Method and apparatus for molding semiconductor test socket

Abstract

The present disclosure comprises the steps of: pressurizing a molding material introduced into a mold; applying a magnetic field to the mold; heating the mold to cure the molding material; and cooling the molding material, wherein the molding material is in the form of a mixture of conductive powder and a liquid insulating elastic material, the step of applying a magnetic field includes a process of self-aligning the conductive powder within the molding material by repeating a forward and reverse direction reversal with respect to the magnetic field a predetermined number of times, and the curing step can be performed while maintaining the magnetic field applied to the mold.

Description

Technology Field

[0001] The present disclosure relates to a method and apparatus for forming an elastic socket for semiconductor testing. Background Technology

[0002] With the advancement of the semiconductor industry, the integration density of semiconductor chips is increasing, and consequently, the spacing between chip pads is also tending to become progressively finer. In the test process for inspecting the performance and operation of semiconductor chips, test sockets that make electrical contact with each pad of the chip are used. These test sockets need to be manufactured to form electrical contacts corresponding to the pad arrangement of the semiconductor chip.

[0003] Test socket manufacturing technology using conductive composite materials has been proposed by dispersing conductive particles within an insulating matrix and aligning the conductive particles in a specific direction to form electrically conductive paths.

[0004] In such technologies, the arrangement state of conductive particles can affect the characteristics of the conductive path where they are formed, so various methods to control the alignment of conductive particles are being studied. For example, a technology has been proposed to control the orientation of particles by applying a magnetic field to magnetic particles or conductive powder within a mold.

[0005] However, in conventional magnetic field-based molding technology, the arrangement of conductive particles can be affected by process conditions depending on the method of applying a magnetic field to the molding material within the mold, the mold structure, or the process control method. In addition, temperature and volume changes may occur during the curing process of the molding material, and these changes can affect the pressure or process conditions inside the mold.

[0006] In particular, during the process of forming columns—that is, the conductive path where the arrangement of conductive particles is formed—adjacent columns must be disconnected and maintained in an insulated state; however, a phenomenon has frequently occurred where some conductive particles unintentionally connect the columns, causing defects.

[0007] Therefore, in order to form an electrically conductive path corresponding to the pad arrangement of a semiconductor chip, technical improvements are required regarding a magnetic field application method, mold structure, and process control method that can control the arrangement of conductive particles. Prior art literature

[0008] Korean Registered Patent Publication 10-0950876 (2010.04.06) The problem to be solved

[0009] An embodiment according to the present disclosure provides that the alignment of conductive powder can be improved through magnetic field control that repeatedly reverses the direction of the magnetic field in the forward and reverse directions.

[0010] In addition, the embodiment according to the present disclosure provides a method for forming an elastic socket for semiconductor testing that prevents unintended conductive bridges from being formed between conductive columns, thereby maintaining an insulating state between adjacent columns.

[0011] In addition, the embodiment according to the present disclosure provides that a magnetic field that may remain after a molding process can be reduced through a stepwise current reduction demagnetization process.

[0012] In addition, the embodiment according to the present disclosure provides a method to control the position in which conductive powder is arranged through a mold structure in which a magnetic material is arranged to correspond to the pad position of a semiconductor chip.

[0013] In addition, the embodiment according to the present disclosure provides that the dimensional accuracy of a molded article can be secured by performing load compensation control during the molding process.

[0014] In addition, the embodiment according to the present disclosure provides that the heat treatment process of the molding process can be efficiently performed through asymmetric thermal cycle control.

[0015] In addition, the embodiment according to the present disclosure provides the ability to automate the molding process through an automatic transfer process of the mold.

[0016] The problems that this disclosure aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0017] A method for forming an elastomer socket for semiconductor testing according to one aspect of the present disclosure for achieving the above-described technical problem comprises the steps of: pressurizing a molding material introduced into a mold; applying a magnetic field to the mold; heating the mold to cure the molding material; and cooling the molding material, wherein the molding material is in the form of a mixture of conductive powder and a liquid insulating elastomer, and the step of applying a magnetic field includes a process of self-aligning the conductive powder within the molding material by repeating a forward and reverse direction reversal with respect to the magnetic field a predetermined number of times, and the step of curing is performed while maintaining the magnetic field applied to the mold.

[0018] The step of applying the magnetic field includes a bidirectional current supply process that selectively supplies a forward or reverse current, and can be controlled to repeat a reversal cycle a predetermined number of times by applying a current in the forward direction for a preset time, and then maintaining a reverse current corresponding to a preset ratio of the forward current for another preset time.

[0019] The method further includes a step of alternating the direction of the current applied to generate the magnetic field in a forward or reverse direction, starting from a preset maximum current, and the alternating step can be controlled to gradually reduce the magnitude of the applied current.

[0020] The above alternating step includes a process of controlling the applied current to decrease stepwise in the order of a first reverse ratio, a second forward ratio, a third reverse ratio, a fourth forward ratio, and a fifth reverse ratio relative to the maximum current, starting from a preset maximum current value, and each stepwise decrease process can be controlled to be maintained for a preset time range.

[0021] The step of applying the magnetic field above can be performed by applying a constant current according to a preset constant current control value so that a constant magnetic flux density is maintained in the molding material.

[0022] The step of pressurizing the molding material may measure the load applied to the molding material to maintain a preset pressure, and the step of curing the molding material may perform load compensation control to maintain the preset pressure even when the molding material expands.

[0023] The step of applying a magnetic field to the mold is controlled to gradually reduce the magnitude of the applied current, and in the process of self-aligning the conductive powder, may further include a process of gradually changing the strength of the magnetic field or the duration of the magnetic field.

[0024] The above mold is provided in a form in which heterogeneous materials are arranged in an alternating manner, and magnetic materials may be arranged on the upper and lower plates of the mold according to a spacing corresponding to the pad positions of the semiconductor chip to be inspected.

[0025] The step of applying a magnetic field to the mold further includes the step of alternating the direction of the current applied to generate the magnetic field in a forward or reverse direction, starting from a preset maximum current, and the alternating step can be controlled to gradually reduce the magnitude of the applied current.

[0026] In addition, a molding device for an elastic socket for semiconductor testing to which one of the above methods is applied may be provided.

[0027] According to another aspect of the present disclosure, a molding apparatus for a semiconductor test socket configured to perform the molding method may be provided. Effects of the invention

[0028] According to the means for solving the problem described above in the present disclosure, the effect of improving the alignment of conductive powder is provided through magnetic field control that repeatedly reverses the direction of the magnetic field in the forward and reverse directions.

[0029] In addition, according to the aforementioned means for solving the problem of the present disclosure, the effect of reducing the magnetic field that may remain after the molding process through a stepwise current reduction demagnetization process is provided.

[0030] In addition, according to the aforementioned means for solving the problem of the present disclosure, the effect of controlling the position in which conductive powder is arranged through a mold structure in which a magnetic body is arranged to correspond to the pad position of a semiconductor chip is provided.

[0031] In addition, according to the aforementioned means for solving the problem of the present disclosure, the effect of ensuring dimensional accuracy of the molded product is provided by performing load compensation control during the molding process.

[0032] In addition, according to the means for solving the problem described above in the present disclosure, the effect of efficiently performing the heat treatment process of the molding process through asymmetric thermal cycle control is provided.

[0033] In addition, according to the above-described means for solving the problem of the present disclosure, the effect of automating the molding process through the automatic transfer process of the mold is provided.

[0034] The effects of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below. Brief explanation of the drawing

[0035] FIG. 1 is a flowchart showing the overall process of a semiconductor test socket forming method according to one embodiment of the present disclosure. FIG. 2 is a flowchart showing a detailed process of a self-alignment step according to one embodiment of the present disclosure. FIG. 3 is a flowchart illustrating a load compensation control method according to one embodiment of the present disclosure. FIG. 4 is a BH curve graph for explaining the principle of a stepwise current reduction demagnetization process according to one embodiment of the present disclosure. FIG. 5 is a graph showing asymmetric thermal cycle control according to one embodiment of the present disclosure. FIG. 6 is a block diagram showing the overall configuration of a semiconductor test socket molding device according to one embodiment of the present disclosure. FIG. 7 is a schematic diagram showing the cross-sectional structure of a semiconductor test socket molded article manufactured by a method according to one embodiment of the present disclosure. Specific details for implementing the invention

[0036] Throughout this disclosure, the same reference numerals denote the same components. This disclosure does not describe all elements of the embodiments, and general content in the art to which this disclosure pertains or content that overlaps between embodiments is omitted. The terms 'part, module, component, block' as used in the specification may be implemented in software or hardware, and depending on the embodiments, a plurality of 'parts, modules, components, blocks' may be implemented as a single component, or a single 'part, module, component, block' may include a plurality of components.

[0037] Throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected, and indirect connections include connections made via a wireless communication network.

[0038] Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0039] Throughout the specification, when it is stated that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0040] Terms such as "first," "second," etc., are used to distinguish one component from another, and the components are not limited by the aforementioned terms.

[0041] Singular expressions include plural expressions unless there is an obvious exception in the context.

[0042] In each step, identification codes are used for convenience of explanation and do not describe the order of the steps; the steps may be performed differently from the specified order unless a specific order is clearly indicated in the context.

[0043] The operating principles and embodiments of the present disclosure will be described below with reference to the attached drawings.

[0044] The present disclosure can improve the alignment of the conductive powder and achieve a fine pitch, and improve the dimensional accuracy and electrical properties of the molded product by repeatedly reversing the direction of the magnetic field applied to the molding material in the mold in the forward and reverse directions to self-align the conductive powder, and by controlling the magnitude of the current applied to generate the magnetic field to be reduced in steps.

[0045] FIG. 1 is a flowchart showing the overall process of a semiconductor test socket forming method according to one embodiment of the present disclosure.

[0046] Referring to FIG. 1, a semiconductor test socket molding method may include the steps of pressing the molding material (S110), applying a magnetic field to perform magnetic alignment (S120), heating the molding material to cure it (S130), cooling the molding material (S140), and removing the residual magnetic field (demagnetizing) (S150).

[0047] First, in the step of pressurizing the molding material (S110), the process of pressurizing the molding material introduced into the mold may be performed. The molding material may be provided in a form in which a conductive powder and a liquid insulating elastic material are mixed, and the conductive powder may be applied without limitation as a metal powder or particle having ferromagnetic properties, for example, nickel (Ni), iron (Fe), cobalt (Co), etc. may be used, but is not limited thereto, and depending on the purpose, rare earth-based ferromagnetic materials or oxide and compound particles such as magnetite (Fe₃O₄) and ferrite, or special alloy powders such as Permalloy and Alnico (AlNiCo) may be used without limitation.

[0048] The liquid elastic insulator material may include at least one of epoxy resin, silicone resin, polyimide resin, or a mixture thereof, but is not limited thereto; thermoplastic elastomers such as olefin-based (TPO), styrene-based (TPS), or urethane-based (TPU), or hybrid resins such as fluorosilicone resin or silica particles may be used without limitation. The average particle size of the conductive powder may be selected within a predetermined micrometer range, and the mixing ratio of the conductive powder and the liquid insulator elastic material may be appropriately adjusted considering at least one of the electrical conductivity and mechanical strength required for the final molded product.

[0049] The step (S110) of pressurizing the molding material can be performed using at least one of a hydraulic cylinder, a pneumatic cylinder, an electric actuator, and a mechanical press, and the pressurizing force applied to the molding material can be measured in real time through at least one of a load cell, a pressure sensor, and a strain gauge.

[0050] The pressure can be set within a predetermined range, and feedback control can be performed to maintain the set pressure. Through this pressure application process, air bubbles within the molding material are removed, and the conductive powder and liquid insulating elastic material can be uniformly distributed within the mold cavity.

[0051] According to one embodiment, the step (S110) of pressurizing the molding material may apply a multi-stage pressurization profile, and the molding material may be filled into the mold cavity at a low pressure initially, and then the pressure may be gradually increased to reach a final target pressurization force. This multi-stage pressurization method can prevent uneven distribution of conductive powder caused by rapid flow of the molding material and improve the adhesion of the molding material to the inner wall of the mold.

[0052] In the step (S120) of applying a magnetic field to perform magnetic alignment, a process of applying a magnetic field to a mold to magnetically align the conductive powder within the molding material may be performed. In the present disclosure, the step of applying a magnetic field may not simply apply a unidirectional magnetic field, but may be performed by repeating the direction reversal with respect to the magnetic field in the forward and reverse directions a predetermined number of times. Such magnetic field direction reversal control can improve the alignment of the conductive powder, minimize the formation of defective bridges between conductive columns, minimize interference between particles, and provide the effect of improving the uniformity of alignment.

[0053] In some embodiments, in addition to reversing the direction of the magnetic field and repeating the number of reversals, the magnetic field strength or the duration of the applied magnetic field may be set differently for each step in the reversal process, and the appropriate magnetic field strength and duration may be changed differently for each step depending on the type or characteristics of the conductive powder material used and the type of liquid insulating elastic material.

[0054] A magnetic field can be generated using at least one of an electromagnet, a permanent magnet, a superconducting magnet, or a combination thereof; for example, an electromagnet capable of controlling the direction of the current may be used. The electromagnets may be placed at the top and bottom of the mold, or simultaneously at the top and bottom of the mold, respectively, but are not limited thereto, and may be arranged in a suitable configuration capable of applying a magnetic field to the conductive particles filled inside the mold.

[0055] The magnetic field strength can be set within a predetermined range of magnetic flux density, and the magnetic flux density can be measured using at least one of a Hall sensor, a fluxmeter, a Gauss meter, or a combination thereof. The number of magnetic field direction reversals can be appropriately set by considering at least one of the characteristics of the molding material, the particle size and shape of the conductive powder, and the required degree of alignment.

[0056] Through the self-alignment process, conductive powder is aligned along the direction of magnetic field lines, forming electrically conductive paths in the final molded product. If the conductive powder is a magnetic material, it can be aligned by being directly magnetized by a magnetic field; even if it is a non-magnetic conductive material, alignment can occur through forces caused by magnetic field gradients or interactions with surrounding magnetic particles. Reversing the direction of the magnetic field prevents the conductive powder from aggregating excessively in one direction and induces the particles to be aligned along the magnetic field lines while being more uniformly dispersed.

[0057] In the step (S130) of heating and curing the molding material, the process of heating the mold to cure the molding material may be performed. In this disclosure, the curing step may be performed while maintaining the magnetic field applied to the mold. This is to ensure that the alignment state of the conductive powder is maintained even during the curing process of the liquid insulating elastic material. If curing is performed without the magnetic field, the aligned conductive powder may be dispersed disorderly again due to the fluidity of the liquid insulating elastic material, and the column-shaped alignment state may be separated as the relatively heavy conductive powder metal material sinks due to gravity; therefore, it is essential to perform curing while maintaining the magnetic field. In some examples, the magnetic field applied during the heating and curing process may be set to a maximum magnetic field value so that the shape and alignment state of the conductive powder in the previous magnetic alignment state, which is vertically aligned conductive column, may be maintained.

[0058] The temperature of the mold can be controlled through a heating means. The curing temperature may vary depending on the type of liquid insulating elastic material used, and in the case of liquid silicone, curing can generally proceed within a predetermined temperature range.

[0059] The curing step may be configured to heat from a first temperature to a second temperature within a predetermined first time, whereby the first temperature may be room temperature or a temperature close thereto, and the second temperature may be the curing temperature of the liquid insulating elastic material. The heating rate may be controlled within a predetermined range, and since a rapid rise in temperature may cause localized curing or the generation of thermal stress in the molding material, it may be important to maintain an appropriate heating rate.

[0060] According to one embodiment, the curing step may apply a multi-stage temperature profile and may be divided, for example, into an initial preheating step, a main curing step, and a post-curing step. In the initial preheating step, the viscosity of the molding material may be lowered to facilitate alignment of the conductive powder, and in the main curing step, the cross-linking reaction of the liquid insulating elastic material may proceed to solidify the molding material, and in the post-curing step, residual stress may be relieved and mechanical properties may be improved. For example, in the main curing step, a second temperature suitable for curing may be continuously maintained for a predetermined period of time or longer, and during this process, a magnetic field may be applied to maintain the alignment state of the conductive column.

[0061] During the curing process, the volume of the molding material may increase due to thermal expansion, which can change the pressure applied to the mold. According to one embodiment, the curing step may perform load compensation control to maintain a preset pressure even when the molding material expands. By measuring the load in real time and adjusting the pressure through feedback control, the load compensation control can stably maintain the dimensional accuracy of the molded product and the alignment state of the conductive powder.

[0062] In the step of cooling the molding material (S140), a process of cooling the molding material may be performed. The cooling step is a process of lowering the temperature of the cured molding material to stabilize the final molded product. According to one embodiment, the cooling step may be configured to cool from a second temperature to a third temperature higher than the first temperature within a second time shorter than a predetermined first time, but is not limited thereto; it may be modified according to the physical properties or characteristics of the final product by performing heating and cooling by combining various temperature conditions. In this example, such asymmetric thermal cycle control can provide the effect of rapidly fixing the alignment state of the conductive powder, improving the mechanical properties of the liquid insulating elastic material, and shortening the overall process time.

[0063] The cooling rate can be controlled within a specified range, and since excessively rapid cooling can lead to deformation or cracking of the molded product due to thermal stress, it may be important to maintain an appropriate cooling rate.

[0064] The cooling medium may use cooling water such as water, but is not limited to this, and various cooling media may be used.

[0065] In some embodiments, the third temperature may be set higher than the first temperature, which may be a suitable temperature for ejecting the molded product from the mold. If the third temperature is too low, ejection may be difficult due to the difference in thermal shrinkage between the mold and the molded product, and if it is too high, the dimensional stability of the molded product may be reduced; therefore, it may be desirable to set it within an appropriate range.

[0066] According to one embodiment, the cooling step may apply a multi-stage cooling profile and may be divided, for example, into an initial rapid cooling step and a later slow cooling step. In the initial rapid cooling step, the alignment state of the conductive powder can be quickly fixed, and in the later slow cooling step, thermal stress can be relieved and dimensional stability of the molded product can be ensured.

[0067] In the step (S150) of removing (demagnetizing) the residual magnetic field, a demagnetization process to remove the residual magnetic field may be performed. The demagnetization process is a process of neutralizing the magnetic properties of the molded product by removing the residual magnetic field remaining in the molded product. If a residual magnetic field remains, it may cause the molded product to attract external magnetic materials, affect surrounding electronic equipment, or cause malfunctions during the semiconductor testing process; therefore, it may be important to remove the residual magnetic field.

[0068] According to one embodiment, the demagnetization process can be controlled to start from a preset maximum current and to gradually reduce the magnitude of the applied current while alternating the direction of the applied current in the forward or reverse direction to generate a magnetic field. This stepwise current reduction demagnetization process can maintain the alignment state of the conductive powder while minimizing the residual magnetic field by gradually reducing magnetization along a hysteresis curve.

[0069] The alternating steps can be controlled to gradually decrease the maximum current in the order of a first reverse ratio, a second forward ratio, a third reverse ratio, a fourth forward ratio, and a fifth reverse ratio, and each step can be maintained for a preset time range. The ratios can be appropriately set by considering at least one of the magnetic properties of the molding material, the required residual magnetic field level, and the demagnetization time.

[0070] In some other embodiments, the step of removing (demagnetizing) the residual magnetic field (S150) may be included in the process of performing the step of applying a magnetic field to perform magnetic alignment (S120). By applying the demagnetizing process to part or all of the process of changing the direction of the magnetic field, the magnetic alignment process can be performed while minimizing the residual magnetic field so that the conductive powder can precisely form a conductive column according to the pad position and maintain an electrically insulated state between adjacent conductive columns.

[0071] The semiconductor test socket molding method of the present disclosure can be performed through steps S110 to S150, and each step can be optimized independently as well as controlled integrally by considering the interaction between steps. Through such integrated control, the alignment of the conductive powder, the dimensional accuracy of the molded product, electrical properties, mechanical properties, etc., can all be improved, and a high-quality semiconductor test socket can finally be manufactured.

[0072] FIG. 2 is a flowchart showing a detailed process of a self-alignment step according to one embodiment of the present disclosure.

[0073] Referring to FIG. 2, the self-alignment step (S120) may include a step of setting a target magnetic field based on a constant current control method (S121), a step of applying a magnetic field with a uniform magnetic flux density to a molding material (S122), a step of performing bidirectional current control by selectively supplying forward and reverse currents (S123), and a step of bridge removal and conductive powder aggregation (S124).

[0074] First, in the step (S121) of setting a target magnetic field based on a constant current control method, a process of setting a target magnetic field based on a constant current control method may be performed. The target magnetic field may be determined by considering at least one of the characteristics of the molding material, the type and particle size of the conductive powder, the structure of the mold, and the required alignment degree. The target magnetic field may be expressed as magnetic flux density.

[0075] The present disclosure allows the step of applying a magnetic field to apply a constant current according to a preset constant current control value so that a constant magnetic flux density is maintained in the molding material. The constant current control method has the advantage of maintaining a stable magnetic field without being affected by temperature changes, magnetic saturation, hysteresis, etc., compared to the voltage control method. Constant current control can be implemented through a constant current power supply, and the constant current power supply includes a feedback control circuit to precisely maintain the preset current value.

[0076] When setting the target magnetic field, the required current value can be calculated by considering at least one of the magnetic properties of the mold, the magnetic resistance of the yoke, and the size of the air gap. The calculation can be performed using at least one of magnetic circuit theory, finite element analysis, experimental correction, or a combination thereof. According to one embodiment, the target magnetic field setting can be automatically adjusted by receiving feedback on real-time measurements from a magnetic flux density sensor, thereby enabling more precise magnetic field control.

[0077] In the step (S122) of applying a magnetic field with a uniform magnetic flux density to the molding material, the process of applying a magnetic field with a uniform magnetic flux density to the molding material may be performed. The magnetic field may be applied in a form that penetrates the mold, and the magnetic field lines may flow from the upper plate to the lower plate of the mold or in the opposite direction. The uniformity of the magnetic field may be influenced by at least one of the design of the yoke, the arrangement of the coil, and the position of the mold, and may be maintained so that a uniform magnetic flux density is maintained within the mold cavity as much as possible.

[0078] A uniform magnetic flux density ensures that the conductive powder within the molding material receives a constant magnetic force regardless of its position, thereby improving the uniformity of alignment. If the magnetic flux density is non-uniform, the conductive powder may aggregate excessively in areas with strong magnetic fields, while alignment may be insufficient in areas with weak magnetic fields. Therefore, maintaining a uniform magnetic flux density can be a critical factor in manufacturing high-quality molded products.

[0079] According to one embodiment, the step (S122) of applying a magnetic field with a uniform magnetic flux density to a molding material can monitor the magnetic flux density at various locations within the mold through multi-point magnetic flux density measurement, and can generate a warning or stop the process if the deviation of the measured magnetic flux density exceeds a predetermined allowable range. Additionally, the step (S122) of applying a magnetic field with a uniform magnetic flux density to a molding material may include an automatic alignment function that can improve the uniformity of the magnetic flux density by finely adjusting the position of the mold.

[0080] In the step (S123) of performing bidirectional current control by selectively supplying forward and reverse currents, the process of performing bidirectional current control by selectively supplying forward and reverse currents may be carried out. The present disclosure can improve the alignment degree of the conductive powder by repeatedly switching the direction of the magnetic field between the forward and reverse directions.

[0081] The forward current may be a current that causes the magnetic field to form in a first direction, and the reverse current may be a current that causes the magnetic field to form in a second direction opposite to the first direction. For example, when a forward current is applied, magnetic field lines may flow from the upper plate to the lower plate of the mold, and when a reverse current is applied, magnetic field lines may flow from the lower plate to the upper plate of the mold.

[0082] Bidirectional current control can be controlled to repeat an inversion cycle a predetermined number of times, in which a current is applied in the forward direction for a preset time, and then a reverse current corresponding to a preset ratio of the forward current is maintained for another preset time. During the process of performing the inversion cycle, a state in which the current is zero can be maintained for a preset time when switching from the forward current to the reverse current, and conversely, a state in which the current is zero can be maintained for a preset time when switching from the reverse current to the forward current.

[0083] In some embodiments, the current may be applied as alternating current rather than direct current, and an additional AC controller may be provided to maximize the reversal effect and self-alignment effect through the alternating current. When the direction of the magnetic field is continuously changed due to the alternating current, physical vibrational energy can be obtained in which the particles inside the resin do not remain fixed but instead vibrate or rotate slightly in place. This fine vibration can overcome the viscosity of the liquid resin or the frictional force between particles, thereby allowing the conductive particles to be aligned more precisely according to the direction of the magnetic field.

[0084] For example, the application time of the forward current can be set to a time during which the conductive powder can be sufficiently aligned in the direction of the magnetic field lines, and this may vary depending on the viscosity of the molding material, the size and shape of the conductive powder, the strength of the magnetic field, etc.

[0085] As another example, the magnitude of the reverse current can be set as a preset ratio of the forward current, and the ratio can be selected within a predetermined percentage range. Since if the reverse current is too large, the forward-aligned conductive powder may be completely realigned in the reverse direction, and if it is too small, the effect of the reverse magnetic field may be negligible, it may be important to select an appropriate ratio.

[0086] As another example, the application time of the reverse current may be the same as or different from the application time of the forward current, and may be set shorter than the application time of the forward current. This is because the reverse magnetic field does not completely realign the conductive powder in the reverse direction, but rather serves to resolve inter-particle interference and improve the uniformity of alignment.

[0087] As another example, the number of iterations of the inversion cycle can be set within a predetermined range, and while alignment may improve as the number of iterations increases, excessive iterations can increase process time and energy consumption; therefore, it is important to select the optimal number of iterations.

[0088] The principle of bidirectional current control can be understood as follows. When a forward magnetic field is applied, the conductive powder begins to align along the magnetic field lines; however, due to inter-particle interactions, the viscous resistance of the liquid insulating elastic material, and friction with the mold walls, it may not be completely aligned, and some particles may remain in a non-aligned state. If a reverse magnetic field is applied in this state, the aligned particles tend to rotate in the reverse direction; however, since the strength of the reverse magnetic field is weaker than that of the forward field, they do not completely realign in the reverse direction. Instead, interference between particles is resolved, and the non-aligned particles are given an opportunity to be repositioned. Subsequently, if a forward magnetic field is applied again, more particles can be aligned in the forward direction than before, and the uniformity of alignment can also be improved. By repeating this process, a high degree of alignment and uniformity can ultimately be achieved.

[0089] According to one embodiment, bidirectional current control can gradually change the magnitude of the current for each inversion cycle. For example, a large current can be used in the initial inversion cycle to perform rough alignment of the conductive powder, and a small current can be used in the later inversion cycle to perform fine alignment. Additionally, bidirectional current control can change the ratio of forward and reverse currents for each inversion cycle; for example, the ratio of the reverse current can be set high in the initial cycle to actively resolve inter-particle interference, and the ratio of the reverse current can be set low in the later cycle to stabilize the alignment state.

[0090] In the bridge removal and conductive powder aggregation step (S124), a vertical alignment state of the conductive powder within the molding material can be formed after performing the preceding magnetic alignment process. Vertical alignment may refer to a state in which the conductive powder is aligned in the direction connecting the upper and lower plates of the mold, that is, in the direction of the magnetic field lines. This vertical alignment state forms a conductive path that electrically connects the pads of the semiconductor chip and the pads of the test substrate in the semiconductor test socket.

[0091] The formation of a vertically aligned state can be achieved through the bidirectional current control described earlier, and the alignment state can be fixed during the curing process while maintaining the magnetic field. During the curing process, as the viscosity of the liquid insulating elastic material increases and it finally solidifies, the position of the conductive powder is fixed and the alignment state can be permanently maintained.

[0092] The quality of the vertical alignment state can be evaluated by at least one indicator among alignment degree, uniformity, and continuity. Alignment degree may be an indicator of how well the conductive powder is aligned in the direction of magnetic field lines, uniformity may be an indicator of how consistent the alignment degree is at various locations within the molded product, and continuity may be an indicator of whether the conductive powder is connected without interruption from the top plate to the bottom plate. The bidirectional current control process of the present disclosure can improve all of these indicators.

[0093] As vertical alignment is achieved, the alignment state of the conductive powder can form multiple conductive columns in the shape of spaced-apart pillars as shown in Fig. 7 described later. During the process of repeated self-alignment, bridge shapes that deviate from the center of the pillar and connect to adjacent pillars can be eliminated, and the aggregation and density per unit area of ​​the conductive powder forming the conductive columns can be improved. Through repeated self-alignment, the aggregation can be improved according to the direction of magnetic field application to the conductive powder.

[0094] FIG. 3 is a flowchart illustrating a load compensation control method according to one embodiment of the present disclosure.

[0095] Referring to FIG. 3, the load compensation control method may include the step of pressurizing a molding material with a predetermined pressure (S131), the step of detecting a change in the volume of the molding material (S132), the step of calculating a predetermined load compensation value (S133), and the step of adjusting the pressure according to the load compensation value (S134).

[0096] In the step (S131) ​​of pressurizing the molding material with a predetermined pressure, the process of pressurizing the molding material with a predetermined pressure may be performed. This involves maintaining the pressure set in the molding material pressurizing step (S110), and the predetermined pressure may be determined by considering at least one of the type of molding material, the size of the mold, and the required density of the molded product. Pressurization may be performed using at least one of a hydraulic cylinder, a pneumatic cylinder, an electric actuator, or a combination thereof, and the pressure may be measured in real time through a load cell.

[0097] In the step (S132) of detecting a volume change of the molding material, a process of detecting a volume change of the molding material may be performed. The volume change may be due to thermal expansion occurring during the curing process, and thermal expansion may occur as the temperature of the molding material rises. The volume change may be measured directly or estimated indirectly.

[0098] A direct measurement method may involve using a displacement sensor to measure the change in position of the mold top plate. The displacement sensor may be at least one of a linear encoder, an LVDT, a laser distance sensor, an ultrasonic sensor, or a combination thereof. When the mold top plate rises, it may indicate that the molding material is expanding, and the change in volume can be calculated from the amount of rise.

[0099] One indirect estimation method involves monitoring changes in load measured by a load cell. When the molding material expands, a force is generated that pushes the top plate of the mold upward, which can reduce the load measured by the load cell. Therefore, the expansion of the molding material can be indirectly detected by sensing a decrease in load. Additionally, volume changes can be estimated using the temperature of the molding material measured by a temperature sensor and its coefficient of thermal expansion.

[0100] In the step of calculating a predetermined load compensation value (S133), a process of calculating a predetermined load compensation value may be performed. The load compensation value may be calculated based on the difference between the set pressure and the currently measured pressure, and may represent the additional pressure or pressure reduction amount required to compensate for the difference.

[0101] According to one embodiment, the calculation of the load compensation value may utilize at least one advanced control algorithm among fuzzy control, model predictive control, adaptive control, or a combination thereof. Additionally, the calculation of the load compensation value may perform more accurate compensation by additionally considering at least one of the temperature of the molding material, the curing progress, and past data.

[0102] In the step of adjusting pressure according to the load compensation value (S134), the process of adjusting pressure according to the load compensation value may be performed. Pressure adjustment may be performed through a proportional control valve that controls the pressure of the hydraulic cylinder. The proportional control valve is a valve capable of adjusting the magnitude of hydraulic pressure in proportion to an electrical signal, and the electrical signal may correspond to the load compensation value calculated in the step of calculating the load compensation value (S133).

[0103] If the measured pressure is lower than the set pressure, that is, if the load decreases due to the expansion of the molding material, the load compensation value becomes positive, and the proportional control valve can operate to increase the hydraulic pressure. Accordingly, the hydraulic cylinder descends further, increasing the pressure applied to the molding material, and the measured pressure can return to the set pressure.

[0104] Conversely, if the measured pressure is higher than the set pressure—for example, if the molding material shrinks or the load increases due to external factors—the load compensation value becomes negative, and the proportional control valve can operate to reduce the hydraulic pressure. Accordingly, the hydraulic cylinder rises, reducing the pressure applied to the molding material, and the measured pressure can return to the set pressure.

[0105] The pressure adjustment process can be performed continuously throughout the curing process, and the control cycle can be set to a predetermined range of milliseconds or seconds. While a faster control cycle enables more precise pressure control, it can increase the computational load of the molding device; therefore, it is important to select an appropriate control cycle.

[0106] The present disclosure can improve the dimensional accuracy of a molded article by maintaining a constant pressure despite the thermal expansion of the molding material through a load compensation control method. Additionally, the present disclosure can prevent the alignment state of conductive powder from being disturbed by pressure fluctuations through a load compensation control method. Furthermore, the present disclosure can improve the mechanical properties of a molded article by maintaining a constant density of the molding material through a load compensation control method. Moreover, the present disclosure can improve process flexibility by automatically adapting to various molding materials and curing conditions through a load compensation control method.

[0107] FIG. 4 is a BH curve graph for explaining the principle of a stepwise current reduction demagnetization process according to one embodiment of the present disclosure.

[0108] Referring to FIG. 4, the BH graph is a hysteresis curve representing the magnetization characteristics of a magnetic material, where the horizontal axis represents the magnetic field strength (H) and the vertical axis represents the magnetic flux density (B).

[0109] Generally, when a magnetic field is applied to a magnetic material, the magnetic flux density increases with the strength of the magnetic field and can move along the initial magnetization curve. If the strength of the magnetic field is continuously increased, the magnetic flux density may reach a saturation state. In this state, if the magnetic field is reduced, the magnetic flux density does not return to the initial magnetization curve but can move along a different path, the hysteresis curve. Even when the magnetic field becomes zero, the magnetic flux density does not become zero and may have a residual magnetic flux density, which can be the cause of the residual magnetic field (Br).

[0110] In order to make the residual magnetic flux density zero, a reverse magnetic field must be applied. However, if the magnetic field is removed after the magnetic flux density is reduced to zero by applying a reverse magnetic field equal to the coercivity (Hc), which is the required magnetic field strength, residual magnetic flux density may reappear, so a more sophisticated method is required for complete demagnetization.

[0111] The stepwise current reduction demagnetization process of the present disclosure is a method that minimizes the residual magnetic field by utilizing the characteristics of a hysteresis curve. The process may consist of starting at a maximum magnetic field and gradually reducing the magnetic field strength while alternating between forward and reverse directions.

[0112] In some embodiments, the current may be applied as alternating current rather than direct current, and an additional AC controller may be provided to maximize the demagnetization effect through the alternating current. The demagnetization effect can be achieved through the continuous reversal of the magnetic field direction and the gradual reduction of its strength. Since the direction of the current coming from the power source itself changes direction 120 times per second in the case of 60Hz, the direction change effect can be naturally achieved by alternating between positive and negative. Unlike DC circuits, which require the addition of a reverse-phase switching circuit, AC circuits can achieve the demagnetization effect without mechanical switching of the current direction by simply gradually reducing the total current strength to zero.

[0113] Specifically, the demagnetization process can proceed as follows on the BH graph of Fig. 4. First, at the point when the curing process is completed, the molding material is magnetized by the maximum positive magnetic field (+Hmax) and may have a corresponding magnetic flux density (+Bmax). In this state, the demagnetization process can be started.

[0114] In the first step, the magnetic field can be switched to a reverse first ratio (-H1). The first ratio (-H1) may be a reverse magnetic field corresponding to a predetermined ratio of +Hmax. Accordingly, the magnetic flux density can shift to -B1 along the hysteresis curve. During this process, the magnetization direction of the magnetic material can be partially reversed.

[0115] In the second stage, the magnetic field can be switched to a second positive ratio (+H2). The second ratio (+H2) may be a positive magnetic field corresponding to a predetermined ratio of +Hmax and may be smaller than the first ratio (-H1). Accordingly, the magnetic flux density can shift to +B2 along the hysteresis curve. During this process, the magnitude of the hysteresis loop may begin to decrease.

[0116] In the third step, the magnetic field can be switched to a reverse third ratio (-H3). The third ratio (-H3) may be a reverse magnetic field corresponding to a predetermined ratio of +Hmax and may be smaller than the first ratio (-H1). Accordingly, the magnetic flux density can shift to -B3.

[0117] In the fourth step, the magnetic field can be switched to a forward fourth ratio (+H4). The fourth ratio (+H4) may be a forward magnetic field corresponding to a predetermined ratio of +Hmax and may be smaller than the second ratio (+H2). Accordingly, the magnetic flux density can shift to +B4.

[0118] In the fifth step, the magnetic field can be switched to the reverse fifth ratio (-H5). The fifth ratio (-H5) may be a reverse magnetic field corresponding to a predetermined ratio of +Hmax and may be smaller than the third ratio (-H3). Accordingly, the magnetic flux density may shift to -B5.

[0119] In the final stage, the magnetic field can be gradually reduced to zero. Accordingly, the magnetic flux density can converge to a value close to zero, and the residual magnetic flux density can be minimized.

[0120] The stepwise current reduction demagnetization process involves gradually reducing the size of the hysteresis loops while converging the magnetic flux density to zero. On the BH graph in Fig. 4, this appears as superimposed hysteresis loops that become progressively smaller, and can be repeated in the demagnetization process in a form that eventually converges to the origin (H=0, B=0).

[0121] The duration for maintaining the magnetic field at each stage of the demagnetization process can be set by considering the magnetization relaxation time of the magnetic material. Maintaining the magnetic field for a sufficient period allows the magnetic domains of the magnetic material to rearrange themselves toward the new magnetic field direction, which can enable more effective demagnetization.

[0122] According to one embodiment, the demagnetization process may consist of more or fewer than five steps. A higher number of steps enables more precise demagnetization, but may increase the process time. Additionally, the ratio of magnetic field strengths in each step may be optimized by considering at least one of the magnetic properties of the molding material and the required residual magnetic field level.

[0123] The present disclosure can reduce residual magnetic flux density to a level below a predetermined level through a stepwise current reduction demagnetization process, and since the alignment state of the conductive powder is already fixed during the curing process, it can be maintained during the demagnetization process. In addition, the present disclosure can improve energy efficiency by minimizing hysteresis losses through a stepwise current reduction demagnetization process, and can minimize the influence of external magnetic fields by neutralizing the magnetic properties of the molded article.

[0124] In some embodiments, the magnetic field may be maintained at zero for a predetermined period between demagnetization processes to increase magnetic field stability and maximize demagnetization efficiency, but is not limited thereto.

[0125] FIG. 5 is a graph showing asymmetric thermal cycle control according to one embodiment of the present disclosure.

[0126] Referring to Fig. 5, the horizontal axis of the graph may represent time and the vertical axis may represent temperature. The graph can be broadly divided into a heating section and a cooling section, and the temperature profile of each section can be clearly displayed.

[0127] Heating of the liquid insulating elastic material can be performed through an external heating block. The heating block is a device placed outside the mold to heat the mold, and may include at least one of a cartridge heater, a band heater, an induction heating coil, or a combination thereof. The temperature of the heating block can be precisely controlled through a PID controller and can be controlled so that the temperature of the mold rises along a set profile.

[0128] According to one embodiment, the heating section may be configured in multiple stages. For example, the temperature may be raised to a preheating temperature at a rapid heating rate initially, and then raised to a curing temperature at a slow heating rate. Additionally, after reaching the curing temperature, the temperature may be maintained for a certain period of time to allow the curing reaction to proceed sufficiently.

[0129] In the cooling section, the temperature of the mold may be lowered from a second temperature (e.g., 160°C) to a third temperature (e.g., 40°C). The third temperature may be set higher than the first temperature, which may be a suitable temperature for ejecting the molded product from the mold. The reason the third temperature is higher than the first temperature may be to shorten the overall process time by ejecting the molded product before it is completely cooled, and to facilitate ejection by maintaining an appropriate difference in thermal shrinkage between the mold and the molded product.

[0130] The alignment of the conductive powder can be rapidly fixed through rapid cooling based on an asymmetric thermal cycle. Although the viscosity of the liquid insulating elastomer increases during the curing process, there is a possibility that the conductive powder may move slightly until it is completely solidified.

[0131] Furthermore, the present disclosure can rapidly solidify a liquid insulating elastomer through rapid cooling based on an asymmetric thermal cycle, thereby securely fixing the position of the conductive powder. Additionally, the present disclosure can improve mechanical properties by influencing the crystal structure or crosslinking structure of the liquid insulating elastomer through rapid cooling based on an asymmetric thermal cycle. For some polymeric materials, the degree of crystallinity, crosslinking density, residual stress, etc., may change depending on the cooling rate, and an appropriate cooling rate can provide optimal mechanical properties.

[0132] In addition, the present disclosure can reduce the overall process time through rapid cooling based on an asymmetric thermal cycle. For example, the thermal cycle time may include maintaining a heating state to increase the temperature for a first time, maintaining a state that has reached a maximum temperature range for a second time, and maintaining a cooling state for extraction again for a third time.

[0133] The cooling process according to the present disclosure may be performed using a chiller. A chiller is a device that cools a mold by circulating cooling water, and may be configured so that cooling water flows through cooling channels formed in the mold. The cooling speed of the mold can be controlled by controlling the temperature and flow rate of the cooling water. According to one embodiment, cooling may be performed using at least one of forced air cooling, liquid nitrogen injection, a Peltier element, or a combination thereof.

[0134] The graph in FIG. 5 may represent a high-speed thermal shock mitigation algorithm. Thermal shock may refer to stress occurring in a material due to a rapid change in temperature, and excessive thermal shock may result in defects such as deformation, cracking, and delamination of the molded product. The asymmetric thermal cycle of the present disclosure may include an algorithm capable of mitigating thermal shock while applying rapid cooling.

[0135] Thermal shock mitigation algorithms can be implemented by applying a relatively slow cooling rate during the initial cooling phase and a faster cooling rate once the temperature of the molding material has dropped to a certain level. Additionally, the cooling process can be divided into multiple stages, with different cooling rates applied to each stage. This approach allows the molding material time to adapt to rapid temperature changes while achieving rapid cooling overall.

[0136] According to one embodiment, the parameters of the asymmetric thermal cycle (first temperature, second temperature, third temperature, first time, second time) can be adjusted by considering at least one of the type of molding material, the size and shape of the molded article, and the required mechanical properties. For example, in the case of a heat-sensitive molding material, both the heating rate and the cooling rate can be lowered, and in the case of a thick molded article, the cooling time can be increased by considering the temperature gradient.

[0137] FIG. 6 is a block diagram showing the overall configuration of a semiconductor test socket molding device according to one embodiment of the present disclosure.

[0138] Referring to FIG. 6, the semiconductor test socket molding device may include a magnetic field application unit (100), a pressurizing unit (200), a heating and cooling unit (300), a transfer unit (400), and a control unit (500).

[0139] The magnetic field application unit (100) can be configured to apply a magnetic field to the mold.

[0140] The mold is provided in a form where heterogeneous materials are arranged in an alternating pattern, and magnetic materials can be placed on the upper and lower plates of the mold according to spacing corresponding to the pad locations of the semiconductor chip to be inspected. The mold can cause the distribution of the magnetic field formed inside the mold to change locally due to the difference in magnetic properties between the area where the magnetic materials are placed and the area where the non-magnetic materials are placed.

[0141] When a magnetic field is applied, the mold can concentrate the magnetic force around the location where the magnetic material is placed, and accordingly, the conductive powder contained in the molding material inside the mold can be induced to be arranged in a direction corresponding to the location where the magnetic material is placed.

[0142] The mold can form a conductive path in which conductive powder is aligned at a position corresponding to the pad array of the semiconductor chip, thereby forming a conductive contact structure that electrically contacts the pads of the semiconductor chip.

[0143] The mold top plate may include a base plate and a plurality of magnetic inserts disposed on the base plate. The base plate may be made of a non-magnetic material and may be at least one of stainless steel, aluminum alloy, brass, or a combination thereof. A plurality of holes for inserting magnetic inserts may be machined in the base plate, and the positions of the holes may be designed to correspond precisely to the pad positions of the semiconductor chip to be inspected.

[0144] The magnetic insert may be made of at least one of pure iron, ferrite, permalloy, silicon steel, or a combination thereof, and may have at least one shape among a cylinder, a prism, a cone, a pyramid, or a combination thereof. The diameter or cross-sectional size of the magnetic insert may be similar to or set at a predetermined ratio to the pad size of the semiconductor chip.

[0145] The spacing between magnetic inserts can be set to match the pad spacing (pitch) of a semiconductor chip. The semiconductor chip may have a very fine pitch. The mold structure of the present disclosure can be manufactured precisely to correspond to such fine pitch.

[0146] The space between the magnetic inserts can be filled with a non-magnetic material. The non-magnetic material may be a composite material obtained by mixing stainless steel powder, aluminum powder, ceramic powder, or a combination thereof with at least one of epoxy resin, polyimide resin, or silicone resin. After filling with the non-magnetic material, the mold surface can be flattened through grinding, thereby allowing the magnetic inserts and the non-magnetic material to form a coplane.

[0147] The lower plate of the mold can be manufactured with a structure symmetrical to the upper plate, and the position of the magnetic insert can be arranged to correspond precisely to that of the upper plate. When the upper and lower plates are assembled, the magnetic inserts of the upper plate and the lower plate are aligned to form a magnetic field line path that penetrates the molding material.

[0148] The operating principle of the heterogeneous material cross-array structure is that when a uniform magnetic field is applied from the outside, magnetic field lines are concentrated in the magnetic material insert portion due to high magnetic permeability, while magnetic field lines can pass relatively less through the non-magnetic material portion due to low magnetic permeability. As a result, a strong magnetic field is formed locally at the location of the magnetic material insert within the molding material, and the conductive powder can move to the strong magnetic field region and be aligned.

[0149] As a result, the conductive powder is intensively aligned with the location of the magnetic insert to form a conductive path, and the conductive path can accurately correspond to the pad location of the semiconductor chip. This structure enables the implementation of fine pitch, improves the positional precision of the conductive path, and can increase the reliability of semiconductor testing.

[0150] According to one embodiment, the mold can be manufactured with a multilayer structure, and each layer may have a different pattern of magnetic material arrangement. The magnetic material insert can be manufactured from a composite material rather than a single material; for example, the center may be composed of a high-permeability material and the outer part of a low-permeability material to more precisely control the magnetic field distribution.

[0151] The magnetic field application unit (100) may include an electromagnet, a yoke, a bidirectional current supply device, and a constant current control circuit, etc.

[0152] Electromagnets can be placed on the upper and lower parts of the mold and can generate a magnetic field by passing current through the coil. The yoke can provide a path for magnetic field lines and improve the efficiency of the magnetic field, and can have various shapes.

[0153] The pressurizing unit (200) may be configured to apply pressure to the molding material. The pressurizing unit (200) may include a hydraulic cylinder, a proportional control valve, a load cell, and a load compensation control circuit.

[0154] The hydraulic cylinder is connected to the mold top plate to lower or raise the plate, and the proportional control valve can control the applied pressure by adjusting the magnitude of the hydraulic pressure. The load cell can measure the applied pressure in real time, and the load compensation control circuit can automatically adjust the proportional control valve by comparing the measured applied pressure with the set applied pressure.

[0155] The heating and cooling unit (300) may be configured to control the temperature of the mold. The heating and cooling unit (300) may include a heating block, a cooling channel, a chiller, a temperature sensor, a temperature controller, etc.

[0156] The heating block can heat the mold, and cooling channels can be formed inside the mold to allow cooling water to flow. The chiller can cool and circulate the cooling water, the temperature sensor can measure the temperature of the mold, and the temperature controller can automatically control the heating block and chiller by comparing the measured temperature with the set temperature.

[0157] The transfer unit (400) may be configured to automatically transfer the mold. The transfer unit (400) may automatically transfer the mold into which the molding material has been introduced to a predetermined center area of ​​the yoke for applying a magnetic field. The transfer unit (400) may include a transfer rail, a transfer carrier, a servo motor, a position sensor, a clamping mechanism, etc., and may precisely position and fix the mold, but is not limited thereto.

[0158] The control unit (500) may be configured to integrally control the magnetic field application unit (100), the pressurizing unit (200), the heating and cooling unit (300), and the transfer unit (400). The control unit (500) may include, for example, a PLC, a microcontroller, an HMI, a communication network, etc., but is not limited thereto. The PLC or microcontroller can transmit control signals to each sub-device, collect data from sensors, and automatically proceed with the process according to a set process sequence. The HMI may provide an interface that allows an operator to set process parameters, monitor the process status, and check alarms.

[0159] FIG. 7 is a schematic diagram showing the cross-sectional structure of a semiconductor test socket molded article manufactured by a method according to one embodiment of the present disclosure.

[0160] Referring to Fig. 7, it can be seen that the conductive powder is aligned and the liquid insulating elastic material is cured.

[0161] The molded article may be composed of a conductive path (21) and a cured liquid insulator (22). The cured liquid insulator (22) may serve to provide mechanical strength to the molded article and electrically insulate the conductive path (21). The conductive path (21) is formed of aligned conductive powder and may serve to provide an electrical connection by connecting from the upper surface to the lower surface of the molded article.

[0162] The conductive path (21) may appear in the form of a column or column of conductive powder arranged in a vertical direction. The conductive powders are aligned along the direction of the magnetic field, and the spacing between particles is minimized to provide electrical continuity. The diameter of the conductive path (21) may correspond to the size of the magnetic insert placed in the mold.

[0163] The spacing between the conductive paths (21) can match the spacing of the pads of the semiconductor chip, which can be determined by the arrangement of magnetic inserts in the mold. The spacing can be controlled very precisely.

[0164] The ends of the conductive path (21) may be exposed on the upper and lower surfaces of the molded product, and the ends may provide an electrical connection by contacting the pads of the semiconductor chip and the pads of the test substrate. The surface of the ends must be flat and clean, and post-processing such as polishing, cleaning, and surface treatment may be performed as needed.

[0165] As described above, the disclosed embodiments have been explained with reference to the attached drawings. Those skilled in the art will understand that the present disclosure may be practiced in forms different from the disclosed embodiments without changing the technical spirit or essential features of the present disclosure. The disclosed embodiments are illustrative and should not be interpreted restrictively. Explanation of the symbols

[0166] 100: Magnetic field application part 200: Pressurizing part 300: Heating and cooling section 400: Transfer unit 500: Control unit

Claims

Claim 1 A step of pressurizing a molding material introduced into a mold; a step of applying a magnetic field to the mold; a step of heating the mold to cure the molding material; A method for molding an elastic socket for semiconductor testing, comprising the step of cooling the molding material, wherein the molding material is in the form of a mixture of conductive powder and a liquid insulating elastic material, the step of applying a magnetic field includes a process of self-aligning the conductive powder within the molding material by repeating a forward and reverse direction reversal with respect to the magnetic field a preset number of times, the step of curing is performed while maintaining the magnetic field applied to the mold, and further includes the step of alternating the direction of the current applied to generate the magnetic field in the forward or reverse direction starting from a preset maximum current, wherein the alternating step is controlled to gradually reduce the magnitude of the applied current, and includes a process of controlling the applied current to gradually reduce the applied current in the order of a first reverse ratio, a second forward ratio, a third reverse ratio, a fourth forward ratio, and a fifth reverse ratio relative to the maximum current starting from a preset maximum current value, and wherein each of the stepwise reduction processes is controlled to be maintained for a preset time range. Claim 2 A method for forming an elastic socket for semiconductor testing according to claim 1, wherein the step of applying the magnetic field includes a bidirectional current supply process that selectively supplies a forward or reverse current, and is controlled to repeat a reversal cycle a predetermined number of times in which a reverse current corresponding to a predetermined ratio of the forward current is maintained for another predetermined time after applying the current in the forward direction for a predetermined time. Claim 3 delete Claim 4 delete Claim 5 A method for forming an elastic socket for semiconductor testing according to claim 1, wherein the step of applying the magnetic field involves applying a constant current according to a preset constant current control value so that a constant magnetic flux density is maintained in the molding material. Claim 6 A method for forming an elastic socket for semiconductor testing according to claim 1, wherein the step of pressurizing the molding material measures the load applied to the molding material to maintain a preset pressure, and the step of curing the molding material performs load compensation control to maintain the preset pressure even when the molding material expands. Claim 7 A method for molding an elastomer socket for semiconductor testing, wherein, in claim 1, the step of applying a magnetic field to the mold is controlled to gradually reduce the magnitude of the applied current, and further comprises the step of gradually changing the strength of the magnetic field or the duration of the magnetic field in the process of self-aligning the conductive powder. Claim 8 A method for forming an elastic socket for semiconductor testing, wherein, in claim 1, the mold is provided in a form in which heterogeneous materials are intersected, and the upper plate and lower plate of the mold have magnetic materials arranged according to a spacing corresponding to the pad positions of the semiconductor chip to be tested. Claim 9 In claim 1, the step of applying a magnetic field to the mold further includes the step of alternating the direction of the current applied to generate the magnetic field in a forward or reverse direction, starting from a preset maximum current, and the alternating step is controlled to gradually reduce the magnitude of the applied current, and a method for molding an elastic socket for semiconductor testing. Claim 10 A molding device for an elastic socket for semiconductor testing to which the method of any one of paragraphs 1 to 2 and 5 to 9 is applied.

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