkụ elektrọn, spectrometer ike nwere ike nyochaa isi, ahịrị na ụgbọ elu, wee nweta ozi nke nkesa ihe dị iche iche.Point analysis yields all elements of a point; Nyocha ahịrị. A na -eme nyocha otu n’otu ahịrị a kapịrị ọnụ oge ọ bụla, a na -enweta nkesa ahịrị nke ihe niile site na ọtụtụ nyocha. Nnyocha elu nyocha nke ihe niile dị n’elu enyere. Ọdịnaya nke ihe a tụrụ atụ bụ nkezi nke oke nha nha.

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. Ezi nyocha nke ọnụọgụ nke spectrometer ike pere mpe, yana ọdịnaya erughị 0.1% anaghị adịkarị mfe ịchọpụta. Nchikota ụdịdị ike na SEM nwere ike nweta ozi nke morphology elu na ihe mejupụtara n’otu oge, nke bụ ihe kpatara eji eme ha ọtụtụ ebe.

8. Nyocha fotoelectron spectroscopy (XPS)

Ihe nlele site na irradiation X ray, elu nke electrons shei ime nke atọm ga -agbanahụ n’agbụ nke akwara na elu siri ike na -akpụ, tụọ ike kinetic nke Ex, enwere ike nweta ike elektrọnị n’ime nke atọm ike ike. Eb, Eb dị iche iche site na ihe dị iche iche na shei elektrọn dị iche iche, ọ bụ “mkpịsị aka” nke njirimara njirimara atọm, nhazi ahịrị spectral bụ fotoelectron spectroscopy (XPS). Enwere ike iji XPS maka nyocha ogo na nha nke ihe ndị dị na elu na -emighị emi (ọtụtụ nanomita) nke nlele elu. Na mgbakwunye, enwere ike nweta ozi gbasara steeti valence kemịkalụ site na ngbanwe kemịkalụ nke ike na -ejikọ. Ọ nwere ike ịnye ozi nke njikọ dị n’etiti steeti valence nke oyi akwa elu yana ihe ndị gbara ya gburugburu. 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; Enwekwara ike nyochaa ọtụtụ ihe ogologo oge site na ibepu argon (lee ikpe dị n’okpuru) nwere nnukwu mmetụta karịa ụdị ike (EDS). A na -ejikarị XPS eme ihe na nyocha nke ịdị mma mkpuchi mkpuchi PCB, nyocha mmetọ na nyocha nzere oxidation, iji chọpụta ihe dị omimi nke ịgbado ọkụ adịghị mma.

9. Differential Scanning Calorim-etry

Usoro iji tụọ ihe dị iche na ntinye ike n’etiti ihe na ihe nrụtụ aka dị ka ọrụ nke ọnọdụ okpomọkụ (ma ọ bụ oge) n’okpuru njikwa ọnọdụ okpomọkụ. 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)

A na -eji nyocha Mechanical Thermal eme ihe iji tụọ njirimara nrụrụ nke ihe siri ike, mmiri mmiri na gels n’okpuru ike ọkụ ma ọ bụ Mechanical n’okpuru njikwa okpomọkụ. Ụzọ ibu ndị a na -ejikarị eme ihe gụnyere mkpakọ, ntinye ntụtụ, ịgbatị, ehulata, wdg. Nnwale nnwale gụnyere nke edobere na cantilever beam na nkwado mmiri nke helical, site na moto nke ibu etinyere, mgbe nrụrụ nlele ahụ mere, igwe mgbanwe dị iche iche iji chọpụta mgbanwe ahụ, yana yana nhazi data, dị ka ọnọdụ okpomọkụ, nrụgide na nsogbu mgbe enwere ike nweta ihe ahụ n’okpuru mmekọrịta nrụrụ dị oke mkpa na ọnọdụ okpomọkụ (ma ọ bụ oge). Dabere na mmekọrịta dị n’etiti nrụrụ na ọnọdụ okpomọkụ (ma ọ bụ oge), enwere ike ịmụ ma nyochaa ihe ọmụmụ physicochemical na thermodynamic. A na -ejikarị TMA eme ihe na nyocha PCB ma a na -ejikarị ya na -atụle ọnụọgụ abụọ kachasị dị mkpa nke PCB: ọnụọgụ ịgbatị ahịrị na mgbanwe mgbanwe iko. PCB nwere ọnụọgụ mgbasawanye buru ibu ga -ebutekarị ọdịda nke oghere ndị nwere metallized mgbe ịgbadochara na mgbakọ.