Probe head with air cooling system

Abstract

A probe head (20) for testing a device under test is described herein, the probe head (20) comprising a body (10') extending along a longitudinal axis (HH) between a first end (10a) and a second end (10b), a plurality of contact probes (10) each configured to abut corresponding pads (22, 24), at least one guide (40) positioned in a plane (α) and having a guide hole (40h) for accommodating a portion of the contact probe (10), and a housing (50) having a body (50') configured to accommodate the contact probe (10). The housing (50) is provided with a conveying means (M) for conveying an air flow (F) configured to promote heat dissipation inside the probe head (20), and the conveying means (M) includes at least one input duct (50in) configured to receive the air flow (F) and convey the air flow (F) into the housing (50), and at least one output duct (50out) configured to discharge the air flow (F) outside the housing (50), the input duct (50in) and the output duct (50out) being formed in the main body (50') of the housing (50).

Description

[Technical Field]

[0001] The present invention relates to a probe head for performing tests on electronic devices integrated on a semiconductor wafer, and the following description will be made with reference to this field of application for the sole purpose of concisely disclosing the invention. [Background technology]

[0002] As is well known, a probe head is essentially a device configured to electrically connect a plurality of pads of a microstructure, in particular an electronic device integrated on a semiconductor wafer, with corresponding channels of a test apparatus.

[0003] This testing on integrated devices is particularly useful for detecting and isolating faulty devices early in the manufacturing process, and so probe heads are typically used for electrical testing of devices integrated on wafers or chips before they are cut and assembled into chip encapsulation packages.

[0004] The probe head essentially comprises a plurality of contact probes held by at least one pair of generally plate-shaped, parallel supports or guides, the plate-shaped supports having appropriate guide holes and spaced at a predetermined distance to leave free space or air gaps for possible movement and deformation of the contact probes, the contact probes usually being made of special alloy wires with excellent electrical and mechanical properties.

[0005] Contact probes generally extend between a first end intended to contact a pad on a device under test and a second end intended to contact a pad on a space transformer or printed circuit board (also called a PCB).

[0006] Proper operation of a probe head is fundamentally related to two parameters: the vertical movement of the contact probe (overtravel) and the horizontal movement (scrub) that the probe's contact tip makes on the pad when making contact with the device under test. All these characteristics must be evaluated and adjusted during the probe head manufacturing process to ensure proper electrical connection between the contact probe and the device under test at all times.

[0007] In the above-described type of probe head and the probe card housing the probe head, the thermal expansion of the components, which are made of different materials and have different thermal expansion coefficients, can impair proper operation during high-temperature testing. In fact, the components constituting the probe head and the associated probe card are typically fastened with screws. These screw connections exert a binding force on multiple plates, tending to distort them, especially during testing temperatures, resulting in malfunction of the entire probe head. This problem is particularly pronounced in large probe heads, such as those used for memory device testing, such as DRAMs, or multi-die testing. In these types of probe heads, failure to control the thermal expansion of the components can significantly disrupt the testing process.

[0008] Furthermore, the components of the probe head itself generate a large amount of heat during testing. For example, contact probes generate heat as various signals pass through them, and the temperature rise inside the probe head increases significantly, especially in probe heads with a large number of contact probes, especially power probes. Similarly, unnecessary heat is generated and accumulated when the contact probes come into contact with the space transformer or pads of the device under test, and also due to friction with the walls of the guide holes. Therefore, it is necessary to suppress the temperature rise of the probe head.

[0009] The technical problem of the present invention is to provide a probe head with structural and functional features that are able to overcome the limitations and drawbacks that remain in the prior art, and in particular to optimize the heat dissipation process within the probe head. Summary of the Invention

[0010] The solution idea underlying the present invention is to use a forced air flow to promote heat dissipation inside the probe head, which is conveyed to the area of ​​interest by means of a suitable geometry of the housing. In particular, the housing itself is provided with suitable channels (i.e. input and output ducts) which allow the air flow (supplied from an external source) to be conveyed to the area of ​​the probe head to be cooled, in particular to the area of ​​the guides which accommodate the contact probes. The channels formed in the housing force the air flow in a direction approximately parallel to the guides. This ensures a compact design and an optimal dissipation of the heat generated inside the probe head.

[0011] Based on this solution concept, the above-mentioned technical problem is solved by a probe head for testing a device under test, comprising: a plurality of contact probes each having a body extending along a longitudinal axis between a first end and a second end, the plurality of contact probes being configured to abut a corresponding pad, at least one guide having a guide hole for accommodating a portion of the contact probe, the at least one guide being positioned in a plane, and a housing having a body configured to accommodate the contact probes. According to the present invention, the housing comprises a conveying means for conveying an air flow, the conveying means being configured to promote heat dissipation inside the probe head, the conveying means including at least one input duct configured to receive the air flow and enable conveying the air flow into the housing, and at least one output duct configured to discharge the air flow out of the housing, the input duct and the output duct being formed directly in the body of the housing.

[0012] More particularly, the present invention includes the following additional and optional features, taken alone or in combination as appropriate:

[0013] According to one aspect of the invention, the input and output ducts may be oriented such that the airflow propagates within the housing along a flow direction that is generally parallel to the plane of the guide.

[0014] According to one aspect of the invention, there may be at least two output ducts for each input duct, such that the airflow exiting the housing is divided into at least two flow portions.

[0015] According to one aspect of the invention, the probe head may further comprise a heat dissipation element configured to collect and dissipate heat generated by the probe head, the heat dissipation element being positioned at a location where the air flow of the conveying means passes through the heat dissipation element, thereby facilitating the dissipation of heat exchanged by the air flow through the heat dissipation element.

[0016] The heat dissipation element may comprise at least one layer of a high thermal conductivity material selected from diamond, silicon carbide and a silver-diamond composite with a diamond content of 50-99%, preferably diamond.

[0017] The layer of high thermal conductivity material may be either a coating layer disposed along at least a portion of at least one surface of the guide, or a guide coating layer including at least one side portion extending along a side wall of the guide and at least one planar portion extending along at least a portion of at least one surface of the guide, the surface being generally perpendicular to the side wall, or a coating layer associated with the housing.

[0018] According to one aspect of the invention, the contact probes may be included in at least one first or active area of ​​the guide, and the active area may be adjacent to a second area that does not include the contact probes.

[0019] According to one aspect of the invention, a heat dissipation element (particularly a layer of high thermal conductivity material) may extend over at least a portion of the second region.

[0020] According to one aspect of the invention, the conveying means may be configured to convey the airflow so as to impinge on the layer of high thermal conductivity material in at least a portion of the second region.

[0021] According to one aspect of the invention, the guide may comprise a plurality of separate active areas, each of which includes a corresponding contact probe and is configured to test a respective die.

[0022] In particular, the active areas are arranged to enable multi-die testing in parallel, each active area corresponding to a respective die (or chip) under test, and the input duct includes a plurality of input subducts configured to divide and convey the input airflow toward each active area, the number of input subducts being selected based on the number of dies to be tested with the probe head.

[0023] According to one aspect of the invention, the active areas may be arranged on the guide along rows and columns in a matrix, for example a 4x4 matrix.

[0024] According to one aspect of the invention, the guide may (but need not) be a bottom guide.

[0025] According to one aspect of the present invention, the probe head may further include an upper guide spaced apart from the lower guide and having respective guide holes, and the housing may be disposed between the lower guide and the upper guide.

[0026] According to one aspect of the invention, the input duct comprises a first portion and a second portion inclined relative to each other, the first portion being configured to be connected to an external source supplying an air flow, and the second portion may be in communication with the interior of the housing (i.e., in communication with the interior of the housing in which the contact probe resides).

[0027] According to one aspect of the invention, the input and output ducts may extend from successive sides (faces) of the main body of the housing.

[0028] According to one aspect of the invention, the input duct and the output duct may be substantially perpendicular to each other at least in the plane, at least for portions of the input duct and the output duct that lie in the plane.

[0029] According to one aspect of the invention, the body of the housing may be in the form of a monoblock, and the input and output ducts may include portions formed within and integrally formed with the monoblock.

[0030] The features and advantages of a probe head according to the invention will become apparent from the following description of one embodiment thereof, which description is given by way of example and not by way of limitation, and which refers to the accompanying drawings, in which: [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 shows a schematic diagram of a probe head according to the present invention. [Figure 2] FIG. 2 is a perspective view of a housing according to an embodiment of the present invention. [Figure 3A] FIG. 3A shows the housing of FIG. 2 and the airflow propagating therein. [Figure 3B] FIG. 3B shows a fluid dynamics simulation of the airflow inside the housing. [Figure 4] FIG. 4 shows an example of the layout of guides of a probe head according to an embodiment of the present invention. [Figure 5] FIG. 5 shows a probe head according to another embodiment of the present invention. [Figure 6] FIG. 6 shows a probe head according to another embodiment of the present invention. [Figure 7] FIG. 7 shows a probe head according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Referring to the drawings, the numeral 20 generally indicates a schematic representation of a probe head made in accordance with the present invention.

[0033] The drawings are schematic and not to scale, and are drawn to emphasize important features of the present invention. Each element is shown conceptually, and the actual shape may vary depending on the application. The same reference numerals in the drawings indicate elements of the same shape or function. Furthermore, specific features described for an embodiment in one drawing may also be applied to embodiments shown in other drawings.

[0034] Unless otherwise indicated, the order of steps may be reversed as desired.

[0035] The probe head 20 is configured to be connected (directly or indirectly via a space transformer and / or PCB) to test equipment (not shown) for testing electronic devices 23 integrated on a semiconductor wafer 23', such as (but not necessarily) high frequency devices or large capacity memory devices.

[0036] In the context of the present invention, the term "probe head" refers to a test apparatus that is not limited by the presence or absence of specific components, in addition to those defined in the appended claims. That is, the term refers to an assembly of components that can be used in combination with other components to test electronic devices 23 integrated on a semiconductor wafer 23', and thus generally refers to an electronic device measurement system.

[0037] Referring to the cross-sectional view of FIG. 1, the probe head 20 includes a plurality of contact probes 10 for connecting a device under test 23 integrated on a semiconductor wafer 23' to a test apparatus.

[0038] To accommodate the contact probe 10, the probe head 20 has at least one guide 40 with a guide hole 40h, within which the contact probe 10 is slidable. Thus, the guide 40, together with the guide hole 40h, slidably accommodates the contact probe 10.

[0039] Each contact probe 10 includes a probe body 10' extending along a longitudinal axis HH between a first end 10a and a second end 10b, each configured to abut a pad. For example, the first end 10a (also called a contact tip) is configured to abut a pad 22 of a device under test 23 integrated on a semiconductor wafer 23', while the opposite second end 10b (also called a contact head) is configured to abut a pad 24 of a space transformer or printed circuit board (PCB), generally designated 25, that is connectable to the probe head 20. While the appended drawings depict the ends 10a and 10b as pointed, this is not intended to limit the scope of the present invention and any other shape may be used depending on the needs and circumstances. While the second end 10b is shown as having an enlarged shape, this configuration is merely illustrative and does not limit the scope of the present invention.

[0040] During bending of the contact probe 10 (especially during vertical movement, so-called "overtravel"), sliding contact is made between the probe body 10' and one or more walls of the guide hole. The probe body 10' comprises a portion that is intended to be inserted at least partially into the guide hole 40h of the guide 40 and is in contact, in particular sliding contact, with this guide hole 40h during movement of the contact probe 10.

[0041] In the illustrated example, guide 40 is the lower guide of probe head 20, and as is well known in the art, is located proximate to first end 10a (the end for contacting the device under test), i.e., is closer to the device under test than the upper or middle guides during testing. Therefore, in the examples herein, guide 40 is also identified as the lower guide of probe head 20, but this is not intended to limit the scope of the present invention.

[0042] In one embodiment, the probe head 20 may further include an intermediate guide (not shown) with corresponding guide holes, with the lower guide 40 positioned between the intermediate guide and the device under test in use.

[0043] 1, the probe head 20 further includes an upper guide 45 spaced apart from the lower guide 40 and having corresponding guide holes 45h. In configurations that also include an intermediate guide, the intermediate guide is positioned between the lower guide 40 and the upper guide 45, but the lower guide 40 is still the guide closest to the device under test.

[0044] As mentioned above, in the technical field of the present invention, the term "lower guide" refers to a guide positioned closer to the device under test, and the term "upper guide" refers to a guide positioned closer to the test equipment connected to the probe head when the probe head 20 is in an operational state as an end element of the test equipment.

[0045] In one embodiment, the lower guide 40, the upper guide 45 and any intermediate guides are plate-like elements arranged parallel to each other and to the plane π of the semiconductor wafer 23′, i.e., the device under test 23. Note that in the context of the present invention, the plane on which the guide 40 is located is referred to as the plane α.

[0046] The guides may be shifted relative to one another in a direction tangent to plane π of semiconductor wafer 23′, i.e., along the x-axis direction of the local coordinate system in FIG. 1, thereby imparting a preferential bending direction to contact probe 10. Such a shift causes guide holes formed in each guide accommodating the same contact probe to become misaligned with one another in a direction perpendicular to plane π (the z-axis direction in FIG. 1), causing bending in probe body 10′ of contact probe 10 and determining the preferential bending direction.

[0047] The probe head 20 further comprises a housing or housing element 50 configured to house the contact probe 10 and provide support and connection structures between the guides.

[0048] In particular, housing 50 includes a body (identified by reference numeral 50') configured to house contact probe 10, body 50' preferably being monoblock in shape.

[0049] In the embodiment of FIG. 1, a housing 50 is interposed between the lower guide 40 and the upper guide 45 to properly maintain the distance between the two guides, and the housing 50 is suitably configured to accommodate the contact probe 10 therein.

[0050] The housing 50 may be formed from a material suitable for controlling the thermal expansion of the probe head, such as Invar or Kovar, although the scope of the invention is not limited in this respect and any suitable material may be used.

[0051] The housing 50 comprises a conveying means (generally indicated by the reference character M) for conveying an air flow (generated externally and indicated in the figures by arrows F) to facilitate heat dissipation inside the probe head 20. That is, a forced air conveying system is provided for conveying an air flow into the housing 50 to facilitate dissipation of heat generated in the probe head 20.

[0052] As shown in FIG. 2, the housing's conveying means includes at least one input duct 50in configured to receive air flow F from an external source (not shown) and enable conveyance of the air flow F into the housing 50, and at least one output duct 50out configured to discharge the air flow F out of the housing 50.

[0053] The input ducts 50in are configured so that air coming from an external source, particularly from the tester side (opposite the wafer 23'), is directed to the guide 40 and divided as needed by the branches of the duct (described in detail below). The number of input ducts 50in (and the number of branches of each duct) can vary depending on the number of dies to be tested by the probe head 20 (for example, four dies are tested in parallel in the example described below).

[0054] In one embodiment, the input duct 50in and the output duct 50out are oriented such that the air flow F propagates within the housing 50 along a flow direction (indicated by arrow D in Figures 3A and 3B) that is generally parallel to the plane α of the guide 40. The passages within the housing 50 thereby ensure that the air flow F is substantially tangential to the guide 40 of the probe head 20.

[0055] The input duct 50in and the output duct 50out are preferably formed within the housing 50, in particular within internal channels within the housing 50, where the parts are integrally formed, so that no additional components are added and the probe head 20 maintains a very compact structure.

[0056] 2 and 3A-3B, in one embodiment of the present invention, for each input duct 50in, there are at least two output ducts 50out, such that the airflow F exiting the housing 50 is divided into at least two flow portions. Of course, the number of output ducts can vary depending on the specific application.

[0057] All this ensures uniform airflow over a large area, optimizing heat dissipation inside the probe head 20, as evidenced by the simulation in Figure 3C.

[0058] According to the present invention, the contact probes 10 are contained within at least one first area, or active area (designated A1), of the guide 40. A second area (designated A2) of the guide 40 that does not contain the contact probes 10 can therefore be defined, with the second area A2 being adjacent (contiguous) to the active area A1. The area is not limited to a particular shape. For example, the second area A2 can be an area that surrounds the active area A1, and there can be multiple active areas on the guide (as described later in this specification).

[0059] As one embodiment of the present invention, as shown schematically in FIG. 4, the guide 40 may include multiple independent active areas A1, each including a corresponding group of contact probes 10 and configured to test a corresponding die on which a circuit under test is formed (although each die is shown as a rectangle in the figure, this shape is not necessarily limited and other shapes are not excluded).

[0060] The active areas A1 are arranged to allow for parallel testing of multiple dies, with each active area A1 corresponding to an associated die under test. In this embodiment, the second area A2 is a region of the guide 40 that does not include probes, surrounds the multiple active areas A1, and does not include any dies.

[0061] In this case, as described above, the input duct 50in may include multiple input sub-ducts (50in') configured to divide and convey the input airflow F toward each active area A1. Figures 2, 3A-3B, and 4 show an example in which two input ducts 50in each branch into two input sub-ducts 50in', separated by recesses 50r, to convey the airflow F to corresponding dies.

[0062] In general, the number of input subducts 50in' can be selected based on the number of dies to be tested by the probe head 20, i.e., the layout and the particular application. Also, as previously mentioned, in one embodiment, the output ducts 50out ensure at least two air outlet paths for each die that extend generally parallel to the guide 40.

[0063] Furthermore, Figure 4 is merely an example showing four active areas A1, and the present invention is not limited thereto. The number of active areas may vary depending on the application. The figure is shown as a non-limiting example that does not limit the present invention.

[0064] In one embodiment, the independent active areas A1 are arranged in a matrix along rows and columns on the guide 40, for example the 4x4 matrix shown in connection with FIG. 4, with the layout on the guide aligned to the layout of the device and / or wafer under test.

[0065] Furthermore, although the above embodiment has been described in relation to the lower guide 40, the same concepts can be applied to any of the other guides in the probe head 20.

[0066] As shown, the housing 50 is provided with an opening 50h at the location of each active area A1 for the passage of a contact probe 10 intended to test the corresponding die.

[0067] 2, in one embodiment of the present invention, the input duct 50in comprises a first portion 50in1 and a second portion 50in2 that are inclined relative to each other, e.g., perpendicular to each other. The first portion 50in1 (vertical portion) is configured to be connected to an external source that supplies airflow F, while the second portion 50in2 (horizontal portion) is in direct communication with the interior of the housing 50 and is, for example, parallel to the guide 40. Both the first portion 50in1 and the second portion 50in2 can be considered separate sections of the same input duct 50in and are suitably connectable (e.g., at an opening in the vertical portion) via an external source means coming from the test apparatus side, such as an external source tube or similar means.

[0068] Additionally, the input duct 50 in and the output duct 50 out extend to successive sides of the main body 50 ′ of the housing 50 .

[0069] In the illustrated embodiment, in order to optimally direct the flow in the desired direction, the output duct 50out is approximately perpendicular to the input duct 50in, at least for the portion located within the plane α (e.g., the portion extending from the main body 50' of the housing 50).

[0070] 5-7, in one embodiment of the present invention, the probe head 20 further comprises a heat dissipation element 70 configured to collect heat generated during testing and dissipate it, preferably by dissipation into the air, thereby making heat dissipation and cooling more effective. The heat dissipation element 70 collects heat generated, for example, by friction as the contact probe slides through the guide holes of the at least one guide, or by signals, such as power signals, passing through the contact probe and which may increase the temperature, and facilitates heat dissipation into the environment, preferably by dissipation into the air.

[0071] The heat dissipation element 70 is at least partially in contact with air, for example, the environment surrounding the probe head 20 .

[0072] In one embodiment, the heat dissipation element 70 comprises at least one layer 70 of a high thermal conductivity material selected from diamond, silicon carbide, and a silver-diamond composite with a diamond content of 50-99%, preferably diamond. This high thermal conductivity allows for optimal collection and subsequent dissipation of heat generated in the probe head 21 during test operation, keeping the increase in operating temperature limited. This material also allows for structures with reduced thickness Sr, particularly thicknesses Sr of less than 500 micrometers, more preferably less than 250 micrometers, while maintaining high heat dissipation performance of the resulting heat dissipation structure.

[0073] In the embodiment shown in Figure 5, the layer 70 of high thermal conductivity material is formed on a surface of the guide 40, for example, on surface FA (although this does not limit the scope of the present invention, the layer 70 may cover only a portion of the surface or the entire surface). However, the present invention is not limited by the location of the heat dissipation layer 70, and the layer 70 may be located on both the upper surface FA and the lower surface FB (using the local coordinate system of the figure and terminology commonly used in the art), or may be located only on surface FB. When located on surface FB, the layer 70 of high thermal conductivity material is exposed to the environment surrounding the probe head 20, making it easier to dissipate heat generated inside into the air.

[0074] In an embodiment not shown, the layer 70 of high thermal conductivity material may be a coating layer of the guide 40, including at least one side portion extending along the side wall of the guide 40 and at least one planar portion extending along at least one face (F1 and / or F2) of the guide 40, said face (F1 and / or F2) being approximately perpendicular to the side wall.

[0075] In the embodiment of FIG. 6, the heat dissipation layer is a layer associated with the housing 50, for example a full covering layer of the housing 50, but in other embodiments not shown it may be a side layer.

[0076] 7, the probe head 20 may also include a heat dissipation structure 80 connected to the layer of high thermal conductivity material 70. In this case, the layer of high thermal conductivity material 70 primarily serves to collect heat generated inside the probe head 20, and the heat dissipation structure 80 primarily serves to dissipate the heat, preferably into the air. For example, the heat dissipation structure 80 may be comb-shaped, i.e., may include multiple fins, to increase the heat dissipation area.

[0077] The layer 70 of high thermal conductivity material extends from the active area A1 (and possibly inward) across the entire or a portion of the surface of the guide 40. Also, as mentioned above, the layer 70 may include sides that wrap around the guide 40 (in whole or in part) and possibly the housing 50. In either case, the layer 70 extends in a manner that promotes heat exchange with the air and thus the airflow F. This allows the combination of the airflow F and the layer 70 of high thermal conductivity material to provide more effective heat dissipation due to its higher thermal conductivity.

[0078] Additionally, in an embodiment not shown, multiple layers 70 of high thermal conductivity material may be provided, depending on the circumstances and needs.

[0079] Furthermore, although the above embodiments have been described with reference to the lower guide 40, similar considerations apply to any of the other guides in the probe head 20.

[0080] Preferably, the layer 70 of high thermal conductivity material is arranged so that the air flow F of the transport means M passes through the layer 70, thereby promoting the dissipation of heat exchanged by the air flow F with the layer 70 of high thermal conductivity material.

[0081] In particular, as described above, the layer 70 of high thermal conductivity material extends over at least a portion of the second area A2, and the conveying means M is configured to convey the air flow F so that the air flow F hits the layer 70 of high thermal conductivity material in the second area A2 where no contact probes 10 are present and so as to facilitate heat dissipation in that area. In other words, the layer 70 of high thermal conductivity material is preferably arranged outside the active area of ​​the guide 40, particularly in the peripheral area where no guide holes are present.

[0082] In summary, the present invention provides the above-mentioned probe head, thereby solving the problems of the prior art and overcoming the drawbacks of the existing technology.

[0083] Preferably, cooling of the probe head is performed by channels in the housing, which guide and force the air flow (F) inside in an optimal way. The various input and output ducts are arranged so that the air flow is spread most homogeneously in the area of ​​interest of the probe head. In other words, the housing is configured so that the air transport system is formed precisely within the housing 50, i.e. so that it forms part of the housing 50 itself (i.e. it can be considered as the body of the system and is configured so that it can transport air appropriately into the probe head). The air is generated by an external air source (not shown), which may be associated with the probe head and transports it inside, in particular by means of the above-mentioned ducts.

[0084] Advantageously, the present invention provides a heat dissipation structure capable of collecting and dissipating heat generated during testing operations of the probe head, for example generated by friction of the contact probes sliding in the guide holes or by signals (such as power signals) passing through the contact probes that may increase their temperature. Such a heat dissipation structure facilitates the diffusion of said heat into the environment, in particular by dissipation into the air by forced airflow.

[0085] Therefore, this solution allows for proper forced air transport and is also advantageous for devices testing multiple dies in parallel.

[0086] The housing transport means, in combination with a layer of a material with high thermal conductivity, can adequately limit the operating temperature rise of the probe head and avoid malfunctions in a simple manner.

[0087] The combination of forced airflow and a layer of high thermal conductivity material is particularly advantageous as said airflow allows the dissipation into the air of heat generated by the probe head and collected by the layer of high thermal conductivity material already inside the probe head itself, further significantly improving heat dissipation since a mere airflow is usually not sufficient to dissipate the heat generated by the innermost contact probes which are not significantly affected by the airflow impinging only on the outermost probes.

[0088] In this way, the probe head according to the present invention is suitable for applications in which the entire head is heated significantly by the test operation, and can ensure accurate operation and increase the reliability of the test results.

[0089] Moreover, all this can be achieved in a simple and compact structure, as the various input and output ducts are formed directly within the body of the housing and are optimally configured to carry the cooling airflow.

[0090] Of course, those skilled in the art can make various modifications and variations to the probe head described above depending on the circumstances and specific requirements, all of which are within the scope of the present invention as defined in the claims that follow.

Claims

1. A probe head (20) for testing a device under test, said probe head (20) comprising: a plurality of contact probes (10) each having a body (10') extending along a longitudinal axis (H-H) between a first end (10a) and a second end (10b), the ends configured to abut against respective pads (22, 24); At least one guide (40) having a guide hole (40h) for receiving a portion of the contact probe (10), the guide (40) being located in a plane (α); a housing (50) having a body (50') configured to accommodate the contact probe (10); Equipped with The housing (50) is provided with a conveying means (M) for conveying an air flow (F), and the conveying means (M) is configured to promote heat dissipation inside the probe head (20), and the conveying means (M) at least one input duct (50 in) configured to receive an air flow (F) and enable the conveyance of said air flow (F) into said housing (50); at least one output duct (50out) configured to discharge the air flow (F) outside the housing (50); Including, The probe head (20) is characterized in that the input duct (50in) and the output duct (50out) are formed in the main body (50') of the housing (50).

2. 2. The probe head (20) of claim 1, wherein the input duct (50in) and the output duct (50out) are oriented such that the air flow (F) propagates within the housing (50) along a flow direction (D) that is substantially parallel to the plane (α) of the guide (40).

3. 3. The probe head (20) of claim 1 or 2, wherein the probe head comprises at least two output ducts (50out) for each input duct (50in) such that the air flow (F) exiting the housing (50) is divided into at least two flow portions.

4. 4. The probe head (20) of claim 1, further comprising a heat dissipation element (70) configured to collect and dissipate heat generated by the probe head (20), the heat dissipation element (70) being arranged at a position where an air flow (F) of a conveying means (M) passes through the heat dissipation element (70), thereby facilitating the dissipation of heat exchanged by the heat dissipation element (70) with the air flow (F).

5. 5. The probe head (20) of claim 4, wherein the heat dissipation element (70) comprises at least one layer of a high thermal conductivity material selected from diamond, silicon carbide and a silver-diamond composite with a diamond content of 50-99%, preferably diamond.

6. the layer of high thermal conductivity material a coating layer disposed along at least a portion of at least one face (F1, F2) of said guide (40), or a guide coating layer comprising at least one lateral portion extending along a side wall of the guide (40) and at least one planar portion extending along at least a portion of at least one face (F1, F2) of the guide (40), the face (F1, F2) being substantially perpendicular to the side wall; or a coating layer associated with said housing (50) Either The probe head (20) of claim 5.

7. A probe head (20) according to any one of claims 1 to 6, wherein the contact probe (10) is contained within at least one first area or active area (A1) of the guide (40), the active area (A1) being adjacent to a second area (A2) of the guide (40) that does not contain the contact probe (10).

8. 8. A probe head (20) according to claims 5 and 7 or claims 6 and 7, wherein the layer of high thermal conductivity material extends over at least a portion of the second area (A2), and the conveying means (M) is configured to convey the air flow (F) so that it impinges on the layer of high thermal conductivity material in said at least a portion of the second area (A2).

9. 9. The probe head of claim 7, wherein the guide comprises a plurality of independent active areas, each of the active areas including a corresponding contact probe and configured to test a respective die, the active areas being arranged to enable multi-die testing in parallel, each of the active areas corresponding to a respective die under test, the input duct including a plurality of input sub-ducts configured to divide the input air flow and convey it toward each active area, the number of the input sub-ducts being selected based on the number of dies to be tested with the probe head.

10. 10. The probe head (20) of claim 9, wherein the active areas (A1) are arranged on the guide (40) along rows and columns in a matrix, for example a 4x4 matrix.

11. The probe head (20) of any one of claims 1 to 10, wherein the guide (40) is a lower guide, the probe head (20) further comprises an upper guide (45) spaced apart from the lower guide (40) and having respective guide holes (45h), and the housing (50) is arranged between the lower guide (40) and the upper guide (45).

12. 12. The probe head (20) of claim 1, wherein the input duct (50 in) comprises a first portion (50 in 1) and a second portion (50 in 2) inclined relative to each other, the first portion (50 in 1) configured to be connected to an external source that supplies the air flow (F), and the second portion (50 in 2) communicating with the interior of the housing (50).

13. The probe head (20) of any one of claims 1 to 12, wherein the input duct (50in) and the output duct (50out) extend from successive sides of the main body (50') of the housing (50).

14. 14. The probe head (20) of claim 1, wherein the input duct (50 in) and the output duct (50 out) are substantially perpendicular to each other at least in the plane (α), at least for portions of the input duct (50 in) and the output duct (50 out) that lie in the plane (α).

15. 15. The probe head (20) of claim 1, wherein the main body (50') of the housing (50) is in the form of a monoblock, and the input duct (50in) and the output duct (50out) are formed within the monoblock and include portions formed integrally with the monoblock.

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