Patent Application
20120155044
Embodiments presented herein relate generally to electronic circuit boards, and more specifically to a digital electronic circuit board and a related method thereof.
A printed circuit board (referred to as “PCB”) is often used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces that may be etched from metal sheets laminated onto a non-conductive substrate. A PCB populated with electronic components is a printed circuit assembly and may also be referred to as a printed circuit board assembly (PCBA).
Conventional conducting layers of the PCB are typically made of thin copper foil. Insulating layers dielectric is typically laminated together with epoxy resin prepreg. The vast majority of printed circuit boards are made by bonding a layer of copper over the entire substrate, sometimes on both sides, then removing unwanted copper after applying a temporary mask (e.g. by etching), leaving only the desired copper traces. Some PCBs are made by adding traces to the bare substrate usually by multiple electroplating steps.
After the PCB is completed, electronic components are attached to form a functional printed circuit assembly. In a through-hole technique, component leads are inserted in holes. In a surface-mount technique, the components are placed on pads on the outer surfaces of the PCB. In both kinds of techniques, component leads may be electrically and mechanically fixed to the board with a molten metal solder. The conventional PCB device may be limited to applications at a temperature below 200 degrees Celsius. Moreover the conventional PCB device may be susceptible to failure due to vibrations and corrosion.
There is a need for an improved electronic circuit device.
In accordance with an exemplary embodiment of the present invention, an apparatus includes a set of first metal contact pads disposed on a low temperature co-fired ceramic substrate. A plurality of metalized interconnectors extend between a digital electronic component and the low temperature co-fired ceramic substrate. The apparatus is configured to operate at a temperature greater than 250 degrees Celsius.
In accordance with an exemplary embodiment of the present invention, a method includes providing an apparatus having a set of first metal contact pads disposed on a low temperature co-fired ceramic substrate, and a plurality of metalized interconnectors extending between a digital electronic component and the low temperature co-fired ceramic substrate. The method also includes utilizing the apparatus at a temperature greater than 250 degrees Celsius.
These and other features, aspects, and advantages will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
According to embodiments presented herein, an apparatus, for example, an electronic circuit board and a related method thereof is disclosed. The electronic circuit board can include a low temperature co-fired ceramic substrate. A set of first metal contact pads can be disposed on the low temperature co-fired ceramic substrate. The electronic circuit board can further include a plurality of metalized interconnectors extending from a digital electronic component to the low temperature co-fired ceramic substrate. An electronic circuit board configured as described herein may be capable of operating at a temperature greater than 250 degrees Celsius, may demonstrate enhanced resistance to failure due to extreme conditions such as high temperature, vibration, and corrosion, and may provide low losses, for example, low inductance, and low resistance.
Referring to
In one embodiment, the plurality of metal bumps 16 may be bonded to the set of first metal contact pads 14 and the set of second metal contact pads 18 via a diffusion bonding. Diffusion bonding involves holding pre-machined components under load at an elevated temperature, possibly in a protective atmosphere or vacuum. In another embodiment, the plurality of metal bumps 16 may be bonded to the set of first metal contact pads 14 and the set of second metal contact pads 18 via a thermo-compression bonding, i.e. by the application of pressure and heat in the absence of an electrical current. In yet another embodiment, the plurality of metal bumps 16 may be bonded to the set of first metal contact pads 14 and the set of second metal contact pads 18 via a thermo-sonic bonding i.e. bonding by using a combination of heat, ultrasonic energy, and pressure generally applied by a bonding tool.
It should be noted herein that the electronic circuit board 10 is applicable for interconnecting the digital electronic component 20 operated at temperatures above 250 degrees Celsius. In accordance with certain embodiments, the digital electronic component 20 may include a wide band gap device such as a silicon carbide device. A plurality of metalized interconnectors 22 may be provided extending from the digital electronic component 20 to the LTCC substrate 12.
The advantage of the LTCC substrate 12 is that the ceramic substrate could be fired below 900 degrees Celsius due to composition of the material. Hence the LTCC substrate 12 permits co-firing with high conductive materials such as silver, copper, gold, or the like. Additionally, the LTCC substrate 12 has low co-efficient of thermal expansion and enhanced flexibility.
As mentioned above the electronic circuit board 10 is applicable for a high temperature device 11 operated at temperature above 250 degrees Celsius. In one embodiment, the high temperature device 11 may be a nitrogen oxide sensor. In another embodiment, the high temperature device 11 may be a drilling device, such as a drilling device for oil and/or gas. In yet another embodiment, the high temperature device 11 may be a digital sensing device. In yet another embodiment, the high temperature device 11 may be an automobile. In a further embodiment, the high temperature device 11 may be a jet engine, or a turbine. It should be noted that the list mentioned herein is not all inclusive and the board may also be applicable for other applications operated above 250 degrees Celsius.
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In the exemplary embodiments discussed herein, the electronic circuit board 10 has enhanced temperature capability, i.e. applicable for digital electronic device 20 operated at temperatures above 250 degrees Celsius. It should be noted herein that digital circuits typically need higher input/output connections than analog circuits. The exemplary electronic circuit board 10 is resistant to the harsh environment (for example, temperature, vibration, corrosion) and provides a low loss (for example, low inductance, low resistance). In accordance with certain embodiments, the LTCC substrate 12 provide a high density circuitry using thick-film printing to 4 mil lines/spaces or using photo-imagable thick-film to 2 mil lines/spaces in single or multilayer circuits.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This invention was made with Government support under contract number DE-EE0002755 awarded by U.S. Dept. of Energy. The Government has certain rights in the invention.
