Solder reflow apparatus and method of manufacturing an electronic device

Abstract

A solder reflow device comprises a steam generating chamber that receives a heat transfer fluid and is filled with steam heated from the heat transfer fluid, a heater for heating the heat transfer fluid received within the steam generating chamber, a substrate stage installed to be vertically movable within the steam generating chamber and for supporting a substrate on which electronic components are mounted via solder, and at least one mesh plate that extends horizontally within the steam generating chamber and has a plurality of openings that allow the movement of the steam.

Description

Technology Field

[0001] The present invention relates to a solder reflow apparatus and a method for manufacturing an electronic device using the same. More specifically, the present invention relates to a solder reflow apparatus using a vapor phase soldering method and a method for manufacturing a semiconductor package using the same. Background Technology

[0002] In the field of surface mount technology, convection reflow, laser-assisted bonding, and vapor phase soldering methods may be used to solder solder paste. Among these, the vapor phase soldering method has the advantage of providing a uniform temperature distribution over the entire substrate, such as a printed circuit board (PCB), while the vapor inside the oven is saturated, and preventing overheating caused by setting a high target temperature because the boiling point of the heat transfer fluid is fixed.

[0003] However, since the vapor density gradient varies with height inside the oven and a temperature gradient is formed accordingly, it is difficult to precisely control the temperature profile suitable for soldering as the pitch between solders becomes finer. The problem to be solved

[0004] One objective of the present invention is to provide a solder reflow device capable of precisely controlling a temperature profile suitable for soldering.

[0005] Another objective of the present invention is to provide a method for manufacturing an electronic device using the solder reflow apparatus described above. means of solving the problem

[0006] A solder reflow device according to exemplary embodiments for achieving one objective of the present invention comprises: a steam generating chamber that receives a heat transfer fluid and is filled with steam heated from the heat transfer fluid; a heater for heating the heat transfer fluid received in the steam generating chamber; a substrate stage installed to be vertically movable within the steam generating chamber and for supporting a substrate on which an electronic component is mounted via solder; and at least one mesh plate having a plurality of openings that extend horizontally within the steam generating chamber and allow the movement of the steam.

[0007] A solder reflow device according to exemplary embodiments for achieving one objective of the present invention comprises a steam generating chamber that receives a heat transfer fluid at the bottom, a heater for heating the heat transfer fluid to generate saturated steam, a substrate stage installed to be vertically movable within the steam generating chamber and for supporting a substrate on which an electronic component is mounted via solder, and a temperature gradient regulator having a first plate and a second plate sequentially arranged from the bottom of the steam generating chamber. The first plate includes a plurality of first openings having a first size, and the second plate includes a plurality of second openings having a second size smaller than the first size.

[0008] A solder reflow device according to exemplary embodiments for achieving one objective of the present invention comprises: a steam generating chamber that receives a heat transfer fluid and in which steam heated from the heat transfer fluid is distributed according to a density difference according to height; a heater for heating the heat transfer fluid received within the steam generating chamber; a substrate stage installed to be vertically movable within the steam generating chamber and for supporting a substrate on which electronic components are mounted via solder; and at least one mesh plate that extends horizontally within the steam generating chamber and has a plurality of openings that allow the movement of the steam. It also includes a plurality of cover members that operate in an openable and closable manner to allow movement of the substrate stage. Effects of the invention

[0009] According to exemplary embodiments, a solder reflow device may include a temperature gradient regulator having at least one mesh plate that extends horizontally within a vapor generation chamber and has a plurality of openings that allow the movement of said vapor. The upper zone and the lower zone are separated by said mesh plate, and the density of said vapor within said upper zone and said lower zone can be adjusted. Accordingly, said upper zone can be maintained to have a first temperature and said lower zone can be controlled to have a second temperature higher than said first temperature.

[0010] Therefore, a desired temperature gradient can be obtained by controlling the vapor density within multiple zones separated along the vertical direction inside the vapor generation chamber. Accordingly, defects in the reflow process for solders arranged with fine pitch can be reduced and bonding quality improved.

[0011] However, the effects of the present invention are not limited to the effects mentioned above and may be extended in various ways without departing from the spirit and scope of the present invention. Brief explanation of the drawing

[0012] FIG. 1 is a cross-sectional view showing a solder reflow apparatus according to exemplary embodiments. Figure 2 is a side view showing the solder reflow apparatus of Figure 1. FIG. 3a is a perspective view showing the closed state of the first mesh plate of the solder reflow device of FIG. 1. FIG. 3b is a perspective view showing the open state of the first mesh plate of FIG. 3a. FIG. 4 is a plan view showing the first cover member of the first mesh plate of FIG. 1. FIG. 5 is a plan view showing the first cover member of the second mesh plate of FIG. 1. Figure 6 is a graph showing the temperature profile inside the steam generation chamber of Figure 1. Figure 7 is a graph showing the soldering profile inside the vapor generation chamber of Figure 1. FIGS. 8a and FIGS. 8b are cross-sectional views showing a first plate according to exemplary embodiments. FIGS. 9 to 12 are cross-sectional views illustrating a method for performing a vapor phase reflow process according to exemplary embodiments. FIG. 13 is a cross-sectional view showing a solder reflow apparatus according to exemplary embodiments. FIG. 14 is a flowchart illustrating a method for manufacturing an electronic device according to exemplary embodiments. FIGS. 15 to 21 are drawings illustrating a method for manufacturing an electronic device according to exemplary embodiments. Specific details for implementing the invention

[0013] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings.

[0014] FIG. 1 is a cross-sectional view showing a solder reflow apparatus according to exemplary embodiments. FIG. 2 is a side view showing the solder reflow apparatus of FIG. 1. FIG. 3a is a perspective view showing the closed state of the first mesh plate of the solder reflow apparatus of FIG. 1, and FIG. 3b is a perspective view showing the open state of the first mesh plate of FIG. 3a. FIG. 4 is a plan view showing the first cover member of the first mesh plate of FIG. 1. FIG. 5 is a plan view showing the first cover member of the second mesh plate of FIG. 1. FIG. 6 is a graph showing the temperature profile inside the vapor generation chamber of FIG. 1. FIG. 7 is a graph showing the soldering profile inside the vapor generation chamber of FIG. 1.

[0015] Referring to FIGS. 1 to 7, the solder reflow device (10) may include a steam generating chamber (100), a heater (110), a substrate stage (200), and a temperature gradient adjuster (300). Additionally, the solder reflow device (10) may further include a lifting / lowering drive unit for raising / lowering the substrate stage (200), an opening / closing drive unit for opening / closing the temperature gradient adjuster (300), and a temperature sensing unit for monitoring the temperature inside the steam generating chamber (100).

[0016] In exemplary embodiments, the solder reflow device (10) may be a vapor phase soldering device for soldering solder paste by heated saturated steam within a steam generation chamber (100).

[0017] The steam generating chamber (100) may have an oven shape that includes a lower reservoir for receiving a heat transfer fluid (F) and provides a space (101) filled with steam formed directly above when the heat cutting fluid (F) boils. The steam generating chamber (100) may extend in the vertical direction (Z) by a preset height. Within the steam generating chamber (100), the heat transfer fluid boils, causing steam to rise to the top, condense back into a liquid state at the top, and flow back into the lower reservoir.

[0018] The pressure inside the steam generating chamber (100) can be maintained at atmospheric pressure. Alternatively, the steam generating chamber (100) may be connected to an exhaust device, such as a vacuum pump, to regulate the pressure inside the steam generating chamber (100). The pressure inside the steam generating chamber may be maintained at a predetermined pressure to change the boiling point of the heat transfer fluid or for a soldering environment.

[0019] The heat transfer fluid (F) may be a chemical selected to provide the vapor required for soldering to occur. The heat transfer fluid may be selected considering its boiling point, environmental influences, and the corrosiveness of the generated vapor. The heat transfer fluid may include an inert organic liquid. For example, the heat transfer fluid may include a Galden solution of the perfluoropolyether (PFPE) series. The boiling point of the Galden solution may be 230°C.

[0020] A heater (110) can generate saturated steam by heating a heat transfer fluid (F) contained within a steam generation chamber (100). The heater (110) may include an electrical resistor immersed in the heat transfer fluid (F) at the bottom of the steam generation chamber (110). Alternatively, the heater (110) may include a coil-shaped resistor that wraps around the perimeter of the tank.

[0021] In addition, a heater (not shown) is installed on the side wall of the steam generation chamber (100) as part of a temperature control mechanism, so that the temperature of the steam generation chamber (100) can be controlled during the reflow process.

[0022] A substrate stage (200) can support an article (S) for soldering within a steam generation chamber (100). The substrate stage (200) may include a mesh-shaped support structure for supporting the article (S). The mesh-shaped support structure may include support wires (202) defining a plurality of open holes (201) that allow the movement of the steam. For example, the article (S) may include a substrate (20) on which an electronic component (30) is mounted via solder (40).

[0023] A substrate stage (200) can be installed to be raised and lowered within a steam generation chamber (100). A lifting and lowering drive unit for raising and lowering the substrate stage (200) may include various types of actuators such as a transfer rail, a transfer screw, or a transfer belt. Both ends of the substrate stage (200) are supported by transfer rods (210), and the substrate stage (200) can be raised and lowered by the lifting and lowering drive unit.

[0024] As shown in FIG. 2, an article (S) to be soldered is transferred into the steam generating chamber (100) through the gate (102) of the steam generating chamber (100), and the article (S) can be loaded onto a substrate stage (200) by a transfer mechanism (104), such as a guide rail or a transfer pusher.

[0025] After the item (S) is loaded, the Galden solution (F) can be heated by the heater (110) and begin to boil. The saturated steam of the Galden can be distributed within the space (101) of the steam generation chamber (100). At this time, the density of the saturated steam varies with height, and a temperature gradient can be formed accordingly.

[0026] In exemplary embodiments, the temperature gradient regulator (300) may include at least one mesh plate (310, 320) extending in a horizontal direction (XY direction) within the steam generating chamber (100). The mesh plate may have a plurality of openings that allow the movement of the steam. The temperature gradient regulator (300) may divide the upper zone and the lower zone with the mesh plate in between and adjust the density of the steam within the upper zone and the lower zone. Accordingly, the upper zone may be maintained to have a first temperature and the lower zone may be controlled to have a second temperature higher than the first temperature.

[0027] The temperature gradient regulator (300) may include a first plate (310) and a second plate (320) arranged sequentially from the bottom of the steam generating chamber (100). The first and second plates (310, 320) may include a plurality of cover members that operate in an openable and closable manner to allow movement of the substrate stage (200). Additionally, the first and second plates (310, 322) may be spaced apart from the inner wall of the steam generating chamber (100) by a predetermined distance.

[0028] As illustrated in FIGS. 2, 3a and 3b, the first plate (310) may include a pair of first cover members (312) spaced apart from each other to allow movement of the substrate stage (200) and second cover members (314) each installed to be movable on the first cover members (312). The first plate (310) may be installed at a first height from the bottom of the steam generating chamber (100), and the second plate (320) may be installed at a second height higher than the first height from the bottom of the steam generating chamber (100).

[0029] The opening / closing drive unit for the opening / closing operation of the first plate (310) may include a drive for moving the second cover member (314) in a first direction (Y direction) on the first cover member (312). For example, the drive may include a linear drive such as an LM guide, a ball screw, etc.

[0030] A pair of second cover members (314) can move in a direction toward each other to a closed position that blocks the movement of the substrate stage (200). A pair of second cover members (314) can move in a direction toward each other to an open position that allows the movement of the substrate stage (200).

[0031] Similarly, the second plate (320) may include a pair of third cover members (322) spaced apart from each other to allow movement of the substrate stage (200) and fourth cover members (324) each installed to be movable on the third cover members (322).

[0032] The opening / closing drive unit for the opening / closing operation of the second plate (320) may include a drive unit for moving the fourth cover member (324) in the first direction (Y direction) on the third cover member (322). For example, the drive unit may include a linear drive unit such as a transfer guide, a ball screw, etc.

[0033] A pair of fourth cover members (324) can move in a direction toward each other to a closed position that blocks the movement of the substrate stage (200). A pair of fourth cover members (324) can move in a direction toward each other to an open position that allows the movement of the substrate stage (200).

[0034] As illustrated in FIGS. 4 and 5, the first cover member (312) and the second cover member (314) of the first plate (310) may include a plurality of first openings (311) having a first size (D1), and the third cover member (322) and the fourth cover member (324) of the second plate (320) may include a plurality of second openings (312) having a second size (D2) smaller than the first size (D1).

[0035] For example, the first cover member (312) may include first fine wires (313) defining a plurality of first openings (311) that allow the movement of the steam. The third cover member (322) may include second fine wires (323) defining a plurality of second openings (321) that allow the movement of the steam. The thickness of the first fine wire (313) may be greater than the thickness of the second fine wire (323).

[0036] The first and second openings may have a circular or polygonal shape. The sizes and shapes of the first and second openings, the thicknesses of the first and second fine wires, etc., may be determined by considering the temperature profile within the zones separated by the first and second plates (310, 320).

[0037] As illustrated in FIG. 6, the space above the second plate (320) is defined as a third zone (Z3) and can be maintained at a first temperature (T1). The space between the first plate (310) and the second plate (320) is defined as a second zone (Z2) and can be maintained at a second temperature (T2) higher than the first temperature (T1). The space below the first plate (310) is defined as a third zone (Z1) and can be maintained at a third temperature (T3) higher than the second temperature (T3).

[0038] The temperatures of the first to third zones may be determined in proportion to the vapor density within each zone. The vapor density distribution within each zone may be determined according to the sizes of the first and second openings of the first plate (310) and the thicknesses of the first and second fine wires.

[0039] For example, the first temperature (T1) may be 100°C, the second temperature (T2) may be 170°C, and the third temperature (T3) may be 230°C. The temperatures within the first to third zones may be determined by considering the temperature profile of the soldering. The solder (40) may include Sn-Ag-Cu (SAC) solder, Sn-Ag solder, etc. Since the boiling point of SAC solder is 217°C, the temperature (T3) of the third zone (Z1), which is the reflow section, may be maintained at 230°C.

[0040] As illustrated in FIG. 7, a soldering temperature profile corresponding to the temperature distribution of the first to third zones can be obtained during the solder reflow process. As the article (S) on the stage (200) moves through the first to third zones (Z1, Z2, Z3) over time, a desired soldering temperature profile can be obtained.

[0041] FIGS. 8a and FIGS. 8b are cross-sectional views showing a first plate according to exemplary embodiments.

[0042] Referring to FIGS. 8a and 8b, at least one mesh plate (310) may include cover members (312a, 312b, 312c) of a telescopic structure that operate in an openable and closable manner.

[0043] A first cover member (312a) may be installed adjacent to a first side wall of a steam generating chamber (100), a second cover member (312b) may be installed so as to be movable in a first direction on the first cover member (312a), and a third cover member (312c) may be installed so as to be movable in the first direction on the second cover member (312b).

[0044] As shown in FIG. 8a, the second and third cover members (312b, 312c) can be moved to a position where they overlap each other adjacent to the first side wall of the steam generating chamber (100) and can be moved to a closed position that blocks the movement of the substrate stage (200).

[0045] As shown in FIG. 8b, the second and third cover members (312b, 312c) can move toward the second side wall opposite to the first side wall of the steam generating chamber (100) to a closed position that blocks the movement of the substrate stage (200).

[0046] Below, we will describe a method for performing a vapor phase reflow process using the solder reflow apparatus of Fig. 1.

[0047] FIGS. 9 to 12 are cross-sectional views illustrating a method for performing a vapor phase reflow process according to exemplary embodiments.

[0048] Referring to FIGS. 9 to 12, an article (S) to be soldered is loaded into a steam generating chamber (100), and a heat transfer fluid (F) inside the steam generating chamber (100) can be heated.

[0049] In exemplary embodiments, a substrate (20) on which an electronic component (30) is mounted via solder (40) is transferred into the steam generating chamber (100) through the gate (102) of the steam generating chamber (100), and an article (S) can be loaded onto a substrate stage (200) by a transfer mechanism (104), such as a guide rail or a transfer pusher.

[0050] After the item (S) is loaded, the Galden solution (F) can be heated by the heater (110) and begin to boil. The saturated steam of the Galden can be distributed within the space (101) of the steam generating chamber (100). At this time, the steam is distributed into the first to third zones (Z3, Z2, Z1), respectively, through the first and second openings of the first and second plates (310, 320), so that it can have a desired constant density within each zone.

[0051] Accordingly, the third zone (Z3) above the second plate (320) is maintained at a first temperature (T1), the second zone (Z2) between the first plate (310) and the second plate (320) is maintained at a second temperature (T2) higher than the first temperature (T1), and the third zone (Z1) below the first plate (310) can be maintained at a third temperature (T3) higher than the second temperature (T3).

[0052] As illustrated in FIG. 10, after the article (S) is preheated in the first zone (Z3), it can be moved to the second zone (Z2) and soaked.

[0053] To prevent various soldering defects and to provide a more robust and conductive bond, the substrate (20) may be preheated. In the first and second zones (Z3, Z3), a secondary vapor phase may exist that is generated at a lower temperature than the main vapor layer. In these zones, soldering does not occur, and only the temperature rises.

[0054] As shown in FIGS. 11 and 12, the article (S) can be moved to a third zone (Z1) so that the solder (40) can be reflowed.

[0055] When the article (S) is submerged in steam within the third zone (Z1), the steam acts as a heat transfer medium. Because the temperature within the third zone (Z1) and the temperature of the substrate (20) are different, the steam can condense on the surface of the article (S) to form a layer. During condensation, the steam transfers latent heat to the surface of the substrate (20), thereby allowing the solder paste to be reflowed.

[0056] Subsequently, after the solder (40) is soldered, the article (S) can be moved through the second zone (Z2) to the first zone (Z3) to be cooled. Accordingly, the solder joints can be cooled and solidified.

[0057] FIG. 13 is a cross-sectional view showing a solder reflow apparatus according to exemplary embodiments. The solder reflow apparatus is substantially the same or similar as the solder reflow apparatus described with reference to FIG. 1, except for the addition of a third plate. Accordingly, identical or similar components are indicated by identical or similar reference numerals, and a repeated description of identical components is omitted.

[0058] Referring to FIG. 13, the temperature gradient adjuster (300) of the solder reflow device (11) may further include a third plate (330) placed below the first plate (310).

[0059] In exemplary embodiments, a third plate (330) disposed below the first plate (310) may include a plurality of third openings (331) having a third size (D3) larger than the first size (D1). The third plate (330) may have a structure substantially identical or similar to the first plate (310).

[0060] The space above the second plate (320) is defined as the third zone (Z3) and can be maintained at the first temperature (T1). The space between the first plate (310) and the second plate (320) is defined as the second zone (Z2) and can be maintained at the second temperature (T2), which is higher than the first temperature (T1). The space between the third plate (330) and the first plate (310) is defined as the third zone (Z1) and can be maintained at the third temperature (T3), which is higher than the second temperature (T3).

[0061] In exemplary embodiments, the temperature gradient adjuster (300) may further include a fourth plate (not shown) disposed on the second plate (320) in place of or together with the third plate (330). The fourth plate disposed on the second plate (320) may include a plurality of fourth openings having a third size smaller than the second size (D2).

[0062] The space between the second plate (320) and the fourth plate is defined as a third zone (Z3) and can be maintained at a first temperature (T1). The space above the fourth plate is defined as a fourth zone and can be maintained at a fourth temperature lower than the first temperature (T1).

[0063] Hereinafter, a method for manufacturing an electronic device using the solder reflow apparatus of FIG. 1 will be described. The case where the electronic device is a semiconductor package will be described. However, it will be understood that the method of manufacturing an electronic device according to exemplary embodiments is not limited thereto.

[0064] FIG. 14 is a flowchart illustrating a method for manufacturing an electronic device according to exemplary embodiments. FIGS. 15 to 21 are drawings illustrating a method for manufacturing an electronic device according to exemplary embodiments. FIG. 15 is a plan view illustrating a strip substrate on which semiconductor chips are mounted. FIGS. 16, 18, and 19 are cross-sectional views taken along the AA' line of FIG. 15.

[0065] Referring to FIGS. 14 to 18, first, a substrate (20) including a plurality of substrate pads (22) is provided, a solder paste (24) is applied on the substrate pads (22) of the substrate (20) (S100), and solder (40) can be placed on the solder paste (24) (S110).

[0066] As illustrated in FIG. 15, the substrate (20) may be a multilayer circuit board as a package substrate having upper and lower surfaces facing each other. The substrate (20) may be a strip substrate for manufacturing semiconductor strips such as a printed circuit board (PCB).

[0067] The substrate (20) may include a first side (S1) and a second side (S2) that face each other by extending in a direction parallel to a second direction parallel to the upper surface, and a third side (S3) and a fourth side (S4) that face each other by extending in a direction parallel to a first direction (X direction) that is orthogonal to the second direction. The substrate (20) may have a rectangular shape when viewed in a plan view. The substrate (20) may have a predetermined area (e.g., 77.5 mm × 240 mm).

[0068] The substrate (20) may include a mounting area (MR) on which a semiconductor chip is mounted and a cutting area (CR) surrounding the mounting area (MR). A plurality of semiconductor chips (30) may each be disposed on the mounting areas (MR) of the substrate (20). For example, tens to hundreds of semiconductor chips (30) may be arranged in a matrix form on the substrate (20).

[0069] As shown in FIG. 16, solder paste (24) can be applied to each of the plurality of substrate pads (22) of the substrate (20). The pitch between the plurality of substrate pads (22) of the substrate (20) can be within the range of tens of micrometers.

[0070] Solder paste (24) can be printed on the substrate pads (22) of the substrate (20). For example, the solder paste (24) can be printed by a stencil printer. The stencil may be a metal foil having a plurality of openings corresponding to an arrangement of solders to be subsequently placed. During printing, the solder paste (24) may be printed to fill the openings of the stencil. The solder paste (24) may include solder powder and flux. The flux may include a resin, a solvent, an activator, and an antioxidant.

[0071] Alternatively, the solder paste can be applied to the surface of the solder (40) formed on the semiconductor chip (30).

[0072] As illustrated in FIG. 17, solder (40) can be formed on an electronic component (30) mounted on a substrate (20). The electronic component (30) may be a semiconductor chip. Alternatively, the electronic component may be a semiconductor package. In this case, the substrate (20) may be a module board.

[0073] A plurality of input / output pads (32) may be formed on the first surface (31a) of the electronic component (30). Solders (40) may be formed on each of the input / output pads (32). Although not shown in the drawing, after forming an Under Bump Metallurgy (UBM) on the input / output pad (32), solder (40) may be formed on the Under Bump Metallurgy.

[0074] As shown in FIG. 18, an electronic component (30) can be placed on a substrate (20) such that solder (40) is interposed between the input / output pad (32) of the electronic component (30) and the solder paste (24). The semiconductor chips can be mounted on the substrate (20) by a flip chip bonding method.

[0075] Next, soldering can be performed using a vapor phase reflow method (S120).

[0076] Referring to FIG. 19, a substrate (20) with an electronic component (30) mounted thereon is loaded into the steam heating chamber (100) of the solder reflow device (10) of FIG. 1, and is sequentially moved to the first to third zones (Z3, Z2, Z1), and a heat transfer fluid in a steam state is brought into contact with the surface of the substrate (20) to heat the solder paste (24), thereby reflowing the solder (40) to form a solder bump (40) between the substrate pad (22) and the input / output pad (32).

[0077] In exemplary embodiments, a desired heating temperature profile over time can be achieved by passing through a plurality of vertically arranged first to third zones.

[0078] Specifically, after the substrate (20) is loaded, the Galden solution (F) can be heated by the heater (110) and begin to boil. The saturated steam of the Galden can be distributed within the space (101) of the steam generating chamber (100). At this time, the steam is distributed into the first to third zones (Z3, Z2, Z1), respectively, through the first and second openings of the first and second plates (310, 320), so that it can have a desired constant density within each zone.

[0079] Accordingly, the third zone (Z3) above the second plate (320) is maintained at a first temperature (T1), the second zone (Z2) between the first plate (310) and the second plate (320) is maintained at a second temperature (T2) higher than the first temperature (T1), and the third zone (Z1) below the first plate (310) can be maintained at a third temperature (T3) higher than the second temperature (T3).

[0080] After the article (S) is preheated in the first zone (Z3), it can be moved to the second zone (Z2) and soaked. The substrate (20) can be preheated to prevent various soldering defects and to provide a more robust and conductive bond. In the first and second zones (Z3, Z3), a secondary vapor phase may exist that is generated at a lower temperature than the main vapor layer. In this zone, soldering does not occur, and only the temperature rises.

[0081] The article (S) is moved to the third zone (Z1) so that the solder (40) can be reflowed. When the article (S) is immersed in the steam within the third zone (Z1), the steam acts as a heat transfer medium. Because the temperature within the third zone (Z1) and the temperature of the substrate (20) are different, the steam can condense on the surface of the article (S) to form a layer. During condensation, the steam transfers latent heat to the surface of the substrate (20), thereby reflowing the solder paste.

[0082] Subsequently, after the solder (40) is soldered, it can be moved through the second zone (Z2) of the article (S) to the first zone (Z3) to be cooled. Accordingly, the solder joints can be cooled and solidified.

[0083] Referring to FIG. 20, a molding member (50) covering semiconductor chips (30) can be formed on a substrate (20) (S130).

[0084] In exemplary embodiments, a molding member (50) may be formed on a substrate (20) by a transfer molding device. The substrate (20) is placed within the molding space of the mold of the molding device, and with the lower mold and the upper mold clamped, a sealant is flowed at high temperature and high pressure so that the liquid sealant flows through the molding space and then solidifies to form a molding member (50) that covers semiconductor chips (30). For example, the sealant may include an epoxy mold compound (EMC).

[0085] Referring to FIG. 21, the substrate (20) can be cut by a sawing process to complete the semiconductor packages (60).

[0086] In exemplary embodiments, external connection members (not shown), such as solder balls, are formed on external connection pads on the lower surface of the substrate (20), and a cutting area (CR) of the substrate (20) can be removed using a cutting device such as a blade. Accordingly, individual semiconductor packages (P) can be separated from the substrate (20).

[0087] Through the aforementioned processes, a semiconductor package including a logic device or a memory device and a semiconductor module including the same can be mass-produced. The semiconductor package may include, for example, a logic device such as a central processing unit (CPU, MPU) or an application processor (AP); a volatile memory device such as, for example, an SRAM device, a DRAM device, or a high-bandwidth memory (HBM) device; and a non-volatile memory device such as, for example, a flash memory device, a PRAM device, an MRAM device, or an RRAM device.

[0088] Although the present invention has been described above with reference to embodiments thereof, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0089] 11: Solder reflow device 20: Substrate 22: PCB pad 24: Solder paste 30: Semiconductor chip 32: Input / output pad 40: Solder 50: Molding component 60: Semiconductor package 100: Vapor generation chamber 102: Gate 104: Transfer mechanism 110: Heater 200: Substrate stage 201: Open hole 202: Support wire 210: Transfer rod 300: Temperature gradient regulator 310: First plate 311: First opening 312: First cover member 314: Second cover member 320: Second plate 321: Second opening 322: Third cover member 324: Fourth cover member 330: Third plate 331: Third opening

Claims

Claim 1 A solder reflow apparatus comprising: a steam generating chamber that receives a heat transfer fluid and is filled with steam heated from said heat transfer fluid; a heater for heating said heat transfer fluid received in said steam generating chamber; a substrate stage installed to be vertically movable in said steam generating chamber and for supporting a substrate on which electronic components are mounted via solder; and a temperature gradient regulator having at least one mesh plate that extends horizontally in said steam generating chamber and has a plurality of openings that allow the movement of said steam, wherein the interior of said steam generating chamber is divided into an upper zone and a lower zone by said at least one mesh plate, and the temperature gradient regulator adjusts such that said upper zone is maintained to have a first temperature and said lower zone is maintained to have a second temperature higher than said first temperature, and said substrate on said substrate stage moves through said upper zone and said lower zone to obtain a desired soldering temperature profile. Claim 2 delete Claim 3 A solder reflow apparatus according to claim 1, wherein the at least one mesh plate comprises a plurality of cover members that operate in an openable and closable manner to allow movement of the substrate stage. Claim 4 A solder reflow apparatus according to claim 3, wherein the at least one mesh plate comprises: a pair of first cover members spaced apart from each other to allow movement of the substrate stage; and second cover members each installed to be movable on the first cover members to block movement of the substrate stage. Claim 5 In claim 3, the solder reflow device comprising at least one mesh plate having a telescopic structure cover member that operates in an openable and closable manner. Claim 6 A solder reflow apparatus comprising: a steam generating chamber that accommodates a heat transfer fluid and is filled with steam heated from said heat transfer fluid; a heater for heating said heat transfer fluid accommodated in said steam generating chamber; a substrate stage installed to be vertically movable within said steam generating chamber and for supporting a substrate on which electronic components are mounted via solder; and at least one mesh plate that extends horizontally within said steam generating chamber and has a plurality of openings that allow the movement of said steam, wherein the at least one mesh plate comprises a first plate and a second plate sequentially arranged from the bottom of said steam generating chamber, and the space below said first plate is maintained at a first temperature, and the space between said first plate and said second plate is maintained at a second temperature lower than said first temperature. Claim 7 A solder reflow apparatus according to claim 6, wherein the first plate comprises a plurality of first openings having a first size, and the second plate comprises a plurality of second openings having a second size smaller than the first size. Claim 8 A solder reflow device according to claim 7, wherein the opening area of ​​the first openings is larger than the opening area of ​​the second openings. Claim 9 A solder reflow apparatus according to claim 6, wherein the at least one mesh plate further comprises a third plate disposed below the first plate or above the second plate. Claim 10 A solder reflow apparatus according to claim 1, wherein the substrate includes a package substrate and the electronic component includes a semiconductor chip.

Images