Multilayer substrate
Provided is a multilayer substrate obtained by laminating semiconductor substrates each having a trough electrode. The multilayer substrate has excellent conduction characteristics and can be manufactured at low cost. Conductive particles are each selectively present at a position where the through electrodes face each other as viewed in a plan view of the multilayer substrate. The multilayer substrate has a connection structure in which the facing through electrodes are connected by the conductive particles, and the semiconductor substrates each having the through electrode are bonded by an insulating adhesive.
1. A multilayer substrate comprising semiconductor substrates which each have a through electrode and are laminated to each other, wherein
conductive particles are each selectively present at least at a position where the through electrodes face each other as viewed in a plan view of the multilayer substrate,
a conductive particle unit including three or more adjacent conductive particles is formed in a two-dimensional array in the plan view,
the multilayer substrate has a connection structure in which the through electrodes are connected by the conductive particle unit, and
the semiconductor substrates are bonded together by an insulating adhesive.
2. The multilayer substrate according to claim 1 , wherein
the semiconductor substrates include a first semiconductor substrate having a through electrode and a second semiconductor substrate having a through electrode,
the first and second semiconductor substrates are laminated together, and
the multilayer substrate has a connection structure in which the through electrode of the first semiconductor substrate and the through electrode of the second semiconductor substrate are connected by the conductive particle unit which is selectively disposed between the through electrodes.
3. The multilayer substrate according to claim 2 , further comprising:
a third semiconductor substrate having a through electrode laminated on the second semiconductor substrate, and having a connection structure in which the through electrode of the second semiconductor substrate and the through electrode of the third semiconductor substrate face each other, and are connected by conductive particles which are selectively disposed between the through electrodes, and
the second and third semiconductor substrates are bonded by insulating adhesive.
4. The multilayer substrate according to claim 1 , wherein a number of conductive particles which are not captured by the facing through electrodes between the first and second semiconductor substrates is 5% or less relative to a total number of the conductive particles present between the first and second semiconductor substrates.
5. The multilayer substrate according to claim 1 , further comprising:
a heat sink in an outermost layer of the multilayer substrate that is connected to the through electrodes.
6. A method for manufacturing the multilayer substrate according to claim 1 , comprising:
putting between the semiconductor substrates an anisotropic conductive film in which the conductive particles are selectively disposed in the insulating adhesive layer so as to each correspond to the position where the through electrodes face each other as viewed in the plan view of the multilayer substrate; and
pressurizing the anisotropic conductive film under heating to achieve anisotropic conductive connection of the semiconductor substrates.
7. The method according to claim 6 , wherein the semiconductor substrates include a first semiconductor substrate and a second semiconductor substrate.
8. The method according to claim 7 , wherein a third semiconductor substrate having a through electrode is laminated on the second semiconductor substrate, and an anisotropic conductive film in which conductive particles are selectively disposed in an insulating adhesive layer so as to correspond to an arrangement of the through electrodes is put between the through electrode of the second semiconductor substrate and the through electrode of the third semiconductor substrate, and pressurized under heating, to achieve anisotropic conductive connection between the second and third semiconductor substrates.
9. The multilayer substrate according to claim 1 , further comprising an anisotropic conductive film comprising the insulating adhesive layer and the conductive particles disposed in the insulating adhesive layer, wherein the conductive particles are selectively disposed at least in the insulating adhesive layer so as to correspond to an arrangement of through electrodes connected by the anisotropic conductive film.
10. The multilayer substrate according to claim 1 , wherein the conductive particles are disposed in the insulating adhesive layer.
11. The multilayer substrate according to claim 1 , wherein the conductive particle unit is disposed so as to correspond to an arrangement of the through electrodes.
12. The multilayer substrate according to claim 1 , wherein the conductive particles are metal-coated resin particles.