Methods for forming reduced warpage electronic devices

Abstract

A method for forming an electronic device is provided. The method comprises the steps that a substrate is provided, and at least one electronic element is installed on the substrate; forming a molding layer on the substrate to encapsulate the at least one electronic component; curing the molding layer to convert it into a mold cover; placing the substrate with the mold cover on a carrier, wherein the carrier is provided with a ventilation channel penetrating through the carrier; applying laser radiation via a laser source to heat the mold cover and the substrate to a temperature above a predetermined temperature threshold; when the temperature of the mold cover and the temperature of the substrate are higher than the preset temperature threshold value, vacuum pressure is applied to the substrate and the mold cover through the ventilation channel of the carrier, so that the substrate and the mold cover are adsorbed to the carrier, in this way, warpage of the mold cover and the substrate generated during the curing step is reduced.

Description

Technical Field

[0001] This application generally relates to semiconductor technology, and more specifically, to methods for forming electronic devices with reduced warpage. Background Technology

[0002] The semiconductor industry has consistently faced complex integration challenges as consumers demand smaller, faster, and higher-performing electronics, packing increasing functionality into single devices. Typically, a semiconductor package is formed by first mounting electronic components onto a substrate using solder bumps, followed by the formation of a mold cap on the substrate to encapsulate the electronic components. The mold cap formation process may involve curing a molding material formed on the substrate, which can then be converted into the mold cap. This curing process can be performed by heating the entire device to cure the molding material. However, due to the mismatch in coefficients of thermal expansion (CTE) between different materials within the device, the curing process can introduce warpage issues between the substrate and the mold cap, potentially adversely affecting device performance and subsequent manufacturing processes.

[0003] Therefore, a method for forming electronic devices with reduced warpage is needed. Summary of the Invention

[0004] The purpose of this application is to provide a method for forming electronic devices with reduced warpage.

[0005] According to one aspect of this application, a method for forming an electronic device is provided. The method includes: providing a substrate on which at least one electronic component is mounted; forming a molding layer on the substrate to encapsulate the at least one electronic component; curing the molding layer to convert it into a mold cover; placing the substrate with the mold cover onto a carrier having a ventilation channel therethrough; applying laser radiation via a laser source to heat the mold cover and the substrate to a temperature above a predetermined temperature threshold; and when the temperature of the mold cover and the substrate is above the predetermined temperature threshold, applying a vacuum pressure to the substrate and the mold cover through the ventilation channel of the carrier, such that the substrate and the mold cover are adsorbed onto the carrier to reduce warping of the mold cover and the substrate during the curing step.

[0006] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and do not limit the invention. Furthermore, the accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with this specification, serve to explain the principles of the invention. Attached Figure Description

[0007] The accompanying drawings, which are incorporated herein by reference, form part of this specification. Unless expressly indicated otherwise in the detailed description, the features shown in the drawings illustrate only some embodiments of this application, and not all embodiments thereof, and should not be construed as implying to the reader of this specification that all embodiments are possible.

[0008] Figures 1A to 1F The various steps of a method for forming an electronic device according to a first embodiment of this application are illustrated.

[0009] Figure 2 The laser radiation step for heating a mold cover and a substrate to form an electronic device is shown according to a second embodiment of this application.

[0010] Figure 3 The laser radiation step for heating a mold cover and a substrate to form an electronic device is shown according to a third embodiment of this application.

[0011] Figure 4 This invention illustrates a cooling step for cooling the mold cover and substrate after a laser irradiation step is performed on the mold cover and substrate, according to a fourth embodiment of the present application.

[0012] Figure 5 This invention illustrates a cooling step for cooling the mold cover and substrate after a laser irradiation step is performed on the mold cover and substrate, according to a fifth embodiment of the present application.

[0013] The same reference numerals will be used throughout the accompanying drawings to refer to the same or similar parts. Detailed Implementation

[0014] The following detailed description of exemplary embodiments of this application takes into account the accompanying drawings, which form a part of the description. The drawings illustrate specific exemplary embodiments in which this application may be practiced. The detailed description, including the drawings, describes these embodiments in sufficient detail to enable those skilled in the art to practice this application. Those skilled in the art may further utilize other embodiments of this application and make logical, mechanical, and other changes without departing from the spirit or scope of this application. Therefore, the reader of the following detailed description should not interpret the description in a limiting sense, and the scope of the embodiments of this application is defined only by the appended claims.

[0015] In this application, unless otherwise expressly stated, the use of the singular includes the plural form. In this application, unless otherwise stated, the use of “or” means “and / or”. Furthermore, the use of the term “comprising” is not restrictive. Additionally, unless otherwise expressly stated, terms such as “element” or “assembly” cover both elements and assemblies comprising one unit and elements and assemblies comprising more than one sub-unit. Furthermore, the section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described.

[0016] As used herein, for ease of description, spatial relative terms such as “below,” “under,” “above,” “upper,” “upper,” “lower,” “left,” “right,” “vertical,” “horizontal,” and “side” may be used to describe the relationship between an element or feature and another element (or feature) or feature (or feature), as shown in the diagrams. In addition to the orientations depicted in the diagrams, the spatial relative terms are intended to cover different orientations of the device in use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein shall be interpreted accordingly. It should be understood that when an element is referred to as “connected to” or “coupled to” another element, the element may be directly connected to or coupled to the other element, or there may be intermediate elements present.

[0017] As mentioned above, electronic components can first be mounted onto a substrate using solder bumps, and then a mold cap can be formed on the substrate to encapsulate the electronic components, thus forming a semiconductor package. The mold cap formation process may include a curing process, which heats the molding material formed on the substrate and transforms it into the mold cap. During the heating process, the mold cap and substrate may deform due to a mismatch in the coefficient of thermal expansion (CTE) between the substrate and the mold cap, a mismatch stemming from material differences between the two. Therefore, both the mold cap and the substrate may experience warpage after mold cap formation. Particularly for mold caps formed from epoxy molding compound (EMC), the CTE of the mold cap may be much larger than that of the substrate. Consequently, the degree of mold cap deformation may be greater than that of the substrate, which can adversely affect device performance and subsequent manufacturing processes.

[0018] To address this issue, a novel method for forming electronic devices is provided. This new method introduces a laser irradiation step after the curing step of the molding layer. This laser irradiation step heats the mold cap and substrate formed by the molding layer to a temperature above a predetermined temperature threshold, thereby making the mold cap and substrate deformable. When the temperature of the mold cap and substrate exceeds the predetermined temperature threshold, a vacuum pressure is applied to the substrate and mold cap via a carrier beneath the substrate. Therefore, the substrate and mold cap can be adsorbed onto the carrier, which reduces warpage of the mold cap and substrate during the curing step, thus improving device performance and facilitating subsequent manufacturing processes.

[0019] Figures 1A to 1F The various steps of a method for forming an electronic device according to a first embodiment of this application are illustrated.

[0020] like Figure 1AAs shown, substrate 100 has embedded interconnects 101. Substrate 100 includes: a front surface that can serve as a platform for mounting electronic components; and a rear surface opposite the front surface. In some embodiments, substrate 100 may be made of silicon or other semiconductor materials, or may comprise a printed circuit board (PCB), carrier substrate, ceramic substrate, laminated interposer, laminated interposer, lead frame, or other suitable substrate. Interconnects 101 may be formed between and through substrates 100. Thus, electronic components and other structures on one or both surfaces of substrate 100 can be electrically coupled to each other to form an integrated electronic system, which will be described in more detail below. In some embodiments, a first set of conductive pads 102 may be formed on the front surface of substrate 100 for mounting electronic components. It will be understood that the first set of conductive pads 102 may be exposed portions of interconnects 101 formed within substrate 100.

[0021] Next, solder paste is applied to each of the first set of conductive pads 102 for mounting electronic components. The solder paste may contain metallic materials or combinations of metallic materials. It is understood that metallic solder may also contain a combination of metallic and non-metallic materials. More specifically, the metallic materials may be Al, Sn, Ni, Au, Ag, lead (Pb), bismuth (Bi), Cu, or combinations thereof.

[0022] Next, at least one electronic component 111 is placed on the front surface of the substrate 100. More specifically, each of the at least one electronic component 111 may include a second set of conductive pads 112 on its rear surface. Each of the second set of conductive pads 112 is aligned with one of the first set of conductive pads 102, with solder paste placed therebetween. In some other embodiments, additional solder paste may be attached to the second set of conductive pads 112. At least one electronic component 111 can then be placed on the front surface of the substrate 100, with solder paste and additional solder paste placed between the first set of conductive pads 102 and the second set of conductive pads 112. In some embodiments, the electronic component 111 may comprise various types of electronic modules, such as semiconductor chips, resistors, capacitors, or other integrated circuit chips. For example, the electronic component 111 may comprise a semiconductor die. Furthermore, as... Figure 1A As shown, one or more electronic components 111 are mounted on the substrate 100, wherein the electronic components 111 may have various sizes and be arranged in different layouts. In some embodiments, flux material may be further applied to the solder paste or dispensed onto the first set of conductive pads 102 to facilitate subsequent reflow soldering processes.

[0023] Next, a heating process (e.g., thermal convection heating or laser radiation heating) can be performed on the substrate 100 to heat the solder paste, allowing it to be heated and reflowed to form solder bumps 105 between the first set of conductive pads 102 and the second set of conductive pads 112. The solder bumps 105 thus formed can create an electrical connection between at least one electronic component 111 and the substrate 100. During the solder paste heating process, a large amount of heat is applied directly to the substrate 100 and at least one electronic component 111, which may temporarily cause warping of the substrate 100. Specifically, in some embodiments, more than one electronic component 111 having various sizes and layouts is mounted on the substrate 100, and different portions or locations of the substrate 100 may absorb different amounts of heat due to the varying sizes and layouts of the electronic components 111 mounted thereon, thereby causing additional warping problems for the substrate 100.

[0024] In some embodiments, substrate 100 may be provided as a strip substrate comprising a plurality of substrate units, such that each of the substrate units can be used as a platform for forming an electronic package. The strip substrate may or may not include multiple connecting portions, each positioned between two adjacent substrate units, thereby connecting the plurality of substrate units as a strip substrate. In this embodiment, each of the substrate units may have the same or similar structure, while the electronic components 111 mounted on the respective substrate units may have different sizes and layouts. It is understood that the same processing can be used simultaneously on multiple substrate units to form multiple electronic packages. Furthermore, it is understood that in some embodiments, both the connecting portions and the substrate units are originally formed within the strip substrate and do not need to be assembled together as a strip substrate.

[0025] Next, as Figure 1B As shown, a molding layer 115 is formed on a substrate 100 to encapsulate at least one electronic component 111. More specifically, the molding layer 115 can be formed using an injection molding process, the molding layer covering the front surface of the substrate 100 and the corresponding surface of at least one electronic component 111 for encapsulation. In some other embodiments, the molding layer 115 can be formed using various other molding techniques, including, for example, transfer molding, compression molding, or film-assisted molding (FAM) processes. In some embodiments, the molding layer 115 can be an epoxy molding compound (EMC). It is also understood that the molding layer 115 can be made of polymer composite materials, such as epoxy resin with fillers, epoxy acrylate with fillers, or polymers with suitable fillers, but the scope of this application is not limited thereto.

[0026] Next, a heating process is performed on the molding layer 115 and the substrate 100 via convective heat transfer or thermal radiation, heating the molding layer 115 to a temperature above its curing temperature, allowing the molding layer 115 to solidify and transform into a mold cap 116. During the heating process, the formed mold cap 116 and substrate 100 may expand to different degrees, possibly due to a mismatch in the coefficients of thermal expansion between the different materials of the mold cap 116 and the substrate 100. Therefore, temporary warping problems may occur on both the mold cap 116 and the substrate 100. Specifically, in some embodiments, electronic components 111 of various sizes and layouts are mounted on the substrate 100, and the molding layer 115 encapsulating the electronic components 111 may absorb different amounts of heat at different locations, resulting in additional warping problems for the mold cap 116.

[0027] Due to the material differences between the mold cap 116 and the substrate 100, and the various sizes and layouts of the electronic components 111 mounted on the substrate 100, warping of the mold cap 116 and the substrate 100 can occur in various forms. In some embodiments, after the curing step, the mold cap 116 and the substrate 100 may have a convex structure relative to the horizontal plane of the work platform or carrier (not shown), such as... Figure 1C As shown. More specifically, in the convex structure, the central portions of the mold cap 116 and the substrate 100 may be higher than the peripheral portions of the mold cap 116 and the substrate 100. In some other embodiments, the mold cap 116 and the substrate 100 may have the same shape as... Figure 1C The concave structure is the opposite of the convex structure shown, wherein the central portion of the mold cover 116 and the substrate 100 may be lower than the peripheral portion of the mold cover 116 and the substrate 100.

[0028] By applying laser radiation and vacuum pressure to the substrate 100 and the mold cap 116, temporary warping of the mold cap 116 and the substrate 100 during the curing step can be reduced. More specifically, laser radiation can be applied to heat the mold cap 116 and the substrate 100, making them deformable under external force. Additionally, vacuum pressure can be applied to cause the mold cap 116 and the substrate 100 to adhere to a carrier, thereby mitigating warping. Details of the laser radiation and vacuum treatment will be described below.

[0029] like Figure 1DAs shown, a substrate 100 is attached to a carrier 130, with a mold cap 116 facing away from and away from the carrier 130. Since the substrate 100 and mold cap 116 may have convex shapes, a gap may exist between the central portion of the substrate 100 and the carrier 130, while the peripheral portion of the substrate 100 may be in direct contact with the carrier 130. The carrier 130 includes a venting channel extending therethrough, which is fluidly connected to a vacuum source to create a vacuum pressure within the venting channel. The venting channel may be exposed from the front surface of the carrier 130, allowing the vacuum pressure to be applied to the substrate 100 through the venting channel. In this way, the substrate 100 can be adsorbed onto the carrier 130 by the adsorption force generated by the vacuum pressure. Since the mold cap 116 and the substrate 100 are integrated, the mold cap 116 is also drawn downwards to the carrier 130 as the substrate 100 moves downwards. In some embodiments, the venting channel may include a plurality of holes distributed throughout the carrier 130 to provide a uniform vacuum pressure. In some other embodiments, the ventilation channels may include interconnected channels or pipes to ensure a uniform vacuum pressure.

[0030] Simultaneously, the laser source 120 is positioned above the substrate 100 and the mold cover 116. The laser source 120 can emit laser radiation (e.g., infrared radiation) towards the mold cover 116 and the substrate 100 to heat them to a temperature above a predetermined temperature threshold. This allows the mold cover 116 and the substrate 100 to deform under external force or pressure, such as vacuum pressure. The laser radiation provides uniform and rapid heating to the substrate 100 and the mold cover 116. In some embodiments, the predetermined temperature threshold can be from 140°C to 180°C, ensuring that the mold cover 116 and the substrate 100 can deform in a suitable manner. In some preferred embodiments, the power of the laser radiation from the laser source 120 can range from 2000W to 6000W. Furthermore, the laser radiation can last from 1 second to 3 seconds to sufficiently heat the substrate 100 and the mold cover 116. It is understood that the laser power and heating duration can vary depending on the object to be heated. Furthermore, in some embodiments, the vacuum pressure applied to the substrate 100 may vary with time, for example, increasing linearly or exponentially with time. Applying a varying vacuum pressure, especially an increasing vacuum pressure, may be beneficial when it is necessary to eliminate more significant warping. In some other embodiments, the vacuum pressure applied to the substrate 100 may vary with the temperature of the substrate, for example, increasing linearly or exponentially with increasing temperature of the substrate 100.

[0031] Still referencing Figure 1DThe front surface of the carrier 130 is a flat surface. Therefore, when the substrate 100 with the mold cap 116 is heated to a deformable state, the substrate 100 and the mold cap 116 can be adsorbed onto the flat surface of the carrier 130 by vacuum pressure. In this way, by using the flat carrier 130 as a reference, the adsorption force generated by vacuum pressure flattens the substrate 100 and the mold cap 116. The warpage of the substrate 100 and the mold cap 116 can be reduced simultaneously, such as... Figure 1E As shown, this ultimately allows the mold cap 116 and substrate 100 to have a flat shape, which facilitates subsequent manufacturing processes. Additionally, it can mitigate misalignment of electronic components 111 within the mold cap 116 caused by warping, and also reduce the risk of mismatch between electronic components 111 and substrate 100, or specifically between the first set of conductive pads 102 and interconnects 101. Better alignment between the first set of conductive pads 102 and interconnects 101 can significantly improve the electrical reliability of the formed electronic package. In some embodiments, the laser radiation applied to the mold cap 116 and substrate 100 after curing the molding layer 115 can be performed using the same process and equipment as the molding layer process, thereby avoiding additional procedures and achieving cost control. Therefore, the process of reducing warping of the mold cap 116 and substrate 100 (i.e., applying laser radiation and vacuum pressure) can be used in large-scale production scenarios to improve the performance of the formed electronic package and increase its yield.

[0032] exist Figure 1D In the illustrated embodiment, laser radiation and vacuum pressure can be applied simultaneously to flatten the substrate 100 and the mold cover 116. In some other embodiments, laser radiation can be applied before applying vacuum pressure, allowing the substrate 100 and the mold cover 116 to be heated to a deformable state before applying external force to flatten them. It can be understood that vacuum pressure can be applied when the temperature of the substrate 100 and the mold cover 116 gradually decreases from a high temperature corresponding to a deformable state to a low temperature, such as room temperature.

[0033] In some other embodiments, the heater may be attached to the bottom surface of the carrier 130. The substrate 100 and the mold cap 116 may be preheated by the heater before laser radiation heating. In this way, the process of heating the mold cap 116 and the substrate 100 to a temperature above a predetermined temperature threshold during the laser radiation step requires less energy from the laser source 120. Furthermore, the duration of laser radiation application may be shortened, which improves process efficiency. In some embodiments, the heater may be heated to a temperature of approximately 90°C, while the carrier 130 may be maintained at a temperature of approximately 70°C.

[0034] In some embodiments, a pressing element, such as a cap, may be introduced to press the mold cap 116 and the substrate 100 against the carrier 130. The pressing element may be located on the top surface of the central portion of the mold cap 116, where the warping of the mold cap 116 and the substrate 100 is most severe, such as... Figure 1D As shown. In this way, the warping of the mold cover 116 and the substrate 100 can be further reduced by additional pressing pressure and the adsorption force brought about by vacuum pressure. It should be noted that the pressing element can have a relatively small size to avoid blocking laser radiation from reaching the mold cover 116.

[0035] In some embodiments, the ventilation channels of the carrier 130 may be distributed differently at various locations on the carrier 130. For the substrate 100 and the mold cover 116 having a convex shape, such as... Figure 1D As shown, the ventilation channels of the carrier 130 below the central portion of the substrate 100 can be arranged more densely than the ventilation channels below the peripheral portion of the substrate 100. It is also understood that most or all of the ventilation channels of the carrier 130 below the central portion of the substrate 100 can have a larger size compared to the ventilation channels below the peripheral portion of the substrate 100. In this way, a greater adsorption force can be applied to further reduce warping of the mold cap 116 and the central portion of the substrate 100. Similarly, in some other embodiments, the substrate 100 and the mold cap 116 have concave shapes, and the ventilation channels of the carrier 130 below the peripheral portion of the substrate 100 can be arranged more densely than the ventilation channels below the central portion of the substrate 100. It is also understood that most or all of the ventilation channels of the carrier 130 below the peripheral portion of the substrate 100 can have a larger size compared to the ventilation channels below the central portion of the substrate 100. Additionally, alignment marks can be formed on the carrier 130 to ensure alignment between the substrate 100 and the carrier 130 relative to the ventilation channels.

[0036] Still referencing Figure 1DIn some other embodiments, the carrier 130 may have a concave shape opposite to the convex shape of the substrate 100 and the mold cap 116. In this way, when the substrate 100 and the mold cap 116 are adsorbed onto the carrier 130 by vacuum pressure, the concave shape of the carrier 130 can provide more correction for the convex substrate 100, thereby better counteracting warping. Similarly, in some embodiments, the substrate 100 and the mold cap 116 may have concave shapes, allowing the use of a convex carrier 130 to reduce warping. It should be noted that a pre-check step may be performed before placing the substrate 100 onto the carrier 130 to ensure that the shape of the carrier 130 to be used is opposite to the shape of the substrate 100 with the mold cap 116 (i.e., convex or concave). The pre-check step may include acquiring the shape of the substrate 100 with the mold cap 116 via a camera or infrared sensor. If the shape of the substrate 100 does not match the carrier 130, the substrate 100 may be flipped to fit properly onto the carrier 130. In addition, alignment marks can be formed on the carrier 130 to ensure that the substrate 100 and the carrier 130 are aligned in a way that can compensate for each other.

[0037] Next, as Figure 1E As shown, a cooling step can be performed on the substrate 100 with the mold cover 116. During the cooling step, a vacuum pressure can be continuously applied to prevent warping due to the different coefficients of thermal expansion between the substrate 100 and the mold cover 116. Alternatively, a vacuum pressure can be omitted during the cooling step to save costs.

[0038] Next, as Figure 1F As shown, additional solder bumps 131 can be formed on the rear surface of the substrate 100 for mounting the substrate 100 onto an external electronic module. In this way, electronic devices with reduced warpage and improved performance can be formed. The solder bumps 131 can be electrically connected to interconnects 101 in the substrate 100, allowing access to at least one electronic component 111 via the additional solder bumps 131.

[0039] As described above, in some embodiments, processing a strip substrate having multiple units simultaneously can simplify the strip substrate into multiple substrate units, thereby batch forming multiple electronic packages.

[0040] In some embodiments, due to the uneven layout and size of the electronic components 111 encapsulated within the mold cover 116, the warping problem of the mold cover 116 may be more severe than that of the substrate 100. Warping can be reduced by providing vacuum pressure to the mold cover 116 more directly, as shown below.

[0041] Figure 2 This illustrates a laser radiation step according to a second embodiment of the present application for heating a mold cover and a substrate to form an electronic device. Figures 1A to 1CThe steps shown are the same as Figure 1E and 1F The steps shown can be implemented between them. Figure 2 The laser radiation steps shown are not Figure 1D The steps are shown below. For details on other steps, please refer to [link / reference]. Figures 1A to 1F The embodiments described herein will not be described in detail below.

[0042] like Figure 2 As shown, after forming the mold cap 216 on the substrate 200, the substrate 200 with the mold cap 216 can be flipped. Next, the mold cap 216 is placed on the carrier 230, with the substrate 200 facing away from and away from the carrier 230. Next, laser radiation is applied via laser source 220 to heat the mold cap 216 and the substrate 200 to a temperature above a predetermined temperature threshold, for example, 140°C to 180°C. Furthermore, when the temperature of the mold cap 216 and the substrate 200 is above the predetermined temperature threshold, a vacuum pressure is applied through the ventilation channel of the carrier 230, causing the mold cap 216 to be adsorbed onto the carrier 230, thereby reducing warping of the mold cap 216 and the substrate 200. Since the mold cap 216 is in direct contact with the ventilation channel of the carrier 230, the vacuum pressure is applied directly to the mold cap 216 to reduce warping of the mold cap more effectively. In some embodiments, a pressing element can be used to press the peripheral portions of the substrate 200 and the mold cap 216 against the carrier 230. It should be noted that the pressing element can have a relatively small size to avoid blocking laser radiation from reaching the substrate 200. Furthermore, in some other embodiments, the ventilation channels of the carrier 230 below the peripheral portion of the mold cover 216 can have a denser arrangement compared to the ventilation channels below the central portion of the mold cover 216, to provide greater adsorption force to the mold cover 216.

[0043] In some other embodiments, the substrate 200 may first be attached to the carrier 230 (e.g., Figure 1D (As shown), vacuum pressure can be applied to substrate 200 to reduce warping. During this process, substrate 200 may experience additional warping in the opposite direction due to the reaction forces generated when substrate 200 and mold cap 216 are subjected to external forces. More specifically, when substrate 200 and mold cap 216, which have convex shapes, are flattened by external forces, reaction forces can be generated within substrate 200 and mold cap 216, which may cause additional warping with concave shapes. Substrate 200 with mold cap 216 can then be flipped so that mold cap 216 can be adsorbed onto carrier 230 and flattened again from different sides by vacuum pressure. In this way, substrate 200 and mold cap 216 can be flattened by adsorption forces from two opposite sides, which helps reduce warping and ultimately achieves a flat shape for mold cap 216 and substrate 200.

[0044] More details about the steps of applying laser radiation and vacuum pressure can be found in similar... Figure 1D The steps shown will not be described in detail below.

[0045] Figure 3 The laser radiation step for heating a mold cover and a substrate to form an electronic device is shown according to a third embodiment of this application. Figure 3 The laser radiation step shown can also be Figure 2 or Figure 1D Alternative steps to any of the laser irradiation steps shown.

[0046] like Figure 3 As shown, laser radiation can be applied using a laser pressure tool to heat the mold cover 316 and the substrate 300. The laser pressure tool may include a light-transmitting element 350 and a laser source 320. More specifically, the light-transmitting element 350 is placed on the top surface of the mold cover 316, and the laser source 320 is placed above the light-transmitting element 350. The laser source 320 emits a laser beam that passes through the light-transmitting element 350 to reach the mold cover 316 and the substrate 300, thereby heating the mold cover 316 and the substrate 300 to a temperature above a predetermined temperature threshold. In some embodiments, the light-transmitting element 350 may comprise glass or quartz. Furthermore, a vacuum pressure can be applied to the substrate 300 through the ventilation channels of the carrier 330. When laser radiation is applied to the mold cover 316, the substrate 300 and the mold cover 316 can be pressed against the carrier 330 by external force through the light-transmitting element 350. Therefore, the pressing force from the light-transmitting element 350 and the adsorption force from the ventilation channel of the carrier 330 can work together to generate a greater resultant force to push the mold cover 316 and the substrate 300 against the carrier 330. In addition, both the mold cover 316 and the substrate 300 can directly receive the pressing force or adsorption force, which helps to reduce the warpage of the mold cover 316 and the substrate 300 from both sides at the same time, thereby improving process efficiency.

[0047] exist Figure 3 In the illustrated embodiment, pressing pressure, laser radiation, and vacuum pressure can be applied simultaneously to the substrate 300 and the mold cover 316 via the light-transmitting element 350, which reduces processing time. In some other embodiments, the pressing pressure, laser radiation, and vacuum pressure can be applied in a more flexible processing sequence based on practical requirements for reducing warping. For example, laser radiation can be applied before applying pressing pressure via the light-transmitting element 350 and vacuum pressure via the carrier 330, so that the substrate 300 and the mold cover 316 can be heated to a deformable state before the external force is applied. It is also understood that the pressing pressure and vacuum pressure can be applied simultaneously or sequentially.

[0048] In some other embodiments, fasteners such as clamps can be used to assemble the light-transmitting element 350 and the carrier 330 together via an interference fit to apply pressure to the mold cover 316 without introducing external force. In some alternative embodiments, the fastener may comprise two magnetic elements, each attached to one of the light-transmitting element 350 and the carrier 330. The two magnetic elements may have an attractive force to each other to assemble the light-transmitting element 350 and the carrier 330 together.

[0049] Figure 4 This illustration demonstrates a cooling step for cooling the mold cover and substrate after a laser irradiation step, according to a fourth embodiment of this application. Figures 1A to 1D The steps shown are the same as Figure 1F The steps shown can be implemented between them. Figure 4 The cooling steps shown are not Figure 1E The steps are shown below. Therefore, details of the other steps can be found in the reference section. Figures 1A to 1F The embodiments described herein will not be described in detail below.

[0050] like Figure 4 As shown, after laser irradiation of the mold cap 416 and substrate 400, the substrate 400 and mold cap 416 are cooled to a lower temperature. During the cooling step, a pressing element 440 can be introduced to press the mold cap 416 and substrate 400 against the carrier 430 by external force to prevent warping. Furthermore, during the cooling step, a vacuum pressure can be continuously applied while the pressing element 440 presses the mold cap 416 and substrate 430 against the carrier 430. In another embodiment, fasteners can be used to assemble the pressing element 440 and carrier 430 together by interference fit to apply pressing force to the mold cap 416 without introducing additional external force.

[0051] Figure 5 This illustration demonstrates a cooling step for cooling the mold cover and substrate after a laser irradiation step, according to a fifth embodiment of this application. Figures 1A to 1D The steps shown are the same as Figure 1F The steps shown can be implemented between them. Figure 5 The cooling steps shown are not Figure 1E The steps are shown below. Therefore, details of the other steps can be found in [reference needed]. Figures 1A to 1F The embodiments described herein will not be described in detail below.

[0052] like Figure 5As shown, a cooler 560 can be attached to the bottom surface of a carrier 530 to cool the carrier 530 and the substrate 500 placed thereon. During the cooling step, the cooler 560 can reduce the temperature of the carrier 530, and thus help to cool the substrate 500 and the mold cover 516 in a shorter time. Rapid cooling of the substrate 500 and the mold cover 516 can further reduce their warping and avoid the risk of warping recurrence. In some embodiments, the cooler 560 may include a cooling element, such as a heat sink, a fan, or an air conditioner.

[0053] While exemplary methods for forming electronic devices have been described in conjunction with the accompanying drawings, those skilled in the art will understand that modifications and adaptations can be made to the methods for forming electronic devices without departing from the scope of the invention.

[0054] Various embodiments have been described herein with reference to the accompanying drawings. However, it will be apparent that various modifications and alterations can be made thereto, and other embodiments may be practiced, without departing from the broader scope of the invention as set forth in the appended claims. Furthermore, other embodiments will be apparent to those skilled in the art upon consideration of the description and practice of one or more embodiments of the invention disclosed herein. Therefore, the examples in this application and herein are intended to be considered exemplary only, and the true scope and spirit of the invention are indicated by the list of exemplary claims appended.

Claims

1. A method for forming an electronic device, characterized in that, The method includes: A substrate is provided on which at least one electronic component is mounted; A molding layer is formed on the substrate to encapsulate the at least one electronic component; The molding layer is cured to convert it into a mold cap; The substrate with the mold cover is placed on a carrier having a ventilation channel therethrough; Laser radiation is applied via a laser source to heat the mold cover and the substrate to a temperature above a predetermined temperature threshold; and When the temperature of the mold cover and the substrate is higher than the predetermined temperature threshold, a vacuum pressure is applied to the substrate and the mold cover through the ventilation channel of the carrier, so that the substrate and the mold cover are adsorbed onto the carrier, thereby reducing the warping of the mold cover and the substrate during the curing step.

2. The method according to claim 1, characterized in that, The step of applying vacuum pressure to the substrate and the mold cover is performed after the step of applying laser radiation to heat the mold cover and the substrate.

3. The method according to claim 1, characterized in that, The step of applying vacuum pressure to the substrate and the mold cover is performed simultaneously with the step of applying laser radiation to heat the mold cover and the substrate.

4. The method according to claim 1, characterized in that, The step of placing the substrate with the mold cover onto the carrier includes: The substrate is placed on the carrier, wherein the mold cover is away from the carrier.

5. The method according to claim 1, characterized in that, Placing the substrate with the mold cover onto the carrier includes: The mold cover is placed on the carrier, wherein the substrate is away from the carrier.

6. The method according to claim 1, characterized in that, The step of applying laser radiation to heat the mold cover and the substrate is performed using a laser pressure tool having a light-transmitting element and the laser source, wherein the step of applying laser radiation to heat the mold cover and the substrate includes: The laser pressure tool is placed above the mold cover and the substrate; Laser radiation is applied through the light-transmitting element via the laser source to heat the mold cover and the substrate; and The light-transmitting element presses the substrate and the mold cover against the carrier.

7. The method according to claim 1, characterized in that, After applying laser radiation, the method further includes: Cool the substrate and the mold cover.

8. The method according to claim 7, characterized in that, The steps of cooling the substrate and the mold cover include: The substrate and the mold cover are cooled while the vacuum pressure is applied to the substrate.

9. The method according to claim 7, characterized in that, The step of cooling the substrate and the mold cover further includes: The substrate and the mold cover are cooled while being pressed against the carrier by a pressing element.

10. The method according to claim 7, characterized in that, The step of cooling the substrate and the mold cover further includes: The substrate and the mold cover are cooled by a cooler attached to the carrier.

11. The method according to claim 1, characterized in that, Prior to the step of applying laser radiation to heat the mold cover and the substrate, the method includes: The carrier, the substrate, and the mold cover are heated by a heater attached to the carrier.

12. The method according to claim 1, characterized in that, The step of applying laser radiation to heat the mold cover and the substrate includes: The laser radiation is applied using a power between 2000W and 6000W from the laser source.

13. The method according to claim 1, characterized in that, The step of applying laser radiation to heat the mold cover and the substrate includes: The laser radiation is applied for a duration of 1 to 3 seconds.

14. An electronic device, characterized in that, The electronic device is formed using the method according to any one of claims 1 to 13.

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