PCB (pirinty boribory pirinty) 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. PCBS can be divided into three quality grades based on quality grade: Class 1, Class 2, and Class 3, with 3 of these having the highest requirements. Differences in PCB quality levels lead to differences in complexity and testing and inspection methods. So far, rigid double-sided and multi-layer PCBS account for a relatively large number of applications in electronic products, and sometimes flexible PCBS are used in certain situations. Therefore, this paper will focus on the quality inspection of rigid double-sided and multi-layer PCBs. After the PCB is manufactured, it must be inspected to determine whether the quality is compatible with the design requirements. It can be considered that quality inspection is an important guarantee of product quality and the smooth implementation of subsequent procedures.

Inspection standard

PCB inspection standards mainly include the following aspects:

A. Fenitra apetraky ny firenena tsirairay;

B. Fenitra miaramila ho an’ny firenena tsirairay;

C. Industrial standard such as SJ/T10309;

D. PCB inspection instructions formulated by equipment supplier;

E. Fepetra ara-teknika voamarika amin’ny sary famolavolana PCB.

For PCBS that have been identified as keyboards in equipment, these key characteristic parameters and indicators must be centralized and checked from the head, in addition to regular inspection. To the toes.

Inspection items

Regardless of the type of PCB, they must undergo similar quality inspection methods and items. Araka ny fomba fanaraha-maso, matetika ny zavatra fanaraha-maso kalitao dia ahitana fanaraha-maso maso, fanaraha-maso amin’ny fahombiazan’ny herinaratra ankapobeny, fanaraha-maso ny fahombiazana ara-teknika amin’ny ankapobeny, ary fanaraha-maso metaly.

• Visual inspection

Ny fanaraha-maso ny maso dia tsotra amin’ny alàlan’ny mpanapaka, kalifera vernier, na fitaratra manalehibe. Ny fanaraha-maso dia misy:

A. hatevin’ny lovia, fahasarotan’ny tany ary ady.

B. Appearance and assembly dimensions, especially assembly dimensions compatible with electrical connectors and guide rails.

C. Integrity and clarity of conductive patterns and the presence of bridging short, open burr, or void.

D. Ny kalitaon’ny velarana, ny fisian’ny lavaka, ny gorodona na ny lavaka amin’ny dian-tongotra na pirinty vita pirinty. Location of pad holes and other holes. Ny lavaka dia tokony hozahana raha tsy totohondry na tsy marina, ny savaivon’ny lavaka dia mahafeno ny fepetra takiana amin’ny famolavolana, ary ny nodules sy ny voids.

F. Pad quality and firmness, roughness, brightness, and clearance of raised defects.

G. Kalitaon’ny firakotra. The coating flux is uniform and firm, the position is correct, the flux is uniform, and the color meets the requirements.

H. Ny kalitaon’ny toetra amam-panahy, toy ny hoe hentitra, madio ary madio, tsy misy ratra, fidirana, na vaky.

• Fanaraha-maso ankapobeny ny fahombiazan’ny herinaratra

Misy fitsapana roa amin’ity karazana fanadinana ity:

A. Fitsapana fampisehoana fifandraisana. In this test, a multimeter is typically used to check the connectivity of conductive patterns through the focused metalized through holes of double-sided PCBS and the connectivity of multi-layer PCBS. For this test, the PCBCart provides general checks on each manufactured PCB before it leaves its warehouse to ensure that its basic functions are fulfilled.

B. Ity fitsapana ity dia natao hijerena ny fanoherana ny insulate an’ny fiaramanidina iray ihany na eo anelanelan’ny fiaramanidina samihafa mba hiantohana ny fahombiazan’ny insulation an’ny PCB.

• Fanaraha-maso ara-teknika ankapobeny

Ny fizahana ara-teknika ankapobeny dia misy fanaraha-maso fanamafisam-peo sy fanamafisam-peo. Ho an’ireo teo aloha dia zahao ny fahaizan’ny solder mankamin’ny lamina fitondran-tena. Ho an’ireto farany dia azo zahana amin’ny alàlan’ny toro-hevitra voafantina izay niraikitra voalohany tamin’ny vodilan’ny plating mba hozahana ary avy eo nesorina haingana rehefa avy noterena nitovy. Next, the plating plane should be observed to ensure that peeling occurs. In addition, some checks can be selected according to the actual situation, such as copper foil anti-fall strength and metalized anti-tensile strength.

• Metallisation amin’ny alàlan’ny fanaraha-maso

Ny kalitaon’ny lavaka metaly dia mitana andraikitra lehibe amin’ny PCB misy lafiny roa sy PCB maro sosona. Ny tsy fahombiazan’ny modules elektrika ary na dia ny fitaovana iray manontolo aza dia vokatry ny kalitaon’ny lavaka vy. Noho izany dia ilaina ny mandinika bebe kokoa ny fizahana ny lavaka metaly. Ireo fanaraha-maso metaly dia misy ireto manaraka ireto:

A. The metal plane of the through-hole wall should be complete and smooth, with no void or nodule.

B. The electrical properties shall be checked according to the short and open circuit of the pad and the resistance between the through-hole and the lead through the metallization of the plating plane. After environmental testing, the resistance change rate of the through-hole should not exceed 5% to 10%. Mechanical strength refers to the bonding strength between the metalized through-hole and pad. Metallographic analysis tests are responsible for checking the quality of the plating surface, the thickness and uniformity of the plating surface, and the bonding strength between the plating surface and the copper foil.

Metallization inspection is usually combined with visual inspection and mechanical inspection. Ny fanaraha-maso ny maso dia ny fandinihana fa ny PCB dia apetraka eo ambanin’ny hazavana ary ny rindrina mihodina amin’ny lavaka feno fitaratra dia manome taratra mazava. Na izany aza, ny mamaky ny rindrina misy nodule na voids dia tsy ho toy ny mazava. For mass production, inspection should be carried out by online testing equipment such as a flying needle tester.

Due to the complex structure of multi-layer PCB, it is difficult to locate faults quickly once problems occur in subsequent unit module assembly tests. Noho izany, ny fanamarinana ny kalitaony sy ny fahamendrehany dia tsy maintsy ho hentitra. In addition to the above routine inspection items, other inspection items include the following parameters: conductor resistance, metalized through-hole resistance, inner short circuit, and open circuit, insulation resistance between wires, electroplating plane bonding strength, adhesion, thermal shock resistance, impact resistance, mechanical impact, current strength, etc. Each indicator must be obtained through the application of specialized equipment and methods.