Burn-in board, and burn-in equipment

Abstract

To provide a burn-in board capable of achieving uniform temperature within the surface, and a piece of burn-in apparatus.SOLUTION: A disclosed burn-in board 100 includes: a board body 110; multiple sockets 130 arranged in a matrix direction on the surface of the board body 110; multiple lamellar heat conduction members 140 arranged in the Y-direction gap among the multiple sockets 130; and an adapter 150 that fixes the end of the heat conduction member 140. The heat conduction member 140 has a vapor chamber structure with a high thermal conductivity and thermal diffusion so that the temperature is made uniform across the burn-in board 100.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a burn-in board and a burn-in device for burn-in testing (testing) electronic components such as semiconductor devices.

Background Art

[0002] Burn-in testing is widely performed on semiconductor devices. The burn-in test enables, for example, operating a semiconductor device in an oven at a high temperature of 85 to 150 degrees and discriminating an initially defective or failed semiconductor device.

[0003] The burn-in device includes an oven or a chamber that houses a plurality of burn-in boards. On the burn-in board, a plurality of sockets arranged in a matrix are mounted, and a semiconductor device is mounted on each of the plurality of sockets. The plurality of lead terminals of the socket are electrically connected to a wiring layer on the burn-in board respectively. At the end of the burn-in board, edge terminals connected to the terminals on the burn-in device side are formed, and the semiconductor device is operated by the power and test signals supplied from the burn-in device via the edge terminals.

[0004] For example, in the burn-in device of Patent Document 1, the socket is provided with a heat sink that contacts the semiconductor device, and a rectifying plate having an opening corresponding to the heat sink is provided on the burn-in board to suppress the turbulent flow of the hot air from the fan and achieve uniform temperature of the semiconductor device. The burn-in device of Patent Document 2 includes a temperature adjustment head that can directly contact individual semiconductor devices on the burn-in board, suppresses the variation in self-heating of individual semiconductor devices, and achieves uniform temperature among the semiconductor devices. The burn-in device of Patent Document 3 is provided with a heat conduction sheet and a heat conduction plate on the surface of the burn-in board opposite to the surface on which the socket is mounted to achieve uniform temperature distribution within the burn-in board.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2005-337835 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2008-128839 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2020-118475 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] FIG. 1 is a schematic plan view showing a configuration example of a burn-in board, and FIG. 2 is a diagram for explaining a schematic configuration of a burn-in apparatus. The burn-in board 10 has a board body 20 having a substantially rectangular shape. A gripping portion 30 is provided at one end thereof, and an edge terminal 40 is provided at the other end thereof. The board body 20 is a circuit board, and a plurality of sockets 50 arranged in a matrix are mounted on its surface. The lead terminals of the mounted sockets 50 are electrically connected to the edge terminal 40 via a wiring layer on the circuit board.

[0007] The burn-in apparatus 60 has an oven (or chamber) 70. For example, a plurality of slots 80 are formed in the vertical direction in the oven 70, and the burn-in board 10 is accommodated in each slot 80. The edge terminal 40 of the burn-in board 10 accommodated in the oven 70 is connected to a terminal on the burn-in apparatus 60 side.

[0008] FIG. 3 is a diagram schematically showing the flow of heated air in the oven. FIG. 3(A) is a plan view thereof, and FIG. 3(B) is a side view thereof. The burn-in device includes a fan inside, and the fan feeds the heated air AF from the supply port of the oven from one longitudinal end 12 of the burn-in board 10 toward the other end 14. The interval S between the vertically aligned burn-in boards 10 is, for example, about 6 to 10 mm, and the fed air AF heats the sockets and semiconductor devices on the burn-in board 10 while passing through the gap S between the burn-in boards. The air AF that has passed through the end 14 of the burn-in board 10 is recovered from the discharge port of the oven.

[0009] FIG. 4 is a diagram for explaining the problems of a conventional burn-in board. As shown in the figure, the planar shape of the burn-in board 10 is, for example, 550 mm × 450 mm, and on the burn-in board 10, sockets 50 having a substantially rectangular parallelepiped shape of 26 mm × 26 mm are mounted, for example, in 14 rows × 16 columns, and semiconductor devices are mounted on each socket 50. The sockets 50 are arranged with a gap of about 2 mm from the adjacent sockets 50 in the row direction and the column direction.

[0010] The hot air AF fed from the fan has poor drainage due to the very narrow interval between the burn-in boards 10. As a result, the air AF heat-exchanged upstream stays downstream, locally generating a high-temperature region R on the burn-in board 10, and the in-plane temperature on the burn-in board, that is, the temperature of each semiconductor device becomes non-uniform. In addition, the semiconductor device mounted on the socket 50 generates self-heat (for example, 1 to 3 W) during the test and can be a heat source by itself. Therefore, if there is variation in the semiconductor devices, this variation in the heat source promotes the non-uniformity of the in-plane temperature. When the in-plane temperature of the burn-in board becomes non-uniform, variation occurs in the temperature load applied to the semiconductor device, and the accuracy of the burn-in test deteriorates.

[0011] An object of the present invention is to provide a burn-in board and a burn-in device that solve the above-described conventional problems and achieve uniform in-plane temperature.

Means for Solving the Problem

[0012] The burn-in board for burn-in test according to the present invention includes a plurality of sockets having a generally rectangular outer shape arranged in a matrix, and a plate-like heat conduction member extending at least partially in a plurality of gaps in the row direction or column direction of the plurality of sockets, and the heat conduction member has a structure including a vapor chamber.

[0013] In one aspect, the heat conduction member is arranged in a determined area of the plurality of gaps. In one aspect, the heat conduction part is arranged in each of the plurality of gaps. In one aspect, a highly thermally conductive joining member is interposed between the surface of the heat conduction member and the surface of the socket facing the surface. In one aspect, the burn-in board further includes a fixing member for fixing at least one end of the heat conduction member protruding from the gap of the socket, and the fixing member has a fitting portion corresponding to the arrangement pitch of the plurality of heat conduction members. In one aspect, the thickness of the heat conduction member is equal to or slightly smaller than the gap of the socket. In one aspect, the vapor chamber contains a refrigerant capable of heat exchange in a sealed chamber. In one aspect, the vapor chamber structure includes a metal top cover, a pair of upper and lower mesh-like wicks, a plurality of posts arranged between the pair of upper and lower wicks, and a metal bottom cover, and the chamber is formed by joining the top cover and the bottom cover, and the wick, the post, and the refrigerant are accommodated in the chamber.

[0014] The burn-in device according to the present invention includes a plurality of burn-in boards and an oven for accommodating the plurality of burn-in boards, and each of the plurality of burn-in boards includes a plurality of sockets having a generally rectangular outer shape arranged in a matrix, and a plate-like heat conduction member extending at least partially in a plurality of gaps in the row direction or column direction of the plurality of sockets, and the heat conduction member has a structure including a vapor chamber. In one aspect, the burn-in device further includes a fan for sending hot air in the direction in which the heat conduction member extends. [Advantages of the Invention]

[0015] According to the present invention, since the heat conductive member is arranged in at least a part of a plurality of gaps in the row direction or the column direction of the socket, it is possible to equalize the in-plane temperature of the burn-in board. [Brief Description of the Drawings]

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention is applied to a burn-in board and a burn-in apparatus using the same. The burn-in apparatus includes an oven or a chamber and heats the burn-in board in the oven, but the heating method is not particularly limited. For example, air is heated using a heater or other heat source, and the heated air is supplied from the supply port of the oven using a blower device such as a fan, and the air used for heating is discharged from the discharge port of the oven. It should be noted that the drawings referred to in the following description are exaggerated for easy understanding of the invention and do not necessarily represent the scale of an actual product.

EXAMPLE

[0018] Next, an example of the present invention will be described. FIG. 5 is a perspective view showing the configuration of the burn-in board according to the example of the present invention, FIG. 6(A) is a perspective view of a heat conduction member having a vapor chamber structure, and FIG. 6(B) is an enlarged view of a part of FIG. 5.

[0019] The burn-in board 100 of the present embodiment includes a board body 110 having a substantially rectangular main surface, a plurality of sockets 130 mounted on the surface of the board body 110, and a plurality of heat conduction members 140 disposed in the gaps in the row direction or column direction of the sockets 130.

[0020] The board body 110 is a circuit board composed of, for example, a glass epoxy resin laminated substrate on which a wiring layer such as copper is formed, although it is not particularly limited. Although not shown in detail here, the board body 110 may include a metal frame portion and a back plate that supports the frame portion on the back side of the circuit board. An edge terminal 120 is formed at one end in the short side direction of the board body 110, and a gripping portion 122 is formed at the other end. The edge terminal 120 is electrically connected to the wiring layer formed on the surface of the board body 110, and the edge terminal 120 is connected to the terminal on the burn-in device side when the burn-in board 100 is housed in the burn-in device.

[0021] In the area where the socket 130 of the board body 110 is to be mounted, conductive lands, connection pads, or through holes are formed, and the lead terminals of the socket 130 are connected to the conductive lands, connection pads, or through holes, for example, by solder. However, the method of mounting the socket on the board body 110 is not particularly limited. The socket 130 has a socket body generally in the shape of a rectangular parallelepiped, and the socket body has a planar size of 26 mm × 26 mm as shown in Fig. 4(B).

[0022] Inside the socket body, a plurality of contacts connected to the external terminals of the semiconductor device to be mounted are provided. The plurality of contacts project as lead terminals from the bottom surface of the socket body and are electrically connected to the conductive lands, connection pads, or through holes of the board body 110 as described above. The semiconductor device to be mounted may be a bare chip or a package such as BGA, LGA, TSOP, QFP, etc., and its configuration is not particularly limited. The semiconductor device mounted on the socket 130 is electrically connected to the edge terminal 120 via the wiring layer of the board body 110.

[0023] Socket 130 is mounted on the board body 110 in a matrix direction. In the example of FIG. 5, 16 sockets 130 are arranged in the X direction and 14 sockets 130 are arranged in the Y direction. Each socket is arranged with a certain gap (for example, about 2 mm) from the adjacent socket as shown in FIG. 4(B). A thin plate-like heat conduction member 140 is arranged between the sockets aligned in the Y direction (for example, column direction) and the adjacent sockets aligned in the Y direction. In other words, the heat conduction member 140 is arranged so as to extend from one end 112 in the longitudinal direction of the board body 110 to the other end 114. In a preferred embodiment, the heat conduction members 140 are arranged in the same direction as the direction in which hot air is sent by the fan. In the example shown here, since the heat conduction member 140 is arranged to extend in the Y direction, the fan sends the heated air in the Y direction.

[0024] One heat conduction member 140 has a generally thin plate-like rectangular shape having a length L, a height H, and a thickness W as shown in FIG. 6(A). The thickness W of the heat conduction member 140 is equal to or slightly smaller than the gap between the sockets. In a preferred embodiment, the surface of the heat conduction member 140 is in surface contact so as to be in close contact with the surface of the socket 130, and the heat conduction member 140 is thermally coupled to the socket 130.

[0025] The height H of the heat conduction member 140 is set to be equal to the upper surface of the socket 130, or slightly lower or slightly larger than the upper surface of the socket 130 when the heat conduction member 140 is arranged in the gap between the sockets. That is, the height H of the heat conduction member 140 is limited so that the amount protruding from the upper surface of the socket 130 is below a certain level in order not to increase the resistance and not to cause turbulent flow when the hot air sent from the fan passes through the surface of the board body 110.

[0026] The length L of the heat conduction member 140 is formed to be equal to or slightly smaller than the width in the short side direction (width in the Y direction) of the board body 110. When the width in the short side direction (width in the Y direction) of the board body 110 is relatively large, since the gap in the column direction of the sockets also becomes long, a plurality of heat conduction members may be arranged in the gap.

[0027] In a preferred embodiment, the heat conduction member 140 has a vapor chamber structure inside. The schematic configuration of the vapor chamber structure is shown in FIG. 7. The vapor chamber structure 200 includes a sealed chamber 210 made of a highly thermally conductive material such as copper, stainless steel, or titanium. The chamber 210 is filled with a refrigerant 220 for heat exchange. When the chamber 210 is thermally coupled to the heat source 230, the refrigerant 220 in the chamber 210 vaporizes by heat exchange with the heat source 230. The vaporized refrigerant 220 dissipates heat on the side of the heat dissipation fins 240 and liquefies again. The refrigerant 220 circulates in the chamber 210 so as to exchange heat with the heat source 230. Such a vapor chamber structure can quickly perform uniform heat diffusion in the planar direction more efficiently than a heat diffusion material such as a graphite type.

[0028] FIG. 8 shows an exploded perspective view of the vapor chamber structure. The vapor chamber structure 300 includes a top cover 310, a pair of upper and lower mesh-like wicks 320, a plurality of posts 330 disposed between the pair of upper and lower wicks 320, and a bottom cover 340. The top cover 310 is made of a material such as copper / copper alloy / stainless steel / titanium and is manufactured by stamping or etching. The wick 320 is manufactured by mesh / sintered powder / etching.

[0029] The post 330 is manufactured by sintered powder / stamp / etching and is fixed in an opening 322 formed in the pair of wicks 320. The bottom cover 340 is made of a material such as copper / copper alloy / stainless steel / titanium and is manufactured by stamping or etching. The bottom cover 340 is joined to the top cover 310 by diffusion bonding, brazing, or laser welding to form a sealed chamber. Further, a filling tube for filling the refrigerant can be attached to the bottom cover 340. Such a vapor chamber is configured to be thin with a thickness of about 2 mm.

[0030] Referring again to FIGS. 5 and 6. As described above, the heat conduction member 140 having the vapor chamber structure is disposed in the gap in the column direction of the socket 130. On the board body 110, a pair of adapters 150 for fixing the respective ends of the heat conduction member 140 are attached. The adapter 150 is a plate-like member extending in the X direction of the board body 110 and is made of, for example, a heat-resistant resin or the like. The pair of adapters 150 are attached to one end 112 side and the other end 114 side in the longitudinal direction of the board body 110. The method of attaching the adapter 150 to the board body 110 is arbitrary. For example, the adapter 150 can be fixed to the board body 110 using screws, or the convex portion provided on the adapter 150 can be fitted into the concave portion of the board body 110. The adapter 150 is formed with a notch 152 corresponding to the pitch in the X direction of the vapor chamber 300, and both ends of the vapor chamber 300 are fitted into the notch 152, and the vapor chamber 300 is fixed to the adapter 150.

[0031] When the number and size of the sockets mounted on the board body 110 are changed, the pitch of the vapor chamber 300 is changed. By preparing adapters 150 corresponding to a plurality of pitches, even if the pitch of the vapor chamber 300 changes, the vapor chamber 300 can be used as it is by simply replacing the adapter 150.

[0032] When the burn-in test is performed, the burn-in board configured as described above is housed in the oven of the burn-in apparatus as shown in FIG. 2. The fan in the burn-in apparatus sends the heated air into the oven to heat the individual semiconductor devices on the burn-in board. Further, the burn-in controller in the burn-in apparatus applies a test signal to the semiconductor device via the edge terminal and discriminates the semiconductor device with an initial defect based on the output result.

[0033] Next, with reference to FIGS. 9 to 11, simulation results by a thermal fluid analysis software when heating the burn-in board of this embodiment and a burn-in board of a comparative example having no vapor chamber structure will be described. In the experiment, a burn-in board with 14 sockets in the Y direction and 16 sockets in the X direction mounted therein was housed in an oven, the temperature in the oven was set to 85 degrees, and the semiconductor device mounted on the socket was set to self-heat at 1 W. Further, the length L of the vapor chamber structure in the Y direction disposed on the burn-in board was set to 430 mm, and the fan was configured to send air heated from the Y14 side toward the Y1 side.

[0034] FIG. 9(A) is a table showing the temperature of each socket of the burn-in board of the comparative example, and FIG. 9(B) is a table showing the temperature of each socket of the burn-in board of this embodiment. In the comparative example, the average temperature of the sockets was 128.7 degrees, the maximum temperature was 146.5 degrees, the minimum temperature was 97.6 degrees, and the standard deviation was 14.0. The maximum temperature was observed in the socket located at Y3:X13.

[0035] On the other hand, in this embodiment, the average temperature of the sockets was 127.9 degrees, the maximum temperature was 137.2 degrees, the minimum temperature was 110.0 degrees, and the standard deviation was 5.2. The maximum temperature was observed in the socket located at Y3:X9. Such results were almost the same within the range where the vapor chamber structure had a certain thermal conductivity.

[0036] FIG. 10(A) is a graph showing the temperature gradient of the comparative example, and FIG. 10(B) is a graph showing the temperature gradient of this embodiment. It can also be seen from these figures that the temperature gradient of the burn-in board of this embodiment is smaller than the temperature gradient of the burn-in board of the comparative example.

[0037] FIG. 11(A) is a diagram schematically showing a local high-temperature region generated in the burn-in board of the comparative example, and FIG. 11(B) is a diagram schematically showing the temperature distribution of the burn-in board of the present embodiment, where the darker part indicates a higher temperature. In the comparative example, it can be seen that a high-temperature region is generated on the leeward side where the heated air stays. On the other hand, in the present embodiment, it can be seen that no high-temperature region is generated on the leeward side due to the vapor chamber structure.

[0038] Thus, according to the present embodiment, by arranging a heat conduction member having a vapor chamber structure so as to extend in the gap in the row direction or column direction of the socket, the sockets are thermally coupled to each other via the heat conduction member, heat conduction or heat diffusion between the sockets is promoted, and the in-plane temperature of the burn-in board can be made uniform. Thereby, the temperature variation of each semiconductor device is suppressed, and the deterioration of the accuracy of the burn-in test is prevented.

[0039] Next, a modified example of the present embodiment will be described. In the above embodiment, the heat conduction members are arranged in all the gaps in the Y direction of the socket, but the present invention is not limited to this, and the heat conduction members may be arranged in some of the gaps. As shown in FIG. 11(A), since the local high-temperature region is generated on the leeward side, the heat conduction members can be arranged only in the leeward region. For example, in the range from X3 to X14, the heat conduction members are arranged in the gaps in the Y direction. Further, the length L of the heat conduction member does not necessarily extend from Y0 to Y14, and for example, it may extend from Y0 to Y5.

[0040] Also, in order to improve the thermal coupling between the heat conduction member 140 and the socket 130, the socket body may be made of a resin having high thermal conductivity. Thereby, the heat conduction or heat transfer between the socket and the heat conduction member is improved.

[0041] Furthermore, a TIM (Thermal Interface Material) may be interposed between the surface of the heat conduction member 140 and the surface of the socket 130 facing the surface. The TIM is a joint member made of a heat conductive material, and is, for example, a heat conduction sheet, a heat dissipation sheet, or the like. Gaps may occur due to minute irregularities on the surfaces of the heat conduction member 140 and the socket 130 or manufacturing variations. Since air has very high heat insulation (low thermal conductivity), the heat transfer efficiency decreases. Therefore, by inserting a heat conduction sheet or a heat dissipation sheet between the heat conduction member 140 and the socket 130, an air layer is prevented from being generated, thereby improving the thermal coupling between the heat conduction member 140 and the socket 130 and increasing the heat transfer efficiency.

[0042] Furthermore, by connecting the adapter 150 to the board body 110 of the burn-in board 100, the metal frame portion at the bottom of the board body 110, and the back plate (back panel) using screws or other connection members made of a thermally conductive material (such as metal), the heat of the heat conduction member 140 can be easily transmitted to the frame portion side of the board body 110 via the adapter 150 and the connection members, and the transmission efficiency can be increased. Furthermore, it is desirable that the adapter 150 be made of a material having high thermal conductivity.

[0043] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the specific embodiments according to the present invention, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of Reference Numerals

[0044] 100: Burn-in board 110: Board body 120: Edge terminal 122: Gripping portion 130: Socket 140: Heat conduction member 150: Adapter 200, 300: Vapor chamber structure

Claims

1. A burn-in board for burn-in testing, comprising: a plurality of sockets having a generally rectangular outer shape arranged in a matrix; and a plate-like heat conduction member extending at least partially into a plurality of gaps in the row or column direction of the plurality of sockets, wherein the heat conduction member has a structure including a vapor chamber, the burn-in board.

2. The burn-in board according to claim 1, wherein the heat conduction member is disposed in a defined area of the plurality of gaps.

3. The burn-in board according to claim 1, wherein the heat conduction member is disposed in each of the plurality of gaps.

4. The burn-in board according to claim 1, wherein a highly thermally conductive joining member is interposed between the surface of the heat conduction member and the surface of the socket facing the surface.

5. The burn-in board further includes a fixing member for fixing at least one end of the heat conduction member protruding from the gap between the sockets, and the fixing member has a fitting portion corresponding to the arrangement pitch of the plurality of heat conduction members. The burn-in board according to claim 1.

6. The burn-in board according to claim 1, wherein the thickness of the heat conduction member is equal to or slightly smaller than the gap between the sockets.

7. The burn-in board according to claim 1, wherein the vapor chamber structure includes a heat-exchangeable refrigerant in a sealed chamber.

8. The vapor chamber structure includes a metal top cover, a pair of upper and lower mesh-shaped wicks, a plurality of posts disposed between the pair of upper and lower wicks, and a metal bottom cover. The chamber is formed by joining the top cover and the bottom cover, and the wick, the post, and the refrigerant are accommodated in the chamber. The burn-in board according to claim 7. Claim 9 A burn-in device comprising a plurality of burn-in boards and an oven for accommodating the plurality of burn-in boards, each of the plurality of burn-in boards includes a plurality of sockets having a generally rectangular outer shape arranged in a matrix, and a plate-like heat conduction member extending at least partially into a plurality of gaps in the row direction or column direction of the plurality of sockets, and the heat conduction member has a structure including a vapor chamber. The burn-in device. Claim 10 The burn-in device according to claim 9, further comprising a fan for blowing hot air in a direction in which the heat conduction member extends.

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