Quelles sont les étapes de fabrication des PCBA?

Qu'est-ce que PCBA? pcba est un processus d'assemblage de composants sur une carte PCB vierge. À travers l'introduction de l'article suivant, vous pouvez avoir une compréhension complète du processus de fabrication des PCBA.

Prototypage de PCB

Avant que la production de masse puisse commencer pour un produit donné, il est nécessaire de créer des échantillons afin de bien comprendre les problèmes potentiels et de développer des solutions. Les étapes impliquées dans Prototypage de PCB sont les suivants:

1. Vérification des nomenclatures et des fichiers Gerber

Ces fichiers contiennent une liste de tous les composants requis pour Assemblage PCB, et il est crucial de vérifier l'exactitude de tous les matériaux avant le début du processus de prototypage.. Des ingénieurs expérimentés examinent attentivement la conception des cartes, échantillons de composants et nomenclature avant de lancer l'assemblage.

2. Fabrication de pochoirs PCB et SMT

Si vous êtes engagé dans l'assemblage de PCB à guichet unique, le Fabrication de PCB l'entreprise produira également les PCB. Pendant la production de PCB, Des pochoirs SMT pour l'assemblage de PCB sont également fabriqués. La durée de production des PCB dépend de la complexité des circuits imprimés.

3. Test de première pièce PCBA

Un test complet est effectué sur la première carte assemblée pour garantir que toutes les fonctions sont normales. Si des problèmes sont identifiés, les ingénieurs y répondront le plus rapidement possible. Divers équipements de test seront utilisés au cours de ce processus, et un rapport de test sera fourni une fois terminé. En supposant que tous les tests sont normaux, la production par lots peut commencer après l'approbation du client.

Étapes de fabrication de production de masse de PCBA

Les étapes de fabrication de la production de masse de PCB sont les suivantes:

1、Programmation et réglage du bonder

Conformément à l'exemple de carte d'emplacement des correctifs de nomenclature fourni par le client, les coordonnées de l'emplacement des composants du patch pour effectuer la procédure. Puis avec le client fourni par le patch SMT traitant les informations pour la première pièce.

2、Impression de pâte à souder

The solder paste will be printed on the pads of the PCB board with a stencil that needs to be soldered to the SMD of electronic components to prepare for the welding of components. The equipment used is the screen printing machine (printing machine), located at the front of the SMT SMT processing line.

3、Spice

Standard solder paste thickness ranges from 0.09mm to 0.15mm, and the solder paste must cover the PCB pads completely. The PCB comes in the SPI machine, and the machine detects if the solder paste thickness and shape are qualified for PCB assembly.

4、Patching

The electronic components SMD will be accurately mounted on the fixed position of the PCB. The equipment used is the mounting machine, which is located behind the screen printing machine in the SMT production line.

SMD machine is divided into high speed machine and general purpose machine

High-speed machine: used to paste the components with large and small pin pitch

Machine à usage général: paste pin pitch small (pin dense), large volume of components.

5、Fusion de la pâte à souder à haute température

The main is the solder paste through high temperature melting, cooling the electronic components SMD and Carte PCB firmly welded together, the equipment used for reflow oven, located in the SMT production line behind the placement machine.

6、Tests AOI

After reflow soldering, the PCBAs have to go through the AOI machine. A camera automatically scans the PCBA. And the AOI machine collects images, compares the tested solder joints with the set-up parameters in the database, checks out the defects on the PCB by image processing, and marks the defects on the screen. If there are defects, a quality control technician marks the defects on the circuit boards for maintenance.

The above is the automatic SMT assembly, and below is the THT assembly line. THT assembly is done manually.

7、Through-Hole (Pth) Assemblée

PTH assembly is the process of mounting PTH components on PCBAs. PTH components have much longer pins than SMDs, and the pins have to go through the PCB through-holes. This operation is quite simple and is usually done manually.

8、 Soudure d'onde

After the PTHT assembly, there is still space between the PTH pins and the PCBA, et soudure d'onde fills the space and connects the PTH components tightly to the PCBA.

The PCBAs go through a pre-heater to warm up and then go through the wave soldering oven. In the oven, the liquid tin fills the space between the PTH pins and the PCBA. When the PCBA leaves the oven, the tin cools down and solidifies. De cette façon, the PTH components are connected firmly to the PCBA.

9. Inspection visuelle

The manual inspection check focuses on the following items: whether there have been any changes to the version of the PCBA; whether the customer requires the use of substitute materials or components of a specified brand or plate; whether the direction of IC, diode, transistor, tantalum capacitor, aluminum capacitor, changer, and other components with direction is correct; defects after welding including short circuit, circuit ouvert, false parts, and false welding.

10. PTH Rework

This step mainly involves trimming the pins of some products that are too long. The technician will trim the PTH legs to 1-2mm long. Another technician uses a soldering iron to repair the PCBA if there are any places that are not soldered properly.

11. PCBA Function Test

Use the PCBA function tester to test the assembled PCBA, mainly testing the current, tension, capacitance, and other aspects of the product’s value.

12. Thermal Aging Test

The PCBAs are placed in a thermal chamber to be powered on for about 250 hours without interruption. All the PCBAs should follow the ECIA – EIA-364-17 standard.

13. Conditionnement

The tested products will be packed separately. The general packaging materials used are anti-static bubble bags, static cotton, and blister trays. Two main ways of packaging are used: the first is to use anti-static bubble bags or static cotton in rolls for separated packaging, which is currently the most common way of packaging; the second is to custom design blister trays according to the size of the PCBA. The PCBA is then placed in the blister tray for open packaging, mainly for PCBA boards with more sensitive or vulnerable SMD components.

Choose Leadsintec as Your PCBA Partner

If you have PCBA manufacturing and processing needs, Leadsintec is an excellent choice. We can provide a one-stop PCB manufacturing and processing service for our customers. Our products include intelligent devices, produits médicaux, aérospatial, military and other fields. We provide PCBA manufacturing services to customers from all over the world.