With the rapid development of BGA (ball grid array) and CSP (chip-level packaging) and other new ICS, IC substrates have been booming, and these ICs need new packaging carriers. As one of the most advanced PCB (printed circuit board), IC PCB, together with any layer of HDI PCB and flexible rigid PCB, has explosive growth in popularity and application. Now it is widely used in telecommunications and electronic updates.
IC Substrates Classification
a. Classification for Package Type of IC Substrates
• BGA IC substrates. This IC substrate performs well in heat dissipation and electrical performance, and can significantly increase chip pins. Therefore, it is suitable for IC packages with more than 300 pins.
• CSP IC substrate. CSP is a single-chip package, which is light in weight, small in size, and similar to IC. CSP IC substrate is mainly used for memory products, telecommunication products and electronic products with a small number of pins.
• FC IC substrate. FC (flip chip) is a flip-chip package with low signal interference, low circuit loss, good performance, and effective heat dissipation.
• MCM IC substrate. MCM is the abbreviation of a multi-chip module. This type of IC substrate absorbs chips with different functions into one package. As a result, the product can be the best solution because its features include lightness, thinness, shortness, and miniaturization. Of course, because multiple chips are packaged in one package, this type of substrate does not perform well in signal interference, heat dissipation, fine wiring, and other aspects.
b. Classification for Material Property of IC Substrates
• Rigid IC substrates. It is mainly made of epoxy resin, BT resin, or ABF resin. It’s CTE (coefficient of thermal expansion) is about 13 to 17 ppm / ° C.
• Flex IC substrates. It is mainly made of PI or PE resin and has CTE 13 to 27 ppm / ° C
• Ceramic IC substrates. It is mainly made of ceramic materials, such as aluminum oxide, aluminum nitrite or silicon carbide. It has a relatively low CTE of about 6 to 8 ppm / ° C
c. Classification for Bonding Technology of IC Substrates
• Wire bonding
• Tab (keyboard auto key)
• FC bonding
Application of IC substrate PCB
IC PCB is mainly used in the light, and powerful electronic products, such as smartphones, laptops, tablets, and networks, etc., in the fields of telecommunications, medical treatment, industrial control, aerospace, and military, etc.
Rigid PCB is a series of innovative PCB from multilayer PCB, traditional HDI PCB, SLP (substrate PCB) to IC. SLP is just a kind of rigid PCB, and its manufacturing processes are similar to the semiconductor scale.
Manufacturing difficulties of IC substrate PCB
Compared with standard PCB, IC substrates must overcome the difficulties of high performance and advanced function in manufacturing.
a. IC Substrate Manufacturing
IC substrate is thin and easy to deform, especially when the thickness is less than 0.2mm. In order to overcome this difficulty, a breakthrough must be made in plate shrinkage, lamination parameters, and layer positioning system, so as to effectively control substrate warpage and lamination thickness.
b. Microvia Manufacturing Technology
Micro via technology includes the following aspects: conformal mask, laser drilling, micro blind through-hole technology, and copper plating filling technology.
• conformal mask is designed to logically compensate the blind hole through the opening and the blind hole can be directly located through the hole diameter.
Laser drilling micro-machining is related to the following technologies: through-hole shape, aspect ratio, side etching, and left gel.
Blind hole copper coating is related to the following technical aspects: through-hole filling capacity, blind hole opening, sinking, copper plating reliability, etc.
c. Patterning and Copper Plating Technology
Patterning and copper plating technology is related to the following technical aspects: circuit compensation technology and control, fine wire manufacturing technology, copper plating thickness uniformity control. /p> As a result,
d. Solder mask
The manufacturing of solder mask for IC PCB includes through-hole filling technology, solder mask printing technology, etc. So far, the surface height difference of IC PCB is less than 10 um, and the surface height difference between the solder mask and pad should not exceed 15 μm.
e. Surface Treatment
The surface treatment of the IC substrate PCB should emphasize the uniformity of thickness. Up to now, the acceptable surface treatment of IC substrate PCB includes ENIG / ENEPIG.
f. Testing Capability and Product Reliability Testing Technology
IC substrate PCB requires different testing equipment from traditional PCB. In addition, there must be engineers who can master the testing skills of operation special equipment.
All in all, IC PCB requires more advanced manufacturing capabilities than standard PCB and PCB, and the manufacturer must be proficient in them.
IC substrates serve as the connection between the IC chip(s) and the PCB through a conductive network of traces and holes. IC substrates support critical functions including circuit support and protection, heat dissipation, and signal and power distribution.
IC substrates represent the highest level of miniaturization in PCB manufacturing and shares many similarities with semiconductor manufacturing.
We produce many types of IC substrates on which an IC chip(s) are attached to the IC substrate utilizing wire bonding and, or flip-chip methods. Advanced technology IC substrates that Highfive can provide include:
- CSP (Chip Scale Packages)
- FC-CSP (Flip Chip) CSP
- BOC (Board on Chip)
- PoP (Package on Package)
- PiP (Package in Package)
- SiP (System in Package)
- RF Module
- LED Package
Advanced Capabilities of
- Minimum line width and spacing: 20/20 µm
- Minimum laser via/pad: 45/95 µm
- Bump pad: minimum 150 µm bump pitch
- Bump material: SAC305
- Structure: any layer, coreless, cavity, embedded passive, embedded circuit
- Wide material and surface finish options available
- Ultrathin board capability:
Thin board layers Thickness capability/(mm) Remark Min. (2L) 0.11+/-0.02 Core Type Min. (3L) 0.12+/-0.02 Coreless Type Min. (4L) 0.15+/-0.02 Core Type Min. (6L) 0.18+/-0.02 Core Type Min. (8L) 0.22+/-0.03 Coreless Type