Method for bonding small electronic components
AssigneeE. I. Du Pont de Nemours and Company
InventorsWilliam F. Graham, Mel A. Lofurno, Byron C. Sakiadis
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Abstract
A method for rapidly bonding a small electronic component to a mating surface of a high surface energy substrate using an adhesive pad made from a substantially amorphous, solvent-free thermoplastic polymer.
Claims12
A method for rapidly bonding a small electronic component having a mating surface smaller than about one square inch selected from the class consisting of capacitor,
- (a) cutting a continuous ribbon having a thickness of 25 to 125 micrometers of non-olefinic, substantially amorphous, solvent-free thermoplastic polymer, the polymer being further characterized in that
- T.sub.g is at least 30.degree. C.
- T.sub.b is below -30.degree. C.
- S.sub.w is less than 1.0% wt. and
- extractable tonics are less than 10 ppm by wt.,
- such that the cut ribbon forms the adhesive pad having both lateral dimensions substantially equal to or greater than the electronic component to be bonded;
- (b) heating mating surfaces of the electronic component and substrate so that the temperature of at least one of the surfaces exceeds the T.sub.g of the adhesive pad;
- (c) positioning the adhesive pad upon the heated substrate with an application of slight pressure to effect heat transfer from the substrate to the adhesive pad, thus softening the adhesive without incurring adhesive flow;
- (d) positioning the small electronic component upon the heated adhesive pad resulting in assembly of the electronic component, adhesive pad and substrates;
- (e) laminating the small electronic component to the substrate by applying a higher pressure to the small electronic component to reduce the thickness of the adhesive pad by 0.5 to 3% followed by a release of pressure within about 5 seconds.
A method for rapidly bonding a small electronic component having a mating surface smaller than about one square inch selected from the class consisting of capacitor, transistor, resistor, diode and integrated circuit chip to a substrate employing an adhesive pad between the electronic component and the substrate comprising the steps of:
- (a) cutting a continuous ribbon having a thickness of 25 to 125 micrometers of non-olefinic, substantially amorphous, solvent-free thermoplastic polymer, the polymer being further characterized in that
- T.sub.g is at least 30.degree. C.
- T.sub.b is below -30.degree. C.
- S.sub.w is less than 1.0% wt. and
- extractable ionics are less than 10 ppm by wt.,
- such that the cut ribbon forms the adhesive pad having both lateral dimensions substantially equal to or greater than the electronic component to be bonded;
- (b) heating mating surface of the electronic component to near the bonding temperature and heating the substrate so that the temperature exceeds the T.sub.g of the adhesive pad;
- (c) positioning the adhesive pad upon the heated substrate with an application of slight pressure to effect heat transfer from the substrate to the adhesive pad, tush softening the adhesive without incurring adhesive flow;
- (d) positioning the small electronic component upon the heated adhesive pad resulting in assembly of the electronic component, adhesive pad and substrates whereby the heating for steps (b), (c) and (d) is about one second;
- (e) laminating the small electronic component to the substrate by applying a higher pressure to the small electronic component to reduce the thickness of the adhesive pad by 0.5 to 5% followed by a release of pressure within about 5 seconds.
The method of claim 10 in which the adhesive is comprised of a mixture of compliant and rigid polymers.
Dependencies are inferred from the claim text.