Probe head with improved cooling system

Abstract

The present specification describes a probe head (20) for testing a device under test integrated on a semiconductor wafer, 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) configured to abut each of the pads (22, 24), at least one guide (40, 40') having guide holes (40h, 40h') for accommodating the contact probes (10), and an air conveying system (60) configured to convey an air flow (F) within the probe head (20) to promote heat dissipation. The probe head (20) further comprises a conductive portion (21) formed on the guide (40, 40'), the conductive portion (21) including at least one hole group of the guide holes (40h, 40h') and configured to contact and short-circuit a corresponding contact probe group housed in the hole group and intended to transmit a predetermined type of signal, thereby defining at least one conductive domain on the guide (40, 40'). The probe head (20) further comprises a heat dissipation conductive portion (65) formed on the guide (40, 40') and arranged so that an air flow (F) of the air conveying system (60) passes through the portion, the heat dissipation conductive portion (65) being connected to the conductive portion (21) to extend the conductive domain and promoting dissipation of heat exchanged by the air flow (F) of the air conveying system (60) through the heat dissipation conductive portion (65).

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 an electronic device integrated on a microstructure, in particular a semiconductor wafer, with corresponding channels of a test apparatus.

[0003] This testing on integrated circuits is particularly useful for detecting and isolating faulty devices early in the manufacturing process, so probe heads are typically used to test circuits integrated on wafers before they are cut and assembled into chip-encapsulated packages.

[0004] The probe head essentially comprises a plurality of movable 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 of a device under test and a second end intended to contact a space transformer or a printed circuit board (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] Furthermore, in an increasing number of applications, for example in high frequency applications, at least one guide has a conductive part (in particular a metallization) for the purpose of electrically connecting (i.e. short-circuiting) certain groups of contact probes together and forming a common conductive surface for said groups of probes, thus improving the high frequency characteristics of the probe head and enabling the transmission of increasingly higher frequency signals with low noise and avoiding the phenomenon of probe burnout.

[0008] In the above-described type of probe head, the components are made of different materials with different thermal expansion coefficients, which can cause the probe head to malfunction during high-temperature testing. In fact, the components of the probe head are typically fastened with screws, which exert a binding force on multiple plates, especially during testing at high temperatures, resulting in malfunction of the entire probe head. This problem is particularly pronounced in large probe heads, such as those used for testing memory devices such as DRAMs, or in general, those used for multi-die testing. In this type of probe head, if the thermal expansion of the components cannot be controlled, significant disruption to the testing process can occur.

[0009] 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. Similarly, unnecessary heat is generated and accumulated when the contact probes come into contact with the pads of the space transformer and through friction with the walls of the guide holes, so it is necessary to suppress the temperature rise in the probe head.

[0010] The technical problem of the present invention is to provide a probe head having structural and functional characteristics that allow overcoming the limitations and drawbacks that still affect known solutions, and in particular a probe head that is able to effectively dissipate heat during operation. Summary of the Invention

[0011] The solution idea behind the present invention is to use the extensions of the conductive domains formed on the guide as heat dissipation elements capable of dissipating heat even from the innermost probe, which is relatively unaffected by the presence of cooling airflows, by providing a system configured to transport air into the probe head, in particular into its housing, and by forming conductive parts for heat dissipation on the guide, which are electrically connected to the conductive domains, so that the heat is transferred to a specific area of ​​the guide, which is directly exposed to the airflow, thereby facilitating the dissipation of the exchanged heat.

[0012] Based on this solution concept, the above-mentioned technical problem is solved by a probe head for testing a device under test, the probe head comprising: a plurality of contact probes each having a body extending along a longitudinal axis between a first end and a second end, the ends being configured to abut against respective pads; at least one guide provided with guide holes for (slidably) accommodating the contact probes; and an air conveying system configured to convey an air flow (e.g., from an external source) to the probe head to promote heat dissipation, the air conveying system comprising: a plurality of contact probes each having a body extending along a longitudinal axis between a first end and a second end, the ends being configured to abut against respective pads; the conductive portion includes at least one group of holes among the guide holes and is configured to contact and short-circuit corresponding contact probes housed in the group of holes, the contact probes being intended to transmit a predetermined type of signal, thereby defining at least one conductive domain on the guide; the probe head further includes a heat dissipation conductive portion formed on the guide and arranged so that an air flow of the air conveying system passes through the heat dissipation conductive portion, the heat dissipation conductive portion extending the conductive domain and electrically connected to the conductive portion so that the air flow of the air conveying system promotes dissipation of heat exchanged by the heat dissipation conductive portion.

[0013] More particularly, the present invention includes the following additional and optional features which may be taken alone or in combination as required:

[0014] According to one aspect of the present invention, the probe head may include a plurality of conductive portions corresponding to different conductive domains, each of which may be configured to short-circuit probes configured to transmit different signals, and at least one of the domains (e.g., the innermost domain) may be connected to a corresponding heat dissipation conductive portion.

[0015] According to one aspect of the invention, the conductive domains may be different power domains and / or ground domains and / or domains configured to carry operating signals, in particular power domains.

[0016] According to one aspect of the present invention, at least one conductive domain is divided into a plurality of conductive subdomains separated from one another, each of which is configured to distribute the same predetermined type of signal between shorted contact elements separated from the other conductive subdomains, and at least one conductive subdomain (e.g., an inner subdomain surrounded by other outermost domains) may be connected to a corresponding heat dissipation conductive portion.

[0017] According to one aspect of the invention, the guide may be a lower guide.

[0018] According to another aspect of the invention, the guide may be an intermediate guide of the probe head, with the lower guide being positioned between the intermediate guide and the device under test.

[0019] According to one aspect of the invention, the probe head further comprises an upper guide spaced apart from the lower guide and having corresponding guide holes, the lower guide being the guide closest to the device under test.

[0020] According to one aspect of the invention, the contact probes may be included within at least one first or active region of the guide, and the active region may be adjacent to a second region of the guide that does not include the contact probes. In particular, the air delivery system may be configured to deliver an air flow to at least a portion of the second region, and the heat dissipation conductive portion may be formed in the second region to extend the conductive domain outside the active region.

[0021] According to one aspect of the present invention, the conductive portion and the heat dissipation conductive portion may be disposed on one surface of the guide.

[0022] According to one aspect of the invention, the probe head may further comprise a heat dissipation layer in contact with at least a portion of the surface of the guide.

[0023] According to one embodiment of the present invention, the heat dissipation layer is formed from a high thermal conductivity material selected from diamond, silicon carbide, and a silver-diamond composite with a diamond content of 50% to 99%, and may preferably be diamond.

[0024] According to one aspect of the invention, the probe head may further comprise a housing configured to house the contact probe, and the air delivery system may be configured to deliver the air flow into the housing.

[0025] According to one aspect of the present invention, the housing may be configured such that at least a portion of the air conveying system is formed within the housing, and the housing may be configured to allow an input duct to convey an air flow into the housing and an output duct to exhaust the air flow to the outside.

[0026] According to one aspect of the invention, the ducts of the housing are configured such that the input air flow flows in a direction in a plane parallel to the guide (e.g., tangential flow) and the output air flow is split into at least two flow portions, and the input air flow may be split based on the number of dies (or chips) being tested by the probe head.

[0027] The features and advantages of a probe head according to the invention will become apparent from the following description of an embodiment given as a non-limiting example, with reference to the accompanying drawings, in which: FIG. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 shows a schematic diagram of a probe head according to an embodiment of the present invention. [Figure 2] FIG. 2 shows a schematic view of a probe head according to another embodiment of the present invention. [Figure 3] FIG. 3 shows a schematic and exemplary plan view of a guide according to one embodiment of the present invention. [Figure 4] FIG. 4 is a purposefully schematic plan view of a guide for a probe head according to an embodiment of the present invention. [Figure 5A] FIG. 5A shows a diagram of a housing and the airflow conveyed therethrough according to an embodiment of the present invention. [Figure 5B] FIG. 5B shows a diagram of a housing and the airflow conveyed therethrough according to an embodiment of the present invention. [Figure 5C] FIG. 5C shows a diagram of a housing and the airflow conveyed therethrough according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Referring to the drawings, the numeral 20 generally indicates a schematic representation of a probe head made in accordance with the present invention.

[0030] 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.

[0031] Unless otherwise indicated, the order of steps may be reversed as desired.

[0032] 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 integrated on a semiconductor wafer 23, such as (but not necessarily) high frequency devices or large capacity memory devices.

[0033] 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 integrated on a semiconductor wafer 23, and thus generally refers to an electronic device measurement system.

[0034] 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 integrated on a semiconductor wafer 23 to a test apparatus.

[0035] 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.

[0036] 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 respective contact pad. For example, the first end 10a (also called a contact tip) is configured to abut a pad 22 of a device under test 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, which is connectable to the probe head 20. Note that although the appended drawings depict the ends 10a and 10b as having a pointed shape, the present invention is not limited thereto and the ends 10a and 10b may have any shape as needed or required.

[0037] During bending of the contact probe 10 (especially during vertical movement of the probe, so-called "overtravel"), sliding contact is made between the probe body 10' and the wall 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.

[0038] The guide 40 is preferably the lower guide of the probe head 20, and as is well known in the art, is located close to the 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 guide during testing. Therefore, in the examples herein, the guide 40 is also identified as the lower guide of the probe head 20.

[0039] In one embodiment, the probe head 20 may further comprise an intermediate guide 40' with respective guide holes 40'h (as shown in Figure 2, for simplicity some components of the probe head are not shown), and in use the lower guide 40 is positioned between the intermediate guide 40' and the device under test.

[0040] 1, in one embodiment, 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 40', 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.

[0041] According to an embodiment of the present invention, the probe head 20 further comprises a housing or receiving element 50 configured to receive the contact probe 10 and provide support and connection structures between the guides.

[0042] In the embodiment of FIG. 1, housing 50 is interposed between lower guide 40 and upper guide 45 and is suitably configured to house contact probe 10 therein.

[0043] Preferably, the probe head 20 further comprises an air delivery system 60 configured to deliver an air flow (generated externally (e.g., by an external source), indicated by arrows F in the figures) into the interior of the probe head 20, and in particular into the housing 50, to facilitate dissipation of the generated heat. Details of the air delivery system 60 are described below.

[0044] Furthermore, it is known in the art that the fixed location of the power and ground signals (due to the pad layout of the device under test) and the geometry of the probes limits the control of signal impedance within the probe head and the control of noise to the signal probe from other nearby signals, which in turn limits the frequency performance of the probe head.

[0045] For this reason, especially in high frequency applications (and more especially RF applications), ground probes (and power / supply probes as well) rely on metallization on the guide to short probes of the same domain together and allow for ground connections within the probe head to connect the shield. Additionally, even when having different ground / power domains on a device that are then connected on the PCB, the metallization can reduce the loop inductance between the power and associated ground.

[0046] These metallizations are also very useful in the power domain, contributing for example to the reduction of probe burnout phenomena.

[0047] As an example, consider a case where a given power supply for a device under test is contacted by a single probe on the head, and this probe is shorted to other supply probes carrying power supplies that share the same power supply. When the current of this power supply reaches the metallization that shorts all the probes in that domain, the current is shunted between all the shorted probes. This allows for a reduction in inductance and equivalent resistance compared to when this current is confined to a single probe all the way to the PCB.

[0048] It is therefore clear that the presence of metallization on the guides, which shorts out groups of probes to form a common conductive plane (i.e., shorts out specific domains to form conductive domains), can both reduce noise and improve the performance of the probe head 20.

[0049] For this purpose, according to the invention, the guide 40 comprises at least one conductive part 21 (also designated conductive plate) which includes at least one group of holes (designated 40h') of the guide holes 40h and is configured to electrically connect them and to contact and thus short-circuit corresponding groups of contact probes intended to carry signals of the same kind, in particular predetermined ground or power or operating signals. In other words, the conductive domains may be different power and / or ground domains and / or domains configured to carry operating signals.

[0050] Thus, at least one conductive domain is defined on the guide 40, which improves the performance of the probe head. For example, the contact probes 10 shorted together by the conductive portion 21 may be contact probes intended to carry a ground signal or may be contact probes intended to carry a power signal.

[0051] Additionally, as mentioned above, the shorted probes may be contact probes intended to carry input / output operational signals between the device under test and a test instrument interfaced with the probe head 20, such as occurs in loopback techniques.

[0052] Of course, the probe head 20 may include any number of conductive portions 21 arranged in any manner, for example, the conductive portions may be arranged on the upper surface F1 of the guide 40 (as shown in the non-limiting example of FIG. 1 ), on the lower surface F2, or in any other suitable manner.

[0053] Additionally, multiple electrically isolated metallizations may be provided to form multiple respective conductive planes for multiple groups of contact probes, such as a first conductive portion for shorting the ground probes and a second conductive portion for shorting the power probes, or different metallizations for different power sources.

[0054] Many other configurations are also possible, as described, for example, in International Patent Application No. PCT / EP2017 / 082180 by the same applicant. Furthermore, the method for forming the conductive portion is not limited to a particular one, and may be, for example, formed by depositing a conductive material on a ceramic guide.

[0055] In other words, the present invention is not limited by the number and arrangement of the conductive parts, which can be determined based on the needs and / or circumstances.

[0056] As mentioned above, guide 40 is preferably the bottom guide, since it is advantageous to short-circuit the probes closest to the device under test. The guide may also be an intermediate guide, and metallization may be formed on both the bottom and intermediate guides. In this regard, although the present invention has been described based on the non-limiting example of guide 40 being a bottom guide with a conductive plate, as shown in Figures 1 and 2, different configurations may be provided, and the inventive concepts described herein also apply to other guides of probe head 20 (e.g., intermediate guide 40').

[0057] It should be noted that in the above type of probe head, especially when there are a large number of contact probes 10, the mere presence of the air conveying system 60 may not be sufficient to ensure effective heat dissipation, since the innermost probes (i.e., probes surrounded by a large number of other contact probes outside them) will not be affected by the air flow F which will mainly only hit the innermost probes.

[0058] Advantageously, the present invention also provides a heat dissipating conductive portion (designated 65) formed on the guide 40 and arranged so that the air flow F of the air conveying system 60 passes through it. This heat dissipating conductive portion 65 can therefore be arranged on the guide 40 so that it is directly hit by the air flow F or in any case receives the beneficial effect of said air flow F. In particular, the heat dissipating conductive portion 65 is electrically connected to the conductive portion 21 so as to extend a conductive domain in further areas of the guide 40 (areas where the conductive portion 21 is not present), and the air flow F of the air conveying system 60 promotes the dissipation of the heat collected by said heat dissipating conductive portion 65, thereby ensuring optimal heat dissipation and high performance of the probe head 20 as a whole. The connection between portion 21 and portion 65 can be made by suitable wiring shaped to pass between the remaining probe and the remaining domain.

[0059] In other words, the heat dissipation conductive portion 65 is a thermal pad (or heat exchange surface) that collects the generated heat and against which the airflow F impinges.

[0060] In this way, the heat generated by the contact probe 10 is first transferred to the conductive portion 21 and then advantageously transferred to the heat dissipating conductive portion 65, which is acted upon by the air flow F. Therefore, thanks to this configuration, the air conveying system 60 can promote heat dissipation inside the probe head 20.

[0061] As with the conductive portion 21, the heat dissipating conductive portion 65 may also be arranged on a surface of the guide 40, for example on the top surface FA shown in the non-limiting example of the drawings.

[0062] The heat dissipation conductive portion 65 may be formed of any suitable conductive material (such as the same material as portion 21), but is not limited by the material used or its surface extent.

[0063] As mentioned above, a plurality of conductive portions may be provided corresponding to different conductive domains, each of which is configured to short-circuit probes configured to transmit different signals, and at least one of the domains (e.g., the innermost domain and therefore not directly affected by the air flow F) may be connected to a corresponding heat dissipation conductive portion 65 located in the outermost region of the guide.

[0064] With particular reference to the diagram of FIG. 3, in accordance with an embodiment of the present invention, contact probe 10 is generally contained within at least one first or active area (designated A1) of guide 40, in which metallization is also formed. A second area (designated A2) of the guide may also be defined that does not include contact probe 10. Of course, these areas are not limited to any particular shape. For example, second area A2 may be an area surrounding active area A1, and there may be multiple active areas on the guide.

[0065] Thus, the active area A1 is adjacent to the second area A2 (as shown schematically in FIG. 4), and the heat dissipation conductive portions 65 are formed in this second area A2, thereby extending the conductive domain outside the active area A1. Suitably, the air delivery system 60 is configured to deliver an air flow F to at least a portion of the second area A2, which, as described above, facilitates the dissipation of heat exchanged by the heat dissipation conductive portions 65 present in the second area A2.

[0066] 4, a rectangular outline is drawn around active area A1 to highlight second area A2, but second area A2 is of course not limited to the highlighted rectangle and may extend outside of it (hence the placement of portion 65 is not limited to this rectangle either).As mentioned above, there may be multiple active areas A1 on guide 40, for example when testing multiple dies in parallel (multi-die devices), and the layout on the guide follows the layout of the device to be tested.

[0067] 3, the conductive domain may be divided into separate conductive subdomains 21p, each configured to distribute the same predetermined type of signal between shorted contact elements 10, independent of the other conductive subdomains. Such a configuration allows for greater flexibility in probe head design, particularly when testing devices corresponding to multiple domains, particularly power domains. As shown, the subdomains 21p are separated by non-conductive regions 31 of the guide 40.

[0068] According to an embodiment of the present invention, at least one of the conductive sub-domains 21p is connected to a respective heat dissipation conductive part 65. In the schematic example of Fig. 3, four conductive domains (three power domains and one supply domain) are shown, three of which are each divided into sub-domains. One of these sub-domains is connected to a heat dissipation conductive part 65 located in the second area A2, thereby facilitating the dissipation of heat generated by the probe corresponding to that sub-domain.

[0069] Of course, it is not necessary to divide the domains into subdomains; what is important is that at least one of the domains of the guide 40 (e.g., an inner domain as shown in the example of FIG. 4) is connected to the heat dissipation conductor 65. In particular, as already mentioned, according to an embodiment of the present invention, one or more conductive domains that do not directly face the second region A2 are electrically connected to a corresponding heat dissipation conductor 65 that extends into the second region A2, thereby facilitating the dissipation of generated heat.

[0070] Further, with continued reference to FIG. 1, in an embodiment, the probe head 20 includes a heat dissipation layer (indicated by reference numeral 70) that is in contact with at least a portion of the surface of the guide (in the example of FIG. 1, the lower surface FB, but not limited to this), thereby providing even more effective heat dissipation.

[0071] In particular, the heat dissipation layer 70 can be made of a material selected from diamond, silicon carbide, and a silver-diamond composite with a diamond content of 50-99%, and is preferably made of diamond. Therefore, the heat dissipation layer 70 is made of a material with a high thermal conductivity λ, for example, a thermal conductivity greater than 500 W / (m·K). This high thermal conductivity λ allows, in particular, optimal collection and subsequent dissipation of heat generated by the probe head 20 during test operation.

[0072] The heat dissipation layer 70 may extend outside the active area A1 and over the entire surface of the guide 40, or only over a portion of it. In some embodiments, the heat dissipation layer 70 may have sides that wrap around (fully or partially) the guide 40. In either case, the heat dissipation layer 70 extends in a manner that facilitates heat exchange with the air, and thus with the airflow F carried by the system 60. In this way, the combination of the airflow F and the heat dissipation layer 70 ensures even more effective heat dissipation due to the high thermal conductivity of this heat dissipation layer 70.

[0073] 5A-5C, the housing 50 is shaped such that the air delivery system 60 is formed directly within the housing 50. That is, the air delivery system 60 is part of the housing 50 itself (and can therefore be considered the body of the system 60, shaped to suitably deliver air into the probe head 20), and has the shape described above.

[0074] As mentioned above, air is generated by an external air source (not shown) associated with the probe head 20, and this air is then transported into the probe head 20 by the transport system 60, in particular its appropriately formed ducts (i.e. channels in the housing).

[0075] In particular, the housing 50 is suitably shaped to convey air flow F coming from an external source into the interior through the input duct 60in and to allow the air flow F to flow out of the probe head 20 through the output duct 60out.

[0076] 5A-5C, the input ducts 60 in are configured so that air coming from an external source, particularly from the side where the test equipment is located, i.e., the side opposite the semiconductor wafer 23, can be directed toward the guide 40 and diverted by the bifurcated branches of the input ducts 60 in. The number of input ducts 60 in (and the number of branches of each duct) can vary based on the number of dies (or chips) to be tested via the probe head 20 (e.g., when testing four dies in parallel as illustrated in the figures).

[0077] An opening 60op is provided in the housing for the passage of a contact probe 10 for testing a corresponding die.

[0078] Both the vertical and horizontal portions shown in Figures 5A and 5B can be seen as separate portions of the same input duct 60in, which can be suitably connected, for example at the opening of its vertical portion, to an external source means (e.g., a tube or similar external source means) coming from the test apparatus side.

[0079] The single input duct 60in, particularly the horizontal portion parallel to the guide, is configured to ensure an air flow F entering in a direction lying substantially in a plane parallel (e.g., tangential) to the guide 40 and thus the metallization. As noted above, the number of these channels, and therefore the number of areas impinged by the tangential air flow, can vary based on the number of dies being tested.

[0080] This solution therefore allows for a good delivery of forced air and is also advantageous for devices testing multiple dies in parallel, such as the example shown in FIG.

[0081] Furthermore, the exhaust ducts 60out ensure at least two air outlet paths (also called exhaust ducts, since they run parallel to the guide 40) for each single die. In other words, for each die there are at least two exhaust ducts 60out configured to ensure an air flow parallel to the guide. In the embodiment of the drawings, the exhaust ducts are substantially perpendicular to the input ducts with respect to the plane in which the guide lies.

[0082] The above configuration ensures uniform airflow over a large area, thus providing optimal heat dissipation, as shown in the simulation in FIG. 5C.

[0083] However, the present invention is not limited to the particular shape or operation of air conveying system 60, which may have other configurations and may include conventional means such as tubing, which are not described herein to avoid overloading the present description. What is important is that airflow F passes through heat dissipating conductive portion 65.

[0084] In conclusion, the present invention successfully overcomes the technical challenges and overcomes all the shortcomings of the prior art by providing the above-mentioned probe head.

[0085] The present invention advantageously provides a heat dissipation structure capable of collecting and dissipating heat generated during testing operation of the probe head, which collects heat that may increase its temperature, for example, generated by friction of the contact probes sliding in the guide holes or by signals (e.g., power signals) passing through the contact probes, and facilitates dissipating it into the environment, particularly by forced air cooling.

[0086] The air transport system in combination with the heat dissipation conductive parts formed outside the active area of ​​the guide adequately suppresses the increase in the operating temperature of the probe head and avoids malfunctions in a simple way.

[0087] The air conveying system is configured to convey air through its ducts towards the interior of the probe head, in particular the heat dissipation conductive part (and the high thermal conductivity coating layer, if any, used in combination with the described solution), thereby improving the dissipation of heat generated in the probe head and collected in the heat dissipation conductive part within the probe head. In fact, the forced air flow is directed to the heat dissipation conductive part, thereby enabling the heat of the innermost probe (in particular the inner power supply probe), which would be less affected by the air flow if this part were not present, to be dissipated as well.

[0088] Of course, those skilled in the art can make numerous modifications and variations to the above-described probe head to meet their fortuitous and specific requirements, all of which fall within the scope of protection of the present invention as defined in the following claims.

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, 40') provided with a guide hole (40h, 40h') for accommodating the contact probe (10); an air delivery system (60) configured to deliver an air flow (F) to the probe head (20) to promote heat dissipation; Equipped with the probe head (20) further comprises a conductive portion (21) formed on the guide (40, 40'), the conductive portion (21) including at least one hole group among the guide holes (40h, 40h') and configured to contact and short-circuit corresponding contact probe groups housed in the hole group, the contact probes intended to transmit a predetermined type of signal, thereby defining at least one conductive domain on the guide (40, 40'); The probe head (20) further comprises a heat dissipation conductive portion (65) formed on the guide (40, 40') and arranged so that the air flow (F) of the air conveying system (60) passes through, the heat dissipation conductive portion (65) extending the conductive domain and connected to the conductive portion (21) so as to promote the dissipation of heat exchanged by the air flow (F) of the air conveying system (60) through the heat dissipation conductive portion (65).

2. 2. The probe head (20) of claim 1, wherein the probe head (20) comprises a plurality of conductive portions (21) corresponding to different conductive domains, each of the conductive domains configured to short-circuit probes configured to transmit different signals, and at least one of the domains is connected to a corresponding heat dissipation conductive portion (65).

3. The probe head (20) according to claim 2, wherein the conductive domains are different power domains and / or ground domains and / or domains configured to carry operating signals, in particular power domains.

4. A probe head (20) according to any one of claims 1 to 3, wherein at least one conductive domain is divided into a plurality of conductive subdomains (21p) separated from each other, each of the conductive subdomains (21p) being separated from the other conductive subdomains and configured to distribute the same predetermined type of signal between shorted contact probes (10), and at least one conductive subdomain (21p) being connected to a corresponding heat dissipation conductive portion (65).

5. said guide (40) being a lower guide; and / or The probe head (20) of any one of claims 1 to 4, wherein the guide (40') is an intermediate guide of the probe head (20), and the lower guide (40) is disposed between the intermediate guide and the device under test.

6. 6. The probe head (20) of claim 5, further comprising an upper guide (45) spaced apart from the lower guide (40) and having a corresponding guide hole (45h), the lower guide (40) being the guide closest to the device under test.

7. 7. The probe head (20) according to claim 1, wherein the contact probe (10) is included in at least one first or active area (A1) of the guide (40, 40'), the active area (A1) being adjacent to a second area (A2) of the guide (40, 40') that does not include the contact probe (10), the air conveying system (60) being configured to convey the air flow (F) to at least a part of the second area (A2), and the heat dissipation conductive portion (65) being formed in the second area (A2) to extend the conductive domain outside the active area (A1).

8. The probe head (20) according to any one of claims 1 to 7, wherein the conductive portion (21) and the heat dissipation conductive portion (65) are arranged on one face (F1, F2) of the guide (40, 40').

9. 9. The probe head (20) of claim 8, further comprising a heat dissipation layer (70) in contact with at least a portion of the faces (F1, F2) of the guides (40, 40'), the heat dissipation layer (70) being formed from a high thermal conductivity material selected from diamond, silicon carbide and a silver-diamond composite with a diamond content of 50-99%, preferably diamond.

10. The probe head (20) according to any one of claims 1 to 9, wherein the probe head (20) comprises a housing (50) configured to accommodate the contact probe (10), and the air conveying system (60) is configured to convey the air flow (F) into the housing (50).

11. 11. The probe head (20) of claim 10, wherein the housing (50) is configured such that at least a portion of the air conveying system (60) is formed within the housing (50), the housing (50) is configured to allow the air flow (F) to be conveyed into the housing (50) by an input duct (60in) and to discharge the air flow (F) to the outside by an output duct (60out), the ducts are configured such that the input air flow (F) flows in a direction in a plane parallel to the guides (40, 40') and the output air flow (F) is divided into at least two flow portions, the input air flow (F) being divided based on the number of dies to be tested by the probe head (20).

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