Test device

Abstract

Disclosed is a test device for testing electrical characteristics of a test object. The test device includes: a socket body including an upper block and a lower block arranged so that a probe accommodating portion can be formed extending vertically; a probe including a tubular barrel that is accommodated in the probe accommodating portion and includes a flange portion protruding along an outer circumference so as to be positioned within the probe accommodating portion of the lower block; and a probe guide unit interposed between the upper block and the lower block to guide the probe to move up and down, including a guide hole having an inner diameter larger than an outer diameter of the barrel and smaller than an outer diameter of the flange portion to limit a movable range of the flange portion within the probe accommodating portion of the lower block.

Description

TEST DEVICE

[0001] The disclosure relates to a test device for testing the electrical characteristics of a test object.

[0002] A test device for testing a high-frequency or high-speed semiconductor includes a conductive socket block having a plurality of probe accommodating holes formed in parallel in a vertical direction, and a pair of insulating support plates arranged on the upper and lower surfaces of the socket block and each having a plurality of probe support holes formed at positions respectively corresponding to the plurality of probe accommodating holes. The probe accommodating holes of the socket block allow signal probes for transmitting test signals to pass therethrough without contact, and the probe support holes of the insulating support plate support the both ends of the signal probes. The conductive socket block is maintained in a grounded state to shield interference or noise between adjacent signal probes.

[0003] The insulating support plate disposed on the conductive socket block adversely affects test performance during a test. The thicker the insulating support plate, the more disadvantageous it is. The insulating support plate not only needs to have a support groove formed for supporting a barrel end of a test probe, but also tends to lift due to the elastic pressing force of the test probe, thereby limiting how thin the insulating support plate thinner can be made.

[0004] An aspect of the disclosure is to provide a test device for testing the electrical characteristics of a test object, which is highly reliable in testing and easy to manufacture.

[0005] According to an embodiment of the disclosure, there is provided a test device for testing electrical characteristics of a test object. The test device including: a socket body comprising an upper block and a lower block arranged so that a probe accommodating portion can be formed extending vertically; a probe comprising a tubular barrel that is accommodated in the probe accommodating portion and comprises a flange portion protruding along an outer circumference so as to be positioned within the probe accommodating portion of the lower block; and a probe guide unit interposed between the upper block and the lower block to guide the probe to move up and down, comprising a guide hole having an inner diameter larger than an outer diameter of the barrel and smaller than an outer diameter of the flange portion to limit a movable range of the flange portion within the probe accommodating portion of the lower block.

[0006] At least one of a bottom surface of the upper block and a top surface of the lower block, which face each other, may be formed with a ground connecting portion that passes through the probe guide unit and connects the upper block and the lower block. Thus, noise caused by the probe guide unit is prevented.

[0007] The ground connecting portion may have a tubular structure to surround the probe. Thus, deterioration in impedance characteristics is prevented.

[0008] The probe accommodating portion may include a ground-probe accommodating portion in which a ground probe for transmitting a ground signal is accommodated, and the ground-probe accommodating portion formed in the lower block may have an inner diameter larger than an inner diameter of the ground-probe accommodating portion formed in the upper block. Thus, an operating space for the ground probe is effectively ensured.

[0009] The test device may further include a sheet-shaped probe supporting portion provided on one support surface of the socket body in an extending direction of the probe and guiding the probe to move up and down. Thus, one end portion of the test probe is effectively supported.

[0010] The test device may further include a pressing film to keep the probe supporting portion pressed against the support surface. Thus, the probe supporting portion is more firmly secured.

[0011] In the test device according to an embodiment of the disclosure, a probe supporting portion for supporting a signal probe can be easily manufactured through machining, and a very thin probe supporting portion can be applied, thereby improving test characteristics.

[0012] FIG. 1 is a view illustrating a test device according to a first embodiment of the disclosure.

[0013] FIG. 2 is a perspective view illustrating a test socket of FIG. 1.

[0014] FIG. 3 is an exploded perspective view of the test socket of FIG. 2.

[0015] FIG. 4 is a cross-sectional view of the test socket taken along line A-A in FIG. 2.

[0016] FIG. 5 is a graph showing comparison in insertion loss between a test device according to the disclosure and a conventional test device.

[0017] FIG. 6 is a graph showing comparison in return loss between a test device according to the disclosure and a conventional test device.

[0018] FIG. 7 is a perspective view illustrating a test socket according to a second embodiment of the disclosure.

[0019] FIG. 8 is an exploded perspective view of the test socket of FIG. 7.

[0020] FIG. 9 is a perspective view illustrating a test socket according to a third embodiment of the disclosure.

[0021] FIG. 10 is an exploded perspective view of the test socket of FIG. 9.

[0022] FIG. 11 is a perspective view illustrating a test socket according to a fourth embodiment of the disclosure.

[0023] FIG. 12 is an exploded perspective view of the test socket of FIG. 11.

[0024] Below, a test device 1 according to embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0025] FIG. 1 is a view illustrating a test device 1 according to a first embodiment of the disclosure.

[0026] Referring to FIG. 1, the test device 1 includes probes 5 and 6, a test socket 10 for vertically supporting the probes 5 and 6 arranged side by side, a socket supporting unit 20 for supporting the test socket 10, and a test circuit board 30 placed in a lower portion of the test socket 10.

[0027] The probes 5 and 6 include a signal probe 5 for transmitting a test signal, and a ground probe 6 for transmitting a ground signal. Hereinafter, the probes 5 and 6 will be described using pogo pins as an example. Of course, the probes 5 and 6 are not limited to the pogo pins.

[0028] The signal probe 5 includes a tubular barrel 5A, a terminal 5B that comes into contact with a ball terminal 7A of a test object 7, a plunger 5C that is inserted into a second end of the barrel 5A so as to partially protrude from and slide within the barrel 5A, and a spring (not shown) that is provided between the terminal 5B and the plunger 5C within the barrel 5A.

[0029] The barrel 5A may be made of a conductive pipe. The barrel 5A includes a flange portion 5D extending along the outer circumference of the barrel 5A.

[0030] The terminal 5B is inserted and fixed in a first end of the barrel 5A so as to partially protrude from the barrel 5A. The terminal 5B may be slidable within the barrel 5A, rather than being fixed therein. The terminal 5B includes a crown-shaped tip at an end portion thereof protruding from the barrel 5A. The tip may come into contact with the ball terminal 7A of the test object 7 during a test.

[0031] The plunger 5C is inserted into the second end of the barrel 5A while partially protruding from the barrel 5A. The plunger 5C may also move sliding within the barrel 5A. The plunger 5C may have an outer end that protrudes from the barrel 5A and comes into contact with a pad terminal 30A of the test circuit board 30.

[0032] The spring is inserted into the barrel 5A and provides elasticity to an inner end of the plunger 5C. When the test object 7 is pressed during the test, the ball terminal 7A of the test object 7 presses the signal probe 5, thereby causing the plunger 5C to move sliding toward the inside of the barrel 5A and compressing the spring (not shown) inside the barrel 5A. As a result, the tip of the terminal 5B of the signal probe 5 and an outer end of the plunger 5C come into close contact with the ball terminal 7A of the test object 7 and the pad terminal 30A of the test circuit board 30, respectively, thereby transmitting the test signal.

[0033] The ground probe 6 includes a tubular barrel 61, a terminal 62 that comes into contact with the ball terminal 7A of the test object 7, a plunger 63 that is inserted into a second end of the barrel 61 so as to partially protrude from and slide within the barrel 61, and a spring (not shown) that is provided between the terminal 62 and the plunger 63 within the barrel 61.

[0034] The ground probe 6 has a structure similar to that of the signal probe 5, and thus repetitive descriptions thereof will be omitted.

[0035] The test socket 10 will be described later with reference to additional drawings.

[0036] The socket supporting unit 20 holds and supports the test socket 10 in a lower portion thereof. The socket supporting unit 20 includes a test object accommodating portion 20A that accommodates the test object 7 therein during the test.

[0037] The test circuit board 30 is provided in the lower portion of the test socket 10. The test circuit board 30 includes the pad terminal 30A connected to a signal line (not shown) via which the test signal is transmitted. The plunger 5C of the signal probe 5 and the plunger 63 of the ground probe 6 come into contact with the pad terminal 30A.

[0038] FIG. 2 is a perspective view illustrating the test socket 10 of FIG. 1, FIG. 3 is an exploded perspective view of the test socket 10 of FIG. 2, and FIG. 4 is a cross-sectional view of the test socket 10 taken along line A-A in FIG. 2.

[0039] Referring to FIGS. 2 to 4, the test socket 10 includes a conductive socket body 12, insulating probe supporting portions 14A and 14B placed on the top and bottom portions of the socket body 12 and supporting the signal probe 5 and the ground probe 6, an insulating probe guide unit 15 placed in the middle of the socket body 12 and supporting the signal probe 5, and insulating pressing films 16A and 16B provided to press the probe supporting portions 14A and 14B against the top and bottom support surfaces of the socket body 12, respectively.

[0040] The socket body 12 includes an upper block 12A and a lower block 12B, which are made of, for example, a conductive material such as brass. The upper block 12A and the lower block 12B are overlapped vertically and coupled to each other by a coupling means.

[0041] The upper block 12A includes a signal-probe accommodating portion 121A that is formed to penetrate the upper block 12A vertically and accommodate an upper portion of the signal probe 5 therein contactlessly, and a ground-probe accommodating portion 122A that is formed to penetrate the upper block 12A vertically and accommodate an upper portion of the ground probe 6 therein contactably. The ground-probe accommodating portion 122A has an inner diameter which is the same as or similar to the outer diameter of the barrel 61 of the ground probe 6, so that the outer circumferential surface of the barrel 61 can be in contact with the inner circumferential surface of the ground-probe accommodating portion 122A of the upper block 12A.

[0042] The upper block 12A includes a tubular ground post 123A that protrudes from the top support surface thereof in an extending direction of the ground-probe accommodating portion 122A and surrounds an end portion of the ground probe 6. The ground post 123A is fitted into a post through-hole 143A of a probe supporting portion 14A, thereby supporting the probe supporting portion 14A and restricting the horizontal movement of the probe supporting portion 14A. The ground post 123A may reduce interference between the adjacent signal probes 5. The upper block 12A includes a tubular ground connecting portion 124 that protrudes from the bottom support surface thereof in the extending direction of the ground-probe accommodating portion 122A and surrounds an end portion of the ground probe 6. The ground connecting portion 124 passes through the probe guide unit 15 and comes into contact with the top support surface of the lower block 12B. The ground connecting portion 124 may be provided on the top support surface of the lower block 12B instead of the bottom support surface of the upper block 12A.

[0043] The lower block 12B includes a signal-probe accommodating portion 121B that is formed at a position corresponding to the signal-probe accommodating portion 121A of the upper block 12A to penetrate the lower block 12B vertically and accommodate a lower portion of the signal probe 5 therein, and a ground-probe accommodating portion 122B formed at a position corresponding to the ground-probe accommodating portion 122A of the upper block 12A to penetrate the lower block 12B vertically and accommodate a lower portion of the ground probe 6 therein.

[0044] The lower block 12B includes a tubular ground post 123B that protrudes from the bottom support surface thereof in the extending direction of the ground-probe accommodating portion 122B and surrounds an end portion of the plunger 63 of the ground probe 6. The ground post 123B includes a plunger through-hole 123C through which the plunger 63 of the ground probe 6 passes and which is in communication with the ground-probe accommodating portion 122B. The ground post 123B is fitted into a post through-hole 143B of a probe supporting portion 14B, thereby supporting the probe supporting portion 14B and restricting the horizontal movement of the probe supporting portion 14B. The ground-probe accommodating portion 122B of the lower block 12B is larger than the outer diameter of a flange portion 61A of the ground probe 6, so that the barrel 61 of the ground probe 6 can move up and down during the test. The flange portion 61A of the ground probe 6 is restricted from moving into the ground-probe accommodating portion 122A of the upper block 12A by the ground connecting portion 124 provided on the bottom support surface of the upper block 12A. The signal-probe accommodating portion 121B formed in the lower block 12B is formed to have the same inner diameter as that of the signal-probe accommodating portion 121A formed in the upper block 12A, thereby stably maintaining the impedance characteristics of the signal probe 5.

[0045] The probe supporting portions 14A and 14B are implemented as, for example, a plate made of an insulating material such as plastic. The probe supporting portions 14A and 14B include the upper probe supporting portion 14A placed on the top support surface in the extending direction of the ground-probe accommodating portions 122A and 122B of the socket body 12, and the lower probe supporting portion 14B placed on the bottom support surface in the extending direction of the ground-probe accommodating portions 122A and 122B of the socket body 12.

[0046] The upper probe supporting portion 14A includes a signal probe through-hole 141A through which an upper end portion of the signal probe 5 passes, and the post through-hole 143A through which the ground post 123A passes. The upper probe supporting portion 14A guides the signal probe 5 not to come into contact with the conductive socket body12 when the upper end portion of the signal probe 5 moves up and down during the test. That is, the upper portion of the signal probe 5 is supported and guided so that the signal probe 5 can move up and down contactlessly within the signal-probe accommodating portions 121A and 121B.

[0047] The lower probe supporting portion 14B includes a plunger through-hole 141B through which the plunger 5C of the signal probe 5 passes, and the post through-hole 143B through which the ground post 123B passes. The lower probe supporting portion 14B guides the signal probe 5 not to come into contact with the conductive socket body12 when the lower end portion of the signal probe 5 moves up and down during the test. That is, the plunger 5C of the signal probe 5 is supported and guided so that the signal probe 5 can move up and down contactlessly within the signal-probe accommodating portions 121A and 121B.

[0048] The probe guide unit 15 is implemented as, for example, a plate made of an insulating material such as plastic. The probe guide unit 15 is interposed between the upper block 12A and the lower block 12B. The probe guide unit 15 includes a guide hole 151 provided at a position corresponding to the signal-probe accommodating portions 121A and 121B, and a ground connecting portion through-hole 153 through which the ground connecting portion 124 passes. The guide hole 151 has an inner diameter that is larger than the outer diameter of the barrel 5A of the signal probe 5 and smaller than the outer diameter of the flange portion 5D, thereby limiting the movable range of the flange portion 5D within the signal-probe accommodating portion 121B of the lower block 12B.

[0049] The pressing films 16A and 16B are implemented as, for example, a film made of an insulating material such as polyimide (PI). The pressing films 16A and 16B include an upper pressing film 16A attached to the top surface of the upper probe supporting portion 14A provided on the top support surface of the upper block 12A, and a lower pressing film 16B attached to the bottom surface of the lower probe supporting portion 14B provided on the bottom support surface of the lower block 12B.

[0050] The upper pressing film 16A keeps the upper probe supporting portion 14A pressed against the top support surface of the upper block 12A, thereby restricting the upward movement of the upper probe supporting portion 14A. The upper pressing film 16A includes a signal probe through-hole 161A through which the upper end portion of the signal probe 5 passes, and a post through-hole 163A through which the ground post 123A passes. As shown in FIG. 1, the upper pressing film 16A may be interposed and firmly secured and supported between the socket supporting unit 20 and the socket body 12.

[0051] The lower pressing film 16B keeps the lower probe supporting portion 14B pressed against the bottom support surface of the lower block 12B, thereby restricting the downward movement of the lower probe supporting portion 14B. The lower pressing film 16B includes a plunger through-hole 161B through which the plunger 5C of the signal probe 5 passes, and a post through-hole 163B through which the ground post 123B passes. As shown in FIG. 1, the lower pressing film 16B may be interposed and firmly secured and supported between the test circuit board 30 and the socket body 12.

[0052] Referring to FIG. 4, the signal probe 5 is restrained within the signal-probe accommodating portion 121A of the socket body 12 and does not exit upward. Further, both end portions of the signal probe 5 simply pass through the signal probe through-hole 141A of the upper probe supporting portion 14A and the plunger through-hole 141B of the lower probe supporting portion 14B, respectively. As a result, during the test, the upward pressure exerted on the upper probe supporting portion 14A and the lower probe supporting portion 14B by the signal probe 5 moving up and down is minimized, so that the upper probe supporting portion 14A and the lower probe supporting portion 14B can be designed with a reduced thickness. Accordingly, by designing the upper probe supporting portion 14A and the lower probe supporting portion 14B with a reduced thickness, the test characteristics can be improved, and only machining is enough to carry out the manufacturing process of the test socket.

[0053] FIG. 5 is a graph showing comparison in insertion loss between a test device 1 according to the disclosure and a conventional test device.

[0054] Ideally, the insertion loss is expected to be zero. Referring to FIG. 5, based on an allowable insertion loss of -1.0 dB, the conventional test device fails to meet the allowable insertion loss at a frequency of about 30.22 GHz, whereas the test device 1 according to the disclosure fails to meet the allowable insertion loss at a frequency of about 59.9 GHz, thereby exhibiting significantly superior insertion loss characteristics.

[0055] FIG. 6 is a graph showing comparison in return loss between a test device according to the disclosure and a conventional test device.

[0056] The return loss is preferably as small as possible. Referring to FIG. 6, based on an allowable return loss of -10 dB, the conventional test device fails to meet the allowable return loss at a frequency of about 31.2 GHz, whereas the test device 1 according to the disclosure meets the allowable return loss at frequencies up to 60 GHz or higher, thereby exhibiting significantly superior return loss characteristics.

[0057] FIG. 7 is a perspective view illustrating a test socket 40 according to a second embodiment of the disclosure, and FIG. 8 is an exploded perspective view of the test socket 40 of FIG. 7. Below, descriptions of the same components as those of the test socket 10 according to the first embodiment shown in FIGS. 2 and 3 will be omitted.

[0058] Referring to FIGS. 7 and 8, a test socket 40 includes a conductive socket body 42, insulating probe supporting portions 44A and 44B placed on the top and bottom portions of the socket body 42 and supporting the signal probe 5 and the ground probe 6, an insulating probe guide unit 45 placed in the middle of the socket body 42 and supporting the signal probe 5, and insulating pressing films 46A and 46B provided to press the probe supporting portions 44A and 44B against the top and bottom support surfaces of the socket body 42, respectively.

[0059] The socket body 42 is identical to the socket body 12 according to the first embodiment, except that the ground posts 123A and 123B shown in FIGS. 3 and 4 are absent.

[0060] The probe supporting portions 44A and 44B includes an upper probe supporting portion 44A placed on the top support surface in the extending direction of the ground-probe accommodating portions 422A and 422B of the socket body 42, and a lower probe supporting portion 44B placed on the bottom support surface in the extending direction of the ground-probe accommodating portion 422A and 422B of the socket body 42.

[0061] The upper probe supporting portion 44A includes a signal probe through-hole 441A through which the upper end portion of the signal probe 5 passes, and a ground probe through-hole 442A through which the ground probe 6 passes.

[0062] The lower probe supporting portion 44B includes a plunger through-hole 441B through which the plunger of the signal probe 5 passes, and a plunger through-hole 442B through which the plunger of the ground probe 6 passes.

[0063] A probe guide unit 45 is identical to the probe guide unit 15 shown in FIGS. 3 and 4, and thus repetitive descriptions thereof will be omitted.

[0064] Pressing films 46A and 46B include an upper pressing film 46A attached to the top surface of the upper probe supporting portion 44A provided on the top support surface of the upper block 42A, and a lower pressing film 46B attached to the bottom surface of the lower probe supporting portion 44B provided on the bottom support surface of the lower block 42B.

[0065] The upper pressing film 46A includes a signal probe through-hole 461A through which the upper end portion of the signal probe 5 passes, and a ground probe through-hole 462A through which an upper end portion of the ground probe 6 passes.

[0066] The lower pressing film 46B includes a plunger through-hole 461B through which the plunger of the signal probe 5 passes, and a plunger through-hole 462B through which the plunger of the ground probe 6 passes.

[0067] FIG. 9 is a perspective view illustrating a test socket 50 according to a third embodiment of the disclosure, and FIG. 10 is an exploded perspective view of the test socket 50 of FIG. 9. Below, descriptions of the same components as those of the test socket 10 according to the first embodiment shown in FIGS. 2 and 3 will be omitted.

[0068] Referring to FIGS. 9 and 10, a test socket 50 includes a conductive socket body 52, insulating probe supporting portions 54A and 54B placed on the top and lower portions of the socket body 52 and supporting the signal probe 5 and the ground probe 6, insulating probe guide units 55 placed in the middle of the socket body 52 and supporting the signal probe 5, and insulating pressing films 56A and 56B provided to press the probe supporting portions 54A and 54B against the upper and bottom support surfaces of the socket body 52, respectively.

[0069] The socket body 52 includes an upper block 52A and a lower block 52B which are overlapped vertically and coupled to each other by a coupling means.

[0070] The upper block 52A is formed with four recessed portions 525A spaced apart from each other so as to include an area where a signal-probe accommodating portion 521A is positioned on the top support surface in the extending direction of the signal probe 5.

[0071] The lower block 52B is formed with four recessed portions 525B spaced apart from each other so as to include an area where a signal-probe accommodating portion 521B is positioned on the top support surface in the extending direction of the signal probe 5.

[0072] The lower block 52B is formed with four recessed portions (not shown) spaced apart from each other to include an area where the signal-probe accommodating portion 521B is positioned on the bottom support surface in the extending direction of the signal probe 5.

[0073] The probe supporting portions 54A and 54B include four upper probe supporting portions 54A accommodated in the four recessed portions 525A of the upper block 52A, and four lower probe supporting portions 54B accommodated in the four recessed portions (not shown).

[0074] The probe guide units 55 are accommodated in the four recessed portions 525B of the lower block 52B. The probe guide unit 55 includes guide holes 551 that accommodate the signal probes 5 and guide the signal probes 5 to move in the vertical direction.

[0075] The pressing films 56A and 56B are similar to the pressing films 46A and 46B shown in FIG. 8, and thus repetitive descriptions thereof will be omitted.

[0076] FIG. 11 is a perspective view illustrating a test socket 60 according to a fourth embodiment of the disclosure, and FIG. 12 is an exploded perspective view of the test socket 60 of FIG. 11. Below, descriptions of the same components as those of the test socket 50 according to the third embodiment shown in FIGS. 9 and 10 will be omitted.

[0077] Referring to FIGS. 11 and 12, an upper block 62A of the test socket 60 includes four communication channels 626A that connects four recessed portions 625A. A lower block 62B of the test socket 60 includes four communication channels 626B that connects four recessed portions 625B.

[0078] The probe supporting portions 64A and 64B includes four upper probe supporting portions 64A accommodated in four recessed portions 625A of the upper block 62A, and four lower probe supporting portions 64B accommodated in four recessed portions (not shown).

[0079] The four upper probe supporting portions 64A are provided with four bridges 647A accommodated in the communication channels 626A and connecting the four upper probe supporting portions 64A.

[0080] The four lower probe supporting portions 64B are provided with four bridges 647B accommodated in the communication channels (not shown) and connecting the four lower probe supporting portions 64B.

[0081] Four probe guide units 65 are accommodated in the four recessed portions 625B of the lower block 62B. The four probe guide units 65 are provided with four bridges 657 accommodated in the communication channel 626B and connecting the four probe guide units 65.

[0082] Although a few embodiments of the disclosure have been illustrated and described above, the disclosure is not limited to the foregoing specific embodiments. Various modifications can be made in the embodiments by those skilled in the art without departing from the scope of the disclosure as claimed in Claims, and these modified embodiments should not be understood separately from the technical spirits or prospects of the disclosure.

Claims

1.A test device for testing electrical characteristics of a test object, the test device comprising:a socket body comprising an upper block and a lower block arranged so that a probe accommodating portion can be formed extending vertically;a probe comprising a tubular barrel that is accommodated in the probe accommodating portion and comprises a flange portion protruding along an outer circumference so as to be positioned within the probe accommodating portion of the lower block; anda probe guide unit interposed between the upper block and the lower block to guide the probe to move up and down, and comprising a guide hole having an inner diameter larger than an outer diameter of the barrel and smaller than an outer diameter of the flange portion to limit a movable range of the flange portion within the probe accommodating portion of the lower block.2.The test device of claim 1, wherein at least one of a bottom surface of the upper block and a top surface of the lower block, which face each other, is formed with a ground connecting portion that passes through the probe guide unit and connects the upper block and the lower block.3.The test device of claim 2, wherein the ground connecting portion has a tubular structure to surround the probe.4.The test device of claim 1, whereinthe probe accommodating portion comprises a ground-probe accommodating portion in which a ground probe for transmitting a ground signal is accommodated, andthe ground-probe accommodating portion formed in the lower block has an inner diameter larger than an inner diameter of the ground-probe accommodating portion formed in the upper block.5.The test device of claim 1, further comprising a sheet-shaped probe supporting portion provided on one support surface of the socket body in an extending direction of the probe and guiding the probe to move up and down.6.The test device of claim 5, further comprising a pressing film to keep the probe supporting portion pressed against the support surface.

Images