Stacked module systems
View Patent ↗The present invention stacks integrated circuit packages into circuit modules. In a preferred embodiment, solder paste and primary adhesive respectively are applied to selected locations on the flex circuitry. Supplemental adhesive is applied to additional locations on the flex circuitry, CSP, or other component. The flex circuitry and the CSP are brought into proximity with each other. During solder reflow operation, a force is applied and the CSP collapses toward the flex circuitry, displacing the primary adhesive and the supplemental adhesive. The supplemental adhesive establishes a bond providing additional support to the flex circuitry. In another embodiment, CSPs or other integrated circuit packages are bonded to each other or to other components with a combination of adhesives. A rapid bond adhesive maintains alignment of the bonded packages and/or components during assembly, and a structural bond adhesive provides additional strength and/or structural integrity to the bond.
1. A circuit module comprising:
a first integrated circuit in stacked conjunction with
a second integrated circuit;
the first integrated circuit and the second integrated circuit being disposed in stacked alignment maintained by a first adhesive bond comprising rapid bond adhesive;
a second adhesive bond disposed on the first integrated circuit and the second integrated circuit comprising structural bond adhesive; and
a flex circuit having plural contact arrays, said flex being attached to the first integrated circuit with supplemental adhesive disposed between the plural contact arrays.
2. The circuit module of claim 1 in which the rapid bond adhesive comprises a pressure sensitive adhesive that bonds quickly and maintains the bond through repeated exposure to temperatures required to form high-temperature solder joints.
3. The circuit module of claim 1 in which the structural bond adhesive comprises thermoplastic bonding film with high shear and peel strength.
4. The circuit module of claim 1 in which the structural bond adhesive comprises a snap-cure or ultraviolet light curable adhesive.
5. The circuit module of claim 1 in which the structural bond adhesive comprises a thermoset adhesive or epoxy or an RTV adhesive.
6. A circuit module comprising:
a first integrated circuit of a first type in a stacked conjunction with two integrated circuits of a second type;
a first adhesive bond disposed on the first integrated circuit comprising rapid bond adhesive;
a second adhesive bond disposed on the two integrated circuits of second type; and
a flex circuit connecting the first integrated circuit of first type and the two integrated circuits of second type, said flex circuit having at least two contact arrays and said flex circuit being attached to said two integrated circuits of second type with supplemental adhesive disposed on the flex circuit between said at least two contact arrays.