Before delving into the custom PCB assembly process, it is important to understand the different types of custom printed circuit boards. PCB is sometimes referred to as "PCB bare board" and is usually classified as follows:

Single sided PCB:The circuit pattern is only printed on one side of the circuit board, which is the simplest type, the most basic processing process, and the lowest cost.

Double sided PCB:Both sides of the PCB have circuit patterns, and the component density is higher than that of single-sided PCBs.

Multilayer PCB:The increasing density and complexity of PCB design have paved the way for the development of multi-layer PCBs. There are several layers in a multi-layer PCB, with pre impregnated material sandwiched in between.

Rigid PCB:Nowadays, most circuit boards are still rigid boards, which means they are made of hard or rigid dielectric woven glass materials.

Flexible circuit board:It is a thin and flexible substrate with excellent thermal and electrical properties. It is composed of high-strength polymer materials and is commonly used in mobile phones, disk drives, and cameras. Fine and tiny patterns can be printed onto flexible circuits.

Rigid joint plate:Rigid flex joint plate is a board formed by bonding rigid and flex plates together. Rigid flex boards and flexible printed circuit boards can also be single-sided, double-sided, or multi-layer.

Flexibility in design and functionality: Flexibly arrange with custom PCB assembly suppliers to meet customer needs and requirements. During the preparation of the circuit board, customers can choose the size and type of components to be used, with unlimited design options. The flexibility of customized PCB assembly services is reflected in the following aspects: flexible technology, flexible and diverse multi skilled engineering support, and flexible organizational structure.

Cost optimization:Select materials based on their functions and purposes to achieve cost optimization.

Higher efficiency:PCB customization can improve efficiency because design and development focus on functionality, eliminating unnecessary elements on the PCB.

Better performance:In customized PCB assembly services, performance is optimized by minimizing noise and enhancing signal integrity. This can be achieved by generating detailed designs while considering component location, size, signal routing, and other specific requirements. Customized PCBs are easier to market due to their uniqueness.

competitive power:Customized PCBs have better competitive advantages due to their unique design and functionality.

Before customizing PCB assembly services, it is necessary to input computer-aided design (CAD) files specifying the positions of customized PCB components and feeders into the system. The design data is processed by a manufacturing file type conversion program to achieve automatic PCB assembly.

The first step in customizing PCB assembly services is solder paste printing. In this step, solder paste is deposited onto the printed circuit board through template printing. To evenly distribute the solder paste, press the scraper into the template holes and cross the surface of the template. Research has shown that over 50% of welding defects are caused by solder paste printing issues. Optimization and evaluation are needed to improve the first pass rate. Various factors can affect the printing performance of templates, including template aperture size, solder paste characteristics, and parameter settings. During the solder paste printing process, some defects may be encountered, such as bridging, where the solder paste 'bridging' to adjacent pads can cause electrical short circuits.

The quality of solder joints is crucial for ensuring electrical connections between components and PCB boards. The volume of solder paste can be measured using an automatic optical inspection system. The solder paste inspection machine captures images of PCBs and uses processing software to analyze them by matching the images of solder paste with known acceptable images. Lighting is crucial in all detection systems to obtain enhanced images, thereby improving accuracy and efficiency. It is also necessary to study the positioning of lighting to ensure that all areas of the solder paste are inspected.

Component placement machine is a high-speed, automated machine that can meet high production demands. In this customized PCB assembly step, various types, shapes, and sizes of electronic components are mounted on the bare PCB. The robotic arm first enters its original position and moves to the gripper fixture. After obtaining the correct gripper, the robotic arm moves to a specific feeder, picks up the components, and places them in the predetermined position on the PCB. The picking and placing action sequence of the machine continues until the last component is placed in the correct position on the circuit board.

One possible issue during component placement is the fluid properties of solder paste and the misalignment of components caused by unbalanced placement during the movement of the robotic arm. Self alignment may still occur during the subsequent reflow process, but component offset should still be minimized and optimized as much as possible. Other sources of component offset include machine vibration, unstable PCB placement, and uneven distribution of solder paste.

A circuit board with solder paste and installed components is preheated in a reflow oven to evaporate the flux, reaching a peak temperature to melt the solder paste and form intermetallic compounds, thereby achieving the desired solder joints. To fully attach the component to the surface of the PCB pad, the temperature must exceed the melting temperature of the solder alloy. The melting process causes metal fillers to aggregate into solder, which then wets the surface of the PCB.

This reflux step is achieved using a furnace with a series of individually programmable heating zones. Modern reflow machines typically use convective heat transfer to effectively heat the entire custom PCB assembly. The common method for evaluating custom PCB reflow curves is to connect external thermocouples based on engineering judgment and professional knowledge of similar product or component types in the past. Then pass the circuit board through the oven, and the initial settings can be modified until the optimal thermal curve is obtained. The heat curve is a time temperature chart that determines the heating distribution in order to have appropriate solder joints between the PCB and solder paste. There are four main stages during reflow soldering:

Preheating: Slowly increase the temperature to preprocess the circuit board.

Soaking: Activate the soldering flux to prevent metal oxidation on the surface solder pads of the PCB.

Reflux: Solder particles melt and become liquid.

Cooling method: Solder joints are ultimately formed between the components and the PCB pads.

Quality is crucial in customized PCB assembly services. During the customized PCB assembly process, any PCB defects should be accurately detected as early as possible to prevent malfunctions during application. Manual visual inspection has limitations such as high false detection rate and low processing rate. The automatic optical inspection system has advantages such as high efficiency, zero processing related defects, and detection accuracy. AOI scans the entire circuit board, captures images, and compares them with reference images to determine if there are any abnormalities or defects.

Cost plays an important role in the decision-making of supplier procurement teams. A customized PCB assembly manufacturer that can provide low prices will have an advantage in being selected from the potential candidate list. Despite unique requirements, custom PCB assembly suppliers should be able to provide competitive price advantages in order to be selected as custom PCB assembly services. More quantity often helps to reduce costs. A detailed quotation will help you understand the cost of each material and custom PCB assembly process, and provide you with tips on how to further reduce costs and negotiate with custom PCB assembly manufacturers. Various factors can affect the price of customized PCBs, such as the number of layers, material selection, PCB size, and design complexity. In this way, Chinese custom PCB assembly manufacturers have a significant advantage over custom PCB assembly manufacturers in European countries.

Customized PCB assembly suppliers that can provide fast turnaround time will have an advantage in the supplier selection process. The turnover time is highly dependent on the complexity and required quantity of customized PCB design. The entire customized PCB assembly service from PCB manufacturing to assembly should be considered to understand delivery time and logistics considerations. If the delivery time is not met, a penalty must be agreed upon. There should be a flexible option to accelerate delivery speed and shorten delivery time. All these terms and conditions should be clearly defined in the quotation. Most of the time, Chinese custom PCB assembly suppliers do a great job in terms of delivery time and logistics.

Custom PCB assembly manufacturers typically provide a checklist that they need to fill out and respond to regarding their quality and regulatory compliance requirements. ISO9001 certification is usually the primary requirement for shortlisted custom PCB assembly suppliers. ISO has a set of standards that define the requirements for a quality management system. Underwriters Laboratories (UL) is also an independent product safety testing organization responsible for certifying electronic products. All components, even the smallest ones, should comply with UL requirements to ensure safety, quality, and performance. Custom PCB assembly service providers should also conduct quality control on their production lines to immediately detect defects and easily correct any issues during the custom PCB assembly process. Electrical testing of the PCB before shipment is a prerequisite, so that only qualified circuit boards can be sent to customers. All of these quality controls must be demonstrated through documentation.

Due to the high technical and professional machinery required for printed circuit board assembly, custom PCB assembly manufacturers should have available resources and capabilities to support custom PCB assembly services. Due to frequent communication and discussions between custom PCB designers and custom PCB assembly suppliers regarding requirements, limitations, and risks, the preferred custom PCB assembly supplier should possess professional knowledge and technical expertise in design rules, equipment capabilities, and potential issues that may arise. If the requirements are misunderstood in the initial stage of a customized PCB project, problems and delays may arise. On site visits will also greatly assist in conducting practical and first-hand evaluations of customized PCB assembly service providers. During the visit, PCB assembly lines and controls can be evaluated and audited to understand whether the manufacturing site can produce high-quality PCBs.

Unlike mass production of PCB assembly, small batch customized PCB assembly requires more time and effort, and the output is relatively low. Therefore, many PCB suppliers have little interest in small batch customized PCB assembly services. This has led to a reduction in the number of custom PCB assembly manufacturers, which can only meet the needs of medium or small batch production. Due to technical limitations and other factors, some custom PCB assembly manufacturers have minimum order quantities. Therefore, it is advisable for customers to discuss with custom PCB assembly service providers in advance to manage costs and related issues. If you plan to cut expenses, it is recommended to contact a Chinese custom PCB assembly manufacturer.

Due to its various advantages, the large-scale production of customized PCBs is becoming increasingly popular. Customized design for specific applications may be the best choice, especially when standard PCBs cannot meet the required performance. Design development and prototype design should be carried out in the initial stage to determine whether the customized PCB can operate according to requirements. If the design and testing are not complete, a series of designs, builds, and tests are required, which means the project requires additional costs and time.

Therefore, finding a suitable custom PCB assembly service provider is crucial for achieving simplified communication and requirement understanding throughout the entire product lifecycle. If you are looking for any possible custom PCB assembly supplier, then Chinese custom PCB assembly supplier Haibo is your best choice.

If pursuing cost-effective FPC manufacturing services, choosing a Chinese manufacturer is the best choice. As a manufacturing powerhouse, China has abundant resources, cheap labor, and a large number of technical personnel. We recommend Haibo, a Chinese FPC assembly service provider with over 10 years of experience, who has performed outstandingly in various aspects

Efficient and reasonable quotation:There is an efficient quotation process to assist you in making decisions, providing reasonable prices and highly competitive quotes in China.
High quality and reliable products:Produce high standard printed circuit boards, manufacture and test according to specifications, international standards, and internal controls, and conduct pre production inspections to ensure robust processes.
Quick and on-time delivery:The assembly equipment is in good condition, with high productivity, minimal downtime, short delivery time, and also provides urgent services.
Timely and effective response:Always respond to customer needs, provide accurate information, answer questions through multiple channels, and offer one-stop services.
Strong technical strength:China's FPC manufacturing technology is leading, and Haibo has a complete SMT solution that covers assembly, inspection, and other capabilities. It also provides prototype production and customization services.