Methods for manufacturing a plurality of electronic circuits
The present invention relates to a method and apparatus for manufacturing a plurality of electronic circuits, each electronic circuit comprising a respective flexible first portion, comprising a respective group of contact pads (contacts), and a respective flexible integrated circuit, IC, comprising a respective group of terminals and mounted on the respective group of contact pads with each terminal in electrical contact with a respective contact pad, the method comprising: providing (e.g. manufacturing) a flexible first structure comprising the plurality of first portions; providing (e.g. manufacturing) a second structure comprising the plurality of flexible ICs and a common support arranged to support the plurality of flexible ICs; dispensing an adhesive onto the first structure and/or onto the flexible ICs; transferring said flexible ICs from the common support onto the flexible first structure such that each group of terminals is mounted on (brought into electrical contact with) a respective group of contact pads to form an electronic circuit, providing a heated surface and an opposing surface together having a gap therebetween, transferring the flexible first structure, comprising the electronic circuits, between the heated surface and the opposing surface such that the adhesive is cured by application of heat and pressure from the heated surface and the opposing surface thereby adhering the IC onto the respective first portion.
1. A method of manufacturing a plurality of electronic circuits, each electronic circuit comprising a respective flexible first portion, comprising a respective group of contact pads, and a respective flexible integrated circuit (IC) comprising a respective group of terminals and mounted on the respective group of contact pads with each terminal in electrical contact with a respective contact pad, the method comprising:
providing a flexible first structure comprising the plurality of first portions;
providing a second structure comprising the plurality of flexible ICs and a common support arranged to support the plurality of flexible ICs;
dispensing an adhesive onto the first structure and/or onto the flexible ICs;
transferring said flexible ICs from the common support onto the flexible first structure such that each group of terminals is mounted on a respective group of contact pads to form an electronic circuit,
providing a heated surface and an opposing surface together having a gap therebetween,
transferring the flexible first structure, comprising the electronic circuits, between the heated surface and the opposing surface such that the adhesive is cured by application of heat and pressure from the heated surface and the opposing surface thereby adhering the IC onto the respective first portion,
wherein a silicone paper layer is located between the electronic circuits and the heated surface to protect the heated surface from fouling with excess adhesive,
wherein the adhesive forms raised bond pads on at least one flexible IC, wherein each bond pad has a depth between 0.5 μm and 10 μm.
2. The method according to claim 1 , wherein the first structure is a flexible web.
3. The method according to claim 1 , wherein the flexible ICs comprise a flexible plastic base material.
4. The method according to claim 1 , wherein the adhesive is applied as a laminate layer to the first structure and/or to the flexible ICs held on the common support.
5. The method according to claim 1 , wherein the adhesive is applied to a predefined area of the first structure, the predefined area comprising at least the area of the first structure comprising the respective group of contact pads of each of the plurality of first portions.
6. The method according to claim 1 , wherein the adhesive is applied to a predefined area of the first structure, the predefined area of the first structure comprising an area around the contact pads and excluding the contact pads.
7. The method according to claim 1 , wherein the adhesive is applied to a predefined area of an IC.
8. The method according to claim 7 , wherein the predefined area comprises at least the area of the IC comprising the respective group of terminals of each of the plurality of ICs, or wherein the predefined area of the IC comprises a base layer of the IC and excludes the terminals of the IC.
9. The method according to claim 1 , wherein a non-conductive adhesive is flowed under heat and pressure applied by the heated surface and opposing surface, wherein the non-conductive adhesive is flowed away from the contact pads of at least one first portion by application of heat and pressure from the heated surface and opposing surface such that the non-conductive adhesive adheres an IC and the at least one first portion together and the terminals of the IC and the contact pads of the first portion are electrically connected and free of non-conductive adhesive.
10. The method according to claim 9 , wherein the non-conductive adhesive is flowed away from the terminals of at least one IC by application of heat and pressure from the heated surface and opposing surface such that the non-conductive adhesive adheres the IC and the first portion together and the terminals of the IC and the contact pads of the first portion are electrically connected and free of non-conductive adhesive.
11. The method according to claim 1 , wherein the flexible first structure is continuously transferred between the heated surface and the opposing surface.
12. The method according to claim 1 , wherein the adhesive is applied to the first structure and/or to the flexible ICs by screen printing, deposition, electro-plating, by jet dispensing or time pressure dispensing.