Rugged CSP module system and method

An electrical assembly, comprising:

• a printed circuit board (PCB);
• an integrated circuit (IC) including a first array of contacts, wherein the IC is disposed adjacent to the PCB and lateral movement of the IC with respect to the PCB is measured as an angular shift;
• and
• an interposer disposed between the PCB and the IC, wherein the interposer comprises a upper surface and a lower surface, the upper surface coupled to the first array of contacts, the lower surface coupled to a second array of contacts;
• wherein the second array of contacts further couple to the PCB, thereby electrically coupling the PCB to the IC;
• wherein a thermally-induced relative angular shift between the PCB and the IC is controlled by varying the cumulative height of a combination of the first and second arrays of contacts and the interposer.

An electrical assembly, comprising:

• a plurality of chip scale packages (CSPs) disposed on a PCB;
• a unitary interposer disposed between the plurality of CSPs and the PCB, the interposer comprising:
• a rigid portion located substantially beneath each CSP within the plurality of CSPs;
• and
• a flexible portion located substantially beneath gaps between the plurality of CSPs, wherein the flexible portion maintains electrical connection between the plurality of CSPs despite lateral shifting between the CSPs and PCB.

A method of manufacturing an electrical assembly, the method comprising the acts of:

• providing a CSP including a first plurality of contacts;
• coupling a unitary interposer to the first plurality of contacts to create a CSP-interposer module;
• and
• coupling the CSP-interposer module to a second plurality of contacts located on a PCB;
• wherein angular shift between the packaged IC and the PCB due to thermal variations is controlled by varying the thickness of the combination of the first and second pluralities of contacts and the interposer.

A computer system, comprising:

• a processor;
• a storage medium coupled to the processor;
• an CSP coupled to the processor, wherein the CSP is disposed above a PCB, and wherein the CSP experiences an angular shift θ with respect to the PCB, the angular shift θ characterized by:
• θ
• =
• tan
• -
• 1
• ⁡
• (
• Δ
• H
• CSP
• +
• H
• I
• +
• H
• R
• )
• ,
• whereby
• (
• 2
• )
• Δ represents lateral shifting of the CSP with respect to the PCB, HCSP represents the height of a first array of contacts, HI represents the thickness of an interposer connected directly to the CSP and the PCB, and HR represents the height of a second array of contacts.

A method for reducing a thermally-induced relative angular shift between a CSP and a PCB, the means comprising the steps of:

• providing a unitary interposer having a first and a second set of contacts accessible from first and second major sides of the unitary interposer;
• disposing the unitary interposer directly between the CSP and the PCB;
• and
• connecting the CSP to the first set of contacts and the PCB to the second set of contacts.