This application claims priority to Japanese Patent Application No. 2022-072106, filed Apr. 26, 2022, the contents of which are incorporated herein by reference in its entirety for all purposes.
The present invention relates to test probes that can be used for electrical testing of electronic devices, for example, array-based electronic devices such as IC chips obtained by placing a plurality of solder balls, pads, leads, and the like on a package, as well as to a test socket in which a plurality of said test probes are disposed.
An example of conventional test probes and a test socket was disclosed in Patent Document 1 (Japanese Patent Publication No. 5,960,383). It should be noted that the reference numerals used in the discussion hereinbelow follow the reference numerals used in Patent Document 1.
Contacts 3, which serve as test probes, have: a generally cylindrical, hollow, electrically conductive outer casing 31, which is inserted into contact apertures 24 formed in a contact holder 2 serving as a test socket; a resilient member 32 such as a coil spring, and the like, which is disposed within the outer casing 31 and is capable of expanding and contracting in the axial direction of the outer casing 31; an electrically conductive first plunger 33, which is disposed at one end of the coil spring 32 while protruding from one end of the outer casing 31, and is configured in a manner permitting electrical connection to a test apparatus; and an electrically conductive second plunger 34, which is disposed at the other end of the coil spring 32 while protruding from the other end of the outer casing 31, and is electrically connectable to an electronic device. The first plunger 33 and the second plunger are electrically connected to each other through the medium of the outer casing 31 because each of them abuts the outer casing 31 and, additionally, can be electrically connected through the medium of the resilient member 32 by forming the coil spring from an electrically conductive material.
The contact holder 2 can hold the plurality of contacts 3 such that each one extends in the through-thickness direction of the base 51. A guide body 4, which supports said contact holder 2, can be attached to the contact holder 2, and a guide portion or a guide wall 41, which is used to dispose electronic devices to be tested at a predetermined location on the contact holder 2, can be provided in the guide body 4. The guide body 4, while supporting the contact holder 2, can be secured to a printed circuit board or another test apparatus using screw holes 51b and the like.
When testing electronic devices, the contact holder 2 is mounted at a predetermined location of the test apparatus, and an electronic device is disposed at a predetermined location on the contact holder 2 with the help of the guide portion of the guide body 4. Although electric power necessary for testing is normally supplied from the test apparatus to the electronic device through the test probes, in a conventional test probe such as the one disclosed in Patent Document 1, and the like, one outer casing 31 has only one set of plungers provided therein, that is, a first plunger 33 and a second plunger 34, and electrical connection between the first plunger 33 and the second plunger 34 is accomplished through abutment with the outer casing 31 or through the resilient member 32, which is why this current flow path is not particularly large. For this reason, it may not be possible to supply a sufficient amount of electric power necessary for testing, and, in addition, attempting to supply sufficient electric power could lead to a considerable amount of Joule heating being generated in the test probes, and there is therefore a risk that testing could not be properly conducted. To be sure, it should be noted that conductor sections 241 formed in the contact holder 2 of Patent Document 1 on the interior surface of the contact apertures 24 are electrically connected to each other through connection portions 26 that are layered or made up of wiring, as a result of which some of the contacts among the plurality of contacts 3 are electrically connected to the connection portions 26 through the medium of the conductor sections 241. However, the electrical connections through these connection portions 26 are intended merely for compensating for changes in the quality of signal transmission by the contacts 3 and are unrelated to the supply of electric power necessary for testing. In addition, since no current flow path large enough to make such supply possible is provided, the electrical connections through the connection portions 26 do not in any way overcome the shortcomings of the prior art noted above.
Patent Document 1: Japanese Patent Publication No. 5,960,383
It is an object of the present invention to provide test probes in which the shortcomings of the prior art noted above are eliminated, as well as a test socket that uses said test probes.
To solve the above-mentioned problems, a test probe according to one aspect of the present invention comprises a support of an electrically conductive material having a first face and a second face, first contact members provided adjacent to the first face of the support, and second contact members provided adjacent to the second face of the support, with at least the first contact member or second contact member being provided as a plurality of members; and is characterized by the fact that a plurality of the first contact members and at least one second contact member, or a plurality of the second contact members and at least one first contact member, are electrically connected through the support, and, in addition, a test socket according to one aspect of the present invention has such test probes.
When the test probe, etc., according to this aspect is used, the support itself is formed from an electrically conductive material, as a result of which the plurality of the first contact members and at least one second contact member, or the plurality of the second contact members and at least one first contact member, can be electrically connected through the support. Along with minimizing Joule heating, this makes it possible to increase the value of the electric current flowing through the test probes, and, for that matter, between the first contact members and second contact members, which, for example, makes it possible to supply a sufficient amount of electric power necessary for electronic device testing.
According to the present invention, it is possible to provide test probes in which the shortcomings of the prior art noted above are eliminated, as well as a test socket that uses said test probes.
Exemplary embodiments for the present invention are described in detail below with reference to drawings. However, the materials, shapes, relative positions of components, and the like described in the embodiments below, except for matters essential to solving the problems of the present invention, are discretionary and can be modified depending on the construction or various conditions of the apparatuses to which the present invention is applied. In addition, unless expressly stated otherwise, the scope of the present invention is not limited to the embodiments specifically described below.
A schematic perspective view of a test socket according to an exemplary embodiment of the present invention is illustrated in
A partial cross-sectional view of the base 51 and the test probes 1 is illustrated in
The frame 52, which includes a plurality of screw holes 52a, is secured with screws to a printed circuit board or another test apparatus (not shown) using these screw holes 52a. The test socket 5 is mounted at a predetermined location of the test apparatus by securing the frame 52. Once it is mounted at the predetermined location, the second contact members 22 provided adjacent to the second faces 12 of the test probes 1 installed in the base 51 of the test socket 5, i.e., on the side opposite to the first faces 11 in the thickness direction of the base 51, are each electrically connected to predetermined sections of the test apparatus. It should be noted that while the present embodiment has been described on the assumption that the side of the second face 12 is the side opposite to the side of the first face 11 in the thickness direction of the base 51, it does not necessarily have to be provided on the opposite side in the thickness direction, and may be provided, for instance, in the lateral direction, etc., of the base 51 as long as the practice of the present invention is not impaired.
An electronic device to be tested (not shown) is inserted into a concave depressed mounting portion 54 formed by the interior wall surface 52b of the frame 52 and the surface 51a of the base 51. As a result, predetermined sections of the electronic device, for example, predetermined solder balls, and the like, in the IC circuits are electrically connected to individual members in the plurality of the first contact members 21 arranged on the surface 51a of the base 51. A plurality of electronic devices to be tested can be plugged and unplugged from the test socket 5 in turn. In order to facilitate electronic device extraction from the mounting portion 54, indentations 52c for inserting an extraction jig are provided in the interior wall surface 52b of the frame 52.
Electric power necessary for electronic device testing can be supplied, for example, from the test apparatus. Electric current from the test apparatus is supplied to the electronic device through the test probes 1, or more specifically, through electrical connections between the test apparatus and the second contact members 22, between the second contact members 22 and the first contact members 21, and between the first contact members 21 and the electronic device, in that order. As described below, with this configuration, the current flow path is of sufficient size, and the Joule heating thus generated in the test probes 1 in this configuration does not present a problem.
While not apparent from the drawings, in a manner similar to the first contact members 21 and second contact members 22, the support 10 consists of an electrically conductive material. The first contact members 21 and second contact members 22 can be manufactured, for example, by stamping and folding a metal plate, while the support 10 can be manufactured, e.g., by machining a block of metal. In a manner similar to the first contact members 21 and second contact members 22, the support 10 is preferably formed from a physically unitary member. However, as long as it is an electrically unitary member, it may be physically formed from a plurality of sections. As used herein, the term “electrically unitary member” refers to a situation in which, for example, a member is physically composed of a plurality of sections, but these sections are in communication with one another, and the member operates as an electrically unitary member with respect to the first contact members 21 and second contact members 22.
The support 10 extends, for example, along the axial direction “a” of the test probe 1, and has its first face 11, where the first contact members 21 are provided, located at one end thereof, and its second face 12, where the second contact members 22 are provided, located at the other end thereof. The first contact members 21 are supported adjacent to the first face 11 and the second contact members 22 are supported adjacent to the second face 12. Although said first contact members 21 and second contact members 22 are supported by the support 10 in a mutually spaced relationship, all of them are electrically connected to the support 10 through abutment with the support 10 and, therefore, are electrically connected to one another through the medium of the support 10. In the test socket 5 illustrated in
In the cross-sectional direction “β-γ” perpendicular to the axial direction “α”, in other words, on the first face 11 and second face 12 of the support 10, the support 10 is of an integral shape produced by coupling to one another, at their lateral faces, a plurality of test probe elements corresponding to typical conventional test probes. For instance,
In order to facilitate contact with the electronic device, the first contact members 21 are preferably provided protruding from the first face 11 of the support 10 and, in a similar manner, in order to facilitate contact with the test apparatus, the second contact members 22 are preferably provided protruding from the second face 12 of the support 10. However, as long as the members can be brought into electrical contact with the electronic device or the test apparatus, they do not necessarily have to be provided in a protruding manner and, for instance, if an electronic device or unit being tested has projections, the first contact members 21 or second contact members 22 may be provided retracted into the interior of the support 10 in alignment therewith.
In the present test probe 1, a support 10 formed from an electrically conductive material is used, and at least one of either the first contact member 21 or second contact member 22 is provided as a plurality of members. Providing at least one of the above as a plurality of members allows for a larger current flow path to be created not only for the electrical connections between the second contact member 22 and the first contact member 21, but also for the electrical connections between the test apparatus and the second contact member 22 and/or the electrical connections between the first contact member 21 and the electronic device. It should be noted that it is sufficient for at least either one of the first contact member 21 or second contact member 22 to be provided as a plurality of members, and that the number of members provided is not limited. For example, in a manner similar to the test probe 1 illustrated in
A schematic cross-sectional view of the test probe 1C illustrated in
The first contact members 21 and second contact members 22, which have shoulder portions 21a, are retained inside the support 10 as a result of engaging these shoulder portions 21a with tapers 13a correspondingly provided in the support 10. Although the first contact members 21 and second contact members 22 may be completely secured within the support 10 with the help of these shoulder portions 21a, and the like, all or part thereof may be enabled for resilient expansion and contraction relative to the support 10 in order to facilitate and ensure contact with the test apparatus or the electronic device.
In order to enable resilient expansion and contraction, in the example of
In this manner, instead of providing resilient members, the first contact members themselves or the second contact members themselves may be used as resilient members. An example in which the second contact members themselves are used as resilient members is illustrated in
A conceptual view of a test probe with added insulation functionality or capacitor functionality is illustrated in
It should be noted that while the first contact members 210 and second contact members 220 in the example illustrated in
A support 100 used for test probes with an added insulating layer (2) is shown in more detail in
In the main body portion 101, three test probe elements are arranged in a mutually orthogonal relationship on the first face 110 and second face 120 of the support 10. On the other hand, in the piece 102, only one test probe element is provided on the first face 110 and second face 120 of the support 10. Through-holes 104, into which a set of the first contact members 21 and second contact members 22 can be mounted, are provided in these test probe elements constituting the main body portion 101 and the piece 102 such that there is one through-hole provided per element. When joined together, the main body portion 101 and the piece 102 produce a shape similar to that of the test probe 1B illustrated in
In order to form a capacitor, a holding space 103, which holds a capacitor component 4, such as a capacitor or the like, is provided in the main body portion 101. In addition, a cover 102b, which seals the top portion of the holding space 103 once joined together with the main body portion 101, is provided in the piece 102. Once the capacitor component 4 has been placed into a placement portion 103a of the holding space 103 and the top has been sealed by the cover 102b, the capacitor component 4, while being held in the holding space 103, comes into contact with both the main body portion 101 and the cover 102b, thereby capacitively coupling the main body portion 101 and the piece 102.
A variation 200 of the support illustrated in
An exemplary method for arranging test probes in the test socket 5 shown in
Furthermore, an exemplary method for arranging test probes in the test socket 5 that makes it possible to achieve a reduction in crosstalk is shown in plan view in
Many modifications or other embodiments of the present invention will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description, and it will be apparent to those skilled in the art that variations and modifications of the present invention can be made without departing from the scope or spirit of the present invention. Therefore, it is to be understood that the present invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.
1 Test probe
2 Additional layer (insulating layer, capacitor layer)
4 Capacitor component
5 Test socket
10 Support
11 First face
12 Second face
13 Through-hole
13
a Taper
14 Cylindrical space
21 First contact member
22 Second contact member
31 Coil spring
32 Coil spring
40 Insulating member
51 Base
Number | Date | Country | Kind |
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2022-072106 | Apr 2022 | JP | national |