BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side cross-sectional view illustrating a portion of a burn-in board in accordance with the prior art.
FIG. 2 is an isometric view of a portion of a testing apparatus with a detachable electronic component in accordance with an embodiment of the invention.
FIG. 3 is a cross-sectional view of a portion of the testing apparatus and the detachable electronic component shown in FIG. 2 taken along line 3-3.
FIG. 4A is an isometric view of a detachable electronic component in accordance with an embodiment of the invention.
FIG. 4B is a front elevational view of a portion of the detachable electronic component shown in FIG. 4A.
FIG. 5 is an isometric view illustrating the operation of the testing apparatus and the detachable electronic component in accordance with an embodiment of the invention.
FIG. 6 is a side schematic view illustrating a detachable electronic component in accordance with another embodiment of the invention.
FIG. 7 is an isometric view illustrating a detachable electronic component in accordance with another embodiment of the invention.
DETAILED DESCRIPTION
A. Overview
The present disclosure is directed toward an apparatus for testing microelectronic devices, methods for testing microelectronic devices, and detachable electronic components. One embodiment of the invention is an apparatus for testing microelectronic devices. A specific embodiment of such an apparatus for testing microelectronic devices in accordance with the invention comprises a board having a primary side, a secondary side, a plurality of test sites at the primary side, and electrical lines electrically coupled to the test sites. The testing apparatus can further include a plurality of lead holes in the board. Individual lead holes have a sidewall and a conductive section plated onto the sidewall. In several embodiments, individual pairs of first and second lead holes are electrically coupled to electrical lines corresponding to an associated test site. The apparatus can further include a plurality of permanent fuses fixed to the board. Individual permanent fuses are electrically coupled to electrical lines associated with an individual test site and an individual pair of first and second lead holes. The testing apparatus can further include a replacement fuse mounted to an individual pair of first and second lead holes at a test site having a blown permanent fuse. The replacement fuse has a first lead with a press-fit member engaged directly with the plated section in the first lead hole. The replacement fuse further includes a second lead engaged with the second lead hole and a fuse element connected in series with the first and second leads.
Another embodiment of the invention is a detachable electronic component for use in a board having a lead hole with a sidewall and a conductive section plated onto the sidewall. A specific embodiment of such a detachable electronic component comprises a first lead, a press-fit member at an end of the first lead, and a second lead. The press-fit member has a distal tip configured to pass into the lead hole and a contact section configured to engage the conductive section on the sidewall of the lead hole. The contact section is further configured to exert an outward force against the conductive section. The electrical component further includes an electrical element having a first contact connected to the first lead and a second contact connected to the second lead such that the electrical component is connected in series with the first and second leads. The detachable electrical component further includes a handle fixed to at least one of the first and second leads.
Another embodiment of the invention is directed toward a fuse for use in a test board having a lead hole with a sidewall and a conductive section on the sidewall. In this embodiment, the fuse includes a first lead, a press-fit member at an end of the first lead, and a second lead. The press-fit member has a distal tip configured to pass into the lead hole and a contact section configured to engage the conductive section on the sidewall such that the contact section exerts an outward force against the conductive section. The fuse further includes a chip-fuse element having a first contact connected to the first lead and a second contact connected to the second lead such that the chip-fuse element is connected in series with the first and second leads. The fuse further includes a handle fixed to at least one of the first and second leads.
Another embodiment of the invention is directed toward a method for repairing a test site on a test board in the testing of microelectronic devices. One specific embodiment of such a method comprises identifying a test site on the test board having a faulty permanent fuse and providing a detachable replacement fuse. The detachable replacement fuse has a first lead, a press-fit member at one end of the first lead, a second lead, and a fuse element connected in series with the first and second leads. The method further comprises inserting the press-fit member into a first hole in the test board such that the first press-fit member directly engages a plated section in the first hole. The method further includes inserting the second lead into a second hole in the test board. The first and second holes are electrically connected to the test site such that the replacement fuse operates in the place of the faulty permanent fuse.
Another embodiment of a method for repairing a test site comprises locating a test site having a socket with contact pins, a first lead hole having a first sidewall with a first plated section on the first sidewall, a second lead hole having a second sidewall with a second plated section on the second sidewall, and a permanent fuse that has blown. The method further includes attaching a replacement fuse to the test site by inserting a first press-fit member into the first hole and a second press-fit member into the second hole. The first press-fit member exerts an outward force directly against the first plated section, and the second press-fit member exerts an outward force directly against the second plated section. The first press-fit member is attached to the first lead of the replacement fuse, and the second press-fit member is attached to the second lead of the replacement fuse.
Another embodiment of the invention is directed toward methods for testing microelectronic components. One specific embodiment of such a method comprises locating a test site having a socket with contact pins, a first lead hole having a first sidewall with a first plated section on the first sidewall, a second lead hole having a second sidewall with a second plated section on the second sidewall, and a permanent fuse that has blown. The method further includes attaching a replacement fuse to the test site by inserting a first press-fit member into the first hole and inserting a second press-fit member into the second hole. The first press-fit member exerts an outward force directly against the first plated section, and the second press-fit member exerts an outward force directly against the second plated section. The first press-fit member is fixed to a first lead of the replacement fuse, and the second press-fit member is fixed to a second lead of the replacement fuse. This method further includes placing a microelectronic device into the socket at the test site, and applying input signals and receiving output signals via the contact pins after attaching the replacement fuse to this test site.
Specific details of several embodiments are described below with reference to burn-in boards with replacement fuses for testing semiconductor devices or other types of microelectronic devices. However, other embodiments can include other types of printed circuit boards with active or passive electronic components that are press-fit onto the boards. Several details describing well known structures or processes often associated with testing or fabricating microelectronic devices are not described herein for purposes of brevity. Also, several of the embodiments can have different configurations, components, or procedures than those described in this section. A person of ordinary skill in the art, therefore, will accordingly understand that the invention may have other embodiments with additional elements, or that the invention may have other embodiments without several of the features and elements shown and described below with reference to FIGS. 2-6.
B. Embodiments of Testing Apparatus and Detachable Electronic Components
FIG. 2 is an isometric view of a testing apparatus 100 in accordance with an embodiment of the invention, and FIG. 3 is a cross-sectional view of a portion of the testing apparatus 100 taken along line 3-3 shown in FIG. 2. Several features of the testing apparatus 100 are shown schematically in FIGS. 2 and 3. The testing apparatus 100 includes a test board 110 having a primary side 112, a secondary side 114, and a plurality of test sites 113 (only one test site is shown in FIG. 3). In the illustrated embodiment shown in FIGS. 2 and 3, the testing apparatus 100 includes a plurality of sockets 115 attached to the test board 110 at corresponding test sites 113. The sockets 115 can be configured to receive packaged microelectronic devices, bare dies, or other types of microdevices for burn-in testing or other types of testing. Suitable sockets are shown and described in U.S. Publication No. 2005/0134299, which is incorporated herein by reference. The test board 110 further includes electrical lines 116 (shown schematically) electrically coupled to the test sites 113. The electrical lines 116 can be located throughout the test board 110, but several of the electrical lines 116 are located in routing lanes 117 (shown in broken lines) between the test sites 113.
Referring to FIG. 3, the board 110 further includes a plurality of lead holes 120. The lead holes 120 can be through holes that pass completely through the board 110 such that they extend from the primary side 112 to the secondary side 114. Individual lead holes 120 have a sidewall 122 and a conductive section 124 on the sidewall 122. The conductive sections 124 can be plated copper or other metals deposited onto the sidewalls 122 such that the conductive sections 124 are integral with the board 110. The conductive sections 124 are electrically coupled to electrical lines 116a that are routed to a specific test site 113 through the board 110. The electrical lines 116a can be a subset of the electrical lines 116 described above with reference to FIG. 2.
The testing apparatus 100 further includes a plurality of permanent fuses 130 (only one shown in FIG. 3) fixed to the test board 110. In the illustrated example, the permanent fuses 130 are surface-mount chip-fuses fixed to the secondary side 114 of the test board 110. Individual permanent fuses 130 include first contacts 132 and 134 coupled to electrical lines associated with a specific test site and a specific pair of lead holes 120. As shown in FIG. 3, for example, the permanent fuse 130 is electrically coupled to the electrical lines 116a associated with the specific test site 113 and pair of lead holes 120. As a result, if the permanent fuse 130 blows, a replacement fuse can be inserted into the corresponding lead holes 120 to repair the associated test site 113.
FIG. 4A is an isometric view of a replacement fuse 140 for use with the test board 110 in accordance with an embodiment of the testing apparatus 100. The replacement fuse 140 is one example of a detachable electronic component. The embodiment of the replacement fuse 140 illustrated in FIG. 4A includes a first lead 142 having a first press-fit member 150 and a second lead 144 having a second press-fit member 150. The press-fit members 150 can be identical to each other, but the first press-fit member can be different than the second press-fit member depending upon the particular test board 110. The press-fit members 150 are fixed with respect to the first and second leads 142 and 144. For example, the press-fit members 150 can be integral with the first and second leads 142 and 144. In one specific embodiment, the first lead 142, the second lead 144, and the press-fit members 150 are stamped from a thin sheet of conductive material. In other embodiments, the first and second leads 142 and 144 can be wires or other conductive members, and the press-fit members 150 can be separately fixed relative to the first and second leads 142 and 144 using a solder or other type of fixed attachment. As explained below, the press-fit members 150 are configured to pass into the lead holes in the test board and engage the conductive sections on the sidewalls to electrically and mechanically attach the replacement fuse 140 to a test site having a blown permanent fuse.
FIG. 4B illustrates an embodiment of the press-fit member 150 in more detail. In this embodiment, the press-fit member 150 includes a distal tip 152 having a dimension less than a lateral dimension of a lead hole in which the press-fit member 150 is to be inserted. The press-fit member 150 further includes a contact section 153 having a dimension larger than the lateral dimension of such a lead hole. The press-fit member 150 can include an opening 154 to allow the contact section 153 to deform or otherwise flex inwardly as the press-fit member 150 moves into a lead hole. For example, the contact sections 153 can flex inwardly from a first dimension D1 to a second dimension D2. As a result, the contact sections 153 of the press-fit members 150 can be flexible members that exert an outward force in two or more directions against the lead holes. The press-fit member 150 can further include a flange 156 having a stop surface 157 to limit the insertion of the distal tip into a lead hole and a drive surface 158 configured to be engaged by an insertion tool as explained in more detail below.
Referring back to FIG. 4A, the replacement fuse 140 further includes a fuse element 160 having a first contact 162 and a second contact 164. The first contact 162 can be attached to the first lead 142, and the second contact 164 can be attached to the second lead 144 such that the fuse element 160 is connected in series with the first lead 142 and the second lead 144. The fuse element 160 can be a chip-fuse having properties that are identical, or at least substantially similar, to the electrical properties of the permanent fuse 130 for the corresponding test site 113. In other embodiments, the fuse element 160 may be a conventional fuse.
FIGS. 2 and 3 illustrate an embodiment of the testing apparatus 100 with a replacement fuse 140 installed at the test site 113. In this example, the press-fit members 150 (FIG. 3) are inserted into the lead holes 120 such that the press-fit members 150 exert an outward force against the conductive sections 124 (FIG. 3). The friction between the press-fit members 150 and the conductive sections 124 secures the replacement fuse 140 to the test board 110 and electrically connects the leads 142 and 144 to the conductive sections 124. As such, the replacement fuse 140 is electrically coupled to the electrical lines 116a to replace the permanent fuse 130. It will be appreciated that the replacement fuse 140 is usually attached to the test board 110 only in the event that the permanent fuse 130 has blown.
The replacement fuse 140 can reside above the routing lanes 117 between adjacent sockets 115 as long as necessary. If the replacement fuse 140 blows to protect the corresponding socket 115, another replacement fuse 140 can be inserted into the lead holes 120 to repair the test site 113. More specifically, the replacement fuse 140 can further include a handle 170 for extracting the replacement fuse 140. The handle 170 can be a cross-bar, such as a portion of the second lead 144. The illustrated embodiment of the handle 170 includes an opening 172 for receiving an extraction tool (not shown). The handle 170 can be formed integrally with the first lead 142 and/or the second lead 144 as shown in FIG. 3, or the handle 170 can be a separate component attached to one or both of the leads. To extract a blown replacement fuse 140, a projection of an extraction tool can be inserted into the opening 172 of the handle 170, and then an upward force can be exerted against the handle 170 to extract the replacement fuse 140.
FIG. 5 is an isometric view illustrating an embodiment of an insertion tool 180 for attaching the replacement fuse 140 to the test board 110. The replacement tool 180 has a guide surface 182 configured to closely engage the outer surfaces of the adjacent sockets 115 in a manner that aligns the first and second leads 142 and 144 with corresponding lead holes 120 in the test board 110. The alignment tool 180 further includes drive elements 184 configured to engage the drive surfaces 158 of the flanges 156. In operation, the insertion tool 180 moves downwardly between adjacent sockets 115 as the guide surfaces 182 align the press-fit members 150 (best shown in FIG. 3) with the lead holes 120. The drive elements 184 exert a drive force against the drive surface 158 until the stop surface 157 engages the primary side 112 of the test board 114. The insertion tool 180 is then withdrawn from between the sockets 115 to leave the replacement fuse 140 electrically and mechanically coupled to the lead holes 120.
Several embodiments of the test board 110 and the replacement fuse 140 eliminate the need for the fuse sockets to be inserted into the lead holes of the test board. More specifically, because the press-fit elements 150 mechanically and electrically couple the first and second leads 142 and 144 directly to the lead holes 120, it is not necessary to insert and solder separate test sockets into the lead holes. Such embodiments can save a significant amount of time in assembling the test board and eliminates the cost of the test sockets. Several embodiments of the test board 110 and the replacement fuse 140 are accordingly expected to reduce the costs of assembling test boards. Additionally, eliminating the conventional fuse sockets for axial-type replacement fuses allows the lead holes to be smaller. This reduces the real estate occupied by the lead holes so that more electrical lines can be located in the routing lanes 117 to accommodate high performance devices without adding more layers to the boards.
Many embodiments of the replacement fuse 140 can also have a chip-fuse element that is identical, or at least substantially similar, to the chip-type permanent fuse surface mounted to the secondary side of the board. As a result, the electrical properties of the repaired sites do not change after a permanent fuse has blown. This is expected to enhance the accuracy and increase the ease with which test sites are repaired.
C. Additional Embodiments of Detachable Electronic Devices
FIG. 6 is a side schematic view of a detachable electronic component 200 in accordance with another embodiment of the invention. The detachable electronic component 200 includes a first lead 202 having a first press-fit element 203 and a second lead 204 having a second press-fit element 203. The device 200 further includes an electrical element 210 and a handle 220 having an opening 221 for receiving a portion of an extraction tool as described above. The electrical element 210 can be a capacitor, resistor, memory chip, sensor, or other type of electrical device. The electrical component 210 may be optional such that the first lead 202 is directly connected to the second lead 204 across the handle 220 to provide a jumper link. The press-fit elements 203 can have a distal tip 230 configured to fit into a lead hole and a contact section 232 configured to engage a sidewall of a lead hole as described above with reference to the press-fit elements 150. In operation, therefore, the detachable electronic component 200 can be any suitable electronic component for detachable insertion into a test board or other type of electrical device.
FIG. 7 is an isometric view illustrating another embodiment of an electronic component 300. In this embodiment, the electronic component has a detachable fuse 140 as described above and a casing 310 around a portion of the fuse 140. The casing 310 can be a dielectric material that is molded around the fuse 140, or the casing 310 can be a dielectric housing to which the fuse 140 is attached. The casing 310, for example, can be formed by injection molding a thermoplastic compound around the fuse element, a portion of the first lead, and a portion of the second lead. The press-fit members 150 of the first and/or second leads are generally not covered by the casing 310 so that they can be electrically coupled to lead holes in the board 110. In the embodiment shown in FIG. 7, the casing 310 has guide surfaces 312 configured to guide the press-fit members 150 into corresponding lead holes and a handle 314 configured to be engaged by a removal tool. The handle 314, for example, can be (a) a loop or hole in the casing, (b) a projection extending from the casing, and/or (c) a recess in the casing. In operation, the guide surfaces 312 slide along corresponding surfaces of adjacent sockets 115 to align the press-fit members 150 with corresponding lead holes for installation. To remove the electronic component 300, a curved pick, pliers, or other existing tools can be used to grip the handle 314 and extract the component 300 from between the sockets 115. Embodiments of the electronic component 300 can accordingly be installed and extracted without specialized tools.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, although the foregoing embodiments are described with respect to burn-in boards, other embodiments can include other types of printed circuit boards with detachable press-fit electronic components. Accordingly, the invention is not limited except as by the appended claims.
Patent Application
20080048704
