Semiconductor devices are often tested to ensure their functionality. Testing may be carried out at the wafer level, prior to individual chips being diced apart and packaged. Wafer level testing may include the use of test probes that are brought into electrical contact with pads on the devices to be tested. Such testing of devices on the wafer is commonly known as “wafer sort”. Devices that fail the testing may be marked and sorted accordingly during a subsequent wafer dicing process.
A wafer sort assembly may include a number of components, including, but not limited to, a probe head coupled to a printed circuit board (PCB) that acts as a sort interface unit (SIU). The PCB is electrically coupled to a tester. The probe head may include test probes that are electrically coupled to a space transformer that is electrically coupled to the PCB. The space transformer generally serves as a pitch transfer medium from a high-density first level interconnect (FLI) to a lower density second level interconnect (SLI). The space transformer proves an electrical path between the FLI and the SLI with internal routing, through which the FLI inputs/outputs (I/Os) are routed through the space transformer and printed circuit board (PCB) to the tester. A force retainer plate (FRP) structure may be utilized to serve as datum and loading frame for the SIU.
Embodiments are described by way of example, with reference to the accompanying drawings, which are not drawn to scale.
Reference below will be made to the drawings wherein like structures may be provided with like reference designations. In order to show the structures of various embodiments most clearly, the drawings included herein include diagrammatic representations of various structures. Thus, the actual appearance of the fabricated structures may appear different while still incorporating the claimed structures of the illustrated embodiments. Moreover, the drawings may show only the structures necessary to understand the illustrated embodiments. Additional structures known in the art have not been included to maintain the clarity of the drawings.
The space transformer in a wafer sort assembly has typically been formed from a multi-layer ceramic. The probe head, which may include the space transformer, an array of probes, and a corresponding assembly fixture, is coupled to the PCB that is in turn electrically coupled to the tester. The probe head acts as a temporary electrical interface between the tester and the device (for example, wafer) to be tested. Elements that may affect probing performance during wafer sort include, but are not limited to, probe head/probe array tip coplanarity, probe actual over travel and corresponding probing force between the wafer bump and each probe, signal integrity of overall assembly, and space transformer deformation and reliability under cyclic probing load. Multi-layer ceramic (MLC) based space transformer structures have useful stiffness and thermal expansion properties, because the MLC has a relatively low coefficient of thermal expansion and a relatively high stiffness (Young's Modulus). However, due to increasing complexity of electrical routing, the manufacturing costs for forming MLC based space transformer structures have risen substantially.
Certain embodiments relate to the use of a space transformer that comprises an organic substrate based space transformer. Such an organic substrate based space transformer comprises an organic substrate including one or more layers of organic material and electrical pathways extending therethrough. In certain configurations, multiple layers of organic material may be laminated together. When compared with MLC based structures, organic substrate based structures generally have a lower stiffness and higher coefficient of thermal expansion. In addition, organic substrate based structures are typically formed thinner than MLC based structures. A thinner structure provides certain advantages related to the ability to form a more narrow device. For example, in certain embodiments, an organic substrate based space transformer may have a thickness of 1 mm or less. However, due to the thickness and material stiffness reduction of the organic substrate based space transformer structure, problems relating to probe tip coplanarity in the assembly process, probe actual over travel, and permanent deformation and reliability of the organic space transformer may occur.
In addition, embodiments permit the probe head including the organic substrate based space transformer to be removable so that it can be changed when desired, for example, when damaged. To be removable, the probe head including the organic substrate based space transformer is coupled to the PCB/SIU in a manner that in certain embodiments utilizes assembly operations that are reversible, such as, for example, mechanical operations including, but not limited to, using screws to hold certain components together.
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In addition, the PCB 210 may be positioned on a probe head support 232 that is positioned on force retainer plate 230. If desired, an attachment mechanism such as screws 238 may be positioned to extend through the probe head support 232, through the PCB 210, and into the carrier 212, to assist in holding the components together. Similarly, an attachment mechanism such as screws 239 may be positioned to extend through the probe head support 232, through the PCB 210, and into the support 215, to assist in holding the components together. The PCB 210 is electrically coupled to a tester. The probes 220 may be brought into contact with a structure to be tested such as a wafer including integrated circuit devices formed thereon.
An architecture such as that illustrated in
Certain embodiments as described above provide the ability to temporarily and removably couple a probe array and organic substrate based space transformer assembly to a PCB. By forming embodiments of the assembly to including removable components, if one part fails, the entire assembly including the PCB, space transformer, and probe array need not be disposed of because the individual component may be replaced. Adhesive material (for example, epoxy) positioned between components may be removed, if necessary, using any suitable process including, but not limited to, the use of heat, chemical, and mechanical removal methods. In addition, the various components that the organic substrate based space transformer is coupled to in certain embodiments (e.g., the clamp and carrier structures) act to stiffen the space transformer to provide better mechanical and reliability properties. In addition, embodiments may utilize a variety of attachment mechanisms and electrically conductive attachment mechanisms.
Terms such as “first”, “second”, and the like may be used herein and do not necessarily denote any particular order, quantity, or importance, but are used to distinguish one element from another. Terms such as “upper”, “lower”, “top”, “bottom”, and the like may be used for descriptive purposes only and are not to be construed as limiting. Embodiments may be manufactured, used, and contained in a variety of positions and orientations.
The following examples pertain to embodiments.
Example 1 is an electronic device assembly comprising: a space transformer comprising an organic substrate; a carrier on which the space transformer is positioned; a clamp positioned to couple the space transformer to the carrier; a probe array positioned on the space transformer, wherein the space transformer is positioned between the probe array and the carrier; a printed circuit board, wherein the carrier is positioned between the printed circuit board and the space transformer; and electrical connections to electrically couple the space transformer to the printed circuit board.
In Example 2, the subject matter of Example 1 may optionally include the electrical connections to electrically couple the space transformer to the printed circuit board extending through the carrier.
In Example 3, the subject matter of any of Examples 1-2 may optionally include the electrical connections comprising a plurality of pins.
In Example 4, the subject matter of Examples 1-3 may optionally include a plurality of screws through which the carrier is removably coupled to the printed circuit board.
In Example 5, the subject matter of any of Examples 1-4 may optionally include the carrier including an open region in a central portion thereof, and wherein a support structure is positioned within the open region, and wherein a central portion of the space transformer is positioned on the support structure.
In Example 6, the subject matter of Examples 1-5 may optionally include the clamp extending above the space transformer a distance greater than that of the probe array.
In Example 7, the subject matter of any of Examples 1-5 may optionally include the clamp extending above the space transformer a distance less than that of the probe array.
In Example 8, the subject matter of any of Examples 1-6 may optionally include a daughter board positioned between the space transformer and the carrier, wherein the space transformer is electrically coupled to the daughter board.
In Example 9, the subject matter of Example 8 may optionally include wherein the space transformer is positioned on the daughter board, and wherein the clamp is positioned to apply a force to the daughter board to couple the daughter board and the space transformer positioned thereon to the carrier.
Example 10 is an electronic device assembly comprising: a space transformer comprising an organic substrate; a probe array comprising a plurality of test probes, the probe array positioned on the space transformer and electrically coupled thereto; a carrier on which the based space transformer is positioned; a clamp coupled to the carrier, the clamp positioned to hold the space transformer on the carrier; and a printed circuit board, wherein the carrier is positioned between the printed circuit board and the space transformer, wherein the carrier is removably coupled to the printed circuit board.
In Example 11, the subject matter of any of Examples 1-10 may optionally include wherein the space transformer is bonded to at least one of the carrier and the clamp using an adhesive.
In Example 12, the subject matter of Example 11 may optionally include wherein the adhesive comprises an epoxy.
In Example 13, the subject matter of any of Examples 1-12 may optionally include wherein the clamp is removably coupled to the carrier.
In Example 14, the subject matter of any of Examples 1-13 may optionally include wherein the carrier is removably coupled to the printed circuit board using a plurality of screws, and the clamp is removably coupled to the carrier using a plurality of screws.
In Example 15, the subject matter of any of Examples 10-14 may optionally include electrical connections extending from the space transformer to the printed circuit board.
In Example 16, the subject matter of Example 15 may optionally include the electrical connections extending through the carrier.
In Example 17, the subject matter of Example 15 may optionally include the electrical connections comprising a plurality of pins extending through the carrier.
In Example 18, the subject matter of any of Examples 10-17 may optionally include a plurality of screws through which the carrier is removably coupled to the printed circuit board.
In Example 19, the subject matter of any of Examples 10-18 may optionally include wherein the carrier includes an open region in a central portion thereof, and wherein a support structure is positioned within the open region, and wherein a central portion of the space transformer is positioned on the support structure.
In Example 20, the subject matter of any of Examples 10-19 may optionally include wherein the clamp extends above the space transformer a distance greater than that of the probe array.
In Example 21, the subject matter of any of Examples 10-19 may optionally include wherein the clamp extends above the space transformer a distance less than that of the probe array.
In Example 22, the subject matter of any of Examples 10-21 may optionally include a daughter board positioned between the space transformer and the carrier, wherein the space transformer is electrically coupled to the daughter board.
In Example 23, the subject matter of Example 22 may optionally include wherein the space transformer is positioned on the daughter board, and wherein the clamp is positioned to apply a force to the daughter board to couple the daughter board and the space transformer positioned thereon to the carrier.
In Example 24, the subject matter of any of Examples 1-23 may optionally include wherein the space transformer is positioned between at least part of the clamp and the carrier.
Example 25 is an electronic device assembly comprising: a space transformer comprising an organic substrate; a probe array positioned on the space transformer, wherein the space transformer is positioned between the probe array and the carrier; a printed circuit board, wherein the carrier is positioned between the printed circuit board and the space transformer; and means for removably coupling the space transformer to the printed circuit board.
In Example 26, the subject matter of Example 21 may optionally include means for electrically coupling the space transformer to the printed circuit board.
In Example 27, the subject matter of any of Examples 25-26 may optionally include wherein the means for removably coupling comprises a carrier on which the space transformer is positioned and a clamp positioned to hold the space transformer on the carrier.
In Example 28, the subject matter of any of Examples 25-27 may optionally include wherein the means for removably coupling includes an adhesive.
In Example 29, the subject matter of any of Examples 25-27 may optionally include wherein the means for removably coupling includes at least one screw.
Example 30 is a method for forming an electronic device assembly, comprising: positioning a space transformer on a carrier, the space transformer comprising an organic substrate; coupling the space transformer to the carrier using a clamp; bonding the space transformer to at least one of the clamp and the carrier using an adhesive, prior to the clamping the space transformer to the carrier; and electrically coupling the space transformer to a printed circuit board through electrical connections extending through the carrier.
In Example 31, the subject matter of Example 30 may optionally include wherein the electrically coupling the space transformer to the printed circuit board includes positioning a plurality of pins extending through one or more openings in the carrier.
In Example 32, the subject matter of any of Examples 30-31 may optionally include wherein the bonding the space transformer includes positioning the adhesive between at least one of: (i) the space transformer and the carrier, and (ii) the space transformer and the clamp.
In Example 33, the subject matter of any of Examples 30-32 may optionally include positioning a probe array on the space transformer.
In Example 34, the subject matter of Example 33 may optionally include positioning the probe array on the space transformer after the coupling the space transformer to the carrier using the clamp.
In Example 35, the subject matter of any of Examples 30-34 may optionally include removably coupling the carrier to the printed circuit board.
In Example 36, the subject matter of any of Examples 30-35 may optionally include coupling the carrier to the printed circuit board using a plurality of screws.
In Example 37, the subject matter of any of Examples 30-36 may optionally include coupling the clamp to the carrier using a plurality of screws.
In Example 38, the subject matter of any of Examples 30-37 may optionally include wherein the carrier defines an open region in a central portion thereof, and further comprising positioning a support structure in the open region, and positioning a central portion of the space transformer on the support structure.
In Example 39, the subject matter of any of Examples 33-38 may optionally include wherein the clamp is positioned to extend above the space transformer a distance greater than that of the probe array.
In Example 40, the subject matter of any of Examples 33-38 may optionally include wherein the clamp is positioned to extend above the space transformer a distance less than that of the probe array.
Example 41 is a method for forming an electronic device assembly, comprising: providing a space transformer comprising an organic substrate; positioning a probe array on the space transformer; removably coupling the space transformer to a printed circuit board; wherein the space transformer is positioned between the probe array and the printed circuit board; and wherein the space transformer is electrically coupled to the printed circuit board.
In Example 42, the subject matter of Example 41 may optionally include positioning the space transformer on a carrier, coupling the space transformer to the carrier using a clamp.
In Example 43, the subject matter of Example 42 may optionally include bonding the space transformer to at least one of the clamp and the carrier using an adhesive.
In Example 44, the subject matter of Example 43 may optionally include wherein the bonding is carried out prior to the coupling the space transformer to the carrier using the clamp.
In Example 45, the subject matter of Example 42-44 may optionally include positioning electrical connections extending through the carrier to electrically couple the space transformer to the printed circuit board.
In Example 46, the subject matter of Example 42-45 may optionally include positioning a plurality of pins extending through the carrier to electrically couple the space transformer to the printed circuit board.
In Example 47, the subject matter of Example 42-46 may optionally include positioning the probe array on the space transformer after the coupling the space transformer to the carrier using the clamp.
In Example 48, the subject matter of any of Examples 42-47 may optionally include removably coupling the carrier to the printed circuit board.
In Example 49, the subject matter of any of Examples 42-48 may optionally include coupling the carrier to the printed circuit board using a plurality of screws.
In Example 50, the subject matter of any of Examples 42-49 may optionally include coupling the clamp to the carrier using a plurality of screws.
In Example 51, the subject matter of any of Examples 42-50 may optionally include wherein the carrier defines an open region in a central portion thereof, and further comprising positioning a support structure in the open region, and positioning a central portion of the space transformer on the support structure.
In Example 52, the subject matter of any of Examples 42-51 may optionally include positioning the clamp to extend above the space transformer a distance greater than that of the probe array.
In Example 53, the subject matter of any of Examples 42-51 may optionally include positioning the clamp to extend above the space transformer a distance less than that of the probe array.
In Example 54, the subject matter of any of Examples 42-53 may optionally include positioning a daughter board between the space transformer and the carrier, wherein the space transformer is electrically coupled to the daughter board.
In Example 55, the subject matter of Example 54 may optionally include wherein the clamp is positioned to apply a force to the daughter board to couple the daughter board and the space transformer positioned thereon to the carrier.
In Example 56, the subject matter may include the formation of an electronic device assembly in accordance with any of Examples 30-55.
Example 57 is a computer program product, comprising a computer readable storage medium having computer readable program code embodied therein executable by a processor to implement a method or realize the apparatus of any one of Examples 1-56.
Various features described above have been grouped together for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
While certain exemplary embodiments have been described above and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive, and that embodiments are not restricted to the specific constructions and arrangements shown and described since modifications may occur to those having ordinary skill in the art. For example, all optional features of the assembly structures as described above may also be implemented with respect to the methods described herein, and specific features in the examples may be used in one or more embodiments.