Q: Drilling Hole for Different Layers Connection

Drilling Hole for Different Layers Connection After lamination, the inner layer is done. What follows next is to drill hole for connection of trace in different layers and also those components holes that will be mounted when assembly. To program the drilling machine as per PCB data from the OP, the drilling hole process begins. Drill Process After the drilling hole process is all done, it is all ready for the next PTH copper plating process.

Question 1

Hablar el soldado de cables de COB y su fuerza de tracción (pulling force)

Accepted Answer

El artículo anterior ha presentado qué es COB y su proceso. Bajo el proceso, ¿qué tipo de soldado de cables y prueba de tracción tiene COB? Después de adherir y hornear el troquel COB, se sigue el proceso del soldado de cables.
El proceso COB es diferente del empaquetado IC. Es alambre de oro para IC y alambre de aluminio para COB. Por lo tanto, la forma de la junta de soldadura será diferente, y, la fuerza de tracción del soldado de cables también será diferente.

Unión de cables

Según la forma de el soldado de cables, el proceso se puede dividir en dos tipos: "Bola de unión" y "Unión de cuña". COB generalmente usa alambre de aluminio (alambre Al) por lo que será Wedge Bond. Sin embargo, según la experiencia y los datos, la resistencia de la soldadura de bola es mejor que la de la soldadura de cuña, pero el "alambre de oro" también es más caro.

Prueba de tracción de alambre
En el proceso de empaquetado de IC, el soldado de cables de unión se juzga mediante tres métodos: tracción del cable, cambio de matriz y cambio de bola. En términos generales, la mayoría de los COB El proceso de fabricación solo probará la tensión del cable, que puede medir si la fuerza de las juntas de soldadura en la PCB es suficiente. El requisito de tensión del cable COB suele ser solo superior a 3 g según la especificación IPC (TM-650 2.4.42.3).

Question 2

¿En dónde aplica la placa de circuito impreso? VI

Accepted Answer

El PCB se aplica en varios sectores. Vamos a habla unas aplicaciones en el producto industrial.PCB es ampliamente utilizados en la parte industrial. El PCB se utliza en el sector industrial, normalmente necesita ser alta potencia y duraderos para soportar las condiciones que existen en el industrial.

Es posible que PCB deban ser resistentes a la manipulación brusca, la vibración de la maquinaria, las temperaturas extremas o los productos químicos agresivos. Para encontrar la necesidad de durabilidad, el PCB de industriales pueden fabricarse con metales duraderos o materiales termorresistentes y ser más gruesos que otros tipos de PCB.

Equipos de fabricación
Equipos de energía
Equipos de medición

Question 3

Revestimiento de cobre del panel  → PTH (Agujero pasante chapado)

Accepted Answer

El paso siguiente a la perforación del agujero es el revestimientp de cobre.
Con excepción de los agujeros de perforación para fines de herrmnientas, el restp de la pared del agujero de perforación se recurirá con cobre para fines de conexión de trazas en diferentes capas o para esos componentes DIP.

Al bloquear los agujeros y las áreas que no necesitan cobre, se aplica el recibrimiento de cobre no solo en la pared del agujero de perforación sino tambien en toda la placa de circuito impreso.
Para el requisito de 70 um terminado, normalmente el proveedor de PCB toma material de 35 um y hace un revestimiento de cobre de 70 um.

Question 4

¿Qué es E-TEST?

Accepted Answer

¿Cómo se asegura el fabricante de PCB de que la PCB desnuda cuumple con los estándares antes de la entrega?

Una de las purebas que se llevará a cabo es la prueba electrónica (E-TEST), el objetivo principal de la prueba electr´´onica es asegurarse de que no hay un circuito abierto ni un cortocircuito.

Cuando se trata de producción de muestra, la mayoría de las veces el fabricante utilizará la "prueba de sonda voladora" para E-TEST. A pesar de que la prueba de la sonda voladora requiere comparativamente mucho tiempo en términos de eficiencia de producción, tiene sentid, especialmente porque el proyecto aún se encuentra en la fase piloto.

Una vez que el proyecto ingresa a la producción en masa, generalmente el fabricante de PCB producirá herramientas especializadas para cada proyecto. No importa si se trata de una "prueba de sonda voladora" o una "prueba de herramientas", el objetivo principal es detectar un circuito NG durante la "ETAPA DE E-TEST" y garantizar que la calidad esté dentro del estándar del cliente.

What is HiPot test?

Question 5

What is impedance control? - Part.2

Accepted Answer

Last time we have briefly introduced the PCB data transmission and impedance control. And the transmission method can be divided in two types – Single-ended and Differential signal. Both have their own pros & cons, and which method to use for transmission depends on the functionality of the IC as well as electrical considerations. Nowadays, differential transmission has become the mainstream of high-speed transmission.

What is Single-Ended Signal
Single-ended signals generally refer to all kinds of signals that can transmit messages with one transmission trace (signals on PCB are mostly this kind). Its biggest pro is that the impedance is easy to control.

What is Differential Signal

Differential signals use two single-ended signal traces (Positive and Negative ) to transmit signals at the same time. These two signals should have two features:
1. Same voltage amplitude
2. The phase of the signal is opposite, that is, one positive and one negative.

What is impedance control? - Part.1

Question 6

What is Glass Transition Temperature, also known as TG?

Accepted Answer

Sometimes you can see TG150/TG170, etc. on the PCB material. What does this TG mean?

TG(Glass Transition Temperature) is one of the most important characteristics of all plastic and epoxy resin materials. In fact, TG(Glass Transition Temperature) value is also one of the quality indicators of glass fiber for PCB.
When the temperature is lower than the glass transition temperature (TG), the plastic enters glassy state which is rigid but with brittle characteristics. Just like the characteristics of glass, it is hard but easily brittle.
When the temperature is higher than the glass transition temperature (TG), the plastic parts will show a soft and flexible rubbery state. Therefore, the glass transition temperature (TG) is generally the temperature at which the plastics undergo a phase transition from the glassy state to the rubber state.

As PCB’s TG(Glass Transition Temperature) increasing, the heat resistance, moisture resistance, chemical resistance, and resistance stability characteristics of PCB prodution will be strengthened and improved. The higher the TG(Glass Transition Temperature) value, the higher temperature PCB can endure, especially in the lead-free manufacturing process, where there are more applications of high TG(Glass Transition Temperature).

High TG(Glass Transition Temperature) refers to high heat resistance. The development of high functionalization and high multi-layering requires higher heat resistance of PCB substrate materials as an important guarantee. The emergence and development of high-density mounting technologies represented by SMT and CMT have made PCBs increasingly require specifications with high heat resistance of substrates in terms of small apertures, fine lines, and thinning.

Thus, regards PCB production, the difference between FR-4 and high TG FR-4 is that in a high temperature state, especially when heated after moisture absorption, the material’s mechanical strength, dimensional stability, adhesiveness, water absorption, thermal decomposition, and thermal expansion.

Question 7

Where are printed circuit boards used? V

Accepted Answer

Today we are talking about some applications in military products. Military-grade PCBs carry stringent performance, sourcing, and manufacturing requirements that are encoded in a number of standards, such as IPC-A-610E Class 3, MIL-PRF-31032, MIL-PRF-55110, etc. These standards specify performance requirements for high-performance electronic products.

These military printed circuit boards will often be subjected to high pressures and stresses, meaning they will frequently require high-temperature substrates like temperature-resistant laminates, copper or aluminum. Military PCB manufacturers must produce PCBs that will resist heat-induced oxidation and effectively dissipate heat in a low-weight design.

• Auxiliary power units for radar control systems
• Radio communications systems
• Control tower systems
• LED lighting systems
• Underwater navigation systems
• Jet instrumentation
• Jamming systems

*Related Article:
Where are printed circuit boards used?
Where are printed circuit boards used? II
Where are printed circuit boards used? III
Where are printed circuit boards used? IV

Question 8

Final step before PCB delivery for International shipment – Standard Packing Procedure at ExPlus

Accepted Answer

«Standard Packing Procedure at ExPlus»

After the PCB passed FQC inspection and OQC inspector confirmed O.K., the PCB will be transferred to the warehouse and waiting for packing. When the packing staff receive PCB, he or she will first check the part number and OP, and then follow client requirements if there’s any for packing.

«Reduce potential risks during International transportation»

Different from domestic delivery, the PCB manufacturer shall consider all kinds of risk such as bumpy, falling and so on during international shipping. To reduce the risk of PCB damage due to transportation, ExPlus’ standard packing procedure will be following. First, the carton shall be multiple layers waterproof carton. Second, before place PCB into the carton, the packing staff will put buffer packaging materials(at ExPlus we use wave board as below image shows) on the bottom of carton and then surround the PCB with more wave boards for protection. Once the packing staff ensure the board won’t slide due to any movement, he or she could seal the box and measure the weight. For safety concern, the Net weight of each carton won’t exceed 20 k.g.. On outside of carton, the details including part number, PO, D/C, quantity and weight shall be listed. Once the box is sealed, it’s all ready to go.

ExPlus package

Question 9

Drilling Hole for Different Layers Connection

Accepted Answer

Drilling Hole for Different Layers Connection

After lamination, the inner layer is done.

What follows next is to drill hole for connection of trace in different layers and also those components holes that will be mounted when assembly.

To program the drilling machine as per PCB data from the OP, the drilling hole process begins.

Drill Process

After the drilling hole process is all done, it is all ready for the next PTH copper plating process.

Question 10

What is impedance control? - Part.1

Accepted Answer

If you have ever seen a printed circuit board, it may be aware that it has many conductors on it. And in these conductors will have different types of signal transmission. Such signal will be changed or even distorted according the trace width and spacing, which may be affected by the etching, stack thickness, and other factors. Therefore, especially PCBs with high speed and high frequency, the impedance value of the conductors should be controlled within a certain range, referred to as “impedance control”.

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