Through hole cover oil: ink must be used to cover the welding-rings of the through hole (via), emphasizing the ink coverage of the hole edge.pcb
Through oil: the through hole (via) is made with ink inside the hole, emphasizing the quality of the hole.It is required that no light is allowed after the oil is plugged.
In order to reduce the confirmation of subsequent documents and avoid the complaints caused by unclear design, please pay attention to the following aspects in the process of design and order placing:
When placing an order, the hole property must be consistent with the file property to reduce the mutual confirmation time.
If required to open the window, the corresponding soldering layer must be drawn.
If there are a large number of plates for subsequent welding, it is recommended to pass through the hole cover oil to reduce the probability of short circuit.If it is debugging proofing stage, through the window is a good choice.
This paper introduces the difference between through hole cover oil, through hole opening and through hole plug oil, then let's analyze the commonly used boards of shengyi board Tg140.The epoxy glass fiber cloth copper plate has high strength, good heat resistance, good dielectric property, the base plate can be metallized through the hole, to achieve the two-side and multi-side printing layer and layer circuit conduction, epoxy glass fiber cloth copper plate is the most widely used copper clad plate of all qualities, the largest amount of a class.Widely used in mobile communications, digital television, satellite, radar and other products.Among all kinds of copper cladding plates in the world, the epoxy glass fiber cloth copper plate and paper base copper plate account for about 92%, and the amount of fr-4 plate in the epoxy glass fiber cloth copper plate accounts for more than 90%.At present, pr-4 board has developed into the general term of epoxy glass fiber cloth copper board applicable for different purposes.
Currently, we use fr-4 shengyi Tg140 and S1141 series plates, and the general parameters are as follows:
Dielectric constant: 4.6
Dielectric loss: 0.035
Tg temperature: 140 ℃ (glassy state transformation temperature Glass?The Transition?Temperature (Tg)
Dimensional stability: 0.492mm /m
Flame retardant grade: v-0
Arc resistance: 60S or above
Interface constant: less than or equal to 5.4