The difference between package substrate and pcb

Packaging substrate is an electronic substrate that can provide electrical connection, protection, support, heat dissipation and assembly for chips and electronic components, thus realizing multi-pins, reducing the volume of packaged products, improving electrical performance and heat dissipation, and has ultra-high density or multi-chip modularity and high reliability.

Packaging substrate can be simply understood as PCB or thin thick film circuit substrate with higher performance or special function. The packaging substrate plays the role of electrical interconnection and transition between the chip and the different circuits of the conventional printed circuit board (mostly main board, auxiliary board, backplane, etc.). ), but also provide protection, support, heat dissipation and assembly for the chip.

PWB and PCBPWB (printed circuit

Board): generally refers to an insulating substrate with conductor patterns on its surface and inside. PWB itself is a semi-finished product, and its function is as a substrate for mounting electronic components. Connect them through conductor wiring to form a unit electronic circuit and play its circuit function.

PCB (printed circuit)

Board) means that the entire substrate of PWB equipped with electronic components is a printed circuit board. In most cases, PWB and PCBs are usually regarded as synonyms, and there is no difference. In fact, PWB and PCBs are different in some cases. For example, PCB sometimes refers to a circuit containing electronic components simply printed on an insulating substrate, which can be self-contained; While PWB emphasizes the carrier function of components, or constitutes an actual circuit or a printed circuit board assembly. Usually called printed circuit board.

Motherboard Motherboard: Also called Motherboard. It is an electronic substrate with various active and passive electronic components installed on a larger PCB, which can be interconnected with auxiliary boards and other devices. Communication industry is generally called backplane.

The word Shi Zhuang comes from Japanese and is borrowed here. The "block" is mounted on the "board", and the bare chip is mounted on the daughter board of the module substrate: also called daughter board or component board, that is, some electronic components are mounted on a small PCB, which together with other components with various functions form cards, storage components, CPU components and substrate. Then the bearing and interconnection with the motherboard are realized through connectors (connectors, cables or rigid-flexible boards, etc.). ). This makes it easier to repair faulty components and upgrade electronic products.

That is, the actual installation refers to the connection technology and technology of the above-mentioned "blocks" installed on the substrate, covering the common insertion, plug-in, surface mount (SMT), installation and micro-assembly.

Module: and the "board" that will be involved below can be regarded as a multidimensional body. The package with lead terminals is a "block", and the chip with bare chip can also be regarded as a block.

Carrier board: printed circuit board bearing various active and passive electronic devices, connectors, units, daughter boards and other electronic devices. Such as sealed carrier, similar carrier, all kinds of common PCB and assembly board.

SubstrateLike-PCB (SLP): As the name implies, it is a kind of PCB with similar specifications. Originally, it was an HDI board, but its specification was close to the level of carrier board for IC packaging. Class carrier board is also a kind of PCB hard board, but the process is closer to the semiconductor specification. At present, the required carrier line width/line spacing ≤30μm/30μm cannot be produced by subtractive method, and MSAP (semi-additive process) technology is needed, which will replace the previous HDIPCB technology. A substrate material integrating the functions of packaging substrate and carrier. However, the manufacturing process, raw materials and design scheme (one or more) are still inconclusive. Apple's new mobile phone gave birth to a carrier-like board. In the 20 17 iPhone8, the HDI board similar to the carrier board is used for the first time, which can make the size of the mobile phone thinner and shorter. The substrate of the carrier board is also similar to the substrate of IC package, mainly the laminated dielectric film of CCL of BT resin and ABF* resin.

Multilayer board: With the improvement of LSI integration and high-speed signal transmission, electronic equipment is developing in the direction of thinness, and it is difficult to wire only by single and double-sided wires. Moreover, if the power line, grounding line and signal line are arranged in the same conductor layer, there will be many restrictions, which greatly reduces the freedom of wiring. If the power layer, grounding layer and signal layer are specially set and arranged in the inner layer of the multilayer board, not only can the freedom of wiring be improved, but also the signal interference and electromagnetic wave radiation can be prevented. This requirement further promotes the development of multilayer substrates. Therefore, PCB integrates the key technologies of electronic packaging and plays an increasingly important role. It can be said that contemporary PCB is a master of various modern technologies.

HDI substrate HDI substrate: generally, it is manufactured by adding layers. The more the number of product layers, the higher the technical grade of the plate. Ordinary HDI boards are basically laminated at 1 time, while high-end HDI adopts two or more lamination processes, and at the same time adopts advanced PCB technologies such as hole overlapping, electroplating hole filling and laser direct drilling. High-end HDI boards are mainly used for 4G mobile phones, advanced digital cameras and IC carrier boards.

In electronic packaging engineering, electronic substrates (PCBs) can be used for different levels of electronic packaging (mainly used for the second to fifth levels of 1 ~ 3 packaging), only the packaging substrates are used for the second, third and second levels of 1, and ordinary PCBs are used for the third, fourth and fifth levels of the second and third levels of packaging. But they all provide interconnection, protection, support, heat dissipation, assembly and other functions for electronic components, aiming at realizing multi-pins, reducing the volume of packaged products, improving electrical performance and heat dissipation, ultra-high density or multi-chip modularization and high reliability.

Main board (motherboard), auxiliary board and carrier board (carrier board) Conventional PCB (mostly main board, auxiliary board, backplane, etc. ) is mainly used for Level 3, 4 and 5 of Level 2 and 3 packages. Active devices, passive discrete devices and electronic components packaged with LSI and ic. Mounted thereon, and exert their circuit functions by interconnecting them to form a unit electronic circuit.

With the continuous progress and development of electronic installation technology, the boundaries of all levels of electronic installation are becoming more and more unclear, and all levels of installation are intertwined. In this process, the role of PCB is becoming more and more important, and higher requirements are put forward for PCB and its substrate materials in terms of function and performance.

Process and reason of separation between package substrate and PCB

After the 1980s, with the wide application of new materials and new equipment, the design and manufacturing technology of integrated circuits developed rapidly according to Moore's Law, tiny and sensitive semiconductor components came out, large-scale integrated circuits and ultra-large-scale integrated circuits appeared, and high-density multilayer packaging substrates appeared, which separated the integrated circuit packaging substrates from ordinary printed circuit boards, forming a proprietary manufacturing technology of integrated circuit packaging substrates.

At present, among the mainstream products of conventional PCB, the products with line width/line spacing of 50μm/50μm belong to high-end PCB products, but this technology still cannot meet the technical requirements of current mainstream chip packaging. In the field of packaging substrate manufacturing, products with line width/line spacing of 25μm/25μm have become conventional products, which reflects that packaging substrate manufacturing is more advanced than conventional PCB manufacturing. There are two fundamental reasons for the separation of package substrate from conventional printed circuit board: on the one hand, the development speed of PCB refinement is lower than that of chip, which makes the direct connection between chip and PCB more difficult. On the other hand, the cost of improving the overall refinement of PCB board is much higher than the cost of interconnecting PCB and chip through packaging substrate.

Main structure and production technology of packaging substrate

At present, there is no unified classification standard for packaging substrate industry. It is usually classified according to the substrate material and manufacturing process suitable for substrate manufacturing. According to different substrate materials, packaging substrates can be divided into inorganic packaging substrates and organic packaging substrates. Inorganic packaging substrates mainly include: ceramic-based packaging substrates and glass-based packaging substrates. Organic packaging substrates mainly include phenolic packaging substrates, polyester packaging substrates and epoxy packaging substrates. According to the different manufacturing methods of packaging substrates, packaging substrates can be divided into core packaging substrates and new coreless packaging substrates.

Coreless and Coreless Packaging Substrates

The substrate with core package is mainly divided into two parts in structure, the middle part is the core plate and the upper and lower parts are the laminated plates. The manufacturing technology of packaging substrate with core is based on the manufacturing technology of high-density interconnection printed circuit board (HDI) and its improvement technology.

Coreless substrate, also called coreless substrate, refers to the packaging substrate with the core plate removed. The new type of nuclear-free packaging substrate mainly adopts bottom-up electrodeposition technology to make interlayer conductive structure-copper column. It only uses build-up (build-up)

Layer) and copper layer realize high density wiring through semi-addition process (SAP for short).

Advantages and disadvantages of nuclear-free packaging substrate

superiority

Thinning;

The electric transmission path is reduced, and the AC impedance is further reduced. The signal circuit effectively avoids the return loss caused by PTH (copper plated through hole) on the traditional cored substrate, reduces the inductance of the power system loop, and improves the transmission characteristics, especially the frequency characteristics.

Direct signal transmission can be realized, because all circuit layers can be used as signal layers, which can improve the freedom of wiring, realize high-density wiring and reduce the limitation of C4 layout;

Except for some working procedures, the original production equipment can be used to reduce the number of working procedures.

Disadvantaged

In the manufacture of coreless substrate, it is easy to warp and deform without the support of core plate, which is the most common and biggest problem at present.

It is easy to damage the laminate;

It is necessary to introduce some new equipment for semiconductor packaging coreless substrates. Therefore, the challenges of coreless substrates for semiconductor packaging mainly lie in materials and processes.