Multilayer PCBs are considered high-speed, multi-functional and of high-capacity despite their small size

The function of Printed Circuit Boards (PCB) is to connect electrical components mechanically. It is a mass product and the manufactures are noted for high-volume production. In the competitive PCB market, maintaining the right product quality is a matter of survival.

One important parameter in PCB production is glass transition temperature (TG). It is an important dimension that denotes the temperature at which resin matrix converts from a glassy, brittle condition into soft and elastic one.

Technically, TG is not the maximum operational temperature. It assumes importance as the temperature at which a material is able to withstand a continuous thermal load at the operating temperature.

Materials, where TG exceeds 170°C is called a high TG material.

High tg PCB materials display the following properties:

 High-temperature durability

 Long delamination durability

 Low Z-axis expansion;

Multilayer PCBs find applications in professional electronic equipment such as computers and military equipment. They are best in high-speed circuit and provide more space for the conductor pattern and power.

In multilayer PCBs, PCBS are stacked together with reliable predefined mutual connection and the costs are high because of the complex manufacturing process.

Multilayer PCB suppliers offer PCBs with varied specifications. Connecting electronic components to a circuit board involves several techniques including the surface mount technique and hole techniques

Multilayer PCBs are considered high-speed, multi-functional and of high-capacity despite their small size. With electronic devices becoming smaller and lighter, PCB design calls for minimizing the length of the signal line and ditching parallel routes.

Since, single-sided or double-sided PCBs cannot meet the requirements multilayer PCBs take the centre stage with high tolerance and even 24 layers. In optimizing the capacity of a printed circuit board, attention has to be paid to the equipment, fabrication, assembly and tests. In prototyping PCBs, outsourcing is a good option to save on costs.

Those with in-house PCB fabrication and assembly facility take up prototyping and makes sense to subcontract a vendor specialized in the prototyping of PCBs.  Those with online quote system can save time and details like design requirements in terms of thickness, type of material and production specifications can be comfortably quoted in the online quote system.

In PCB production, the cost is deeply linked to the volumes. It is less expensive to manufacture big volumes of PCBs.

*Bio

The author, David Spencer, is an electrical engineer with long experience in PCBs industry and runs a consultancy in London.

The secret of High Tg PCB Supplier From China

The Printed circuit boards (PCB) market is thriving. Being indispensable products for the electronics industry, PCBs are catalysts of growth in the industrial manufacturing sector.

With more electronics products entering the market, the demand for PCB is always high. The companies involved in PCB are in a race to satisfy varied requirements.

Generally, the PCB manufacturer will be playing a volume game for economies of scale. There are thousands of companies involved in high scale production of PCBs. But all of them cannot be called as manufacturing prime quality products.

There is high competition in domestic, as well as global markets. Positively, it presents an opportunity for manufacturers to establish themselves with better quality standards to grab more customers.

As a product, PCB is exposed to high thermal loads and can endure long-term operating temperature. So the use of most appropriate material that can withstand high temperature is number one factor in deciding a supplier or manufacturer.

There may be other specifications — 3/3 space/trace, gold plating, thin dielectrics, impedance control, micro via, etc. So, all these mean higher-technology designs and more attention to quality.

Many high-end industries seek high TG PCB. Basically, TG (Glass transition) is the value in determining the temperature at which a resin matrix converts itself from a glassy, brittle condition to a soft elastic one.

There will be an upper TG value at which the resin decomposes and delamination takes place. When TG is over 170°C, it is called high TG material. In choosing a PCB firm it is critical that an informed choice and decision is made. They must be capable of performing conventional assembly of mixed technology for double sided configuration and electronic components have to be on standard rigid, hybrid ceramic or flexible circuit substrates.

Other particulars include conductive materials suiting requirements in both automated and manual equipment to assemble low volume PCB.

What is important is ensuring that the processes are in place. If a board has BGAs, the supplier must make sure they have BGA assembly and rework capability and include X-ray to verify the assembly is good.

For large volumes, check whether they have sophisticated pick and place equipment. Also, the resources are n place to make paste stencils and blank PCBs while testing the boards for the desired parameters and output.

For prototyping pre-check all errors in layout and remove mistakes in the BOM as parts not matching the footprints on the board will turn out to be a risk.