JP2004288771A - Electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component which makes coating easy with the sealing resin of an electronic component packaging substrate which mounts electronic components. <P>SOLUTION: In the electronic component which performs coating with the sealing resin after mounting in the packaging substrate, a sealing resin strip composed of a prescribed amount of sealing resin is previously attached, the electronic component is mounted on the packaging substrate by reflow, and continuously the sealing resin strip is melted, thereby performing coating. The sealing resin is melted at a resin melting temperature higher than heating condition of reflow for attaching the electronic component to the packaging substrate, and heated to the resin melting temperature in the case of reflow. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic component, and more particularly to an electronic component that is mounted on a mounting board using solder or the like and then coated using a sealing resin.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, electronic component mounting boards having various functions have been formed by mounting required electronic components on a mounting board provided with required electric wiring.
[0003]
When it is desired to improve moisture resistance, water resistance, insulation properties, and the like in such an electronic component mounting board, a sealing resin is applied to an upper surface of the electronic component mounting board, and the electronic component on the mounting board is formed by the sealing resin. Is applied to hermetically seal.
[0004]
That is, in the electronic component mounting board, first, a solder paste (cream solder) is applied to a required position on the upper surface of the mounting board by screen printing or the like, and then a required electronic component is applied to a required position on the mounting board via the solder paste. After mounting, the mounting board on which the electronic component is mounted is passed through a reflow furnace to reflow the solder paste to make electrical connection between the electronic component and the mounting board by soldering. Using a dispenser or needle capable of discharging the resin, apply the sealing resin to the required electronic components on the mounting board, or the required area of the mounting board, and then apply the applied sealing resin by heating or UV irradiation. An electronic component mounting board coated by curing with an appropriate curing means has been formed (for example, see Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-057171
[Problems to be solved by the invention]
However, when the sealing resin is applied by using a dispenser or the like and the sealing resin is cured by a required curing unit, the application of the sealing resin by the dispenser and the applied sealing are performed. It takes a long time to cure the resin, which is a major obstacle to shortening the working time, and it has been difficult to improve the working efficiency.
[0007]
In addition, in the coating operation performed by dispensing the sealing resin with the dispenser, a larger amount of the sealing resin is applied than necessary in order to prevent the occurrence of coating failure. It would take more time.
[0008]
[Means for Solving the Problems]
Therefore, in the present invention, in an electronic component to be coated with a sealing resin after being mounted on a mounting board, a sealing resin piece made of a predetermined amount of the sealing resin is mounted in advance, and the electronic component is mounted on the mounting board by reflow. It is an object of the present invention to provide an electronic component configured to perform coating by melting a sealing resin piece after mounting.
[0009]
In addition, the sealing resin is characterized by being configured to melt at a resin melting temperature higher than the reflow heating condition for mounting the electronic component on the mounting board and to be heated to the resin melting temperature at the time of reflow. is there.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The electronic component of the present invention is one in which a sealing resin piece made of a predetermined amount of sealing resin is mounted in advance.
[0011]
After the electronic component is mounted on the mounting board by reflow, the sealing resin piece is subsequently melted, so that the electronic component can be coated with the sealing resin.
[0012]
In this way, by mounting the sealing resin piece on the electronic component itself in advance, it is possible to omit the operation of applying the sealing resin using a dispenser or the like, and furthermore, following the mounting of the electronic component on the mounting board. Since the coating of the electronic component can be performed only by melting the sealing resin piece, the working efficiency can be greatly improved.
[0013]
In addition, the sealing resin piece can be composed of the minimum necessary sealing resin, thereby reducing the manufacturing cost and shortening the curing time of the sealing resin, thereby further improving the working efficiency. Can be done.
[0014]
In particular, by using a resin that melts at a higher resin melting temperature than the reflow heating conditions for mounting the electronic component on the mounting board for the sealing resin, and by heating the resin to the resin melting temperature during reflow, By heating the mounting board with the reflow, and subsequently heating the mounting board to the melting temperature of the sealing resin, from mounting the electronic components on the mounting board to coating the mounted electronic components with the sealing resin Can be performed continuously, so that the working efficiency can be improved.
[0015]
Hereinafter, embodiments will be described in detail with reference to the drawings.
[0016]
【Example】
(First embodiment)
FIG. 1 is a process explanatory diagram illustrating a process of mounting the electronic component A1 on the mounting board 1 according to the first embodiment. The electronic component A1 of the first embodiment is a semiconductor device configured by extending external connection terminals 3 by leads from a sealing portion 2 configured by sealing a required semiconductor chip (not shown) with a mold resin. is there.
[0017]
Then, as shown in FIG. 1A, in the electronic component A1 of the first embodiment, a sealing resin piece 4 formed by curing a required amount of sealing resin into a flat plate on the sealing portion 2 is formed. Is installed.
[0018]
In this embodiment, the sealing resin piece 4 is made of a polyamide resin. When the sealing resin piece 4 is mounted on the upper portion of the sealing portion 2, the sealing resin piece 4 is formed using an adhesive. It is mounted on the upper part of the sealing part 2. After the electronic component A1 to which the sealing resin piece 4 is not mounted is mounted on the mounting board 1, the sealing resin piece 4 may be mounted on the upper portion of the sealing portion 2.
[0019]
As the sealing resin piece 4, one having a melting temperature higher than the melting temperature of the solder paste 6 described later is used. This prevents the sealing resin piece 4 from melting.
[0020]
In this way, the electronic component A1 having the sealing resin piece 4 mounted on the sealing portion 2 abuts the external connection terminal 3 via the solder paste 6 on the connection pad 5 provided at a required position on the mounting board 1. It is installed. In this embodiment, the solder paste 6 is applied to each connection pad 5 on the mounting board 1 by screen printing, but the connection pad 5 may be attached with solder or solder paste by an appropriate method.
[0021]
After the electronic component A1 including the sealing resin piece 4 is mounted on the mounting substrate 1, the mounting substrate 1 is passed through a reflow furnace, so that the external components including the respective leads of the electronic component A1 are soldered. The connection terminal 3 is electrically connected to each connection pad 5 of the mounting board 1.
[0022]
In particular, in the case of this embodiment, the reflow furnace not only heats up to the reflow temperature of the normal solder paste, but also reaches the reflow temperature in the reflow furnace, and then reaches the resin melting temperature of the sealing resin piece 4 higher than the reflow temperature. It is configured to be heated.
[0023]
Therefore, when the mounting board 1 is sent to the reflow furnace, as shown in FIG. 1B, the mounting board 1 first reaches the reflow temperature of the solder paste 6, so that the solder paste 6 is melted and the solder 6 'is melted. The external connection terminals 3 of the electronic component A1 can be electrically connected to the connection pads 5 of the mounting substrate 1 via the connection terminals. At this time, the sealing resin piece 4 is softened by being heated to the reflow temperature of the solder paste 6, deformed by its own weight, and starts flowing down to the mounting board 1 side.
[0024]
Then, when the temperature in the reflow furnace reaches the resin melting temperature of the sealing resin piece 4, the sealing resin piece 4 becomes a liquid state, and as shown in FIG. Is configured to be coated.
[0025]
In the present embodiment, the temperature in the reflow furnace is set to the curing temperature of the sealing resin 4 '. After the sealing resin 4' is cured under the curing temperature, the mounting substrate 1 is removed from the reflow furnace. I'm taking it out. Before the sealing resin 4 ′ is cured, the mounting substrate 1 is taken out of the reflow furnace, and the sealing resin 4 ′ is cured by an appropriate curing means for the sealing resin 4 ′, for example, irradiation with ultraviolet light or heating by an oven. You may.
[0026]
As described above, the operation from the mounting of the electronic component A1 on the mounting board 1 by the solder 6 'to the coating of the electronic component A1 by the sealing resin 4' is continuously performed by the reflow furnace, thereby greatly reducing the working time. And work efficiency can be improved.
[0027]
In particular, by setting the amount of the sealing resin piece 4 to the minimum necessary for coating the electronic component A1, it is possible to reduce the manufacturing cost and to cure the melted sealing resin piece 4. Time can be shortened, and work efficiency can be further improved.
[0028]
As another embodiment, the sealing resin piece 4 is not formed in a flat plate shape as shown in FIG. 1A, but is formed in a portion corresponding to a central portion of the upper surface of the sealing portion 2 as shown in FIG. A rectangular frame-shaped sealing resin piece 8 having an opening 7 may be used.
[0029]
By providing the opening 7 in the sealing resin piece 8, a suction nozzle (not shown) of a mounter used for mounting the electronic component A 1 at a required position on the mounting board 1 is connected to the sealing section 2 through the opening 7. The electronic component A1 can be reliably transported by suction.
[0030]
Further, by forming a fitting recess 9 on the lower surface of the sealing resin piece 8 to be fitted with the upper part of the sealing part 2, the sealing resin piece 8 is fitted on the upper part of the sealing part 2 and joined. The electronic component A1 having the sealing resin piece 8 mounted thereon can be easily formed without using an adhesive or the like.
[0031]
In addition, when the fitting recess 9 is formed, the sealing resin piece 8 has a thicker outer peripheral portion than the portion near the opening 7, so that when the sealing resin piece 8 is in a softened state, In addition, the outer peripheral edge portion of the sealing resin piece 8 has a greater effect of flowing down to the mounting substrate 1 side due to its own weight, so that the coating of the electronic component A1 with the sealing resin can be performed more quickly.
[0032]
(Second embodiment)
FIG. 3 is a process explanatory diagram illustrating a process of mounting the electronic component A2 on the mounting board 11 according to the second embodiment. The electronic component A2 of the second embodiment is a semiconductor device called a BGA (Ball Grid Array), which is formed on a lower surface side of a sealing portion 12 configured by sealing a semiconductor chip (not shown) with a mold resin. A plurality of external connection terminals 13 made of solder balls or metal bumps are provided. In this embodiment, the external connection terminals 13 are formed of solder balls.
[0033]
Then, as shown in FIG. 3A, in the electronic component A2 of the second embodiment, a ring-shaped sealing resin piece 14 is mounted along the outer peripheral edge of the sealing portion 12.
[0034]
The sealing resin piece 14 is formed by curing a sealing resin made of a required amount of polyamide resin into a ring shape that can be mounted on the outer peripheral edge of the sealing portion 12. In particular, in the present embodiment, an inclined surface 17 is formed on the outer peripheral edge of the upper portion of the sealing portion 12 so as to be inclined downward in the outward direction. The sealing resin piece 14 is mounted on the sealing portion 12 by projecting the piece 18 from the inner peripheral edge and engaging the engaging projection 18 with the inclined surface 17.
[0035]
Since the sealing resin piece 14 is provided along the outer peripheral edge of the sealing portion 12 as described above, the suction nozzle of the mounter used to mount the electronic component A2 at a required position on the mounting board 11 can be used. The electronic component A2 can be directly brought into contact with the electronic component A2, and the electronic component A2 can be reliably transported by suction.
[0036]
The sealing resin piece 14 has a melting temperature higher than the melting temperature of the solder ball serving as the external connection terminal 13, and when the solder ball is reflowed by a reflow furnace as described later, This prevents the sealing resin piece 14 from melting before the solder.
[0037]
The electronic component A2 is mounted such that the external connection terminals 13 are in contact with connection pads 15 provided at required positions on the mounting board 11, respectively. In this embodiment, a flux (not shown) is applied to each connection pad 15 on the mounting substrate 11 by screen printing. Note that a solder paste may be applied instead of the flux.
[0038]
After the electronic component A2 provided with the sealing resin piece 14 is mounted on the mounting substrate 11, the mounting substrate 11 is passed through a reflow furnace, so that the external connection terminals 13 of the electronic component A2 are soldered. Is electrically connected to each connection pad 15 of the mounting board 11.
[0039]
In particular, in the case of the present embodiment, the reflow furnace is configured to heat the inside of the reflow furnace to the reflow temperature of the solder ball as the external connection terminal 13 and then to the resin melting temperature of the sealing resin piece 14 higher than the reflow temperature. ing.
[0040]
Therefore, when the mounting substrate 11 is passed through the reflow furnace, as shown in FIG. 3B, the mounting substrate 11 first reaches the reflow temperature of the solder ball, which is the external connection terminal 13, so that the solder ball is melted. The electronic component A2 is electrically connected to the mounting board 11 via the solder 13 '. At this time, the sealing resin piece 14 is softened by being heated to the reflow temperature of the solder ball, deformed by its own weight, and starts flowing down to the mounting board 11 side.
[0041]
When the temperature in the reflow furnace reaches the resin melting temperature of the sealing resin piece 14, the sealing resin piece 14 becomes a liquid state, and as shown in FIG. The space between the connection pad 15 and the solder 13 ′ is filled between the sealing member 11 and the sealing portion 12. That is, in this embodiment, the sealing resin 14 'is an underfill material.
[0042]
Particularly, in the present embodiment, the sealing resin 14 ′ in a liquid state is provided on the mounting board 11 side by providing the inclined surface 17 having a downward slope toward the outside in the upper outer peripheral edge of the sealing portion 12. It is easy to flow down, and the space between the mounting substrate 11 and the sealing portion 12 can be quickly filled with the sealing resin 14 ′.
[0043]
In this embodiment, the temperature in the reflow furnace is set to the curing temperature of the sealing resin 14 '. After the sealing resin 14' is cured under the curing temperature, the mounting substrate 11 is removed from the reflow furnace. I'm taking it out.
[0044]
As described above, the process from the mounting of the electronic component A2 on the mounting board 11 by the solder 13 'to the underfill coating of the electronic component A2 by the sealing resin 14' are continuously performed, thereby greatly reducing the working time. And work efficiency can be improved.
[0045]
In this embodiment, in order to mount the sealing resin piece 14 on the sealing portion 12, an inclined surface 17 is provided on the outer peripheral edge of the upper portion of the sealing portion 12, and an engaging projection 18 engaging with the inclined surface 17 is provided. Are projected from the inner peripheral edge of the sealing resin piece 14, but a locking projection (not shown) or the like for locking the sealing resin piece 14 may be provided on the sealing portion 12.
[0046]
In the above-described embodiment, the electronic components A1 and A2 have been described as semiconductor devices having the sealing portions 2 and 12. However, the present invention is not limited to the semiconductor devices, and the electronic components A1 and A2 may be sealed on the upper surfaces of electronic components such as chip resistors and chip capacitors. A resin piece may be provided, and the present invention can be applied to all electronic components that require coating with a sealing resin.
[0047]
【The invention's effect】
According to the first aspect of the present invention, in an electronic component to be coated with a sealing resin after being mounted on a mounting substrate, a sealing resin piece made of a predetermined amount of a sealing resin is mounted in advance, and the electronic component is reflowed. Since the coating is performed by melting the sealing resin piece after the mounting on the mounting substrate, the operation of applying the sealing resin is not required, and the working efficiency can be improved. In addition, by mounting the sealing resin pieces made of the necessary amount of the sealing resin in advance for coating, it is possible to reliably coat the electronic component with the minimum necessary amount of the sealing resin. Can be reduced, and the curing time of the sealing resin can be shortened, so that the working efficiency can be further improved.
[0048]
According to the second aspect of the present invention, a sealing resin that melts at a resin melting temperature higher than the reflow heating condition for mounting the electronic component on the mounting board is used, and the resin is heated to the resin melting temperature during the reflow. Thus, the process from mounting the electronic component on the mounting board to coating the mounted electronic component with the sealing resin can be performed continuously, so that the working efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a mounting process of an electronic component on a mounting board according to a first embodiment.
FIG. 2 is an explanatory diagram of an electronic component according to another embodiment.
FIG. 3 is an explanatory view of a mounting process of an electronic component on a mounting board according to a second embodiment.
[Explanation of symbols]
A1, A1 Electronic component 1, 11 Mounting board 2, 12 Sealing part 3, 13 External connection terminal 4, 14 Sealing resin piece 5, 15 Connection pad 5
6 solder paste 6 ', 13' solder 4 ', 14' sealing resin 17 inclined surface 18 engaging projection

Claims (2)

After mounting on the mounting board, in the electronic component to be coated with the sealing resin,
An electronic device characterized in that a sealing resin piece composed of a predetermined amount of a sealing resin is mounted in advance, and after the electronic component is mounted on a mounting board by reflow, the sealing resin piece is subsequently melted to perform coating. parts. 2. The sealing resin according to claim 1, wherein the sealing resin is melted at a resin melting temperature higher than a reflow heating condition for mounting an electronic component on a mounting board, and is heated to the resin melting temperature during reflow. Electronic components.

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