Press-fit integrated circuit package involving compressed spring contact beams
View Patent ↗An insulative substrate includes a plurality of flexible retaining clips and a plurality of alignment and retaining pins. A metal leadframe includes a plurality of leads. Each lead terminates in a spring contact beam portion. The leadframe is attached to the substrate (for example, by fitting a hole in each lead over a corresponding alignment and retaining pin and then thermally deforming the pin to hold the lead in place). An integrated circuit is press-fit down through the retaining clips such that pads on the face side of the integrated circuit contact and compress the spring contact beams of the leads. After the press-fit step, the retaining clips hold the integrated circuit in place. The resulting assembly is encapsulated. In a cutting and bending step, the leads are singulated and formed to have a desired shape. The resulting low-cost package involves no wire-bonding and no flip-chip bond bump forming steps.
1. A package integrated circuit assembly comprising:
A molded insulative plastic substrate including a plurality of flexible retaining clips;
a plurality of metal leads, wherein each of the plurality of leads extends along a surface of the molded insulative plastic substrate and includes a spring contact beam portion;
an integrated circuit die that is contacting and is retained by the retaining clips such that the spring contact beam portions are compressed by the die and are pressing against the die but are not welded to the die; and
wherein each of the leads has a hole, and the molded insulative plastic substrate includes a plurality of alignment and retaining pins, and wherein each pin extends through a hole in a respective one of the leads.
2. The packaged integrated circuit assembly of claim 1 , wherein the plurality of metal leads are stamped metal leads.
3. The packaged integrated circuit assembly of claim 1 , wherein the molded insulative plastic substrate includes a second plurality of retaining clips, and wherein each lead is retained by and is in contact with at least one of the second plurality of retaining clips.
4. The packaged integrated circuit assembly of claim 1 , further comprising:
a glob top of conformal encapsulant that encapsulates the integrated circuit die and the plurality of flexible retaining clips.
5. The packaged integrated circuit assembly of claim 1 , further comprising:
an amount of injection molded plastic material that encapsulates at least the integrated circuit die and the plurality of flexible retaining clips.
6. The packaged integrated circuit assembly of claim 1 , wherein the molded insulative plastic substrate forms a plurality of guide slots, and wherein each lead extends through a corresponding respective one of the guide slots.
7. The packaged integrated circuit assembly of claim 1 , wherein the integrated circuit die includes a plurality of conductive contact pads, and wherein each of the contact pads has a substantially planar and aluminum surface that is in direct contact with the spring contact beam portion of a corresponding respective one of the leads.
8. The packaged integrated circuit assembly of claim 1 , wherein the integrated circuit die is not wire-bonded to any of the leads.
9. The packaged integrated circuit assembly of claim 8 , wherein the integrated circuit die does not include any flip-chip bonding bumps.
10. The packaged integrated circuit assembly of claim 1 , wherein the leads press-fit engage the substrate.
11. A package integrated circuit assembly comprising:
an insulative plastic substrate;
a plurality of stamped metal leads, wherein each of the plurality of stamped metal leads extends along a surface of the molded insulative plastic substrate and includes a spring contact beam portion, wherein each of the stamped metal leads is attached to the insulative plastic substrate;
an integrated circuit die that is retained with respect to the insulative plastic substrate and the plurality of stamped metal leads such that the spring contact beam portions are compressed by the die and are contacting the die, wherein the integrated circuit die is not wire-bonded to any of the stamped metal leads and wherein the integrated circuit die does not include flip-chip bonding bumps;
an amount of conformal encapsulant that encapsulates the integrated circuit die; and
wherein each of the leads is attached to the substrate by press-fit engagement.
12. The packaged integrated circuit assembly of claim 11 , wherein the integrated circuit die press-fit engages the insulative plastic substrate such that retaining clips of the insulative plastic substrate retain the integrated circuit die with respect to the spring contact beam portions of the leads so that the spring contact beam portions of the leads are compressed and are pressing against the integrated circuit die.
13. A press-fit integrated circuit package comprising:
a plurality of metal leads, wherein each lead has a spring contact beam portion;
means for press-fit engaging and retaining an integrated circuit die such that the spring contact beam portion of each lead is compressed and is in contact with the respective one of a plurality of contact pads of the integrated circuit; and
wherein the means includes a plurality of mushroom-shaped pin portions, and wherein each of the leads is held in place with respect to the means by a respective one of the mushroom-shaped pin portions.
14. The press-fit integrated circuit package of claim 13 , wherein said contact pad that the spring contact beam portion of said each lead is in contact with has an aluminum surface, and wherein the spring contact beam portion is in direct contact with the aluminum surface.
15. The press-fit integrated circuit package of claim 13 , further comprising:
an integrated circuit that is press-fit engaged and retained by the means, wherein the integrated circuit includes no flip-chip bonding bumps, and wherein the integrated circuit is not wire-bonded to any portion of the means or to any of the leads.