China Shenzhen blind hole 4-34 layer PCB circuit board board company - Juding Circuit Technology
Blind hole: Blind Via Hole (BVH)
The outermost circuit of the PCB board is connected to the adjacent inner layer by a plated hole, and since it is not visible, it is called a "blind hole". In order to increase the space utilization of the PCB circuit board layer, a "blind hole" process has emerged.
The blind holes are located on the top and bottom surfaces of the board and have a certain depth for the connection of the surface lines to the underlying inner lines. The depth of the holes generally has a prescribed ratio (aperture). This type of production requires special attention, and the drilling depth must be just right. If you do not pay attention, it will cause plating difficulties in the hole. Therefore, few factories use this method of production. In fact, it is possible to drill holes in the circuit layers that need to be connected in advance, and finally glue them together, but it requires a more precise positioning and alignment device.
High-quality PCB circuit boards need to meet the following requirements; 4-34 layer PCB circuit board
It is required that the telephone should be used after the components are installed, that is, the electrical connection should meet the requirements; the line width, line thickness and line spacing of the line meet the requirements, so as to avoid the line heating, breaking, and short circuit; the copper sheet is not easily peeled off by the high temperature copper surface; It is not easy to oxidize, affecting the installation speed. It will be destroyed soon after oxidation; there is no extra electromagnetic radiation; the shape is not deformed, so as to avoid deformation of the outer casing after installation and the screw holes are misaligned. Now it is mechanized installation, the hole position of the circuit board and the deformation error of the line and design should be within the allowable range; and the high temperature, high humidity and special environment should also be considered;
Introduction to the process of silk screen printing on PCB boards:
First of all, the design documents provided by the customer are converted into white letters of the GERBER file, and the white-painted film is output. In order to improve production efficiency, the customer's documents are generally spelled and assembled into a work piece of about 50*60 cm. The size of the working piece is generally matched with a drilling machine, an automatic sinking copper wire, an automatic circuit wire, an exposure machine, an etching machine, and the like. 4-34 layer PCB circuit board company - Juding Circuit Technology.
The silk screen staff applied a layer of photosensitive film on the aluminum mesh frame of the stretch net sand, and stacked the white light-painted film on the photosensitive film for exposure. Rinse with water to obtain a white silk screen frame for silk screen printing.
Finally, manually screen the screen or automatically screen printing on the frame. In general, small batches and prototypes are made by manual screen printing stations. Only high-volume boards use self-automatic screen printing machines.
Introduction to the method of silk screen printing on the circuit board plus production cycle
When the engineering department produces the white-faced film, the production cycle position of the four-digit code is placed in a blank area that does not affect the customer's use. Due to the wide variety of customer designs, this location varies by customer design. Some small boards are hard to find a location.
Layout design specification for circuit board design; 4-34 layer PCB circuit board
A: Is it possible to complete the production through the simplest assembly process?
B: Whether the high-power device is evenly laid out, whether the heat dissipation direction is considered, and the board is subjected to strength.
C: Does the mass device add a fixture?
D: Have you considered the insulation measures of the device?
E: Is the arrangement of components horizontal or vertical?
F: The heat sink cannot touch the surrounding components.
G: Whether the pad position design is evenly distributed
H: Is there a nail bottom element and flying line?
I: Whether the heat sink is installed in accordance with the heat dissipation direction, whether to use the existing heat sink as much as possible, and reduce the possibility of making new heat sinks.
J: Whether the maximum PCB board length is not more than 600 mm and the width is not more than 360 mm.
K: Is there a grounding piece at the fixed hole position in the cold place, and the grounding piece is enough?
L: Whether there are more than three global Mark points on the copper foil surface of the board, whether the position meets the process requirements and affects the safety spacing.
M: Whether the arrangement of the vertical electrical plug components can ensure that the distance between the member and the outer edge of the member is more than 1 mm.
N: Whether there are tin-friendly pads and copper foil on the edge of the printed board makes assembly difficult.
O: Does the riser take into account the fixed way?
P: Whether the components fixed on the heat sink have space to be removed without disassembling the heat sink.
Q: Whether there are tall and dense components around the plug or the sharp corners of the radiator.
R: Whether the input/output plug placement position meets the convenience of connecting with other boards of the whole machine.
S: Whether the patch component is placed perpendicular to the long side of the board to avoid breakage or damage due to deformation
T: Whether the plug-in IC and the chip IC are horizontally placed in line with the wave soldering direction conforms to the wave soldering process, and whether the IC is designed to have a soldering pad at the appropriate position during the wave soldering to avoid the soldering of the soldering pad.
U: Whether to consider the shadow effect when all the placement components are placed.
V: Whether the fixing component and the heat sink's screws and on-board components have positional interference.
High quality raw materials
*Board: Rogers, Arlon, Shengyi
* Potion: Rohm Haas, Atotech, Cerambus
*Dry film: Hitachi
Rigorous quality control system
* Controlled by IPC standards, strictly control the qualified rate of finished product shipments.
* Perform PDCA processes to continuously improve quality and product performance.
Strict control of delivery
* Implement lean production, effectively monitor production schedules and increase the rate of quasi-intersection.
*The expedited order rate is greater than 99%, and the regular order rate is greater than 95%.
Juding Circuit Technology: is a professional PCB circuit board manufacturer, providing you with: PCB prototype, batch board, 1-34 layer PCB board, TG board, HDI board, Rogers board, microwave board, RF board, radar board , thick copper foil board, PCB manufacturing and production of various processes and materials, welcome to consult the staff for more details!