Patent Application
20140327462
Electrical devices are generally tested for manufacturing defects before they are put into commercial circulation. Such testing may be performed by connecting the devices to a test instrument using a test socket having probes such as pogo pins.
Referring to
In general, a handler having a driving unit such as stepping motor is utilized to move DUT 20 toward pogo pins 12. DUT 20, however, may be susceptible to mechanical disturbances such as vibrations or shock caused by the driving unit. The mechanical disturbances may cause a contact failure between pogo pins 12 and DUT 20 where DUT 20 is brought into contact with pogo pins 12. For example, DUT 20 may be tilted from a desired position 30 as illustrated in
In view of the above and other shortcomings of conventional test sockets, there is a general need for test sockets having a reduced likelihood of contact failures between pogo pins and a DUT.
In a representative embodiment, a test socket for electrically connecting a DUT to an electrical signal source comprises a plurality of pogo pins spaced apart from each other, a stabilizing plate supporting the plurality of pogo pins, a plurality of conductive lines passing through the stabilizing plate and configured to electrically connect the electrical signal source to the pogo pins, and at least one inner stabilizer disposed in the stabilizing plate between the conductive lines and configured to apply an elastic force toward the DUT where the DUT is brought into contact with the pogo pins. In certain embodiments, the test socket further comprises a guide disposed on the stabilizing plate around the pogo pins and configured to guide the DUT toward the pogo pins. The guide is typically a metal guide having a height greater than or equal to a sum of a height of the DUT and a height of the pogo pins. In certain embodiments, the electrical signal source is configured to transmit an RF signal to the DUT through the conductive lines and the pogo pins.
In certain embodiments, the test socket further comprises an outer stabilizer disposed in the stabilizing plate outside the conductive lines. A width of the outer stabilizer is typically greater than or equal to a width of the inner stabilizer.
In certain embodiments, the test socket further comprises an additional stabilizing plate disposed below the stabilizing plate, wherein the plurality of conductive lines pass through the additional stabilizing plate, and an internal stabilizer disposed in the additional stabilizing plate between the conductive lines and configured to apply an elastic force toward the DUT where the DUT is brought into contact with the pogo pins. An external stabilizer may be disposed in the additional stabilizing plate outside the conductive lines.
In certain embodiments, the test socket further comprises a socket housing comprising a radio frequency (RF) port for transmitting an electrical signal from the electrical signal source to the pogo pins, a base substrate disposed between the stabilizing plate and the RF port, and a plurality of RF cables disposed in the base substrate and configured to connect the RF port to the conductive lines of the stabilizing plate. The socket housing may further comprise a wall disposed on the base substrate to cover outer surfaces of the stabilizing plate and a guide formed around the pogo pins.
In another representative embodiment, a test system comprises a test instrument configured to generate test signals to be applied to a DUT, and a test socket configured to connect the test instrument to the DUT, and comprising a plurality of pogo pins spaced apart from each other, a stabilizing plate supporting the plurality of pogo pins, a plurality of conductive lines passing through the stabilizing plate and configured to electrically connect the test instrument to the pogo pins, and at least one inner stabilizer disposed in the stabilizing plate between the conductive lines and configured to apply an elastic force toward the DUT where the DUT is brought into contact with the pogo pins.
The present teachings are best understood from the following detailed description when read with the accompanying drawing figures. The features are not necessarily drawn to scale. Wherever practical, like reference numerals refer to like features.
In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth in order to provide a thorough understanding of the present teachings. However, it will be apparent to one having ordinary skill in the art having the benefit of the present disclosure that other embodiments according to the present teachings that depart from the specific details disclosed herein remain within the scope of the appended claims. Moreover, descriptions of well-known apparatuses and methods may be omitted so as to not obscure the description of the example embodiments. Such methods and apparatuses are clearly within the scope of the present teachings.
The terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. The defined terms are in addition to the technical, scientific, or ordinary meanings of the defined terms as commonly understood and accepted in the relevant context.
The terms ‘a’, ‘an’ and ‘the’ include both singular and plural referents, unless the context clearly dictates otherwise. Thus, for example, ‘a device’ includes one device and plural devices. The terms ‘substantial’ or ‘substantially’ mean to within acceptable limits or degree. The term ‘approximately’ means to within an acceptable limit or amount to one of ordinary skill in the art. Relative terms, such as “above,” “on”, “below,” “under”, etc., may be used to describe the various elements' relationships to one another, as illustrated in the accompanying drawings. These relative terms are intended to encompass different orientations of the device and/or elements in addition to the orientation depicted in the drawings. For example, if a device were inverted with respect to the view in the drawings, an element described as “above” another element, for example, would now be below that element. Other relative terms may also be used to indicate the relative location of certain features along a path such as a signal path. For instance, a second feature may be deemed to “follow” a first feature along a signal path if a signal transmitted along the path reaches the second feature before the second feature.
Referring to
Pogo pins 110 each have substantially the same height and are disposed on a top surface of stabilizing plate 120. Additionally, pogo pins 110 are spaced apart from each other as a plurality of contact terminals 22 are spaced apart from each other. Where DUT 20 is brought into contact with pogo pins 110, pogo pins 110 touch contact terminals 22.
Stabilizing plate 120 comprises a plurality of conductive lines 121 and an inner stabilizer 122 disposed between conductive lines 121. The electrical signal source is electrically connected to pogo pins 110 through conductive lines 121. Inner stabilizer 122 applies an elastic force toward DUT 20, i.e. upward where DUT 20 is brought down into contact with pogo pins 110. That is to say, inner stabilizer 122 is configured to absorb an impact that occurs where DUT 20 is pressed downward. Thus, although DUT 20 is tilted at a specific slope where DUT 20 moves downward to pogo pins 110. DUT 20 may become parallel as stabilizing plate 120 applies the elastic force to DUT 20 to thereby suppress a contact failure between DUT 20 and pogo pins 110.
In some embodiments, stabilizing plate 120 comprises an outer stabilizer 123 disposed outside conductive lines 121. A width of outer stabilizer 123 is typically greater than or equal to a width of inner stabilizer 122.
Inner and outer stabilizer 122 and 123 may be made of an elastic material. For instance, inner and outer stabilizer 122 and 123 is made of silicon (Si), or inner and outer stabilizer 122 and 123 is an air stabilizer. Furthermore, a spiral groove may be formed along an outer surface of inner and outer stabilizer 122 and 123. Owing to the spiral groove, inner and outer stabilizer 122 and 123 may absorb external impacts and apply the elastic force outwardly.
Metal guide 130 is disposed on stabilizing plate 120 and surrounds pogo pins 110. Metal guide 130 guides DUT 20 to an inside of metal guide 130 where DUT 20 is brought in contact with pogo pins 110. In some embodiments, a height of metal guide 130 is greater than or equal to a sum of a height of DUT 20 and a height of pogo pins 110 to guide DUT 20 more effectively. In some embodiments, the metal guide is made of copper (Cu).
Base substrate 150 is disposed between stabilizing plate 120 and RF port 160. PCB 152 of base substrate 150 comprises a plurality of cables 156 for electrically connecting RF port 160 to conductive lines 121 of stabilizing plate 120. Contact body 154 of base substrate 150 is disposed on a top surface of PCB 152, and it is fastened to PCB 152 by at least one fastening element 158. Furthermore, contact body 154 acts as a connection medium between stabilizing plate 120 and PCB 152.
RF port 160 is disposed below PCB 152 and is configured to transmit an electrical signal from the electrical signal source to pogo pins 110.
Wall 170 is disposed on base substrate 150, and it covers outer surfaces of stabilizing plate 120 and metal guide 130. In some embodiments, wall 170 is made of gold (Au).
In various alternative embodiments, stabilizing plate 120 and additional stabilizing plate 125 have the same or different heights. In general, the height of each of stabilizing plate 120 and additional stabilizing plate 125 may be determined based on yield rates of DUT 20.
Stabilizing plate 120 and additional stabilizing plate 125 are typically formed by laying conductive lines 121 on top of conductive lines 126 and inner and outer stabilizer 122 and 123 on top of internal and external stabilizer 127 and 128 in a vertical direction, respectively. Furthermore, pogo pins 110 may be disposed on the top surface of conductive lines 121.
Test socket 100 may be used for a test instrument to test a large number of PCBs with improved test results. It may potentially reduce the number of situations where a PCB that is not actually defective is classified as a defective product in a test due to a contact failure. Further, test socket 100 may change the relative orientation of DUT 20 from tilted to parallel by employing stabilizers 122, 123, 127 and 128 in stabilizing plates 120 and 125. Furthermore, test socket 100 can potentially reduce contact failure between contact terminals 22 of the DUT and pogo pins 110 by employing metal guide 130.
Referring to
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Because the unit of the isolation value is −dB, the lower the value, the better the isolation performance. Curve A for a test socket 100 indicates higher isolation performance than curve B for the conventional test socket.
Referring to
As illustrated by
As indicated by the foregoing, a test socket in accordance with various representative embodiments may be used for an apparatus for testing a large number of PCBs, acquiring relatively accurate test results, and reducing a problem where a PCB that is actually not defective is determined to be defective during a test due to a contact failure. Such test sockets may be capable of changing the relative orientation of a DUT from tilted to parallel to pogo pins or the ground by employing stabilizers in stabilizing plates. Furthermore, such test sockets may be capable of reducing contact failures between the contact terminals of the DUT and the pogo pins using the metal guide.
While example embodiments are disclosed herein, one of ordinary skill in the art appreciates that many variations that are in accordance with the present teachings are possible and remain within the scope of the appended claims. The embodiments therefore are not to be restricted except within the scope of the appended claims.
