bondable bumpable adapted for contact by spring interconnects such as those manufactured by form factor inc known as microsprings u2122 or spring pins made by everett charles corp under the trade name pogopin u2122 or adapted for connection to a lateral interposer as disclosed in u s patent application ser no 11 226 568 assigned to touchdown technologies inc the disclosure of which is incorporated by reference some probe card architectures employ an interposer 1700 between the wiring board and the probe head 100 300 that imparts a very small force on the probe head 100 300 in this architecture it is desirable to have a probe head with tight planarity in such cases it is required that the attachment structure 200 is compliant to absorb any expansion differences in the probe contactor substrate 100 and the space transformer substrate 300 so that the probe head 100 300 planarity does not change with operating temperature preferably the probe contactor substrate 100 and the space transformer substrate 300 are joined together by an attachment structure 200 such as a compliant adhesive chosen with suitable modulus to account for the thermal mismatch between the space transformer 300 and probe contactor substrate 100 some suitable options for such an attachment structure 200 may include adhesive polymers such as silicone elastomers polyimides bcb benzo cyclo butene or hard materials such as solder thermally compliant mechanical attachments between the space transformer 300 and the probe contactor substrate 100 such as screws and clips are also possible if adhesive is used it can be dispensed in place screen printed or any other means commonly known in the art b stage preform may also be used if solder is used it.