KR20240079125A - Solder reflow apparatus and method of manufacturing an electronic device - Google Patents

Abstract

In a method of manufacturing an electronic device, a substrate having opposing first and second surfaces is provided. First electronic components are each mounted on the first side of the substrate using first bumps. At least one vapor shield cover is placed on the first side of the substrate to cover at least one of the first electronic components. Second electronic components are respectively disposed on the second surface of the substrate using second bumps. The second bumps are soldered using a vapor phase reflow method, but the heat transfer fluid in a vapor state is prevented from moving to the first electronic component within the vapor shielding cover.

Description

Solder reflow device and manufacturing method of electronic device using the same {SOLDER REFLOW APPARATUS AND METHOD OF MANUFACTURING AN ELECTRONIC DEVICE}

The present invention relates to a solder reflow device and a method of manufacturing an electronic device using the same. More specifically, the present invention relates to a solder reflow device using a vapor phase soldering method and a method of manufacturing an electronic device using the same.

In the field of surface mount technology, convection reflow, laser assisted bonding, vapor phase soldering, etc. can be used to solder solder paste. Among these, in the case of the vapor phase soldering method, uniform temperature distribution can be provided throughout the entire substrate such as a printed circuit board (PCB) during saturation of steam inside the oven, and the boiling point of the heat transfer fluid is determined, so the target There are advantages to preventing overheating by setting the temperature high.

Meanwhile, after mounting the electronic components on the first side of the substrate and placing the electronic components on the second side opposite to the first side of the substrate, when soldering the electronic components on the second side of the substrate There is a problem in that the bumps between the first surface of the substrate and the mounted electronic components are remelted, causing the mounted electronic components to fall.

One object of the present invention is to provide a method of manufacturing an electronic device that can efficiently mount electronic components on both sides of a substrate by partially soldering only desired areas in a vapor phase manner.

In the method of manufacturing an electronic device according to exemplary embodiments for achieving the object of the present invention, a substrate having a plurality of mounting areas on which electronic components are respectively mounted and having first and second surfaces opposing each other provides. First electronic components are each mounted on the first side of the substrate using first bumps. At least one vapor shield cover is placed on the first side of the substrate to cover at least one of the first electronic components. Second electronic components are respectively disposed on the second surface of the substrate using second bumps. The second bumps are soldered using a vapor phase reflow method, but the heat transfer fluid in a vapor state is blocked from moving to the first electronic component within the vapor shielding cover.

In the method of manufacturing an electronic device according to exemplary embodiments for achieving the object of the present invention, first electronic components are each mounted on the first surface of a substrate via first bumps. At least one vapor shield cover is placed on the first side of the substrate to cover at least one of the first electronic components. Second electronic components are respectively disposed on the second side of the substrate opposite to the first side via second bumps. The substrate on which the at least one vapor shielding cover is disposed is loaded into a vapor generation chamber containing a heat transfer fluid. The heat transfer fluid is heated to form the vaporous heat transfer fluid within the chamber. The second bumps are soldered using heat generated when the vaporous heat transfer fluid condenses in contact with the surface of the substrate.

In the method of manufacturing an electronic device according to exemplary embodiments for achieving the object of the present invention, first and second electronic components are formed on the first side of the substrate and the second side opposite to the first side. Implement them respectively. Defective electronic components are removed from the first and second electronic components mounted on the first and second sides of the substrate. Vapor shield covers are placed on the first and second sides of the substrate to cover at least one of the remaining first and second electronic components on the first and second sides of the substrate. Instead of the defective electronic component, a good electronic component is placed on the substrate using first bumps. The first bumps are soldered using a vapor phase reflow method, but the heat transfer fluid in a vapor state is prevented from moving to the electronic components within the vapor shielding covers.

According to exemplary embodiments, the first electronic components are each mounted on the first side of the substrate via first bumps, and the first electronic components are mounted on the first side of the substrate to cover at least one of the first electronic components. At least one vapor shielding cover may be disposed on the substrate, second electronic components may be disposed on the second surface of the substrate via second bumps, and the second bumps may be soldered by a vapor phase reflow method. there is.

The substrate on which the vapor shielding cover is disposed may be loaded into a vapor heating chamber of a vapor phase solder reflow device, and a heat transfer fluid in a vapor state may be brought into contact with the surface of the substrate to reflow the second bumps. At this time, the vapor shielding cover may block the heat transfer fluid in a vapor state from moving to the first electronic components within the vapor shielding cover.

Accordingly, the first bumps between the first surface of the substrate and the mounted first electronic components are re-melted, thereby preventing defects in which the first electronic components fall from the first surface of the substrate. Accordingly, defects in the reflow process for solders arranged at a fine pitch can be reduced and bonding quality can be improved.

However, the effects of the present invention are not limited to the effects mentioned above, and may be expanded in various ways without departing from the spirit and scope of the present invention.

1 is a cross-sectional view showing a solder reflow device according to example embodiments.
FIG. 2 is a side view showing the solder reflow device of FIG. 1.
FIG. 3 is a perspective view showing the substrate stage of the solder reflow device of FIG. 1.
Figure 4 is a perspective view showing an article supported on the substrate stage of Figure 3;
FIG. 5 is a cross-sectional view showing electronic components mounted on a substrate on the substrate stage of FIG. 1 by a vapor phase reflow method.
6 is a flowchart showing a method of manufacturing an electronic device according to example embodiments.
7 to 16 are diagrams showing a method of manufacturing an electronic device according to example embodiments.
17 is a flowchart showing a method of manufacturing an electronic device according to example embodiments.
18 to 22 are diagrams showing a method of manufacturing an electronic device according to example embodiments.
Figure 23 is a cross-sectional view showing vapor shielding members covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.
Figure 24 is a cross-sectional view showing vapor shielding members covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.
Figure 25 is a cross-sectional view showing a vapor shielding member covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.

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

1 is a cross-sectional view showing a solder reflow device according to example embodiments. FIG. 2 is a side view showing the solder reflow device of FIG. 1. FIG. 3 is a perspective view showing the substrate stage of the solder reflow device of FIG. 1. Figure 4 is a perspective view showing an article supported on the substrate stage of Figure 3;

Referring to FIGS. 1 to 4 , the solder reflow device 10 may include a vapor generation chamber 100, a heater 110, and a substrate stage 200. In addition, the solder reflow device 10 may further include a raising and lowering driving unit for raising and lowering the substrate stage 200 and a temperature sensing unit for monitoring the temperature within the steam generation chamber 100.

In example embodiments, the solder reflow device 10 may be a vapor phase soldering device for soldering solder paste using saturated vapor heated within the vapor generation chamber 100 .

The steam generation chamber 100 has an oven shape that includes a bottom reservoir for receiving the heat transfer fluid F and provides a space 101 filled with the vapor formed immediately above when the thermal cutting fluid F boils. You can have it. The steam generation chamber 100 may extend in the vertical direction (Z) by a preset height. In the steam generation chamber 100, the heat transfer fluid boils and the vapor rises to the top, condenses back to a liquid state at the top, and flows back to the reservoir at the bottom.

The pressure inside the steam generation chamber 100 may be maintained at atmospheric pressure. Alternatively, the steam generation chamber 100 may be connected to an exhaust device such as a vacuum pump to control the pressure inside the steam generation chamber 100. The pressure inside the steam generation chamber may be maintained at a predetermined pressure to change the boiling point of the heat transfer fluid or for a soldering environment.

The heat transfer fluid (F) may be a chemical selected to provide the vapor needed for soldering to occur. The heat transfer fluid may be selected taking into account the boiling point, environmental effects, and corrosiveness of the vapor produced. The heat transfer fluid may include an inert organic liquid. For example, the heat transfer fluid may include a perfluoropolyether (PFPEs)-based Galden solution. The boiling point of the Galden solution may be 230°C.

The heater 110 may heat the heat transfer fluid (F) contained in the steam generation chamber 100 to generate saturated steam. 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 surrounding the receiving tank.

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

As shown in FIGS. 3 and 4 , the substrate stage 200 may support an article S for soldering within the 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 movement of the vapor. For example, the article S may include a substrate 20 on which electronic components 30a and 30b are mounted via bumps 40a and 40b. The open holes may have a circular or polygonal shape. The sizes and shapes of the open holes, thicknesses of the support wires, etc. may be determined considering the temperature profile within the steam generation chamber.

The substrate stage 200 may be installed to be raised and lowered within the steam generation chamber 100. The raising and lowering driving unit for raising and lowering the substrate stage 200 may include various types of drivers such as transfer rail, transfer screw, and transfer belt types. 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 raising and lowering driving unit.

As shown in FIG. 2, the article (S) for soldering is transferred into the steam generation chamber 100 through the gate 102 of the steam generation chamber 100, and the article (S) is connected to the guide rail or transfer pusher. It can be loaded on the substrate stage 200 by a transfer mechanism 104 such as .

After the article S is loaded, the Galden solution F may be heated by the heater 110 and begin to boil. The saturated vapor of the galden can be distributed within the space 101 of the vapor generation chamber 100. At this time, the density of the saturated steam varies depending on the height, and a temperature gradient may be formed accordingly.

For example, the temperature (T1) of the steam generation chamber 100 at the third height (H3) is 100°C, and the temperature (T2) of the steam generation chamber 100 at the second height (H2) is 170°C. °C, and the temperature (T3) of the steam generation chamber 100 at the first height (H1) may be 230 °C. The bump 30 may include Sn-Ag-Cu (SAC) solder, Sn-Ag solder, etc. Since the boiling point of SAC solder is 217°C, the temperature (T3) at the third height (H1), which is the reflow section, can be maintained at 230°C.

Hereinafter, a method of performing a vapor phase reflow process using the solder reflow device of FIG. 1 will be described.

FIG. 5 is a cross-sectional view showing electronic components mounted by a vapor phase reflow method on a substrate supported on the substrate stage of FIG. 1 .

First, an article (S) for soldering is loaded into the steam generation chamber 100, and the heat transfer fluid (F) within the steam generation chamber 100 may be heated.

In exemplary embodiments, the substrate 20 on which the electronic component 30 is disposed via the bump 30 enters the steam generation chamber 100 through the gate 102 of the steam generation chamber 100. After being transferred, the article S may be loaded onto the substrate stage 200 by a transfer mechanism 104, such as a guide rail or transfer pusher.

After the article S is loaded, the Galden solution F may be heated by the heater 110 and begin to boil. The saturated vapor of the galden can be distributed within the space 101 of the vapor generation chamber 100. At this time, the steam has a density gradient according to height, and accordingly, a temperature gradient along the vertical direction may be formed within the steam generation chamber 100.

After the article S is preheated at the third height H3 (preheat), it may be moved to the second height H2 and activated (soak). The substrate 20 may be preheated to prevent various soldering defects and to provide a more robust and conductive joint. At the third and second heights H3 and H2, there may be a secondary vapor phase generated at a lower temperature than the main vapor layer. In this area, soldering does not occur, and only the temperature rises.

The article S is moved to the first height H1 so that the bumps 40b can reflow. When the article S is immersed in steam at the first height H1, the steam acts as a heat transfer medium. Since the temperature at the first height H1 and the temperature of the substrate 20 are different, vapor may condense on the surface of the article S to form a layer. The vapor may reflow the solder paste by transferring latent heat to the surface of the substrate 20 during condensation.

At this time, vapor at the bottom of the substrate stage 200 may pass through the open hole 201 of the substrate stage 200 and be supplied to the bump 40b on the substrate 20 and the space around the bump 40b. Accordingly, the steam can be sufficiently supplied to the entire surface of the substrate 20 to achieve uniform heat transfer throughout the entire area of the article S.

As shown in FIG. 5, a vapor shielding cover 50 is disposed on the first side 21a of the substrate 20 supported on the substrate stage 200 to cover the substrate 20 by the first bumps 40a. ) can cover the first electronic components 30a mounted on the first surface 21a. Second electronic components 30b may be disposed on the second surface 21b of the substrate 20 via the second bumps 40b. When the substrate stage 200 is located at the third height H1, which is the reflow section, the second bumps 40b reflow to form second electronic components on the second surface 21b of the substrate 20. (30b) can be mounted.

In this case, the vapor shielding cover 50 includes a cover portion 52 extending parallel to the first surface 21a of the substrate 20 from the top of the first electronic components 30a and the second portion of the substrate 20. It may include a support portion 54 extending from the first side 21a and supporting the cover portion 52. The cover part 52 and the support part 54 may be spaced apart from the first electronic components 40a to form a closed space V blocked from the outside. For example, the cover portion 52 may have a rectangular plate shape, and the support portion 54 may include first to fourth support plates extending vertically from first to fourth sides of the cover portion 52. there is.

The cover portion 52 of the vapor shield cover 50 may be supported on the support wires 202 of the substrate stage 200, and the substrate 20 may be supported on the support portion 54. The substrate 20 may be supported on the vapor shielding cover 50 so that the first side 21a of the substrate 20 faces the substrate stage 200 .

When the article S is immersed in steam at the first height H1, the steam acts as a heat transfer medium. Since the temperature at the first height H1 and the temperature of the substrate 20 are different, vapor may condense on the surface of the article S to form a layer. The vapor transfers latent heat to the second surface 21b of the substrate 20 during condensation, thereby reflowing the solder paste to solder the second bumps 40b. At this time, the vapor shielding cover 50 may block the heat transfer fluid in a vapor state from moving to the first electronic components 30a within the vapor shielding cover 50.

Accordingly, the first bumps 40a between the first surface 21a of the substrate 20 and the mounted first electronic components 30a are re-melted and the mounted first electronic components 30a are formed on the substrate ( It is possible to prevent defects falling from the first surface 21a of 20). Accordingly, defects in the reflow process for solders arranged at a fine pitch can be reduced and bonding quality can be improved.

Subsequently, after the second bumps 40b are soldered, the article S can be moved to the upper part of the chamber and cooled. Accordingly, the solder joints can be cooled and solidified.

Hereinafter, a method of manufacturing an electronic device using the solder reflow device 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 example embodiments is not limited thereto.

6 is a flowchart showing a method of manufacturing an electronic device according to example embodiments. 7 to 16 are diagrams showing a method of manufacturing an electronic device according to example embodiments. Figure 7 is a plan view showing a strip board on which semiconductor chips are mounted. Figures 8, 10 to 15 are cross-sectional views taken along line II' of Figure 7.

Referring to FIGS. 6 to 16, first, a double-sided mounting board 20 having a first side 21a and a second side 21b opposing each other is provided (S10), and the first side of the board 20 is provided. The first electronic components 30a may each be mounted on (21a) (S20).

As shown in FIG. 7, the substrate 20 may be a multilayer circuit board as a package substrate having a first surface 21a and a second surface 21b facing each other. The substrate 20 may be a strip board for manufacturing a semiconductor strip, such as a printed circuit board (PCB).

The substrate 20 has a first side S1 and a second side S2 extending in a direction parallel to the second direction parallel to the first surface 21a and facing each other, and a second side S1 orthogonal to the second direction. It may include a third side S3 and a fourth side S4 that extend in a direction parallel to one direction (X direction) and face each other. The substrate 20 may have a square shape when viewed in plan view. The substrate 20 may have a preset area (eg, 77.5 mm x 240 mm).

The substrate 20 may include a mounting region MR on which at least one electronic component is mounted and a cut region CR surrounding the mounting region MR. A plurality of semiconductor chips serving as electronic components may be disposed on the mounting regions MR of the substrate 20, respectively. For example, the semiconductor chip may include a logic semiconductor device and a memory device. The logic semiconductor device may be an ASIC as a host such as CPU, GPU, or SoC. The memory device may include a high bandwidth memory (HBM) device. Alternatively, the electronic component may include passive elements such as capacitors.

For example, dozens to hundreds of semiconductor chips may be arranged in a matrix form on the substrate 20. As will be described later, the semiconductor chips may be mounted on both sides of the substrate 20, that is, the first side 21a and the second side 21b.

As shown in FIG. 8, solder paste 24 may be applied on each of the plurality of first substrate pads 22a on the first surface 21a of the substrate 20. The pitch between the plurality of first substrate pads 22 of the substrate 20 may be within the range of several tens of microns.

Solder paste 24 may be printed on the first substrate pad 22a of the substrate 20. For example, solder paste 24 may be printed by a stencil printer. The stencil may be a metal foil with a plurality of openings corresponding to the arrangement of bumps that are subsequently placed. During printing, solder paste 24 may be printed to fill the openings in the stencil. Solder paste 24 may include solder powder (solder power) and flux. The flux may include resin, solvent, activator, and antioxidant.

Alternatively, the solder paste may be applied to the surface of the bump formed on the semiconductor chip.

As shown in FIG. 9 , first bumps 40a may be formed on the first electronic component 30a to be mounted on the first surface 21a of the substrate 20. The first electronic component 30a 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.

A plurality of input/output pads 32 may be formed on the first surface 31a of the first electronic component 30a. First bumps 40a may be formed on the input/output pads 32, respectively. Although not shown in the drawing, after forming an under bump metallurgy (UBM) on the input/output pad 32, the first bump 40a may be formed on the under bump metal.

As shown in FIG. 10, the first electronic component 30a is connected to the substrate 20 so that the first bump 40a is interposed between the input/output pad 32 of the first electronic component 30a and the solder paste 24. It can be placed on the first side 21a. Subsequently, the semiconductor chips can be mounted on the first side 21a of the substrate 20 by flip chip bonding.

For example, the first bumps 40a may be reflowed using a convection reflow method. While sequentially moving the substrate 20 on which the first electronic components 30a are mounted to the first to third heating chambers of the convection reflow type solder reflow device, the solder paste 24 is sold within each heating chamber. A solder bump can be formed between the first substrate pad 22a and the input/output pad 32 by heating and reflowing the first bumps 40a.

Alternatively, the first bumps 40a may be reflowed using a vapor phase reflow method. It is loaded into the vapor heating chamber 100 of the solder reflow device 10 of FIG. 1, and while moving in the vertical direction within the vapor heating chamber 100, the heat transfer fluid in a vapor state is brought into contact with the surface of the substrate 20. By heating the solder paste 24, the first bumps 40a can be reflowed to form a solder bump between the first substrate pad 22a and the input/output pad 32.

Next, the vapor shielding cover 50 covering the first electronic components 30a may be placed on the first surface 21a of the substrate 20 (S30).

As shown in FIG. 11 , the vapor shielding cover 50 is disposed on the first side 21a of the substrate 20 to cover the first side 21a of the substrate 20 by the first bumps 40a. It can cover the first electronic components 40a mounted on it.

The vapor shielding cover 50 may be a cover for a strip to cover the entire first electronic components 40a on the first surface 21a of the substrate 20. The vapor shielding cover 50 includes a cover portion 52 extending parallel to the first surface 21a of the substrate 20 from the top of the first electronic components 40 and a first surface 21a of the substrate 20. It may include a support portion 54 extending from and supporting the cover portion 52. The cover part 52 and the support part 54 may be spaced apart from the first electronic components 40a to form a closed space V blocked from the outside. For example, the cover portion 52 may have a rectangular plate shape, and the support portion 54 may include first to fourth support plates extending vertically from first to fourth sides of the cover portion 52. there is.

The vapor shielding cover 50 may be detachably attached to the first side 21a of the substrate 20 using an adhesive member such as solder paste, thermal tape, adhesive film, or the like. Alternatively, the vapor shielding cover 50 may be arranged to be in close contact with the surface of the substrate 20 without the adhesive member. Additionally, the support portion 54 of the vapor shielding cover 50 may have a stepped portion in contact with the surface of the substrate 20 . The sides of the substrate 20 can be seated and supported on the stepped portion of the vapor shield cover 50 without the adhesive member.

For example, the vapor shielding cover 50 may include glass, plastic, ceramic, or a metal material such as aluminum. In this embodiment, a vapor shielding cover 50 manufactured in the form of a metal can may be placed on the first surface 21a of the substrate 20. The area and thickness of the cover portion of the vapor shielding cover 50 may be determined by considering the size and heat generation amount of the electronic components to be covered.

Thereafter, the second electronic components 30b may be respectively placed on the second surface 21b of the substrate 20 (S40).

In example embodiments, the structure of FIG. 11 is turned over and processes identical or similar to those described with reference to FIGS. 8 to 10 are performed to form a second bump on the second side 21b of the substrate 20. The second electronic components 40b may be arranged through the fields 40b.

As shown in FIG. 12, solder paste 24 may be applied on each of the plurality of second substrate pads 22b on the second surface 21b of the substrate 20. Solder paste 24 may be printed on the second substrate pad 22b of the substrate 20. For example, solder paste 24 may be printed by a stencil printer.

As shown in FIG. 13, second bumps 40b are formed on the second electronic component 30b to be mounted on the second surface 21b of the substrate 20, and the second electronic component 30b is formed. The second electronic component 30b may be placed on the second surface 21b of the substrate 20 so that the second bump 40b is interposed between the input/output pad 32 and the solder paste 24.

Thereafter, soldering of the second electronic components 30b may be performed using a vapor phase reflow method (S50).

As shown in FIG. 14, the substrate 20 on which the first and second electronic components 30a and 30b are mounted is loaded into the vapor heating chamber 100 of the solder reflow device 10 of FIG. 1, While moving in the vertical direction within the vapor heating chamber 100, the solder paste 24 is heated by contacting the surface of the substrate 20 with a heat transfer fluid in a vapor state, thereby reflowing the second bumps 40b. 2 A solder bump can be formed between the substrate pad 22b and the input/output pad 32.

In exemplary embodiments, after the substrate 20 is loaded, the Galden solution F may be heated by the heater 110 and begin to boil. The saturated vapor of the galden can be distributed within the space 101 of the vapor generation chamber 100. At this time, the steam has a density gradient according to height, and accordingly, a temperature gradient along the vertical direction may be formed within the steam generation chamber 100.

After the substrate 20 is preheated at the third height H3 (preheat), it may be moved to the second height H2 and activated (soak). The substrate 20 may be preheated to prevent various soldering defects and to provide a more robust and conductive joint. At the third and second heights H3 and H2, there may be a secondary vapor phase generated at a lower temperature than the main vapor layer. In this area, soldering does not occur, and only the temperature rises.

The article S is moved to the first height H1 so that the solder 40 can reflow. When the article S is immersed in steam at the first height H1, the steam acts as a heat transfer medium. Since the temperature at the first height H1 and the temperature of the substrate 20 are different, vapor may condense on the surface of the substrate 20 to form a layer. The vapor may reflow the solder paste by transferring latent heat to the surface of the substrate 20 during condensation.

Referring again to FIG. 14, the cover portion 52 of the vapor shielding member 50 is supported on the support wires 202 of the substrate stage 200, and the substrate 20 is supported on the support portion 54. You can. The substrate 20 may be supported on the vapor shielding cover 50 so that the first side 21a of the substrate 20 faces the substrate stage 200 .

When the substrate 20 is immersed in steam at the first height H1, the steam serves as a heat transfer medium. Since the temperature at the first height H1 and the temperature of the substrate 20 are different, vapor may condense on the surface of the substrate 20 to form a layer. The vapor transfers latent heat to the second surface 21b of the substrate 20 during condensation, thereby reflowing the solder paste to solder the second bumps 40b. At this time, the vapor shielding cover 50 may block the heat transfer fluid in a vapor state from moving to the first electronic components 30a within the vapor shielding cover 50.

Accordingly, the first bumps 40a between the first surface 21a of the substrate 20 and the mounted first electronic components 30a are re-melted and the mounted first electronic components 30a are formed on the substrate ( It is possible to prevent defects falling from the first surface 21a of 20). Accordingly, defects in the reflow process for solders arranged at a fine pitch can be reduced and bonding quality can be improved.

Subsequently, after the second bumps 40b are soldered, the substrate 20 can be moved to the upper part of the chamber and cooled. Accordingly, the solder joints can be cooled and solidified.

After unloading the substrate 20 on which the first and second electronic components 30a and 30b are mounted from the solder reflow device 10 of FIG. 1, the vapor shielding member 50 is placed on the substrate 20. It can be removed from one side (21a).

Afterwards, rework of defective electronic components can be performed (S60).

In exemplary embodiments, in the rework step, among the first and second electronic components 30a and 30b mounted on the first side 21a and the second side 21b of the substrate 20, Defective electronic components can be removed and new good electronic components can be installed. A method of manufacturing an electronic device using the rework step will be described later with reference to FIGS. 17 to 22.

Next, a molding member 60 may be formed to cover the first and second electronic components 30a and 30b mounted on both sides of the substrate 20.

As shown in FIG. 15, first and second electronic components cover the first and second electronic components 30a and 30b, respectively, on the first side 21a and the second side 21b of the substrate 20. Molding members 60a and 60b can be formed.

In example embodiments, the first and second molding members 60a and 60b may be formed on the substrate 20 by a transfer molding device. The substrate 20 is placed in the molding space of the mold of the molding device, and the sealing material is flowed at high temperature and pressure while the lower mold and the upper mold are clamped, so that the liquid sealing material flows inside the molding space and solidifies to form electronic components. First and second molding members 60a and 60b may be formed to cover the surfaces 30a and 30b, respectively. For example, the sealant may include epoxy mold compound (EMC).

Thereafter, the substrate 20 may be cut through a sawing process to complete the semiconductor packages 70 .

As shown in FIG. 16, the cut region CR of the substrate 20 can be removed using a cutting device such as a blade. Accordingly, the substrate 20 can be separated into individual semiconductor packages 70.

Hereinafter, a method of manufacturing an electronic device using the rework step will be described.

17 is a flowchart showing a method of manufacturing an electronic device according to example embodiments. 18 to 22 are diagrams showing a method of manufacturing an electronic device according to example embodiments.

17 to 22, first, a defective electronic component 30f is selected from among the first and second electronic components 30a and 30b on the first and second surfaces 21a and 21b of the substrate 20. ) can be removed (S100).

First, the same or similar processes as those described with reference to FIGS. 7 to 14 are performed to form first and second electronic components ( 30a and 30b) are mounted respectively, and the first and second electronic components 30a and 30b bonded to both sides of the substrate 20 are inspected using inspection equipment to detect the location of the defective electronic component 30f. can do.

As shown in Figures 18 and 19, hot air is applied using a heat gun (H) to the defective electronic component (30f) confirmed by the inspection equipment, and the solder of the heated defective electronic component (30f) is melted and soldered to the substrate. It can be eliminated from (20). Subsequently, the removed portion of the substrate 20 may be cleaned.

Thereafter, first and second vapor shielding covers 50a and 50b were placed on the first side 21a and the second side 21b of the substrate 20 to cover the remaining electronic components 30a and 30b. It can be placed (S110).

As shown in FIG. 20, when the defective electronic component 30f is removed from the first side 21a of the substrate 20, a first vapor shield cover is placed on the first side 21a of the substrate 20. (50a) is disposed to cover the first electronic components 30a mounted on the first side 21a of the substrate 20 by the first bumps 40a, and to cover the first electronic components 30a mounted on the first side 21a of the substrate 20. The second vapor shielding cover 50b is disposed on (21b) to cover the second electronic components 30b mounted on the second surface 21b of the substrate 20 by the second bumps 40b. can do.

The first vapor shielding cover 50a is spaced apart from the first electronic components 30a to form a sealed space Va blocked from the outside, and the second vapor shielding cover 50b is spaced apart from the first electronic components 30a ( 30b) can form a closed space (Vb) that is separated from the outside and blocked. The portion from which the defective electronic component 30f was removed may be exposed by the first and second vapor shielding covers 50a and 50b.

Thereafter, a good electronic component (30g) can be placed on the substrate 20 in place of the defective electronic component (S120).

As shown in FIG. 21, the same or similar processes as those described with reference to FIGS. 8 to 10 are performed to remove the substrate 20 exposed by the first and second vapor shielding covers 50a and 50b. A third electronic component 30g of good quality can be placed on the first surface 21a using the third bumps 40g.

Specifically, solder paste 24 may be applied on each of the plurality of first substrate pads 22a on the first surface 21a of the substrate 20. Solder paste 24 may be printed on the first substrate pad 22a of the substrate 20. For example, solder paste 24 may be printed by a stencil printer.

Third bumps 40g are formed on the third electronic component 30g to be mounted on the first surface 21a of the substrate 20, and the input/output pad 32 of the third electronic component 30g is soldered. The third electronic component 30g may be placed on the first surface 21a of the substrate 20 so that the third bump 40g is interposed between the pastes 24.

Next, soldering of the third electronic component 30g can be performed using a vapor phase reflow method (S130).

As shown in FIG. 22, the substrate 20 on which the first to third electronic components 30a, 30b, and 30c are mounted is loaded into the vapor heating chamber 100 of the solder reflow device 10 of FIG. 1. And, while moving in the vertical direction within the vapor heating chamber 100, the solder paste 24 is heated by contacting the surface of the substrate 20 with a heat transfer fluid in a vapor state, thereby reflowing the third bumps 40g. A solder bump can be formed between the first substrate pad 22a and the input/output pad 32.

The second vapor shielding member 50b is supported on the support wires 202 of the substrate stage 200, and the substrate 20 can be supported on the second vapor shielding member 50b. The substrate 20 may be supported on the second vapor shielding cover 50b so that the second surface 21b of the substrate 20 faces the substrate stage 200 .

When the substrate 20 is immersed in steam at the first height H1, the steam serves as a heat transfer medium. Since the temperature at the first height H1 and the temperature of the substrate 20 are different, vapor may condense on the surface of the substrate 20 to form a layer. The vapor transfers latent heat to the first surface 21a of the substrate 20 during condensation, thereby reflowing the solder paste to solder the third bumps 40g. At this time, the first and second vapor shielding covers 50a and 50b allow the heat transfer fluid in a vapor state to flow through the first and second electronic components 30a within the first and second vapor shielding covers 50a and 50b. , movement to 30b) can be blocked.

Accordingly, the first and second bumps 40a and 40b between the first and second surfaces 21a and 21b of the substrate 20 and the mounted first and second electronic components 30a and 30b. It is possible to prevent the re-melted and mounted first and second electronic components 30a and 30b from falling from the first and second surfaces 21a and 21b of the substrate 20. Accordingly, defects in the reflow process for solders arranged at a fine pitch can be reduced and bonding quality can be improved.

Figure 23 is a cross-sectional view showing vapor shielding members covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.

Referring to FIG. 23 , a plurality of vapor shielding members 51a may cover the first electronic components 30a on the first surface 21a of the substrate 20. One vapor shielding member 51a may be a package cover for covering only the first electronic components 30a in the mounting area MR on the first surface 21a of the substrate 20.

A plurality of vapor shielding members 51a may be respectively disposed on mounting regions MR on the first surface 21a of the substrate 20 . The plurality of vapor shielding members 51a may be spaced apart from each other.

Figure 24 is a cross-sectional view showing vapor shielding members covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.

Referring to FIG. 24 , the plurality of vapor shielding members 51b may each cover the first electronic components 30a on the first surface 21a of the substrate 20 . One vapor shielding member 51a may be a cover for an individual component to cover only one first electronic component 30a on the first surface 21a of the substrate 20.

The plurality of vapor shielding members 51a may be arranged to each cover only some of the first electronic components 30a on the first surface 21a of the substrate 20.

Figure 25 is a cross-sectional view showing a vapor shielding member covering electronic components on a substrate in a vapor phase reflow process according to example embodiments.

Referring to FIG. 25, at least one vapor shield cover includes a first cover 50c having a first height H1 from the first surface 21a of the substrate 20 and a first surface 21a of the substrate 20. ) may include a second cover (50d) having a second height (H2) greater than the first height (H1).

The first cover 50c covers the first electronic component 30c having a third height, and the second cover 50d covers the first electronic component 30d having a fourth height greater than the third height. can do. The first cover 50c and the second cover 50d may be spaced apart from each other. Alternatively, the first cover 50c and the second cover 50d may be formed integrally with each other.

The first and second covers 50c and 50d may cover electronic components such as semiconductor chips, but may not cover electronic components such as the passive element 30e.

Through the above-described processes, a semiconductor package including a logic device or memory device and a semiconductor module including the same can be mass-produced. The semiconductor package includes logic elements such as, for example, a central processing unit (CPU, MPU), an application processor (AP), etc., such as an SRAM device, a DRAM device, and a high-bandwidth memory (HBM) device. It may include volatile memory devices such as flash memory devices, PRAM devices, MRAM devices, and RRAM devices.

Although the present invention has been described above with reference to embodiments, those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it is possible.

10: solder reflow device 20: substrate
22a, 22b: substrate pad 24: solder paste
30a, 30b, 30c, 30d, 30e, 30f, 30g: Electronic components
32: input/output pad 40a, 40b, 40g: bump
50a, 50b, 50c, 50d, 51a, 51b: vapor shield cover
60, 60a, 60b: molding member 70: semiconductor package
100: steam generation chamber 102: gate
104: transfer mechanism 110: heater
200: substrate stage 201: open hole
202: support wire

Claims (10)

Providing a substrate having a plurality of mounting areas on which electronic components are respectively mounted and having first and second surfaces opposing each other;
Mounting first electronic components on the first side of the substrate using first bumps, respectively;
positioning at least one vapor shield cover on the first side of the substrate to cover at least one of the first electronic components;
disposing second electronic components on the second side of the substrate via second bumps; and
A method of manufacturing an electronic device, comprising soldering the second bumps by a vapor phase reflow method and blocking a heat transfer fluid in a vapor state from moving to the first electronic component within the vapor shielding cover. The method of claim 1, wherein the at least one vapor shielding cover comprises glass, plastic, metal, or ceramic. 2. The method of claim 1, wherein the at least one vapor shielding cover comprises:
a first cover having a first height from the first side of the substrate; and
A method of manufacturing an electronic device including a second cover having a second height greater than the first height from the first side of the substrate. The method of claim 1, wherein the at least one vapor shield cover is a cover for a strip to cover all of the first electronic components on the first side of the substrate, and the first electronic components in the mounting area on the first side of the substrate. A method of manufacturing an electronic device comprising a cover for a package to cover electronic components or a cover for an individual component to cover any one of the first electronic components on the first side of the substrate. The method of claim 1, wherein soldering the second bumps by the vapor phase reflow method comprises:
loading the substrate onto a substrate stage in a vapor generation chamber containing a heat transfer fluid;
heating the heat transfer fluid to form the vaporous heat transfer fluid within the chamber; and
A method of manufacturing an electronic device comprising soldering the second bumps using heat generated when the vapor-state heat transfer fluid condenses in contact with the substrate surface. The method of claim 1, wherein each of the second electronic components is disposed on the second surface of the substrate via the second bumps.
printing solder paste on substrate pads on a second side of the substrate;
forming the second bumps on input/output pads of the electronic component; and
A method of manufacturing an electronic device including disposing the second electronic component on the second surface of the substrate so that the second bumps are interposed between the input/output pad and the solder paste. The method of claim 1, wherein each of the first electronic components is mounted on the first surface of the substrate via the first bumps by soldering the first bumps by a convection reflow method or a vapor phase reflow method. A method of manufacturing an electronic device comprising: According to claim 1,
removing defective electronic components from among first and second electronic components mounted on the first and second sides of the substrate;
positioning second vapor shield covers on the first and second sides of the substrate to cover at least one of the remaining first and second electronic components on the first and second sides of the substrate;
placing a good electronic component on the substrate using third bumps in place of the defective electronic component; and
Soldering the third bumps by a vapor phase reflow method, and further comprising blocking vapor heat transfer fluid from moving to the electronic components within the second vapor shielding covers. According to claim 1,
After soldering the bumps,
A method of manufacturing an electronic device further comprising cutting the substrate along a cut area dividing the mounting areas. Mounting first electronic components on the first side of the substrate using first bumps, respectively;
positioning at least one vapor shield cover on the first side of the substrate to cover at least one of the first electronic components;
disposing second electronic components via second bumps on a second side of the substrate opposite to the first side;
loading the substrate on which the at least one vapor shielding cover is disposed into a vapor generating chamber containing a heat transfer fluid;
heating the heat transfer fluid to form the vaporous heat transfer fluid within the chamber; and
A method of manufacturing an electronic device comprising soldering the second bumps using heat generated when the vapor-state heat transfer fluid condenses in contact with the substrate surface.