Several stages of ore crushing and grinding classification

The crushing and grinding of the ore is a preparation before the sorting. The prerequisite for mineral processing is to achieve the separation of useful minerals in the ore. Since the useful minerals have a small particle size, it is often necessary to grind the ore very finely to achieve a monomer separation. . The ore from the stope is very large. For example, the mining block of the exposed mining can reach a maximum of 1000-1500 mm, so it is necessary to crush the nugget up to 1500 mm to only a few tens of microns (1 micron-10-3). Fine particles of millimeters, the same below, often have to be completed in several stages. In terms of crushing, in large-scale plants, coarse, medium and fine three-stage crushing (also using four-stage) is adopted, so that the size of the ore block is gradually reduced to about 8 to 25 mm, and then sent to a grinding machine for grinding. . Until the useful mineral particles can achieve monomer separation, the grinding is usually one or two stages, sometimes up to three stages. The division of the number of fractures and grinding is roughly as shown in Table 2-3.

It should be noted that the division of the number of crushing and grinding sections in Table 2-3 is relative, which is related to the size of the plant, the type specification of the crushing and grinding equipment, the requirements for product fineness and other conditions.

Use 3


HDI Printed Circuit Boards - High Density Interconnect PCB Technology

With the development of society, the progress of technology comes from people's constant pursuit of life and their yearning for higher quality of life. Personal consumer electronic products such as notebook computers, personal computers and mobile phones require lighter weight and smaller volume, while smaller volume requires smaller design accuracy and higher density. At the same time, the quality and speed of interconnection technology should be better. This requires designers who make these products to design better components to improve electrical performance, such as circuit boards and so on.

In order to manufacture PCB products of this kind, PCB manufacturers need more advanced manufacturing technology. Of course, from the point of view of product cost, it needs lower cost. This seems contradictory, but HDI PCB can solve this problem very well. HDI PCB has numerous advantages, such as high speed, small size and high frequency.

HDI PCB is the better option for high-layer count and costly laminated boards.

What is a HDI PCB, The definition of HDI PCB

HDI stands for High Density Interconnector, HDI Printed Circuit Board. A circuit board which has a higher wiring density per unit area as opposed to conventional board is called as HDI PCB. HDI PCBs have finer spaces and lines, minor vias and capture pads and higher connection pad density. It is helpful in enhancing electrical performance and reduction in weight and size of the equipment.

High density interconnect (HDI) PCBs represent one of the fastest-growing segments of the printed circuit board market. Because of its higher circuitry density, the HDI PCB design can incorporate finer lines and spaces, smaller vias and capture pads, and higher connection pad densities. A high-density PCB features blind and buried vias and often contains microvias that are .006 in diameter or even less.

Regarding the electrical needs of high-speed signal, the board should have various features i.e. high-frequency transmission capability, impedance control, decreases redundant radiation, etc. The board should be enhanced in the density because of the miniaturization and arrays of the electronic parts. In addition, to the result of the assembling techniques of leadless, fine pitch package and direct chip bonding, the board is even featured with exceptional high-density.

There were a lot of different names for the PCB with such structures. For example, it was called SBU (Sequence Build up the Process) in European and American industry as the program production is in the constructive mode of sequence. It was called MVP (Microvia Process) in Japanese industry because the hole of such products is much smaller than the previous one. It was also called BUM (Build up Multilayer PCB Board) because the traditional multilayer is known as MLB (Multilayer PCB Board).In order to avoid confusion, IPC Printed Circuit Association proposed to call it HDI (High Density Interconnection Technology) as the common name, but it can not reflect the characteristics of the circuit board. So the majority in the PCB industry define such products as HDI PCB.

Innumerable benefits are associated with HDI PCB, like high speed, small size and high frequency. It is the primary part of portable computers, personal computers, and mobile phones. Currently, HDI PCB is extensively used in other end user products i.e. as MP3 players and game consoles, etc.

HDI PCBs take advantage of the most recent technologies existing to amplify the functionality of circuit boards by means of the similar or little amounts of area. This development in board technology is motivated by the tininess of parts and semiconductor packages that assist superior characteristics in innovative new products like touch screen tabs.

HDI PCBs are described by high-density features comprising of laser micro-vias, high performance thin materials and fine lines. The better density allows extra functions per unit area. These types of multifaceted structures give the required routing resolution for large pin-count chips which are used in mobile devices and other high technology products.

The placement of the parts on the circuit board needs extra precision than conservative board design due to miniature pads and fine pitch of the circuitry on the circuit board. Leadless chips require special soldering methods and additional steps in the assembly and repair process.

The lesser weight and size of the HDI circuitry means the PCBs fit into the little spaces and have a smaller amount of mass than conservative PCB designs. The smaller weight and size even signifies that there is lesser chance of harm from mechanical shocks.

Consumer Driven Technology

The via-in-pad process supports more technology on fewer layers, proving that bigger is not always better. Since the late 1980's we have seen video cameras using cartridges the size of a novel, shrink to fit in the palm of your hand. Mobile computing and working from home pushed technology further to make computers faster and lighter, allowing the consumer to work remotely from anywhere.

HDI Technology is the leading reason for these transformations. Products do more, weigh less and are physically smaller. Specialty equipment, mini-components and thinner materials have allowed for electronics to shrink in size while expanding technology, quality and speed.


According to layer up different, currently DHI board is divided into three basic types:

1) HDI PCB (1+N+1)


  • Suitable for BGA with lower I/O counts
  • Fine line, microvia and registration technologies capable of 0.4 mm ball pitch
  • Qualified material and surface treatment for Lead-free process
  • Excellent mounting stability and reliability
  • Copper filled via

Application: Cell phone, UMPC, MP3 Player, PMP, GPS, Memory Card

1+N+1 HDI PCB Structure:

1+N+1 HDI PCB Structure

2) HDI PCB (2+N+2)


  • Suitable for BGA with smaller ball pitch and higher I/O counts
  • Increase routing density in complicated design
  • Thin board capabilities
  • Lower Dk / Df material enables better signal transmission performance
  • Copper filled via
Application: Cell phone, PDA, UMPC, Portable game console, DSC, Camcorder

2+N+2 HDI PCB Structure:


3) ELIC (Every Layer Interconnection)


  • Every layer via structure maximizes design freedom
  • Copper filled via provides better reliability
  • Superior electrical characteristics
  • Cu bump and metal paste technologies for very thin board
Application: Cell phone, UMPC, MP3, PMP, GPS, Memory card.

Every Layer Interconnection Structure:


JHY PCB' HDI PCB Capabilities

HDI PCB manufacturing requires an advanced level of technical expertise and the latest state-of-the-art equipment for exacting precision.

JHY PCB offer solutions for low-volume/high-mix PCB manufacturing on a quickturn basis, as well as production quantities and high-tech capabilities for advanced builds with demanding requirements for aerospace, defense, medical, and commercial applications. Capabilities include:

Type of
Micro vias
Prototype Available
1+N+1 Blind vias Yes Yes Yes 4 layers+
2+N+2 Blind/Buried
staggered vias
Yes Yes Yes 6 layers+
2+N+2 Blind/Buried
stacked vias
Yes Yes Yes 6 layers+
3+N+3 Blind/Buried
staggered vias
/ Yes Yes 8 layers+
3+N+3 Blind/Buried
stacked vias
/ / Yes 8 layers+

Check our HDI PCB capabilities by reviewing the table found below:

Feature Capability
Quality Grade Standard IPC 2
Number of Layers 4 - 24layers
Order Quantity 1pc - 10000+pcs
Build Time 2days - 5weeks
Material FR4 standard Tg 140°C,FR4 High Tg 170°C, FR4 and Rogers combined lamination
Board Size Min 6*6mm | Max 457*610mm
Board Thickness 0.4mm - 3.0mm
Copper Weight (Finished) 0.5oz - 2.0oz
Min Tracing/Spacing 2.5mil/2.5mil
Solder Mask Sides As per the file
Solder Mask Color Green, White, Blue, Black, Red, Yellow
Silkscreen Sides As per the file
Silkscreen Color White, Black, Yellow
Surface Finish HASL - Hot Air Solder Leveling
Lead Free HASL - RoHS
ENIG - Electroless Nickle/Immersion Gold - RoHS
Immersion Silver - RoHS
Immersion Tin - RoHS
OSP - Organic Solderability Preservatives - RoHS
Min Annular Ring 4mil, 3mil - laser drill
Min Drilling Hole Diameter 6mil, 4mil - laser drill
Max Exponents of Blind/Buried Vias stacked vias for 3 layers interconnected, staggered vias for 4 layers interconnected
Other Techniques Flex-rigid combination
Via In Pad
Buried Capacitor (only for Prototype PCB total area ≤1m²)

Benefits of HDI PCB Technology with Micro Circuits:

The evolution of high-density PCB technology has given engineers greater design freedom and flexibility than ever before. Designers using HDI high density interconnect methods now can place more components on both sides of the raw PCB if desired. In essence, an HDI PCB gives designers more space to work with, while allowing them to place smaller components even closer together. This means that a high-density interconnect PCB ultimately results in faster signal transmission along with enhanced signal quality.

HDI PCB is widely used to reduce the weight and overall dimensions of products, as well as to enhance the electrical performance of the device. The high-density PCB is regularly found in mobile phones, touch-screen devices, laptop computers, digital cameras and 4G network communications. The HDI PCB is also prominently featured in medical devices, as well as various electronic aircraft parts and components. The possibilities for high-density interconnect PCB technology seem almost limitless.

  • Shorter PCB manufacturing lead times and improved device performance for Flip Chip, BGA, MCM, SIP technologies and medical devices.

  • Allows utilization of technologies that require ultra thin cores, fine line geometries and alternative via technologies for enhanced thermal transfer in the case of a thermal PCB.

  • Allows utilization of the technologies that require 20um circuit geometries, 30um dielectric layers, 50um laser vias and 125um bump pitch processing.

  • Allows reducing the [time to market" equation by combining the process capabilities with a strong comprehension of high speed digital and high frequency RF PCB package requirements.

  • Increases the area for the PCB designer provider to place circuit components as the components are decreased in size and spaced much closer together. This also improves faster signal transmission and reduced signal loss.

HDI PCB Applications

HDI PCBs are appropriate for a wide range of industries. As mentioned above, you'll find them in all types of digital devices, like smartphones and tablets, where miniaturization is key to the effective application of the product. You can also find high-density interconnect PCBs in automobiles, aircraft and other vehicles that rely on electronics.

One of the most critical areas where the high-density PCB is making huge inroads is in the medical arena. Medical devices frequently need small packages with high transmission rates that only HDI PCBs can supply.

For example, an implant needs to be small enough to fit in the human body, but any electronics involved in that implant absolutely must efficiently allow for high-speed signal transmission. Here, the HDI PCB indeed is a godsend. HDI PCBs can also be useful in other medical equipment, like emergency room monitors, CT scans and much more.

No matter your industry, you're probably already getting some ideas about how high-density interconnect PCBs can make the electronics you produce or use even better - get in touch with us PCBCart to discuss it. We'll let you know if you're on the right track and help you decide exactly how beneficial an HDI PCB can be to your industry. Then, you can determine whether or not to take the next step.

High Density PCBs of Impeccable Quality manufacturer

Over the course of a decade in business, JHY PCB has established a hard-earned reputation for manufacturing PCBs of the highest quality. Our custom PCB manufacturing capabilities enable you to get the finest quality HDI PCBs at competitive prices without min order quantity requirement. Our team run design for manufacture check on your custom PCB file and consult with you to ensure it is ready for manufacturing and that your boards will meet your performance requirements. We also have an on-site quality control department to verify the finished product meet your high quality standards.

Laser Drill & Laser Direct Imaging: Technology for High Quality HDI PCB Manufacturing.

HDI PCB designs push the limits of technology and JHY PCB is at the forefront of innovation, satisfying the most rigorous requirements.

The demand for HDI PCB manufacturing has been increasing due to the advancements in technology and the many benefits HDI PCBs provide for high-tech applications. Fitting more technology in less space with fewer layers creates limitations for many PCB manufacturers that do not have the specialized equipment and the capacity for advanced features, finer lines, and tighter tolerances.

HDI printed circuit board designs utilize a combination of advanced features like microvias, blind vias, via-in-pad, along with stacked and staggered vias to maximize the the space of the board while increasing its performance and functionality.

JHY PCB achieves high quality and precision with in-house laser drill capabilities that include precise depth control. Laser direct imaging (LDI) capabilities ensure exacting registration and all multilayer inner cores receive a thorough check using Automated Optical Inspection (AOI) units for excellent defect detection of the finest features.

Advanced PCB Materials for HDI PCB Fabrication

JHY PCB offers vast material options for different applications from top manufacturers, such as Isola, Nelco, Arlon, Rogers, and Taconic. Our laminate options offer advanced properties that include:
  • High Thermal Reliability
  • Ultra-Low Loss
  • High Speed Digital
  • Halogen-Free
  • RoHS Compliant
  • Lead-Free High Tg HDI Printed Circuit BoardHDI Printed Circuit BoardHDI Printed Circuit Boards

Additional informations

The HDI PCB Technology

What is an HDI stackup in Multilayer PCB Design?

Electronic PCB Board,HDI PCB,HDI Printed Circuit Board,HDI Circuit Board

JingHongYi PCB (HK) Co., Limited ,