Bwrdd cylched printiedig (PCB) can be divided into rigid PCB and flexible PCB, the former can be divided into three types: single-sided PCB, double-sided PCB and multi-layer PCB. According to the quality grade, PCB can be divided into three quality grades: 1, 2 and 3, of which 3 is the highest requirement. Mae gwahaniaethau yn lefelau ansawdd PCB yn arwain at gymhlethdod a gwahaniaethau mewn dulliau profi ac arolygu.

Hyd yn hyn, mae PCBS anhyblyg dwy ochr ac aml-haen wedi meddiannu ystod gymharol fawr o gymwysiadau mewn electroneg, gyda PCBS hyblyg weithiau’n cael ei ddefnyddio mewn rhai achosion. Therefore, this paper will focus on the quality inspection of rigid double-sided and multi-layer PCB. After PCB manufacturing, inspection must be carried out to determine whether the quality meets the design requirements. It can be said that quality inspection is an important guarantee to ensure the quality of products and the smooth implementation of subsequent procedures.

Safon arolygu

Mae safonau arolygu PCB yn cynnwys yr agweddau canlynol yn bennaf:

A. Standards set by each country;

B. Safonau milwrol ar gyfer pob gwlad;

C. Industrial standards, such as SJ/T10309;

D. PCB inspection instructions formulated by the equipment supplier;

E. Gofynion technegol wedi’u marcio ar luniad dylunio PCB.

Ar gyfer PCBS y nodwyd eu bod yn hanfodol i’r offer, rhaid archwilio’r paramedrau a’r dangosyddion nodweddiadol hanfodol hyn o’r pen i’r traed yn ogystal ag archwiliad rheolaidd.

Eitemau arolygu

Waeth bynnag y math o PCB, rhaid iddynt fynd trwy ddulliau a rhaglenni arolygu ansawdd tebyg. According to the inspection method, the quality inspection items usually include appearance inspection, general electrical performance inspection, general technical performance inspection and metal coating inspection.

• Archwiliad ymddangosiad

Mae archwiliad gweledol yn hawdd gyda chymorth pren mesur, caliper vernier, neu chwyddwydr. Mae’r eitemau a wiriwyd yn cynnwys:

A. Thickness, surface roughness and warpage of the plate.

B. Dimensiynau ymddangosiad a chynulliad, yn enwedig dimensiynau’r cynulliad sy’n gydnaws â chysylltwyr trydanol a rheiliau tywys.

C. Integrity and clarity of the conductive pattern, and whether there are bridge short circuits, open circuits, burrs or gaps.

D. Ansawdd wyneb, p’un a oes pyllau, crafiadau neu dyllau pin ar wifrau neu badiau printiedig.

E. Lleoliad tyllau padiau a thyllau eraill. Check whether the through holes are missing or drilled incorrectly, whether the diameter of the through holes meets the design requirements and whether there are nodules and gaps.

F. Quality and firmness of pad coating, roughness, brightness and voidage of raised defects.

G. Ansawdd cotio. Electroplating flux is uniform, firm, position is correct, flux is uniform, its color is in line with relevant requirements.

H. Character quality, such as whether they are firm, clear and clean, without scratches, punctures or breaks.

• Archwiliad perfformiad trydanol arferol

There are two types of tests under this type of check:

A. Connection performance test. During this test, a multimeter is usually used to check the connectivity of the conductive pattern, with emphasis on the metallized perforations of double-sided PCBS and the connectivity of multi-layer PCBS. Ar gyfer y prawf hwn, bydd y gwneuthurwr PCB yn darparu archwiliad arferol o bob PCB parod cyn iddo adael y warws i sicrhau bod ei swyddogaethau sylfaenol yn cael eu cyflawni.

B. Prawf perfformiad inswleiddio. This test is designed to check the insulation resistance on the same plane or between different planes to ensure the insulation performance of the PCB.

• Archwiliad technegol cyffredinol

Mae arolygiad technegol cyffredinol yn cynnwys archwaeth hydoddedd ac adlyniad cotio. Ar gyfer y cyntaf, gwiriwch natur wlyb y sodr i’r patrwm dargludol. For the latter, inspection can be carried out by qualified tips that are first glued to the plating surface to be examined and can then be quickly removed even after pressing. Nesaf, dylid arsylwi ar yr awyren blatio i sicrhau bod plicio yn digwydd. Yn ogystal, gellir dewis rhai dulliau arolygu yn ôl y sefyllfa wirioneddol, megis cryfder cwympo ffoil copr a metaleiddio trwy gryfder tynnol.

• Meteleiddio trwy arolygiad

The quality of metallized through holes is very important for double-sided PCB and multi-layer PCB. Many failures of electronic modules and even the whole equipment are due to the quality of the metallized holes. Therefore, it is necessary to pay more attention to the inspection of metallized through holes. A. Rhaid i awyren fetel y wal dwll drwodd fod yn gyflawn, yn llyfn ac yn rhydd o geudodau neu fodylau bach trwy wirio metaleiddiad sy’n cwmpasu’r agweddau canlynol.

B. Electrical properties should be checked according to the short and open circuit of pad and metallized through hole coating, and the resistance between the through hole and the lead.

C. After environmental testing, the resistance change rate of the through-hole should not exceed 5% to 10%.

D. Mechanical strength refers to the bonding strength between the metallized hole and pad.

E. Metallographic analysis tests check coating quality, coating thickness and uniformity, and adhesion strength between coating and copper foil.

Metallization through inspection is usually a combination of visual inspection and mechanical inspection. Mae archwiliad gweledol yn golygu dinoethi’r PCB i oleuo a gweld a yw’r wal drwodd, llyfn trwy dwll yn adlewyrchu golau yn gyfartal. However, walls containing nodules or voids will not be too bright. For volume production, an in-line inspection device (e.g., a flying needle tester) should be used.

Due to the complex structure of multi-layer PCBS, it is difficult to locate faults quickly once problems are found during subsequent unit module assembly tests. As a result, inspections of its quality and reliability must be very rigorous. In addition to the above routine inspection items, other inspection items also include the following parameters: conductor resistance, metallization through hole resistance, inner short circuit and open circuit, insulation resistance between the lines, coating adhesion strength, adhesion, thermal impact resistance, mechanical impact impact strength, current strength, etc. Each indicator must be obtained through the use of specialized equipment and methods.