Embedded Substrate Assembly for Reliable Conductive Paste Contact
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Solution Overview
Problem
The existing multilayer wiring boards face reliability issues in electrical connections due to insufficient contact of conductive paste with conductor layers and adhesive flow during thermal compression bonding, leading to unreliable connections between electronic devices and substrates.
Innovation Solution
A method involving the use of a first wiring layer with a concave part and a convex part on an insulating layer, ensuring the conductive paste is in contact with the convex part during temporary fixation, followed by heating and pressing to establish reliable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the adhesive and conductive paste are heated below their curing temperatures to temporarily fix the electronic device, then the electronic device can be temporarily fixed to the substrate, but the conductive particles in the conductive paste are not in sufficient contact with the conductor layer
Solution Approach 1:
The land portion surface is prepared in advance to be higher than the insulating layer surface before the temporary fixing process, ensuring that when the conductive paste is applied and pressed, it will naturally contact the conductor layer first due to the height difference, achieving sufficient contact before curing
Solution Approach 2:
The land portion is given a different surface height compared to the insulating layer, creating a local height difference that directs the conductive paste to contact the conductor layer preferentially, ensuring reliable electrical connection while maintaining overall structure integrity
2Ease of manufacture
If the surface of the land portion is lower than the surface of the insulating layer, then the structure is simplified, but the adhesive may come into contact with the insulating layer before the conductive paste contacts the land portion and may flow into the interface
Solution Approach 1:
The land portion surface height is adjusted in advance to be higher than the insulating layer surface, so that during the temporary fixing process, the conductive paste will naturally contact the conductor layer first due to gravity and height difference, preventing adhesive contamination before electrical connection is established
Solution Approach 2:
By creating a height difference that favors conductive paste contact first, the invention preemptively prevents the harmful effect of adhesive flowing into the conductive paste-conductor layer interface, eliminating the reliability issue before it can occur
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures sufficient contact of conductive particles with conductor layers, reducing adhesive interference and enhancing the reliability of electrical connections between electronic devices and boards.
Implementation Method 1
the adhesive and the conductive paste are cured by this thermal compression bonding
Implementation Method 2
the adhesive and conductive paste are heated below their curing temperatures to temporarily fix the electronic device to the substrate with the wiring
Data Source
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AI summary
A method of manufacturing a device-embedded board includes: steps S10 to S30 of preparing an electronic device 10, an inner board 40 and outer boards 50B and 60B; a step S40 of temporarily fixing the electronic device 10 to the outer board 50B; a step S50 of stacking the outer boards 50B and 60B and the inner board 40 with each other so that the electronic device 10 is inserted into the first opening 411; and a step S60 of fixing the outer boards 50B and 60B and the inner board 40 to each other. The electronic device 10 includes: a device main body 20; an insulating layer 33 having an opening 331; and a wiring layer 34 disposed on the insulating layer 33 to cover the opening 331. The second step S40 includes pressing the electronic device 10 against the outer board 50B in a state in which the conductive paste 55B is in contact with the wiring layer 34.