Abstract: In a method of determining a critical temperature of a semiconductor package, heat is applied to at least one semiconductor package. Temperatures of the semiconductor package are measured during the heating. Heights of the semiconductor package are also measured during the heating. A temperature of the semiconductor package measured at a point at which a height from among the measured heights of the semiconductor package is sharply increased so that swelling of the semiconductor package occurs is determined as the critical temperature of the semiconductor package. Thus, the critical temperature of the semiconductor package may be accurately determined.

Abstract: Disclosed herein is an integrated heater and measurement (IHM) device comprising heating-sensing element(s) and heating-sensing circuit(s). A heating-sensing element generates heat and determines the temperature of the IHM device. In some embodiments, the heating-sensing element may operate in a plurality of modes: heating mode, sensing mode, and/or off mode. A controller may dynamically adjust the properties of the operation mode and/or time periods based on the determined temperature. The adjusted properties may include the duration of the heating mode, the ON time for a heating-sensing element, etc. The controller may adjust the duration of heating mode based on the temperature difference between the determined temperature and a set point temperature, such as decreasing the duration of the heating mode when there is a low temperature difference, and increasing the duration of the heating mode when there is a high temperature difference.

Abstract: Disclosed herein are thermal heads and corresponding test systems for independently controlling a one or more components while testing one or more devices under test. In some embodiments, a thermal head comprises a plurality of adapters, one or more heaters, and one or more thermal controllers for independently controlling temperatures of the components. The thermal controllers may control the temperatures of at least some of the components independently such that thermal control of one component does not affect the thermal control of the other component. In some embodiments, the thermal control is by way of one or more cold plates, and the thermal head comprises one or more cold plates. Embodiments of the disclosure further include independent control of one or more forces using one or more force mechanisms.

Abstract: Disclosed herein are thermal heads and corresponding test systems for independently controlling a one or more components while testing one or more devices under test. In some embodiments, a thermal head comprises a plurality of adapters, one or more heaters, and one or more thermal controllers for independently controlling temperatures of the components. The thermal controllers may control the temperatures of at least some of the components independently such that thermal control of one component does not affect the thermal control of the other component. In some embodiments, the thermal control is by way of one or more cold plates, and the thermal head comprises one or more cold plates. Embodiments of the disclosure further include independent control of one or more forces using one or more force mechanisms.

Abstract: A method for performing temperature control of a mounting base on which a substrate is to be mounted. A substrate mounting surface of the mounting base is divided in the radial direction into a plurality of regions, and a heater is provided to each of the plurality of regions. The method includes: a step for performing feedback control that adjusts the operation amount of the heater in the centermost region of the plurality of regions of the substrate mounting surface such that the centermost region is at a set temperature; and a step for performing feedback control that adjusts the operation amount of the heater in an outside region that is further to the outside than the centermost region of the plurality of regions of the substrate mounting surface such that the temperature difference between the outside region and the region that is adjacent to the outside region on the inside in the radial direction is a preset value.

Abstract: A thermal conditioning device (100) is proposed, wherein a process heat-conductive fluid (110) is caused to circulate in a plurality of extensible elements (105); a pressure of the process heat-conductive fluid (110) is regulated to lengthen the extensible elements (105) so that they are pressed against corresponding electronic devices under test (205) for conditioning them thermally. A test apparatus (200) comprising this thermal conditioning device (100) is also proposed. Moreover, a corresponding method for condition electronic devices under test (105) thermally and a corresponding method for testing electronic devices (205) are proposed.

Abstract: Disposing a DUT between a cold plate and an active thermal interposer device of the thermal management head. The DUT includes a plurality of modules and the active thermal interposer device includes a plurality of zones, each zone of the plurality of zones corresponding to a respective module of the plurality of modules and operable to be selectively heated. Receiving a respective set of inputs corresponding to each zone of the plurality of zones. Performing thermal management of the plurality of modules of the DUT by separately controlling temperature of each zone of the plurality zones by controlling a supply of coolant to a cold plate, and individually controlling heating of each zone of the plurality zones.

Abstract: A semiconductor package test apparatus includes an interface board having connection terminals for electrically connecting a semiconductor package to a tester, a push block for pressing the semiconductor package toward the interface board to bring external terminals of the semiconductor package into contact with the connection terminals of the interface board, a temperature adjustment unit connected with the push block to heat or cool the semiconductor package to a test temperature through the push block, and a heat transfer member for thermally connecting the push block and the interface board.

Abstract: The socket 20 comprises a first contact probe 21 which has a first end which is to contact with a first terminal 91 of the DUT 90, a second contact probe 22 which has a second end which is to contact with a second terminal 92 of the DUT 90, and an inner housing 23 which holds the first and second contact probes 21, 22 so that the first end and the second end are located on substantially the same virtual plane VP, and the length L2 of the second contact probe 22 is shorter than the length L1 of the first contact probe 21. The interposer 30 comprises a substrate 31 which has a through hole 311 into which the first contact probe 21 is to be inserted, and a wiring pattern 32 which is disposed on the substrate 31, and the wiring pattern 32 has a pad 321 with which the second contact probe 22 is to contact.

Abstract: A mechanism for performing thermal testing is described. The system for performing thermal testing may include a housing, a heating element and a processor. The housing is configured to be compatible with a plurality of different types of transceiver form factors. The heating element is configured to be at a location within the housing to approximate an integrated circuit chip heat source of the plurality of different types of transceiver form factors. The processor is configured to automatically conduct a thermal test and provide thermal test results.

Abstract: An example test system includes a test head and a probe card assembly connected to the test head. The probe card assembly includes: a probe card having electrical contacts, a stiffener connected to the probe card to impart rigidity to the probe card, and a heater to heat to at least part of the probe card assembly. A prober is configured to move a device under test (DUT) into contact with the electrical contacts of the probe card assembly.

Abstract: A method selects one or a plurality of sets of values characterizing an electric power of a power source capable of powering a device coupled to the power source via a connection interface. The selection is carried out according to values, characterizing the power supplied by the power source, measured at the connection interface.

Abstract: Apparatus and methods provide burn-in testing for semiconductors. A burn-in test apparatus (1) may include an outer housing forming an aperture with a test socket to receive a tile or wafer. The tile or wafer may include semiconductor device(s) for burn-in testing. The apparatus may include a thermal control unit to regulate testing temperature and/or drive electronics for powering the socket. The apparatus may include an inlet for gas pressure from a pressure source. The apparatus may include a lid covering the aperture when a tile/wafer is at the test socket. The apparatus may include a seal carrier in the aperture to form a pressure chamber with a surface of the tile. The pressure chamber may pneumatically couple with the inlet. Pressure of the pressure chamber may act upon the tile/wafer to urge a device under testing into thermal and/or electrical contact with the socket for conducting the burn-in test.

Abstract: An assembly for controlling the temperature of a device includes: a heat sink configured to be maintained at a temperature below a desired set point temperature; a heater element having a surface configured to be thermally coupled to a surface of the device; and a thermally conductive pedestal interposed between the heat sink and the heater element. The heater is configured to apply heat to the device when the temperature of the device falls below the set point temperature, and heat is transferable to the heat sink through the pedestal and heater element when the temperature of the device is above the set point temperature.

Abstract: A probe card includes a probe having a spring property and a probe head that holds the probe. The probe head includes a guide portion that holds the probe such that the probe can move in an axis direction Z. The guide portion includes a heat radiation structure that absorbs heat of the probe generated by energization and emits the heat to the outside of the probe.

Abstract: A method of forming a fibre composite component (10), the method comprising: providing a plurality of first fibres (102), the first fibres (102) being arranged in a plurality of layers (104a-e) with an uncured thermoset resin matrix (106) being provided therebetween. The resin matrix (106) comprises a plurality of second electrically conductive fibres (108) suspended therein having a shorter length than the first fibres (102). The method comprises then applying an energy field to the resin matrix (106) to thereby align the second fibres (108) such that they provide an electrically conductive path between adjacent layers (104a-e) of first fibres (102) to form an electrically conductive fibre network comprising the first and second fibres (102, 108). The method comprises then inducing an electric current through the electrically conductive fibre network to thereby heat and cure the resin matrix (106).

Abstract: A dew resistant module for a test socket, and an electronic component testing device having the same are provided. An enclosure body is provided to circumscribe the test socket; and a test socket base plate provided on top of the test socket and enclosure body. A cover is provided to cover the test socket, enclosure body and test socket base plate. With the provision of the enclosure body and the cover, the test socket, test socket base plate and a portion of the thermal head are prevented from coming into contact directly with the atmosphere, whereby condensation or dewing is prevented, thermal insulation achieved and energy consumption minimized.

Abstract: A temperature controller for a substrate support in a substrate processing system includes memory that stores a first model correlating temperatures of a plurality of first thermal control elements (TCEs) arranged in the substrate support and first temperature responses of the substrate support. The first temperature responses correspond to locations on a surface of the substrate support. A temperature estimation module calculates resistances of the first TCEs, determines, based on the calculated resistances, the temperatures of the first TCEs, and estimates, using the stored first model and the determined temperatures of the first TCEs, an actual temperature response of the substrate support. The temperature controller is configured to control the first TCEs based on the actual temperature response of the substrate support.

Abstract: A multi-zone heater with a plurality of thermocouples such that different heater zones can be monitored for temperature independently. The independent thermocouples may have their leads routed out from the shaft of the heater in a channel that is closed with a joining process that results in hermetic seal adapted to withstand both the interior atmosphere of the shaft and the process chemicals in the process chamber. The thermocouple and its leads may be enclosed with a joining process in which a channel cover is brazed to the heater plate with aluminum.

Abstract: Featured are devices, systems and methods for testing an electronic device, such as an integrated chip. Such a testing method includes disposing a thermal clutch between a variable heat sink that absorbs heat energy and a heat source member that selectively delivers heat energy. When the thermal clutch is operated in a first manner the thermal clutch thermally couples the variable heat sink to the electronic device under test (DUT) and when operated in the second manner, the thermal clutch thermally de-couples the variable heat sink from the DUT. Also, when the thermal clutch is operated in the second manner, the heat source member is thermally coupled to the DUT and is operated so as to produce heat energy which is thus provided to the thermally coupled DUT.

Abstract: A testing unit including a substrate, a plurality of vias located in the substrate, a plurality of pin traces having a height and a width and each extending from a respective via towards an edge of the substrate, a plurality of end traces having a height and a width with each end trace extending from an end of a respective pin trace towards the edge of the substrate, a plurality of branch traces having a height and a width and each extending from a side of a respective pin trace, a plurality of traces extending from the end of a respective end trace, branch trace or pin trace to the edge of the substrate.

Abstract: A thermal controller includes a thermal control interface to receive test data from an automated test equipment (ATE) system and dynamically adjust a target setpoint temperature based on the data and a dynamic thermal controller to receive the target setpoint temperature from the thermal control interface and control a thermal actuator based on the target setpoint temperature.

Abstract: There is provided an electronic device transfer apparatus which has an excellent capacity of transferring DUTs between trays. An electronic device transfer apparatus, which transfers DUTs between trays, includes a device conveying unit. The device conveying unit includes a plurality of shuttles which hold the DUTs, an endless first guide rail which guides the shuttles, and first to third feeders which move the shuttles on the first guide rail. The shuttles are movable on the first guide rail over the entire circumference of the rail.

Abstract: A first cooling unit is provided for an exothermic member and has a capability of cooling the exothermic member to a temperature less than an ambient temperature of the exothermic member by absorbing heat from the exothermic member. A second cooling unit has a capability of cooling the exothermic member by blowing air onto the exothermic member. A temperature of the exothermic member is detected. It is determined that whether or not the exothermic member is in a supercooled state based on a detection result. The cooling capability of the first cooling unit is decreased and the cooling capability of the second cooling unit is increased, when the exothermic member is in the supercooled state.

Abstract: A light emitting diode (LED) lighting assembly (200) includes an LED lighting source (223) and a heat sink assembly (209) that is configured between a power source and the LED light source (223) that works as an electrical conductor for the LED light source (223) and for removing heat generated by the LED light source (223).

Abstract: A method of manufacturing a nitride semiconductor device, the nitride semiconductor device having an input terminal, a drain terminal, a gate terminal, and an output terminal, includes a burn-in step in which the nitride semiconductor device is heated while inputting an RF signal to the input terminal, applying a drain voltage to the drain terminal, and applying a gate voltage to the gate terminal. The burn-in step is continued until the nitride semiconductor device exhibits a decrease in gate current.

Abstract: A power measurement transducer includes a first surface configured to thermally couple the power measurement transducer to a device under test. A second surface is essentially parallel to and spaced apart from the first surface. Two or more temperature measurement elements are positioned between the first and second surfaces. The power measurement transducer is configured to allow at least a portion of the power generated within the device under test to enter the power measurement transducer through the first surface and exit the power measurement transducer through the second surface.

Abstract: An integrated circuit (IC) device tester maintains a set point temperature on an IC device under test (DUT) having a die attached to a substrate. The tester includes a thermal control unit and a fluid management system configured to supply the thermal control unit with fluids for pneumatic actuation, cooling, and condensation abating. The tester can includes a box enclosing the thermal control unit thereby providing a substantially isolated dry environment during low humidity testing of the DUT. The heat exchange plate may include an inner structure for thermal conductivity enhancement.

Abstract: A device tester for an IC device under test (DUT), the DUT having a substrate and an attached die. The device tester includes a thermal control unit and a test socket assembly which conforms to the DUT's profile. The thermal control unit includes a pedestal assembly, a heater having a fuse coupled to a heating element, a substrate pusher, and a force distributor for distributing force between the pedestal assembly and the substrate pusher. The test socket assembly includes a socket insert that supports and also conforms to the DUT's profile.

Abstract: Embodiments of the present disclosure describe thermal interface techniques and configurations. In some embodiments, a thermal interface apparatus may include a flexible container, a plurality of thermally conductive objects disposed within the flexible container, and an attachment member coupled to the flexible container for attaching the thermal interface apparatus to a heat sink. The thermally conductive objects may be movable to rearrange their packing within the flexible container in response to deformation of the flexible container. Other embodiments may be described and/or claimed.

Abstract: An apparatus controls a temperature of a device by circulating a fluid through a heat sink in thermal contact with the device. The apparatus includes an adjustable cold input, which inputs a cold portion of the fluid having a first temperature, and an adjustable hot input, which inputs a hot portion of the fluid having a second temperature higher than the first temperature. The apparatus further includes a chamber, connected to the cold input and hot input, in which the cold and hot portions of the fluid mix in a combined fluid portion that impinges on the heat sink. The combined fluid portion has a combined temperature that directly affects a temperature of the heat sink. The cold input and hot input are adjusted to dynamically control the combined temperature, enabling the heat sink temperature to compensate for changes in the device temperature, substantially maintaining a set point temperature of the device.

Abstract: A test system, and a method of manufacture thereof, including: a thermal management head including a heat spreader; an electronic device in direct contact with the heat spreader; and an electrical current for transferring energy between the heat spreader and the electronic device.

Abstract: A micro-spray cooling system beneficial for use in testers of electrically stimulated integrated circuit chips is disclosed. The system includes micro-spray heads disposed about a probe head. The spray heads and probe head are disposed in a sealed manner inside a spray chamber that, during operation, is urged in a sealing manner onto a sealing plate holding the integrated circuit under test. The atomized mist cools the integrated circuit and then condenses on the spray chamber wall. The condensed fluid is pumped out of the chamber and is circulated in a chiller, so as to be re-circulated and injected again into the micro-spray heads. The pressure inside the spray chamber may be controlled to provide a desired boiling point.

Abstract: Embodiments of the present disclosure provide an apparatus configured to engage a device for testing the device via automatic test equipment. The apparatus includes a heat sink, wherein the heat sink comprises a plurality of fins extending from the heat sink, and wherein the heat sink is configured to engage the device. The apparatus further includes a heat conduction layer coupled to the heat sink, a first leg coupled to the heat conduction layer, and a second leg coupled to the heat conduction layer. The second leg is spaced apart from the first leg. A vacuum path is defined through (i) the heat conduction layer and (ii) the heat sink. The vacuum path permits the apparatus to engage the device to be tested by the automatic test equipment.

Abstract: The present document relates to voltage regulators (101). In particular, the present document relates to the testing of voltage regulators subject to load transients. A test device (110) configured to generate a load current to be drawn at an output of a voltage regulator (101) is described. The test device (110) comprises a load connector (116) for coupling the test device (110) to the output of the voltage regulator (101); a transistor (113) configured to modulate the current through the load connector (116) subject to a control signal (123); wherein the current through the load connector (116) corresponds to the load current; a current sense resistor (112) arranged in series with the transistor (113) and configured to provide a feedback voltage (121) which is substantially proportional to the load current; and an operational amplifier (111) configured to generate the control signal (123) based on the feedback voltage (121) and based on a target voltage (122).

Abstract: An exemplary heat sink includes a heat-conducting substrate and a heat-conducting film formed on an outer surface of the substrate. A heat resistance of the heat-conducting film is lower than that of the heat-conducting substrate. A heat conductivity coefficient of the heat-conducting film is higher than that of the heat-conducting film. The heat-conducting film is thinner than the heat-conducting substrate, and a thickness of the heat-conducting film is in a range from about 0.025 mm to about 0.05 mm.

Abstract: Thermal control units (TCU) for maintaining a set point temperature on an IC device under test (DUT) are provided. The units include a pedestal assembly comprising a heat-conductive pedestal, a fluid circulation block, a thermoelectric module (Peltier device) between the heat-conductive pedestal and the block for controlling heat flow between the pedestal and fluid circulation block, and a force distribution block for controllably distributing a z-axis force between different pushers of the TCU. Alternatively, instead of a thermoelectric module, a heater can provide heat to the DUT. Optionally, a swivelable temperature-control fluid inlet and outlet arms may be provided to reduce instability of the thermal control unit due to external forces exerted on the TCU such as by fluid lines attached to the fluid inlet and outlet arms. Also optionally, an integrated means for abating condensation on surfaces of the TCU during cold tests may be provided.

Abstract: An IC socket is pneumatically actuated and has an integrated heat sink. Thermally conductive elements of the heat sink extend through an opening of a pneumatically actuated element shaped as a closed curve of finite width so that heat radiating from the thermally conductive elements may dissipate through a top opening of the IC socket. Downward force exerted by the pneumatically actuated element is transferred through a gimbaled multi-plate and spring arrangement to provide even pressure on the die and substrate of an IC device being held in place by the IC socket. A spring-loaded ground tab on the bottom of the IC socket simplifies grounding of the IC socket to avoid damaging the held IC device by static discharge.

Abstract: Thermal control units (TCU) for maintaining a set point temperature on an IC device under test (DUT) are provided. The units include a pedestal assembly comprising a heat-conductive pedestal, a fluid circulation block, a thermoelectric module (Peltier device) between the heat-conductive pedestal and the block for controlling heat flow between the pedestal and fluid circulation block, and a force distribution block for controllably distributing a z-axis force between different pushers of the TCU. Optionally, a swivelable temperature-control fluid inlet and outlet arms may be provided to reduce instability of the thermal control unit due to external forces exerted on the TCU such as by fluid lines attached to the fluid inlet and outlet arms. Also optionally, an integrated means for abating condensation on surfaces of the TCU during cold tests may be provided.

Abstract: Methodologies and test configurations are provided for testing thermal interface materials and, in particular, methodologies and test configurations are provided for testing thermal interface materials used for testing integrated circuits. A test methodology includes applying a thermal interface material on a device under test. The test methodology further includes monitoring the device under test with a plurality of temperature sensors. The test methodology further includes determining whether any of the plurality of temperature sensors increases above a steady state.

Abstract: A heat spreader comprising a sheet of transparent diamond with an aperture therein that accommodates a solid-immersion lens (SIL). The heat spreader may be mounted within a clamp which allows the heat spreader to move freely across the Device Under Test (DUT) while maintaining a very high degree of planarity and contact between the diamond and the silicon substrate of the DUT. The DUT is secured to its electrical interface with a low profile clamp, the DUT may be held within the clamp by a mechanism that applies a pressure to the sides of the DUT package.

Abstract: A temperature control unit for an electronic component and a handler apparatus, which are excellent in responsibility during cooling and heating, is obtained. The temperature control unit for an electronic component includes a cooling cycle device having a refrigerant passage circulating through a compressor, a condenser, an expander, and an evaporator; a thermally conductive block having an outer surface capable of coming in contact with the electronic component that is an object to be temperature-controlled, where an inner surface corresponding to the outer surface is placed opposite to the outer surface so as to be brought in contact with or apart from the evaporator; at least one first heater for heating the thermally conductive block; and a compressed air feeding circuit for feeding compressed air between facing surfaces of the evaporator and the thermally conductive block to part them.

Abstract: The invention relates to a method for monitoring an electrical heating apparatus and to a corresponding apparatus. The electrical heating apparatus has at least one heating element. A measured value, which is dependent on the resistance and/or the inductance of the electrical heating element, is measured, the measurement being carried out by means of the measured value being sampled. Owing to the use of sampled values, the measurement process can be shortened.

Abstract: A micro-spray cooling system beneficial for use in testers of electrically stimulated integrated circuit chips is disclosed. The system includes micro-spray heads disposed about a probe head. The spray heads and probe head are disposed in a sealed manner inside a spray chamber that, during operation, is urged in a sealing manner onto a sealing plate holding the integrated circuit under test. The atomized mist cools the integrated circuit and then condenses on the spray chamber wall. The condensed fluid is pumped out of the chamber and is circulated in a chiller, so as to be re-circulated and injected again into the micro-spray heads. The pressure inside the spray chamber may be controlled to provide a desired boiling point.

Abstract: Non-corrosive thermal interface materials for use in a test structure and method of use. The test structure includes a heat sink for dissipating heat away from a device under test. The test structure further includes a non-corrosive thermal interface material disposed between the heat sink and the device under test. The non-corrosive thermal interface material is capable of withstanding test conditions for at least 60 minutes for at least 115° C. without staining or leaving residue on the device under test after baking.

Abstract: A temperature control device that includes a miniature liquid-cooled heat sink with integral heater and sensing elements is used as part of a system to provide a controlled temperature surface to an electronic device, such as a semiconductor device, during the testing phase. The temperature control device includes an interface surface configured to provide a thermal path from the device to a device under test. One such device has a liquid-cooled heat sink comprising a first heat transfer portion in a first plane and a second heat transfer portion in a second plane. The first and second heat transfer portions establish a three-dimensional cross-flow of coolant within the heat sink structure. An alternate embodiment includes parallel fluid conduits, each having a three-dimensional microchannel structure that directs coolant flow in three dimensions within the fluid conduits.

Abstract: A heat sink pedestal device allows for the use of generic thermal units such as heat sinks. An interposer configured to fit a specific device under test is mounted to a retainer. The retainer firmly holds the interposer in position. In addition, the retainer may be mounted to a thermal unit. An interface sealant with a diameter less than that of the interposer, creating the perimeter of an interface medium chamber, is positioned at the periphery of the interposer between the interposer and the thermal unit. Interface material, having high thermal conductive properties, is positioned within the interface sealant. The interface medium chamber provides a high thermally conductive interface between the interposer and the thermal unit. In addition, the heat sink pedestal device minimizes customization because it allows a single heat sink or thermal unit assembly to be used to accommodate a wide range of unit sizes.

Abstract: A cooling apparatus includes a refrigerating machine including a cooling portion fixed to a support body and cools a cooling target through the cooling portion. The cooling target and the cooling portion are connected by a structure including an extendable pipe filled with a fluidized refrigerant. A first magnetic body fixed to a side of the support body and a second magnetic body fixed to a side of the pipe are arranged around the pipe. The first magnetic body and the second magnetic body are maintained in non-contact with each other.

Abstract: A universal test fixture for testing and characterization of high-power flange-packaged RF and microwave transistors and diodes includes a precision-machined heat sink having a built-in center cavity with a finger catch on either side of the cavity which uses a plurality of matching modules that are installed in the center cavity and designed as transistor or diode carrier modules to provide mounting for the high-power packaged RF and microwave devices in a wide variety of flange type packages, an adjustable clamping structure connected to a movable arm, and a plurality of non-conductive high temperature pressure clamps. Each carrier module is made of a gold-plated rectangular aluminum block having a center cavity that is machined to the package outline. A non-conductive black-anodized high-temperature resistant pressure clamp machined to the package outline holds the packaged device in the carrier module.

Abstract: A system and method for thermal management of a device under test (DUT). In particular, a system is described for performing optical microscopy. The system includes a heat spreader window that consists of substantially undoped silicon. The window is configured to be coupled to a back side of a substrate of a DUT such that thermal energy from the DUT is spread to the heat spreader window. A contact region is coupled to the heat spreader window. The contact region is configured for contact with a solid immersion lens (SIL) optical system for optical examination of the DUT. A heat exchanger is coupled to the heat spreader window for removing the thermal energy from the DUT during its operation, wherein the heat exchanger is configured to allow access to the heat spreader window.