As the carrier of various components and the hub of circuit signal transmission, PCB ua lilo i mea nui a koʻikoʻi nui o nā huahana ʻike uila, ʻo kona kūlana a me ka pae hilinaʻi e hoʻoholo i ka maikaʻi a me ka hilinaʻi o nā pono āpau. Eia naʻe, ma muli o ke kumu kūʻai a me nā kumu loea, nui nā pilikia kūleʻa i ka hana a me ka noi PCB.

No kēia ʻano pilikia pilikia ʻole, pono mākou e hoʻohana i nā ʻano loiloi manuahi hoʻohana pinepine ʻia e hōʻoia i ka pae o ka maikaʻi a me ka hilinaʻi o PCB i ka hana ʻana. Hōʻuluʻulu kēia pepa i nā ʻenehana kālailai pono ʻole he ʻumi.

ʻO ka hana a hana i ke anamanaʻo o PCB holo pono ʻole

1. Nānā ʻike maka

Nānā ka nānā ʻana e nānā a hoʻohana paha i kekahi mau mea maʻalahi, e like me ka microscope stereoscopic, microscope metallographic a i ʻole ke aniani hoʻonui, e nānā i ka hiʻohiʻona o PCB a loaʻa i nā ʻāpana kūleʻa a me nā hōʻike kino pili. ʻO ka hana nui e huli i ka ʻole a e hoʻokolokolo mua i ke ʻano hemahema o PCB. Nānā ka nānā nui ʻana i ka haumia PCB, ka popopo, kahi o ka pahū papa, kaapuni kaapuni a me ka maʻamau o ka holo pono ʻole, inā he pūʻulu a kanaka paha ia, inā paha e noʻonoʻo mau ʻia i kekahi wahi, a pēlā aku. 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

No kekahi mau ʻāpana i hiki ʻole ke nānā ʻia e ka helehelena, a ʻo loko hoʻi o ka PCB ma o ka puka a me nā hemahema ʻē aʻe o loko, pono mākou e hoʻohana i ka ʻōnaehana fluoroscopy X-ray e nānā. ʻO ka ʻōnaehana fluoroscopy X-ray ka hoʻohana ʻana i nā mānoanoa o nā mea like ʻole a i ʻole ka nui o nā kumuwaiwai o ka X-ray hygroscopicity a i ʻole ka transmittance o nā kumuhana ʻokoʻa i ke kiʻi. Hoʻohana ʻia kēia ʻenehana e nānā i ka wahi o nā kīnā i nā hui solder PCBA, ma o nā kīnā o nā puka a me nā kīnā i nā hāmeʻa BGA a i ʻole CSP me ka hoʻopili kiʻekiʻe. 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. Nānā ʻāpana

ʻO ka ʻāpana slice ke kaʻina hana o ka loaʻa ʻana o ka ʻāpana keʻa PCB ma o ka laʻana ʻana, Mosaic, ʻāpana, anai ʻana, ka popopo, ka nānā ʻana a me nā ʻano hana a me nā ʻanuʻu. 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; I ka manawa like, kiʻekiʻe ke ʻano o nā koina laʻana, lōʻihi hoʻi ka manawa hoʻomākaukau sample, ka pono no nā limahana loea i hoʻomaʻamaʻa e hoʻopau. For detailed slicing procedures, please refer to IPC standards IPC-TM-650 2.1.1 and IPC-MS-810.

4. Ke nānā pono ʻana i ka microscope acoustic

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. I kēia manawa, hōʻike ka microscope acoustic scanning i kāna pono kūikawā i ka loaʻa ʻana o ka PCB kiʻekiʻe kiʻekiʻe. The general obvious bursting plate can be detected by visual inspection.

5. Nānā Microinfrared

ʻO ka anamanaʻo infrared micro ka infrared spectroscopy i hui pū ʻia me ka microscope analysis analysis, hoʻohana ia i nā mea like ʻole (ʻo ka mea nui o nā mea ʻokanika) ma ke kumumanaʻo o ka omo infrared spectrum, ke kālailai ʻana i ka hui pū ʻana o nā mea, a me ka microscope hiki ke ʻike ʻia ka mālamalama a me ke kukui infrared. me ke ala māmā, ʻoiai ka lōʻihi ma lalo o ke kahua ʻike, hiki ke nānā no ke kālailai ʻana i nā mea hoʻohaumia ʻokanika. I ka loaʻa ʻole o kahi microscope, hiki i ka spectroscopy infrared ke kālailai wale i nā laʻana nui. 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. Ka nānā ʻana i ka ʻikepili microscopy electron

ʻO ka nānā ʻana i ka microscope electron (SEM) kekahi o nā ʻōnaehana kiʻi nui microscopic electron nui loa e pono ai no ka loiloi ʻole. ʻO kāna kumumanaʻo hana e hana i kahi kukuna uila me ke anawaena o nā ʻumi a hiki i nā tausani o nā angstroms (A) ma ke kau ʻana i ke kaola uila i hoʻoili ʻia mai ka cathode i hoʻonui ʻia e ka anode. Ma lalo o ka hana o ka deflection o ka wili scanning, Nānā ka uila uila i ka ʻili o ka laʻana ma kahi kiko i kekahi manawa a me kahi hoʻonohonoho. Pahu ka uila uila ikaika i ka ʻilikai o kahi hāpana a hana i nā ʻano ʻikepili like ʻole, i hiki ke hōʻiliʻili ʻia a hoʻonui ʻia e kiʻi i nā kiʻi like ʻole ma ka pakuhi hōʻike. 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. Hoʻokumu ʻia nā electron backscattered hauʻoli i ka laulā o 100 ~ 1000nm ma ka ʻili o ka hāpana, a hoʻopuka lākou i nā ʻano like ʻole me ka ʻokoʻa o ka helu ʻĀtoma o ka waiwai. No laila, he kiʻi morphologic a me ka hiki ke hoʻokae helu helu ʻĀtoma i ke kiʻi uila uila backscattered, a no laila, hiki i ke kiʻi uila uila backscattered ke hōʻike i ka hoʻokaʻawale ʻana o nā mea kemika. He mana loa ka microscope electron scanning o kēia manawa, hiki ke hoʻonui ʻia i kekahi hanana maikaʻi a i ʻole nā ​​hiʻohiʻona i nā haneli he mau kaukani mau manawa no ka nānā a me ke kālailai.

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. Hoʻohui ʻia, ʻoi aku ka nui o ka hohonu o ke kahua o ka kiʻi aniani microscope ʻoi aku ka nui ma mua o ka microscope ʻōnohi, kahi ʻano nui ia no ke kālailai ʻana i ke ʻano metalagraphic, uhaʻi microscopic a me nā whiskers tin.

7. X-ray energy spectrum analysis

ʻO ka microscopy electron scanning i ʻōlelo ʻia i luna e hoʻomākaukau mau ʻia me kahi spectrometer ikehu 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. I ka manawa like, ua kapa ʻia nā mea kani e like me ka spectrometer dispersion spectrum (WDS no ka pōkole) a me ka spectrometer hoʻopuehu ikehu (EDS no ka pōkole) e like me ke ʻano o ka nalu lōʻihi a i ʻole ka ikehu ʻano o ka ʻike ʻana i ka hōʻailona X-ray. ʻOi aku ka kiʻekiʻe o ka hoʻonā o ka spectrometer ma mua o ka spectrometer ikehu, a ʻoi aku ka wikiwiki o ka anamanaʻo o ka spectrometer ikehu ma mua o ka spectrometer ikehu. Ma muli o ka wikiwiki a me ke kumu kūʻai haʻahaʻa o nā spectrometers ikehu, hoʻolako ʻia ka microscopy electron SCANNING nui me nā spectrometers ikehu.

Me ka ʻokoʻa kaʻimi ʻana o ka uila uila, hiki i ka spectrometer ikehu ke kālailai i ke kiko, ka laina a me ka mokulele o ka ʻili, a loaʻa ka ʻike o ka hoʻokaʻawale ʻokoʻa o nā mea.Point analysis yields all elements of a point; Hoʻohālikelike laina Hana ʻia kahi loiloi ma kahi laina i kuhikuhi ʻia i kēlā me kēia manawa, a loaʻa ka hoʻokaʻawale laina o nā mea āpau e ka scanning he nui. Ka nānā ʻana i luna o ke aniani o nā mea āpau i kahi i hāʻawi ʻia. ʻO ka ʻikepili o nā mea i ana ʻia ka awelika o ka laulā o nā ana o luna.

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. Kaupalena ʻia ka helu helu o ka spectrometer ikehu, a ʻaʻole maʻalahi ka ʻike ma lalo o 0.1%. Hiki i ka hui pū ʻana o ka spectrum ikehu a me SEM ke loaʻa i ka ʻike o ka morphology o luna a me ka hoʻohui ʻana i ka manawa like, ʻo ia ke kumu e hoʻohana nui ʻia ai lākou.

8. ʻO ke anamanaʻo photoelectron spectroscopy (XPS)

ʻO nā laʻana e ka hoʻowalewale ʻana o X ray, e pakele ka ʻili o nā electrons pūpū o loko o ka atoma mai ke kauā o ka nucleus a me ka papa paʻa e ana ana, e ana ana i kona ikehu kinetic ka Ex, hiki ke loaʻa i nā electrons shell o ka atomo i ka ikehu paʻa o ʻElua ʻo Eb, ʻokoʻa ʻo Eb mai nā mea like ʻole a me nā pūpana uila ʻokoʻa, ʻo ia nā “manamana lima” o nā palena ʻike ʻoma, ʻo ka hoʻokumu ʻana i ka laina spectral ka spectroscopy photoelectron (XPS). Hiki ke hoʻohana ʻia ka XPS no ke kālailai qualitative a me ka nui o nā mea ma kahi papa pāpaʻu (kekahi mau nanometers) o ka laʻana o ka laʻana. Hoʻohui ʻia, hiki ke kiʻi ʻia ka ʻike e pili ana i nā kūlana valence kemika o nā mea mai nā loli kemikal o ka hoʻopaʻa paʻa ʻana i ka ikehu. Hiki iā ia ke hāʻawi i ka ʻike o ka pili ma waena o ke kūlana valence o ka papa o luna a me nā mea e pili ana. 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; Hiki ke kālailai lōʻihi ʻia nā multilayers e ka stron ion stripping (e ʻike i ka hihia ma lalo) me ka ʻike ʻoi aku ka ʻoi aku ma mua o ka spectrum o ka ikehu (EDS). Hoʻohana nui ʻia ka XPS i ke kālailai ʻana i ka anamanaʻo maikaʻi o ka uhi PCB, ka hōʻiliʻili haumia a me ke aniani degere, i mea e hoʻoholo ai i ke kumu hohonu o ka maikaʻi ʻole o ka wili.

9. Differential Scanning Calorim-etry

ʻO ke ʻano o ke ana ʻana i ka ʻokoʻa o ka hoʻokomo mana ma waena o kahi mea a me kahi mea kuhikuhi e like me ka hana o ka mahana (a i ʻole ka manawa) ma lalo o ka kaohi wela i hoʻolālā ʻia. 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. Test probe consists of fixed on the cantilever beam and helical spring support, through the motor of the applied load, when the specimen deformation occurs, differential transformer to detect the change, and together with the data processing, such as temperature, stress and strain after the material can be obtained under the negligible load deformation relations with temperature (or time). Wahi a ka pilina ma waena o ka deformation a me ka mahana (a i ʻole ka manawa), hiki ke hoʻopaʻa ʻia a kālailai ʻia nā waiwai physicochemical a me thermodynamic o nā mea. Hoʻohana ākea ʻo TMA i ka hoʻopili ʻana PCB a hoʻohana nui ʻia i ke ana ʻana i nā ʻaoʻao koʻikoʻi ʻelua o PCB: ka laulā hoʻonui hoʻonui a me ka mahana o ka hoʻololi aniani. ʻO PCB me ka coefficient hoʻonui nui loa e alakaʻi pinepine ai i ka haki ʻole o nā lua metallized ma hope o ka hoʻopili ʻana a me ka hoʻākoakoa.