1. A method for forming an assembly including semiconductor devices in stacked arrangement, the method comprising:
attaching a first semiconductor device including an active surface to a surface of a substrate;
disposing a plurality of discrete spacers on the active surface of the first semiconductor device;
extending a plurality of discrete conductive elements between a plurality of bond pads positioned in a central region of the active surface of the first semiconductor device and the substrate, comprising:
extending the plurality of discrete conductive elements from the plurality of bond pads over the active surface of the first semiconductor device;
extending a portion of the plurality of discrete conductive elements through a common aperture formed between two of the plurality of discrete spacers on a first side of the first semiconductor device;
extending a remaining portion of the plurality of discrete conductive elements through another common aperture formed between two of the plurality of discrete spacers on a second, opposing side of the first semiconductor device;
extending another plurality of discrete conductive elements from a plurality of peripherally located bond pads on the active surface of the first semiconductor device to the surface of the substrate, comprising:
extending a portion of the another plurality of discrete conductive elements through a third common aperture formed between two of the plurality of discrete spacers on a third side of the first semiconductor device;
extending a remaining portion of the another plurality of discrete conductive elements through a fourth common aperture formed between two of the plurality of discrete spacers on a fourth side of the first semiconductor device opposing the third side;
positioning a second semiconductor device having a back side over the first semiconductor device;
attaching the back side of the second semiconductor device to the plurality of discrete spacers; and
electrically isolating the plurality of discrete conductive elements from the back side of the second semiconductor device.
2. A method for forming an assembly including semiconductor devices in stacked arrangement, the method comprising:
attaching a first semiconductor device including an active surface to a surface of a substrate;
disposing a plurality of discrete spacers on the active surface of the first semiconductor device;
positioning each spacer of the plurality of discrete spacers at a peripheral corner of the active surface of the first semiconductor device;
extending a plurality of discrete conductive elements between a plurality of bond pads positioned in a central region of the active surface of the first semiconductor device and the substrate, comprising:
extending the plurality of discrete conductive elements from the plurality of bond pads over the active surface of the first semiconductor device;
extending a portion of the plurality of discrete conductive elements through a common aperture formed between two of the plurality of discrete spacers on a first side of the first semiconductor device; and
extending a remaining portion of the plurality of discrete conductive elements through another common aperture formed between two of the plurality of discrete spacers on a second, opposing side of the first semiconductor device;
positioning a second semiconductor device having a back side over the first semiconductor device;
attaching the back side of the second semiconductor device to the plurality of discrete spacers; and
electrically isolating the plurality of discrete conductive elements from the back side of the second semiconductor device.
3. The method of claim 2, further comprising encapsulating the first semiconductor device, the second semiconductor device, the plurality of discrete conductive elements, and at least a portion of the substrate.
4. The method of claim 2, further comprising extending at least one of the plurality of discrete conductive elements through at least one discrete spacer of the plurality of discrete spacers.
5. The method of claim 2, further comprising extending another plurality of discrete conductive elements from a plurality of peripherally located bond pads on the active surface of the first semiconductor device through a third common aperture formed between two of the plurality of discrete spacers on a third side of the first semiconductor device to the surface of the substrate.
6. The method of claim 2, wherein electrically isolating the plurality of discrete conductive elements from the back side of the second semiconductor device comprises at least partially encapsulating the plurality of discrete conductive elements.
7. The method of claim 2, further comprising attaching the plurality of discrete spacers to the back side of the second semiconductor device; and
attaching the plurality of discrete spacers protruding from and attached to the back side of the second semiconductor device directly to and in direct contact with the active surface of the first semiconductor device.
8. The method of claim 2, wherein attaching the first semiconductor device to the surface of the substrate comprises attaching the first semiconductor device to one of a circuit board, an interposer, another semiconductor device, and leads.
9. The method of claim 2, wherein extending the plurality of discrete conductive elements comprises at least one of wire bonding bond pads to the substrate, tape-automated bonding bond pads to the substrate, and thermocompression bonding leads to bond pads and the substrate.
10. The method of claim 2, further comprising extending the plurality of discrete conductive elements to a plurality of contact areas on the surface of the substrate.
11. The method of claim 10, further comprising extending a second plurality of discrete conductive elements from an active surface of the second semiconductor device to a second plurality of contact areas on the surface of the substrate.
12. The method of claim 2, further comprising encapsulating at least portions of the first semiconductor device, the second semiconductor device, the plurality of discrete conductive elements, and the substrate.
13. The method of claim 12, wherein encapsulating comprises one of transfer molding, pot molding, and glob-top encapsulation.
14. The method of claim 12, wherein encapsulating comprises forming a plurality of at least partially superimposed, contiguous, mutually adhered material layers.
15. The method of claim 14, further comprising forming the plurality of at least partially superimposed, contiguous, mutually adhered material layers from a photocurable material.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for making a solid cured porous phenolic resin having mesoporesmacropores of diameter >2 nm as estimated by nitrogen adsorption porosimetry, the differential of pore volume V with respect to the logarithm of pore radius R (dVd log R) for pores of size 2-10 nm being less than values of dVd log R for pores of size >10 nm, and values of dVd log R being >0.2 for at least some values of pore size in the range 10-50 nm, said method comprising
reacting without catalyst in a pore-forming solvent selected from the group consisting of diols, diol-ethers, cyclic esters, linear and cyclic substituted amides, aminoalcohols and optionally added water (a) a nucleophilic component which comprises a phenol condensation prepolymer optionally with one or more modifying reagents selected from the group consisting of hydroquinone, resorcinol, urea, aromatic amines and heteroaromatic amines and (b) an electrophilic crosslinking agent selected from the group consisting of formaldehyde, paraformaldehyde, furfural, hexamethylene tetramine, melamine and hydroxymethylated melamine,
the amount of pore former exceeding the capacity of the cross-linked resin domains, forming a solution with partially cross-linked polymer between the domains, increasing the volume of material in the voids between the domains and thereby giving rise to mesoporosity.
2. The method of claim 1, wherein the pore-forming solvent comprises ethylene glycol.
3. The method of claim 1, wherein the nucleophilic component comprises a novolac.
4. The method of claim 1, wherein the pore-forming solvent comprises ethylene glycol, the nucleophilic component comprises a novolak, the cross-linking agent comprises hexamine and the pore former is in an amount >120 parts by weight per 100 parts by weight of novolac.
5. The method of claim 4, wherein about 9 parts by weight of hexamine are used per 100 parts by weight of novolak.
6. The method of claim 1, wherein the resin is produced in the form of beads.
7. The method of claim 6, wherein the particle size of the beads is 5-2000 \u03bcm.
8. The method of claim 6, wherein a solution of the novolak and hexamine in ethylene glycol is smoothly increased in temperature to about 100-105\xb0 C. and dispersed into oil at about the same temperature after which the temperature is gradually rised to about 150-160\xb0 C. to complete cross-linking.
9. The method of claim 1, wherein the resin is produced in the form of powder.
10. The method of claim 9, wherein the particle size of the powder is between 1 and 1000 \u03bcM.
11. The method of claim 1, further comprising removing the pore former below 100\xb0 C. by washing the resin with water or by vacuum distillation.