Looking at a Circuit Board from a recent consumer product, I still see many discrete components (diodes, resistors, capacitors, amplifiers), which occupy space and have to be soldered into the board.

Would it be viable to integrate all passive components into one package?

Obs: Trying to improve on previous question which was found inadequate. I got the following suggestions: "Perhaps you could limit this to passives (for now)"; "Can you add a sentence with a question mark? What are you asking? For instance, "Will integration eliminate all external components? Or will there always be discrete components regardless of how much functionality is provided into silicon?".

  • \$\begingroup\$ And still You are trying to ask the same question, ehhh... \$\endgroup\$ – Jakub Rakus Jul 8 '16 at 16:35
  • \$\begingroup\$ Is this question about all uses of passive components? If it is, then I think it is clear that even a small number of different components, e.g. capacitors and resistors, available in several different component values, would lead to an enormous number of component permutations. Then think about the economic implications of making, shipping and storing millions of different chips. That is not a technical problem but complexity and economics problems. Worse, connecting to one of those chips creates new complexity for the PCB to solve. Placing simple, two pin components anywhere is helpful. \$\endgroup\$ – gbulmer Jul 8 '16 at 16:41
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    \$\begingroup\$ Summary: it may be viable to integrate all passive components for a specific circuit into one package. However, the cost of engineering, testing and manufacturing is likely not viable for anything less than massive quantities. Worse, any fix or change to the integrated part will likely be a larger engineering, manufacturing and write-off cost than changing discrete part values, or even changing the PCB. \$\endgroup\$ – gbulmer Jul 8 '16 at 16:46
  • \$\begingroup\$ So what is your analysis? What costs for engineering and manufacturing an integrated part vs discrete parts on a PCB are you using in your analysis model? \$\endgroup\$ – gbulmer Jul 8 '16 at 16:47
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    \$\begingroup\$ There are cases where this is done. They are called Modules. Analog Devices has isolators such as the AD202KN and AD210KN which are small modules, but much larger than an IC. Point of use DC-DC converters for PCB use are modules. What cannot be reduced are parts for high voltage, as this would violate creapage and clearance rules. \$\endgroup\$ – user105652 Jul 8 '16 at 17:07

Yes, there are ways to integrate all kinds of passive devices into a printed wiring board (PWB).

Capacitors can be made by laminating a high-dielectric-constant material into the PWB stackup and patterning the copper layers above and below it to form capacitors.

Inductors can be formed by patterning coils into the copper layers.

Resistors can be formed by laminating in a resistive layer to the stack up, or by printing with conductive inks on top or bottom of an insulating layer.

But this has many drawbacks:

  • Design changes may require a full board re-spin just to change a component value.

  • Inductors are limited in value due to essentially being all air-core types. The number of turns is also limited by the space/trace limits of the PWB manufacturing process.

  • Capacitors must all use the same (or a small set of) dielectric materials, whereas different dielectrics might be preferred for high-value capacitors vs lower-value but tighter-tolerance capacitors.

  • Resistor precision may be poor unless a cost-additive laser-trimming process is added.

  • Resistors must all use the same (or a small set of) resistive materials. This will require some resistor values to consume a large amount of space.

  • Space savings are unlikely, particularly compared to 0201 or 0402 sized SMT components.

  • \$\begingroup\$ Not to mention voltage or power ratings of different parts, like resistors. You're not going to be able to get a 5W resistor in an IC. \$\endgroup\$ – DerStrom8 Jul 8 '16 at 17:57
  • \$\begingroup\$ @DerStrom8, The question is tagged with "PCB" so figured that is what OP was interested in and I didn't even try to address ICs. \$\endgroup\$ – The Photon Jul 8 '16 at 19:17
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    \$\begingroup\$ Despite the tag, I think the OP is asking whether it is possible to collect all the passives in a circuit into one or more IC's. Might as well throw in the transistors and diodes too. Not very cost-effective. And as you pointed out in the case of a PCB, design changes including component values will require a new IC. \$\endgroup\$ – tcrosley Jul 8 '16 at 20:24

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