Ying-Jiunn Lai

Embedded passives technology for Bluetooth application in multi-layer printed wiring board (PWB)

This study was to investigate the use of a special high dielectric constant (Hi-DK) material for embedded passives in a Bluetooth system module. The stack structure of the module substrate was comprised of three kinds of material; Hi-DK, low loss-tangent and general organic material. Both experimental circuit and embedded passives can be implemented in this substrate for normal printed wiring board (PWB) lamination processing. The embedded capacitor electrode area can be reduced considerably by taking advantage of the Hi-DK material. After consideration of carefully simulated electrical characteristics, SMT matching network inductors could be replaced with a solenoid or spiral embedded layout structure. With embedded passives built into a Bluetooth substrate, this design can shrink the area by at least 14%, 38%. Area reduction was also realized by a double-side package layout design.

Embedded capacitors technology in 2.4 GHz power amplifier with multi-layer printed wiring board (PWB) process

In addition to the technology of system on a chip (SOC), the board level, system in a package (SIP) technology, will be another trend concordant with SOC technology to meet the requirements of future high frequency products. Therefore, the Embedded Passives technology becomes an important subject for both SOC and SIP technology to implement and extend their application field. For SIP technology, the integral substrate technology is a solution to realize embedded passives. The integral substrate technology is a noble design and manufacturing methodology which uses special materials to achieve specific circuit functions, and combines fine processes such as high density interconnection (HDI) technology. In this paper, a newly achieved high dielectric constant (Hi-DK) material, which is suitable for the Multi-Layer Printed Wiring Board (PWB) lamination process, is used to implement embedded capacitors. The electrical parameters such as dielectric constant and loss tangent versus frequency of the Hi-DK material were extracted from circuit characteristics. Many different types and sizes of embedded capacitors were designed and had been fitted by some circuit equivalent models; then we constructed a library of these elements. Furthermore, we verified these embedded capacitors by a 2.4 GHz power amplifier on a 6-layer, built-up process PWB, for wireless LAN application. The performance of the power amplifier designed by embedded capacitors was as good as the one designed by surface mount capacitors.

Functional embedded RF circuits on multi-layer printed wiring board (PWB) process

For getting more economy and smaller electronic products, technology of system in package (SiP) could complement the technology of system on a chip (SoC) perfectly. About SiP technology, we chose integral substrate technology to realize embedded passives, and used fine process such as high density interconnection (HDI) technology with a special dielectric material to achieve specific circuit functions. The special material is a high dielectric constant (Hi-DK; DK>40 @ 1GHz) material, which is suitable for Multi-Layer Printed Wiring Board (PWB) lamination process, and it was used to fulfill embedded capacitors. In the past years, we had utilized the technology to design Bluetooth/sup TM/ module, or other RF circuits. Furthermore, this technology is more economy than any other SiP processes, like Low Temperature Co-fired Ceramic (LTCC) substrate or silicon substrate, because it bases on the conventional PCB process. In this paper, we introduce not only the embedded capacitors but also some functional embedded passives in RF front-end circuits design on the Hi-DK organic substrate. Moreover, the RF front-end circuits include some functional passive elements: band pass filter, balun, and antenna, etc. Thus, in high frequency circuits, this kind organic substrate can reduce the module size, and in high-speed digital circuits, it also provides inexpensive decoupling capacitors. In the future, we will use this cost-effective technology to design analog and digital circuits on the same board, and the technology of SiP and SoC can be co-designed.

Embedded passives on multi-layer printed wiring board (PWB) for 5GHz front-end module

As wireless communication devices become smaller and lighter, less space is allowed for the placement of the RF components. Area reduction of circuit design is becoming more and more notable. This paper introduces the design and model for the basic embedded passives, and methods of circuits design with embedded elements for 5 GHz RF front-end module for IEEE 802.11a on PWB lamination process. The developed front-end module includes PA (power amplifier) and SPDT (single pole, double throw) switch. The power amplifier exhibits 25.5 dB of gain, 26 dBm of output P1dB, and output IP3 of 37.6 dBm. The SPDT switch shows 2 dB of insertion loss and 18dB of port return loss. Six layer stacks and three kinds of materials, such as Hi-DK material, low-loss material and commercial organic material were applied in this design. In this substrate, we use special high dielectric constant (DK >60 @ 1MHz) material to design embedded capacitors and use the embedded resistors (1k ohm/per square) for whole SiP module. The simulation and measured results have demonstrated a successful circuits design of RF front-end module for 802.11a WLAN

2.4 GHz Bluetooth module with integral passives in multi-dielectric layer printed-circuit boards

The motivation to further miniaturize and reduce the cost of portable electric devices has recently focused on the task of integration of the passive functions. In this paper, implications for integrating inductors and capacitors with standard multi-layer printed wiring board (PWB) lamination processes on organic substrates is discussed. To improve the circuit performance and obtain greater benefits of the integral passives, a multi-dielectric substrate with layer-specific dielectric constant and thickness is used to fulfill the designing of various integral passives. With these different material characteristics, we extract electrical parameters such as dielectric constant and loss tangent versus frequency of the special materials and then design various integral passives in a 6-layer multi-dielectric PWB substrate. Finally the potential advantages of using the PWB process on organic substrate with integral passives for a Bluetooth (BT) module are demonstrated.