pcb assembly china



Introduction to Pcb Assembly China

PCBアセンブリ中国企業 are manufacturing analog circuit signals for more than 60 % of electric devices.  A PCB is a crucial part of any electronic gadget for tiny devices or complex computers. Its complex interconnect components include resistors, diodes, capacitors, etc., enabling the devices to work in series. generally, a printed circuit board works as a soul of any electrical component. it is very importantly, so the PCB assembly process should be error-free and requires attention to common mistakes in assembly making process. Here are some factors to note:

Pcb Assembly China Basis rules for designing

There are three basic thoughts for designing rules.
  1. Component placement
  2. Signal conductor
  3. Supply and ground line conductors

Component placement

Component of PCB

In analog circuit design, component placement has significant role.

Following are the pcb component placement guideline:

  • Front panel components should have proper alignment.
  • Internal components must have a board edge placement
  • Metal case components should be far from internal components.
  • Heat sensitive and heat-producing components should not have side by side placement. Therefore proper planning must be there for the arrangement of both. The heat-producing components should be arranged all over the board evenly to avoid overheating and the heat-sensitive components must be placed with appropriate space from them.
  • Similarly, mounting screws, it is necessary to have proper space between nuts and washer and there must not be any conductive track beneath this.

Signal conductor instructions for Pcb Assembly China

Reference level, feedback, input, output, etc. are some important tasks for pcb assembly china. Moreover, the signal conductor has to be short as possible for all analog circuit design. The signal conductor for the following circuits should have an adequate formation.


  1. High gain DC Amplifier
  2. Differential Amplifier
  3. Low-level signal Amplifier
  4. High-frequency Amplifier
  5. Multi-stage Amplifier

Brief description of Pcb Amplifier Types

  1. High gain DC Amplifier

Generally, Pcb assembly china uses this device to amplify low-level signals. You can easily form a thermocouple junction between lead and copper. This thermocouple junction forms different voltages which cause noise signals. A pcb manufacturer should place the input stage in a separate edge to keep the temperature stable.

  1. Differential Amplifier

The Differential Amplifier is important as it moves between tow signals and dismisses the common voltage. If the differential amplifier or PCB設計 is not proper and the level of the signal is low then the common voltage creates a small difference signal. The geometrical symmetry while designing the amplifier must be correct otherwise the unbalanced impedance can disturb the performance of the circuit. Similarly, the leakage resistance creates unbalance voltage. Moreover, the guard conductor connects the signal conductor to the guard of the equipment. This method helps in handling differential signals at a low level. Furthermore, the glass epoxy base for differential amplifier helps in minimizing the leakage problem.

Pcb Assembly china High-frequency Amplifier

Pcb Assembly manufacturers

Inappropriate PCB layout of high-frequency layout results lessens the bandwidth of the amplifier. The closeness of the ground and signal conductor results in high capacitance, which acts as a low filter pass filter, which reduces the bandwidth of the amplifier. Moreover, the closeness of output and input conductors result in vibrations. According to leading pcb assembly china manufacturer, the frequency of more than 10 MHz will cause vibration. But the amplifier will not oscillate when the desired frequency is given. The capacitive coupling between signal lines cause such problems. Thus the capacitive coupling should be less while making PCB設計.

Supply and Ground Conductors

The power supply must have enough thickness to keep the resistance and inductance low. But the conductance is directly proportional to thickness or width. If analog and digital circuits are on the same PCB then they must have their own separate ground conductors. For reference voltage circuits, the supply lines must attach to input and the ground line must attach to the stable ground reference.  Subsequently, stable ground reference is sensitive to the changes in ground potential. Simultaneously, the ground conductors have resistance, inductance, the doubtful current which causes voltage drops when passes from the ground impedance.

 What are the basic rules for designing analog PCB?

Pcb assembly china states general rules for designing analog PCB circuit areas;

  • 導体を介した電圧降下と電磁干渉を制御するには、信号経路を短くします。
  • 同様に、同じボード上のアナログとデジタルのグランドは別々に配置する必要があります。
  • 信号グランドをアースグランドに接続します。
  • 容量性シールドを接続して、ノイズ源へのリターンパスを与えます。
  • 磁気シールドの材質は透磁率が高い必要があります
  • さらに、回路に使用されている金属は適切に配置されており、動いてはいけません
  • コモンモード信号が区別されないように、システムは安定している必要があります
  • システムの帯域幅は、信号帯域幅の要件に従う必要があります。
  • 電流の流れに応じてループの経路を作ります。
  • とりわけ、2つのPCB間のノイズ除去を制御またはアップグレードするには、ケーブルのペアを使用してそれらをねじります。

What problems pcb assembly china face in designing digital PCB?

The demand for PCB in digital circuits is very much because of its performance but the knowledge of electronic transmission lines is also important.

designing digital PCB

If the design of digital PCB is not proper it may cause following problems for pcb assembly china manufacturer like

  • Convert one pulse into two or more (double pulsing) which is known as Reflection.
  • Produce delay signals
  • Interrupt the signals known as Cross-talk.
  • Can produce ground and supply signal noise
  • Cause of electromagnetic interference.

What are the guidelines for pcb assembly china manufacturer for high-frequency PCB circuit design?

Following are the instructions for high-frequency PCB circuit
  • For ground conductors, pcb assembly china manufacturer uses a large ground surface
  • The wide power supply conductors are used
  • Furthermore, ground and power supply lines must be parallel and close to each other
  • The ground and power supply must have a decoupling capacitor in between
  • The length of the conductor for a fast pulse should be kept small because the dielectric loss is directly proportional to length.
  • Moreover, the dielectric loss is very important in the PCB however a PCB with proper high-frequency dimension should be used
  • Designing the layout of the conductor is according to the capacitor and inductor. The more harmful element must not be used
  • The lines should be kept small or the increase in the rise time must be as high as 1 sec/cm
  • Prepare ground line via capacitor even the parasitic capacitance has a worse result.