The next generation of passive electronic components

Passive components are important in terms of how future technologies will improve while becoming smaller. In the past, design engineers have followed a strict bill of materials to produce a 'black box'. And were always distracted by expensive silicon and noticed passive components simply because they were well below the cost list, ending up at 2.3% of the BOM1. Today, however, the realisation that most of the physical space on a printed circuit board is dominated by passive components (with a focus on ceramic chip capacitors, thick film chip resistors, ceramic chip inductors and multilayer ferrite beads) is finally becoming a key issue. The next area driving end-product technology forward.

The trend towards miniaturisation

Smaller case size passive components are an important development to help reduce the physical size of electronic products sold. Products that have had a major impact on driving the development of smaller case size capacitors, resistors and inductors* include smartphones, laptops, personal digital assistants, digital cameras and camcorders; and flat panel displays.

Among ceramic capacitors, the trend towards miniaturisation with a focus on MLCCs is significant, with demand shifting from larger 0805 case size components to smaller 0603 and 0402 case size components and then down to the impressive 0201 (EIA) case size in 2003 to 2016, with 01005 establishing a firm foothold as the next generation of very small electronic components. The trend is now moving forward with the introduction of 008004 in MLCC thick film resistors and ceramic chip inductors (very cutting edge, very). But with many of the major branded OEMs dominating the high-tech economy talking around the boardroom, the goal must be to be able to produce entire power amplifiers or communication modules in 0201 case sizes. To achieve this in the future, to drive the Internet of Everything into the granularity of human existence, the passive components in the design need to provide their functionality but not be visible, and their performance as accurate as possible. To achieve this, major design houses will have to expand the palette of materials they use; a more extended view of the periodic table of elements; and expand the processing power of the machines they use to build the products of the future.

Next Generation = Integration and Modularity

In the 1960s, resistor manufacturers such as Vishay Intertechnology, Inc. began to package individual resistors into single-in-line in-line packages (SIPs) that could hold four to eight individual components. This package reduced the cost of placing the resistors on the printed circuit board ("conversion cost").

It wasn't long before component manufacturers realised that their ability to create networks on alumina bridges also meant they could offer value-added configurations (e.g. bus and R2R ladder circuits for filtering and line termination). Over time, this concept was enhanced with thick film networks containing 16 to 32 resistive elements in double in-line packages with plastic housings with gull-wing leads for easy surface mounting. The double in-line package (DIP) allowed resistor manufacturers to integrate different types of passive components, typically chip resistors and ceramic chip capacitors.

In the early 1990s, new developments in passive component configurations were pioneered by companies in the discrete semiconductor industry who successfully used semiconductor manufacturing techniques to manipulate specific raw materials such as tantalum nitride, chromium silicide and nickel-chromium to create resistive layers. They also use ion implantation equipment to design silicon oxide and silicon nitride capacitors; thus creating complex Integrated Passive Devices (IPDs). The additional silicon treatment in the films adds transistor functionality and circuit protection to the IPDs. New silicon-based thin-film designs are beginning to compete with traditional thick-film DIPs and SIPs in terms of termination and filtering functions, especially in high-frequency applications.

As thin film resistor IPDs found their niche, chip resistor manufacturers developed multi-chip arrays based on thick film technology. Multi-chip arrays are a low-cost alternative to traditional thick film SIP products, which reduce PCB placement costs. The combination of low-cost array components, combined with additional savings in conversion costs for customers, has led to rapid growth in the array market, particularly in markets where volume efficiency is important.

Companies that had been manufacturing arrays and networks (particularly those using multi-layer technology) began to realise the components and modules that they could produce using their manufacturing knowledge and techniques. The result is the complex integration of capacitors, resistors and inductors in low temperature co-fired ceramic (LTCC) substrates.

As a by-product of this technological advancement, a portion of the R&D expenditure is shifted from the customer to the component supplier.

LTCC components and modules have been used in automotive applications for some time, particularly for engine control. Now, wireless devices present a new, high growth opportunity for LTCC. A typical wireless handset has 500 to 1000 passive components, of which about 45% are MLCCs and 25% are chip resistors (thin film resistor models). Over time, these components are gradually shifting from being picked up and placed directly on the printed circuit board to appearing inside the module (power amplifiers, communications), which makes them harder to count, but it also means that modularity is the future goal to make chipsets smaller.

Component integration and material manipulation

Integrated passive components and modules enable capacitors, resistors and inductors by combining individual components on the substrate material or internally.

Considerable efforts are being made to develop high K and high Q materials that can easily be used for co-fire (for LTCC) or FR4 laminate assembly. Manufacturers of FR4 modules see integrated passive substrates as a way to move beyond the two-dimensional (lower density) model of FR4. manufacturers of LTCC modules are interested in integrated passive substrates because they offer lower parasitic inductance in the finished module compared to co-fired individual discrete components. of parasitic inductance.

Component manufacturers are also smart

Companies such as Murata Manufacturing in Japan have pushed the technology forward by taking a step forward in the miniaturisation of MLCCs and chip inductors. The material engineering and process control required to successfully produce 008004 EIA case size components is an enabling technology, as the consistent performance of the components provides module manufacturers with greater batch-to-batch quality consistency. But the discussion always points to the fact that components at 008004 are barely visible to the naked eye. This is exactly what module manufacturers want for their more expensive processes, but they also know that at a certain point

Predictions

The impact of component modularity may be as great as the recent shift in manufacturing from OEMs to CEMs. Component modularity offers significant value-added opportunities for component suppliers. As prefabricated modules contain ever larger suppliers of passive component circuit modules, they will take some of the power away from the mass assembly plant in order to increase manufacturing throughput. Individual component manufacturers who have invested heavily in the production of capacitors and resistors in the large scale economy will realise that by working with raw material suppliers to develop higher quality ceramics and metals, and the process technology required to manufacture thin plates and layers, they can continue to drive the technology forward by creating smaller and smaller components.