High Density Interconnect PCB, with microvia≤0.15mm， use fine feature technology to connect components in small packages. HDI’s smaller geometry allows for higher wiring density. The electrical performance is greatly improved because of control on lower parasitic, minimal stubs, removal of decoupling capacitors and lower crosstalk. RFI and EMI is much lower due to ground planes being closer together, distributed capacitance is closer.
Many electronic applications are seeing a need for increasingly faster frequencies. As frequency increases, the margin for error and/or deviations in the pcb is significantly reduced. The use of high frequency material like PTFE substrates, blind vias and tightly controlled etch tolerances are required to achieve such high frequencies.
High layer count PCBs, widely found in file servers, data storage, GPS technology, satellite systems, weather analysis and medical equipment are usually ≥12L with special performance requirement raw material.
MCPCB, A metal-based PCB, is comprised of a metal substrate (ie Aluminum, Copper or Stainless Steel ect.,), thermal dissipating dielectric and the copper circuit. Due to its superior heat dissipation, MPCBs are used for a wide array of applications. You can find them in power supplies, LED lighting or anywhere that heat is a major factor.
The conventional PCBs have electrical connection on the normal FR-4 material through the vias. After a long-term development, it has evolved from single-layer to double-layer, multi-layer PCBs.
What information is required to fabricate a countersink holes pcb?
Countersinks most commonly will have either an 82 degree or 90 degree angle so a primary consideration is the desired angle. Additionally, you would need to specify the diameter of the smaller hole, and either the maximum diameter or the depth of the countersink. And, whether that hole is to be plated or non-plated. In most cases, these are non-plated but there could be situations where you may be grounding to a chassis and would need to have plating in the hole.
Why build selective gold plating pcb?
The hard gold finish basically offers tough resistance to friction compared to other finishes. It is used to create gold fingers on circuit boards. This finish is the best option when a PCB is designed to be inserted into another board, such as RAM. Hard gold is extremely durable, thus can withstand repeated usage. This finish is expensive and has poor solderability, hence, it is not applied on solderable surfaces.
For any areas on a circuit board that will require wire bonding or touch pads, ENIG is often a good choice. Organic solderability preservative (OSP) is good match for the ENIG finish, as it is lower in cost and will not harm the gold. The process of combining OSP and ENIG is referred to as “SENIG” or selective ENIG. The problem with using the ENIG and OSP process for manufacturing is the potential corrosion of the nickel used in the product. The nickel used must be highly resistant to corrosion, as the processing of the OSP finish leaves it vulnerable.
Whenever there is a requirement to plate specific areas on the board with hard gold, you can opt for selective gold plating. The process of selective gold plating is a bit different. For this reason, it is necessary to specify your requirements while raising a quotation.
Press-fit holes are plated through holes with tighter tolerances than the standard +/-0.10mm. Press-fit holes fit the leads of connectors that will not be soldered but pressed into the holes. To accommodate lead and hole to tightly fit together, the tolerances are well defined and more tight than standard.
The typical tolerances for the PTH depends on the type of connector, which is specified by the connector manufacturer.
Therefore it is of utmost importance that these tolerances are well defined in your PCB data and that the parameter “Press fit” is checked in the order details.
SEMI-FLEX is flex to install. Unlike polyamide, the FR4 core is not capable of continuous flexing.
With simple depth-milling a standard printed circuit board can be prepared for flexible installations. So called "semi-flexible" printed circuits are offering a cost-efficient solution. They save connectors and increase reliability while decreasing size of the application and time needed for assembly. Semi-flexible PCBs are the perfect solution if you have flex-to-install requirements only and there is no dynamic bending during operation.
Production of a semi-flexible PCB is identical with the manufacturing process of standard printed circuits. Semi-flexilbe boards can be produced as single-layer, double-layer or multilayer PCBs. With the exemption of a special solder mask that sustains bending, the materials are also identical to standard printed circuits. The only difference happens at the end of the production process when dedicated bending areas are milled down by z-axis routing. The remaining material can be bend and is thin enough to only carry the copper traces and little base material.
However it will bend a limited number of times at a controlled radius and to any angle.
This makes it an ideal solution where you need to mount two PCB’s in a unit at an angle to each other. Instead of using connectors and cables or a composite flex-rigid PCB, you can design a single FR4 SEMI-FLEX PCB which can be safely bent a sufficient number of times to allow installation and subsequent maintenance as needed.
Why hard gold pcb?
For the Hard Gold Plating, the entire panel is covered by tape. Only the part that requires the application of a surface finish is removed. Unlike ENIG, in this case, the copper thickness can vary by controlling the duration of the plating cycle. The nickel is first electrodeposited, then the gold is deposited according to the customer's request. The gold thickness provides an excellent shelf life but also one of the most expensive surfaces finishing options. To sum things up, Hard Gold Plating surface finish has mechanical properties, excellent shelf life and provides a flat surface. There are also drawbacks such as high cost, poor solderability and the process is complex.
Often a PCB is used in combination with a membrane switch where the underlying gold must withstand many actuation forces of a keypad. The gold plating on tabs of a keypad is usually defined by the engineer at 200-300 micro inches. Hard gold is meant to survive many actuation forces or insertion and removal up to 1,000 actuations or more.
To better understand the longevity, think of your keyboard or calculator. Each depression to make a contact must hold up to long usage. This type of gold plating is electroplated or electrolytic plated by using an electrical charge as opposed to a purely chemical reaction. Thickness may be controlled by varying the plating cycle time. Thickness is usually between .000015”-.000050” standard processing.
Flash electrolytic is a thin coating of hard gold. Unlike thicker hard gold coatings, flash gold remains solderable for SMT assembly because its coating thickness is approximately 10% as thick as hard tab gold. Like ENIG, its thickness range is limited – typically .0000015”-.000003” thick.
Hemeixinpcb offers two types of gold finish: Electroless Nickel Immersion Gold (ENIG) as a surface finish for the whole PCB, and hard plated gold over plated nickel for edge-connector fingers. Electroless gold gives excellent solderability, but the chemical deposition process means that it is too soft and too thin to withstand repeated abrasion. Electroplated gold is thicker and harder making it ideal for edge-connector contacts for PCBs which will be repeatedly plugged in and removed.
Hard gold finish, also known as electrolytic hard gold, is made of a layer of gold with hardeners that will maximize durability. Using an electrolytic process, it is plated over a nickel barrier coating. The thickness of this plating varies according to the duration of the plating cycle.
The plating procedure uses gold because gold has high corrosion resistance, high electrical conductivity, and can be alloyed with cobalt or nickel to develop resistance to wear and tear. Gold plating can range in thickness from 3µ” to 50µ”.
Why are castellated hole?
A popular trend among manufacturers is board-to-board soldering. This technique allows companies to produce integrated modules (often containing dozens of parts) on a single board that can be built into another assembly during production. One easy way to produce a PCB that is destined to be mounted to another PCB is to create castellated mounting holes. These are also known as "castellated vias" or "castellations."
Plated half-holes (or castellated holes) are predominantly used for board-on-board connections, mostly where two printed circuit boards with different technologies are combined. E.g. the combination of complex microcontroler modules with common, individually designed PCBs.
The board-on-board PCBs therefore need plated half-holes, which serve as SMD connection pads. Through directly connecting the PCBs together, the whole system is considerably thinner than a comparable connection with multi-pin connectors.
Hemeixinpcb is your one-stop shop for all types of PCBs – Printed Circuit Board Manufacture, PCB Design, PCB Fabrication Full Turnkey PCB Assemblies . We specialize in high layer count PCBs, Engineering Prototypes, and the full range of Electronics Manufacturing Services. Every PCB is built to the highest quality standards, including Rigid PCB, Flex PCB and Rigid-Flex PCB. All PCB assemblies are built and certify accordingly ISO 9001:2015, ISO 14001:2015, ISO/TS 16949:2016,J-STD-001, IPC-A-610E .PCB, PCB Design, Fabrication, Our Electronic Assembly Service is unmatch anywhere in speed, quality, and workmanship. From bare circuit boards to box build and final assembly, Hemeixin Electronics Co.,Ltd. is your premier one-stop shop, with the most competitive pricing in the industry and a commitment to total customer satisfaction.