Probe head with metallization-based guide and method using the probe head

Abstract

A probe head (20) for testing a device under test (DUT) is described, the probe head (20) comprising: a plurality of contact elements (10) each having a body (10p) extending between respective ends (10a, 10b) configured to contact respective contact pads; at least one guide (40) having guide holes (40h) for accommodating at least a portion of the contact elements (10); and at least one conductive portion (30) formed in the guide (40) including at least one group (40hg) of the guide holes (40h) configured to contact and short-circuit a corresponding group of contact elements accommodated within the group of guide holes (40hg) and intended to carry a given signal (Sgn) of the same type, thereby forming a given conductive domain. Preferably, the conductive portion (30) is divided into separate sub-conductive portions (30p) that are separated from one another so that a given conductive domain is divided into separate conductive sub-domains, and each of the sub-conductive portions (30p) is configured to distribute a given signal of the same type (Sgn) among contact elements (10) that are thereby short-circuited separately from other sub-conductive portions, and each sub-conductive portion comprises between 2 and 50 contact elements.

Description

[Technical Field]

[0001] The present invention relates to a probe head configured to perform testing of electronic devices integrated on a semiconductor wafer, and the following description is written with reference to that field of application solely for the purpose of simplifying the description of the invention. [Background technology]

[0002] As is known, a probe head is essentially a device configured to electrically connect a plurality of contact pads of a microstructure, in particular an electronic device integrated on a semiconductor wafer, to corresponding channels of a test apparatus that performs a functional test thereof, in particular an electrical test, or a test in general.

[0003] Testing of integrated circuits is particularly used early in the manufacturing process to detect and isolate defective circuits. Probe heads are typically used to test circuits integrated on a wafer before they are cut and assembled into an encapsulating package.

[0004] The probe head essentially comprises a plurality of movable contact probes held by at least a pair of supports or guides, substantially plate-like and parallel to one another, the plate-like supports being provided with suitable guide holes and spaced apart so as to create free areas or gaps for the movement and possible deformation of the contact probes, the contact probes usually being made of wire made of a special alloy having good electrical and mechanical properties.

[0005] Contact probes typically extend between a first end intended to contact a contact pad of a device under test and a second end intended to contact a space transformer or printed circuit board (PCB) associated with the probe head.

[0006] In an increasing number of applications, for example high frequency applications, at least one of the guides of the probe head has conductive portions (particularly metallization) intended to electrically connect certain groups of contact probes to one another and to form a common conductive plane for these groups of probes. Thus, among other advantageous aspects of this solution, the signal is distributed to several contact probes, improving the frequency characteristics of the probe head and making it possible to carry higher frequency signals with less noise.

[0007] In particular, according to known solutions, a single conductive part with a large surface extension is formed on the guide, for example in the form of a metallization extending over the surface of the guide, shorting out multiple contact probes to each other and forming a single large conductive domain, but this has the disadvantage of occupying a lot of space on the guide, leaving little space for shorting out different types of contact probes to each other. In practice, there are devices that provide multiple power domains, so known solutions do not easily allow for the formation of conductive parts in all domains.

[0008] The technical problem of the present invention is to provide a probe head having functional and structural characteristics that allow overcoming the limitations and drawbacks that still affect known solutions, and in particular to provide a probe head that allows easily managing various metallizations of different domains within a guide. Summary of the Invention

[0009] The solution underlying the present invention is to devise a probe head with different metallizations corresponding to different domains on the guide, each domain being divided into a number of independent conductive sub-domains containing a limited number of contact elements (e.g. contact probes, possibly pogo pins) shorting each other, this number being suitably chosen, for example, between 2 and 50, better between 4 and 10 and / or between 10 and 20. In this way, conductive sub-domains related to different signals can be arranged among different conductive sub-domains of the same signal, thus forming a conductive part divided into separate and independent sub-conductive parts so as to reserve enough space on the guide for alternating arrangement of sub-domains related to different signals (e.g. different power supplies).

[0010] Based on this solution, 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 elements having bodies extending between respective ends configured to contact respective contact pads; at least one guide provided with guide holes for accommodating at least a portion of the contact elements; and at least one conductive portion (30) formed in the guide including at least one group of guide holes and configured to contact and short-circuit a corresponding group of contact elements accommodated within the group of guide holes and intended to carry a given same type of signal, thereby forming a given conductive domain, the conductive portion being divided into separate sub-conductive portions separated from one another so that the given conductive domain is divided into separate conductive sub-domains, each of the sub-conductive portions being configured to distribute the given same type of signal among contact elements thereby being short-circuited separately from other sub-conductive portions, each sub-conductive portion comprising a number of contact elements between 2 and 50, thus limited.

[0011] More particularly, the present invention comprises the following additional and optional features, taken individually or in any combination as appropriate:

[0012] According to one aspect of the present invention, each secondary conductive portion may comprise from 4 to 20 contact elements, more preferably from 10 to 20 contact elements, without excluding other numerical ranges.

[0013] According to one aspect of the present invention, the sub-conductive portions of a conductive portion may be electrically insulated from each other.

[0014] According to one aspect of the present invention, the conductive portion, and therefore each sub-conductive portion, may be configured to carry a given power signal, thereby collectively forming a given power domain.

[0015] According to one aspect of the present invention, a probe head may include at least one first conductive portion and one second conductive portion, the first conductive portion including holes of a first group of guide holes electrically connecting with each other, the first group accommodating a first contact element, the second conductive portion including holes of a second group of guide holes electrically connecting with each other, the second group accommodating a second contact element, the first contact element and the second contact element being connectable to respective different sources for carrying different types of signals, and the first conductive portion and the second conductive portion being divided into respective sub-conductive portions.

[0016] According to one aspect of the invention, the probe head may comprise a plurality of conductive portions corresponding to different power domains, each intended to carry a respective different power signal.

[0017] According to one aspect of the invention, the probe head may further comprise conductive portions configured to carry ground and / or operating signals to / from the device under test.

[0018] According to one aspect of the invention, sub-portions of a domain may be interleaved with sub-portions of different domains configured to carry different types of signals, and the interleaved domains (carrying different signals, e.g., different power supplies) are electrically isolated from each other.

[0019] According to one aspect of the invention, the at least one conductive portion can coat at least a portion of at least one wall of the guide hole, preferably the entire wall of said hole is coated with the conductive portion.

[0020] According to one aspect of the invention, the conductive portion (and therefore the secondary conductive portion) may be disposed on the surface of the guide.

[0021] According to one aspect of the present invention, the guide may be a bottom guide or a middle guide of the probe head, where the bottom guide is the guide closest to the device under test and is positioned between the device under test and the middle guide.

[0022] According to one aspect of the invention, the sub-conductive portions may be separated from one another by at least one non-conductive region so that no electrical connection occurs between the sub-conductive portions and, in some cases, with contact elements intended to carry different signals.

[0023] According to one aspect of the invention, at least one guide may optionally comprise at least one coating dielectric portion covering at least one non-conductive region.

[0024] According to one aspect of the invention, the contact element may be in the form of a buckling beam contact probe, the body having a deformation.

[0025] Alternatively, according to one aspect of the invention, the contact element may be in the form of a pogo pin, in which case the body comprises a casing and a resilient element disposed within the casing, the casing defining a first surface and a second surface, at least one of the surfaces being configured to abut the guide, and the electrical connection between the contact element and the conductive portion being a pressure contact by the first and / or second surface.

[0026] According to one aspect of the present invention, each conductive portion may comprise between two and ten sub-conductive portions.

[0027] The present invention also provides a method for testing an electronic device, comprising the steps of positioning a probe head of the type described above; contacting pads of an interface board (such as a space transformer and / or a PCB) simultaneously with pads of a device under test by first and second ends of contact elements of the probe head, respectively; and routing (sending) a signal of a given type to at least one contact element (thus connecting, directly or indirectly, a conductive portion to a source sending said signal, for example, but not limited to, via a pad or group of pads), such that the signal of the given type is routed (sent) to each of the sub-conductive portions, each of which therefore distributes the given signal of the same type among the contact elements which are thereby isolated and shorted from the other sub-conductive portions.

[0028] According to one aspect of the invention, the given type of signal may be a power signal, and the conductive portion, and therefore each sub-conductive portion, may carry the given power signal, thereby collectively forming a given power domain.

[0029] According to one aspect of the invention, the probe head comprises at least one first conductive portion and one second conductive portion (and is not limited to any particular number), the first conductive portion including holes of a first group of guide holes electrically connecting with each other, the first group accommodating a first contact element, and the second conductive portion including holes of a second group of guide holes electrically connecting with each other, the second group accommodating a second contact element, the method further comprising: routing (sending) a first type of signal, e.g., a first power signal, to at least one of the first contact elements (and thus connecting, directly or indirectly, the first conductive portion to a first source sending said signal, e.g., a power signal). The method includes a step of routing (sending) a second type of signal different from the first type of signal, for example, but not limited to, connecting via a first pad or group of pads, to at least one of the second contact elements (thus connecting, directly or indirectly, the second conductive portion to a second source that routes said signal, for example, but not limited to, via a second pad or group of pads), the first conductive portion being divided into sub-conductive portions through which the first type of signal is routed, and the second conductive portion being divided into sub-conductive portions through which the second type of signal is routed.

[0030] The features and advantages of a probe head according to the invention will become apparent from the following description of exemplary embodiments given as non-limiting examples, with reference to the accompanying drawings, in which: FIG. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 2 is a schematic diagram of a probe head according to one embodiment. [Figure 2] FIG. 2 is a schematic top view of a probe head in accordance with one embodiment of the present invention. [Figure 3] FIG. 2 is a schematic diagram of a probe head with different conductive portions for each different domain, in accordance with one embodiment of the present invention. [Figure 4]1 is a schematic top view of a probe head guide with different conductive portions for each different domain, in accordance with one embodiment of the present invention; [Figure 5] 10 is another schematic top view of a probe head guide with different conductive portions for each different domain, in accordance with one embodiment of the present invention; [Figure 6] FIG. 10 is a schematic diagram of a probe head according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] Referring to the drawings, there is shown generally at 20 a schematic diagram of a probe head configured to perform testing of electronic devices integrated on a semiconductor wafer fabricated in accordance with the present invention.

[0033] It should be noted that the drawings are schematic and not drawn to scale, but rather are drawn to highlight important features of the present invention. Furthermore, the various elements are depicted schematically in the drawings, and their shapes may vary depending on the desired application. It should also be noted that identical reference numerals throughout the drawings refer to identical elements in terms of shape or function. Finally, a particular arrangement described in connection with an embodiment shown in one drawing may also be used with other embodiments shown in other drawings.

[0034] Additionally, it should be noted that unless expressly stated to the contrary, process steps can be reversed if desired.

[0035] The probe head 20 is configured to connect to equipment (not shown) that performs testing of electronic devices, such as high frequency devices, integrated on a semiconductor wafer 23 .

[0036] 1, the probe head 20 comprises a plurality of contact elements 10, which are slidably accommodated within the probe head and are intended to connect devices under test integrated on a semiconductor wafer 23 to a test apparatus. To accommodate the contact elements 10, the probe head 20 comprises at least one guide 40 provided with guide holes 40h in which the contact elements 10 can slide.

[0037] Each contact element 10 includes a body 10p extending along a longitudinal axis HH between a first end 10a and a second end 10b, each configured to contact a contact pad. For example, the first end 10a (also referred to as a contact tip) is configured to contact a contact pad 22 of a device under test integrated on a semiconductor wafer 23, and the second end 10b (also referred to as a contact head) is configured to contact a contact pad 24 of an interface board, such as a space transformer (these components are collectively identified by the reference numeral 25), or of a printed circuit board (PCB) associated with the probe head 20 during testing. While the ends 10a and 10b are shown in the accompanying Figures 1 and 3 as having a pointed shape, they are not limited thereto and may have any shape as needed and / or suited to the circumstances.

[0038] In the illustrated embodiment, guide 40 is the lower guide, and therefore, as is known in the art, is the guide closest to first end 10a intended to contact a test device. In an embodiment not shown, guide 40 may be an intermediate guide located above the lower guide (e.g., located between the lower and upper guides, typically located close to the former). As a result, as will be described below, the guide relevant to the present invention is the guide closest to the device under test and most likely to contribute to improving the frequency characteristics of the probe head.

[0039] 1 and 3, the body 10p preferably has a square or rectangular cross-section (i.e., is preferably rod-shaped), although the invention is not limited thereto. For example, the body 10p could also have a circular cross-section, or any cross-section as needed and / or suited to the circumstances. In either case, the body 10p has at least one wall W, the surface of which is planar (e.g., for a probe having a square or rectangular cross-section) or curved (e.g., for a probe having a circular cross-section) and which contacts the respective wall of the guide hole.

[0040] According to the embodiment of Figures 1 and 3, the contact element 10 is a type of contact probe known in the art as a "buckling beam", i.e., having a constant cross-section, preferably square or rectangular, along its entire length, with the body 10p deforming substantially at a central location and configured to flex and further deform during testing of the device under test.

[0041] The deformation of the main body 10p is generally achieved by a so-called shift plate guide structure of the probe head 20. In this structure, a pair of guides are first overlapped and the positions of their guide holes are aligned. When the contact probe 10 is then inserted into the guide holes, the guides separate, forming a gap between them, and the guides then shift, causing the deformation of the main body 10p.

[0042] In this case, the contact probe 10 can bend further while in contact with the pad 22 of the device under test, and this bending determines the lateral displacement of the probe in a certain direction, referred to herein as the bending direction. In particular, the relative shift of the guides determines the bending direction of the contact probe 10, and thus the movement direction of each end. This movement may cause at least one first wall of the contact probe 10 to contact the corresponding wall of the guide hole, defining a gap between the second wall of the contact probe 10 and the opposite wall of the guide hole, or both opposite walls of the contact probe 10 may contact the corresponding opposite wall of the guide hole. In other words, during bending, one or more walls W of the probe (in particular, two walls opposite each other along the bending direction) contact the wall of the guide hole in which the contact probe 10 is housed.

[0043] Furthermore, during flexing of the contact probe 10 (particularly during vertical movement of the probe, referred to in the art as overtravel), sliding contact occurs between the body 10p and the walls of the guide hole.

[0044] In this embodiment of Figures 1 and 3, the body 10p has a portion configured to be at least partially inserted into the guide hole 40h of the lower guide 40 of the probe head 20, and during movement of the contact probe 10, this body 10p comes into contact, in particular sliding contact, with the guide hole 40h.

[0045] Therefore, the remainder of this specification will identify the contact element 10 as a contact probe, and finally, an example will be given in which the contact element 10 is a pogo pin, although the same inventive concepts apply.

[0046] It is known in the art that the fixed locations of power and ground signals (due to the pad layout of the device under test) and the geometry of the probes limit the control of signal impedance within the probe head, which also limits the control of noise generated in the signal probe by other nearby signals, and limits the frequency response of the probe head.

[0047] Therefore, in high frequency applications (especially RF applications), the metallization on the guide shorts the power and ground probes, thereby shorting probes of the same domain together. Furthermore, when devices with different ground / power domains on the device are joined on a PCB, the metallization can reduce the loop inductance between the power supply and the associated ground.

[0048] Furthermore, metallization can reduce the phenomenon of probe burnout, especially in the case of power probes.

[0049] Consider the case where a probe in a probe head contacts a given power supply in a device under test and shorts out other probes carrying power signals that share the same power supply. When this power supply current contacts the metallization that shorts out all probes in this domain, it is distributed among all shorted probes, thereby reducing the inductance and equivalent resistance compared to when the current is confined to a single probe all the way to the PCB.

[0050] Thus, it is clear how the presence of metallization on the guides, shorting groups of probes together and creating a common conductive plane, reduces noise and improves the frequency performance of the probe head.

[0051] To this end, according to the invention, the guide 40 of the probe head 20 comprises at least one conductive portion (designated with reference numeral 30) containing holes of at least one group (designated with reference numeral 40hg) of guide holes 40h, electrically connecting them and configured to contact and thus short-circuit the corresponding group of contact probes intended to carry signals of the same type, in particular a given ground, power or operating signal domain, thereby forming a given conductive domain on the guide 40 and shorting out the probes designed to carry the given signal, forming a common conductive plane within the probe head and consequently improving the performance of the probe head.

[0052] The applicant has found that contact elements 10 located at the ends of a conductive domain do not contribute significantly to the above benefits, particularly in the case of extended domains with a large number of contact probes, and that the contribution of probes within a domain decreases as a function of distance, and therefore the same performance can be achieved with a limited number of probes within a domain.

[0053] In view of the above, advantageously, according to the present invention, the conductive portion 30 is divided into separate sub-conductive portions (identified by reference numeral 30p) that are separated from one another, such that a given conductive domain is divided into smaller separate conductive sub-domains, each sub-conductive portion including a limited number of contact probes.

[0054] In particular, each sub-conductive portion 30p is configured, independently of the other sub-conductive portions, to distribute a given signal of the same type (denoted by the reference symbol Sgn) between the contact elements 10 that are shorted by it, thereby forming sub-conductive portions (or conductive subdomains) that are structurally independent and electrically isolated from one another.

[0055] In this way, the secondary conductive portions 30p are independent but configured to carry the same given type of signal, for example a given power supply (as well as ground and operating signals I / O, as described in more detail below).

[0056] Generally, according to the present invention, there is at least one conductive portion 30 configured to form a power domain, a ground domain, or a common conductive plane for one of a set of contact probes 10 carrying the same operational signal I / O (there is no restriction on the type of signal carried), and this conductive portion 30 is suitably divided into multiple sub-conductive portions 30p.

[0057] In a non-limiting example, conductive portion 30, and therefore sub-conductive portions 30p, are configured to carry a given power signal, thereby collectively forming a given power domain, with each sub-conductive portion 30p carrying power separately from the other sub-conductive portions.

[0058] Preferably, each secondary conductive portion 30p comprises between 2 and 50 contact elements.

[0059] However, there may be various ranges for the selection of the number of contact elements, for example, from 2 to 100, the aforementioned 2 to 50 (generally above 50 and even above 100, the contribution of additional probes is minimal), from 2 to 20, from 2 to 10, or even from 4 to 50, from 4 to 20, from 4 to 10, etc. A preferred range is from 4 to 20, more preferably from 10 to 20.

[0060] 2 (showing individual sub-conductive portions 30p of a single conductive domain), the sub-conductive portions 30p are separated from each other and from other non-shorting probes by at least one non-conductive region 31 to prevent electrical connections between the sub-conductive portions and to prevent electrical connections with other contact probes intended to carry different signals. In certain embodiments, the guide 40 optionally comprises at least one coating dielectric portion covering the non-conductive region 31.

[0061] As shown in FIG. 3, the probe head 20 may include any number of conductive portions 30 arranged in any manner on the guide or embedded within the guide to carry any type of signal. Although FIG. 3 shows two different conductive portions 30′ and 30″ intended to carry two different signals (e.g., two power supplies), it is clear that all drawings are merely non-limiting examples to illustrate the scope of the present invention, and any number and type of conductive portions can be selected based on the situation. Furthermore, as mentioned above, the present invention is applicable to any type of signal, such as ground, power, or operational signal I / O, and even in combination, and the number and type of conductive portions are adjusted based on the situation.

[0062] More specifically, in the embodiment of FIG. 3, the probe head 20 comprises at least one first conductive portion 30' and one second conductive portion 30", the first conductive portion 30' including a hole of a first group 40hg' of guide holes 40h that accommodates a first contact element 10' and electrically connects them to each other, while the second conductive portion 30" includes a hole of a second group 40hg" of guide holes 40h that accommodates a second contact element 10" and electrically connects them to each other.

[0063] The first contact element 10' and the second contact element 10" are connectable to different sources (e.g., two different power supplies via one or more of the pads mentioned above) to carry different types of signals, and according to the present invention, preferably both the first conductive portion 30' and the second conductive portion 30" are divided into respective sub-conductive portions in the above-mentioned mode.

[0064] FIG. 4 is a schematic example showing various sub-conductors associated with different domains, specifically three different domains (each sub-conductor is designated 30p', 30p", and 30p"'). For example, two domains may be associated with two different power sources and the third domain may be associated with a ground domain, but this is a non-limiting example only, and the configuration (number, type, and placement of domains) can be changed according to requirements and / or needs.

[0065] Figure 5 shows a more complex example where different colors correspond to different domains that are well-separated and closely related to one another. As shown, one advantage of the present invention is that sub-conductors in one domain can actually be interleaved with sub-conductors in a different domain (i.e., a domain configured to carry a different type of signal). These interleaved domains are electrically isolated from one another, essentially forming a puzzle-like configuration.

[0066] As mentioned above, latest generation devices have many different power sources, and therefore the probe head 20 may have multiple conductive portions corresponding to different power domains (more than 10), each intended to carry a different power signal. Obviously, the above description does not exclude the existence of other types of domains, such as ground domains (represented by grey boxes in Figure 5) or signal I / O domains (in the latter case, for example, for implementing loopback techniques).

[0067] In one embodiment of the present invention, the conductive portion 30 can be formed not only on the upper surface F1 of the guide 40 (as shown), but also on the lower surface F2, and can also be formed inside the guide.

[0068] Obviously, as mentioned above, the present invention is not limited by the number and arrangement of conductive parts, which can be configured based on the needs and / or circumstances, for example as described in International Patent Application No. PCT / EP2017 / 082180 in the name of the present applicant.

[0069] 1 and 3, the conductive portions 30 cover at least a portion of the walls of the guide holes 40hW of the group 40hg, forming metallized portions of the guide holes that come into contact with the contact probes 10, in particular the metallized portions of the guide holes with which the contact probes 10 make the sliding contact described above. Preferably, the conductive portions 30 can completely cover some or all of the walls of the guide holes (so that in this case the metallized portion coincides with the entire hole wall 40hW), or alternatively, the conductive portions 30 can only partially cover the walls 40hW of the guide holes.

[0070] In either case, what is important is that by properly dividing at least one conductive portion 30, it is possible to form conductive domains that electrically connect the contact probes together, improving the overall performance of the probe head 20 and also enabling a very advantageous layout of the guide 40 as described above.

[0071] Furthermore, according to an embodiment of the present invention, each conductive portion 30 includes between 2 and 10 sub-conductive portions, although any suitable number may be employed.

[0072] Finally, in an alternative embodiment of the invention shown in FIG. 6, the contact element 10 may be in the form of a pogo pin. In this case, the body 10p comprises a casing 33 and a resilient element 34 disposed within the casing 33, the resilient element 34 defining a first surface S1 and a second surface S2, which form suitable shoulders for abutting against a guide of the probe head. As shown in FIG. 6, the probe head 20 may comprise an upper guide 42 separated from a lower guide 40 by a gap 35, and the upper guide 42 may comprise one or more conductive portions. Preferably, at least one of the surfaces S1 and S2 is configured to abut against a guide (in this case, typically both surfaces S1 and S2 of both guides 40 and 42), and the electrical connection between the contact element 10 and the at least one conductive portion 30 is a pressure contact by the first surface S1 and / or the second surface S2.

[0073] From the above discussion, it is clear that the present invention also relates to a method for testing electronic devices using the probe head 20, to which all of the technical features of the probe head 20 are applicable. In one embodiment, during testing, the probe head is connected to an interface board, which in turn is connected to a test apparatus, and signals are transmitted to the probes (e.g., via different sources transmitting signals through one or more pads, which in turn connect conductive parts directly or indirectly to said sources).

[0074] In conclusion, the present invention provides the above-mentioned probe head, which makes it possible to successfully overcome the technical challenges while resolving all of the shortcomings of the prior art.

[0075] The invention advantageously allows a very advantageous layout on the guide of the probe head due to the finely divided individual metallizations, so that even if there are several different domains, all the metallizations on a single face of the guide can be well interleaved / closely spaced with individual sub-domains with a limited number of probes.

[0076] This configuration is achieved without compromising the frequency response of the probe head, i.e. dividing a single domain into multiple sub-domains does not result in a loss of efficiency, making it easy to manage multiple different domains on a single guide in a reasonable manner.

[0077] It is therefore evident that the probe head of the present invention is also particularly suitable for testing high frequency devices in the radio frequency domain, for example high frequency devices having multiple power domains.

[0078] Obviously, in order to meet possible specific requirements, those skilled in the art are allowed to bring about various modifications and substitutions to the above-mentioned probe head, all of which fall within the scope of protection of the present invention as defined by the following claims.

Claims

1. A probe head (20) for testing a device under test (DUT), comprising: The probe head (20) a plurality of contact elements (10) each having a body (10p) extending between respective ends (10a, 10b) configured to contact a respective contact pad; at least one guide (40) provided with a guide hole (40h) for receiving at least a portion of said contact element (10); and at least one conductive portion (30) formed in the guide (40) including at least one group (40hg) of the guide holes (40h) and configured to contact and short-circuit a corresponding group of contact elements housed in the group (40hg) of guide holes and intended to carry a given signal (Sgn) of the same type, thereby forming a given conductive domain; the conductive portion (30) is divided into distinct sub-conductive portions (30p) that are separate from one another such that the given conductive domain is divided into distinct conductive sub-domains; each of said sub-conductive portions (30p) is configured to distribute said given same type of signal (Sgn) among said contact elements (10) which are thereby short-circuited in isolation from other sub-conductive portions; The probe head (20) has from 2 to 50 contact elements in each sub-conductive portion (30p).

2. The probe head (20) of claim 1, wherein each secondary conductive portion (30p) comprises between 4 and 20 contact elements, more preferably between 10 and 20 contact elements.

3. The probe head (20) according to claim 1 or 2, wherein the sub-conductive portions (30p) of the conductive portion (30) are electrically insulated from each other.

4. The probe head (20) of any one of claims 1 to 3, wherein the conductive portion (30), and therefore each sub-conductive portion (30p), is configured to carry a given power supply signal, thereby collectively forming a given power supply domain.

5. The probe head (20) comprises at least one first conductive portion (30') and one second conductive portion (30"); the first conductive portion (30') includes and electrically connects the holes of the first group (40hg') of the guide holes (40h); said first group contains a first contact element (10'); the second conductive portion (30") includes and electrically connects the holes of the second group (40hg") of the guide holes (40h); said second group contains a second contact element (10"); the first contact element (10') and the second contact element (10") are connectable to different sources for carrying different types of signals; The probe head (20) of any one of claims 1 to 4, wherein the first conductive portion (30') and the second conductive portion (30'') are divided into respective sub-conductive portions.

6. The probe head (20) of claim 5, comprising a plurality of conductive portions corresponding to different power domains, each intended to carry a respective different power signal.

7. The probe head (20) of claim 6, further comprising conductive portions configured to carry ground and / or operational signals to / from the device under test (DUT).

8. 8. A probe head (20) according to any one of claims 5 to 7, wherein sub-portions of a domain are interleaved with sub-portions of different domains, the different domains being configured to carry different types of signals, and the interleaved domains being electrically isolated from each other.

9. The probe head (20) according to any one of claims 1 to 8, wherein the conductive portion (30) is arranged on a face (F1, F2) of the guide (40).

10. The probe head (20) of any one of claims 1 to 9, wherein the guide (40) is a lower guide or an intermediate guide of the probe head (20).

11. 11. A probe head (20) according to any one of claims 1 to 10, wherein the sub-conductive portions (30p) are separated from one another by at least one non-conductive region (31) so as to prevent electrical connections between the sub-conductive portions and, in some cases, with contact elements intended to carry different signals, and wherein the at least one guide (40) optionally comprises at least one coating dielectric portion covering the at least one non-conductive region (31).

12. The probe head (20) according to any one of the preceding claims, wherein the contact element (10) is in the form of a buckling beam contact probe, the body (10p) having a deformation.

13. said contact elements (10) being in the form of pogo pins; The body (10p) comprises a casing (33) and an elastic element (34) disposed within the casing (33); the casing (33) defines a first surface (S1) and a second surface (S2); At least one of the surfaces (S1, S2) is configured to abut against the guide (40); The probe head (20) according to any one of claims 1 to 11, wherein the electrical connection between the contact element (10) and the at least one conductive portion (30) is by pressure contact with the first and / or second surfaces (S1, S2).

14. 1. A method for testing an electronic device, comprising: Positioning the probe head (20) of claim 1; contacting the pads (22) of the device under test and simultaneously the contact pads (24) of the interface board (25) with the first end (10a) and the second end (10b) of the contact elements (10) of the probe head (20), respectively; a step of passing a signal (Sgn) of a given type through at least one of said contact elements (10), said signal of said given type passing through each of said sub-conductive portions (30p), each of said sub-conductive portions (30p) therefore distributing the given signal (Sgn) of the same type among said contact elements (10) which are thereby short-circuited in isolation from other sub-conductive portions; A method comprising:

15. 15. The method of claim 14, wherein the given type of signal is a power signal, and the conductive portion (30), and therefore each sub-conductive portion (30p), carries a given power signal, thereby collectively forming a given power domain.

16. The probe head (20) comprises at least one first conductive portion (30') and one second conductive portion (30"); the first conductive portion (30') includes and electrically connects the holes of the first group (40hg') of the guide holes (40h); said first group contains a first contact element (10'); the second conductive portion (30") includes and electrically connects the holes of the second group (40hg") of the guide holes (40h); said second group contains a second contact element (10"); The method further comprises: passing a first type of signal, e.g., a first power signal, through at least one of said first contact elements (10'), and passing a second type of signal, different from said first type of signal, e.g., a second power signal or a ground signal, through at least one of said second contact elements (10"); 16. The method according to claim 14 or 15, wherein the first conductive portion (30') is divided into sub-conductive portions through which signals of the first type are carried, and the second conductive portion (30'') is divided into sub-conductive portions through which signals of the second type are carried.

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