JPH10214924A - Resin sealing structure of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop flow of coating resin to an outer periphery at a desired position and prevent resin from covering an adjacent part due to flow by forming resist protecting the top of a wiring board in an outer periphery of a semiconductor device of a material which repels resin. SOLUTION: Spot coat resin 16 which is viscous liquid is dropped on a semiconductor stop 14 from syringe, spreads while flowing on a wiring board, is repelled by surface tension of solder resist 13 with property to repel the spot coat resin 16 on reaching a frame of the solder resist 13 and is prevented from flowing onto solder resist. Then, the spot coat resin 16 is subjected to hardening reaction treatment of resin and resin sealing treatment is finished. The structure has an effect to prevent resin from flowing without enlarging a space especially. Failure regarding resin coating is prevented by stopping flow of resin by carrying out resin hardening treatment while holding a range of resin coating in a proper form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure in which a semiconductor element is mounted on a wiring board and the periphery of the semiconductor element is sealed with a spot coat resin.

[0002]

2. Description of the Related Art As a current spot-coating resin sealing structure of a semiconductor element, as shown in FIG.
A bare semiconductor element 4 called a bare chip is mounted on the
The wiring is connected to the wiring pattern 2 on the wiring substrate 1 from the peripheral portion of the semiconductor element 4 with the metal wires 5 and then sealed with a spot coat resin. In such a semiconductor resin sealing structure, as shown in FIG. 6B, the spot coat resin 6 having appropriate fluidity is applied to a syringe 61.
The wire portion 5 is further dropped to cover the wire portion 5, and then the resin sealing is completed in a curing step such as a thermosetting treatment. Heretofore, it has been customary to adjust the specifications of the spread portion and the thickness of the spot coat resin 6 to the intended range by the amount of dropping, the flowability, and the properties of the coating surface.

Prior to the step of curing the spot coat resin, there may be cases where another element, for example, a component such as a resistor is already mounted on the wiring board.

[0004]

However, when the spot coat resin 6 flows to an unnecessary portion due to the variation in the fluidity of the spot coat resin and the arrangement of components on the wiring board, as shown in FIG. 6C. In some cases, quality problems such as the occurrence of serious defects may occur. FIG. N shows a portion where the coating height is reduced and the wire portion 5 is exposed when the flow is excessive, and the function of coating is incomplete. FIG. 7K shows a portion where the spot coat resin 6 covers the solder fillet portion 8 of the adjacent electronic component 7 and is re-melted when reflow processing is performed again in a post-process after the resin curing process. There is a possibility that the solder particles may leak out of the gap between the cured spot coat resins 6. In the case where such re-melted and leaked solder generates solder particles and causes quality defects, the substrate 1 on which the semiconductor element 4 is mounted is mounted on another substrate in order to mount it as an element circuit, and then re-assembled. It is also experienced in passing through the soldering process.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to prevent the spot coat resin coating from flowing to the outer periphery at a desired position when flowing, and to prevent the adjacent parts from being covered by the flow. Further, by keeping the shape of the spot coat 6 at the minimum size, it is possible to reduce the margin in consideration of the shape variation in the design of the wiring board, so that the occupied area can be minimized, and the design advantage and the substrate The goal is to save money.

[0006]

According to the present invention, there is provided a resin sealing structure for a semiconductor device in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin. A resist for protecting the wiring substrate is formed, and the resist is made of a material that repels the resin.

Further, according to the present invention, in a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, the semiconductor element is protected on the wiring board around the outside of the semiconductor element. A resist is formed, and an oil made of a material that repels the resin is applied on the resist in a frame shape. Further, according to the present invention, in a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, a resist for protecting the wiring board around the outside of the semiconductor element is provided. It is characterized in that a wall-shaped solid fat is applied in a frame shape on the resist.

According to the present invention, in a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, the resin is applied to an electronic component adjacent to the semiconductor element. It is characterized in that oil made of a repelling material is applied. Further, according to the present invention, in a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, an opening of a casting mold is joined to an outer periphery of the semiconductor element. ,
A resin is injected into the casting mold.

[0009]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a first embodiment using a solder resist having a property of repelling a spot coat resin. FIG.
(A) is a plan view showing the arrangement before the spot coat resin coating, and (b) is an AA cross-sectional enlarged view after the spot coat resin coating. Reference numeral 11 denotes a wiring board, 12 denotes a wiring pattern made of a conductive foil, and 13 denotes a solder resist, which is formed by laminating a resin film for preventing solder from adhering to the wiring pattern 12. The solder resist 13 is made of a resin such as a silicone resin or a fluorine resin having a property of repelling JCR, and has a frame shape so as to surround the outer periphery of the semiconductor element 14. Originally, the solder resist (resist) is applied on the substrate except for the mounting position of the bare chip or the like to protect the substrate. In this example, the resist is made to have a property of repelling the spot coat resin. Thus, the substrate is used for both protecting the substrate and preventing excessive flow of the spot coat resin.

Reference numeral 14 denotes a semiconductor element, which is usually called a bare chip. Reference numeral 15 denotes a metal wire, and the semiconductor element 1
4 is used for connection from the electrode portion to the wiring pattern. Reference numeral 16 denotes a spot coat resin, which is made of, for example, an epoxy resin, and insulates the metal wire 15 and the semiconductor element 14 from the outside by covering them. First,
The spot coat resin 16 which is a viscous liquid is shown in FIG.
When the spot coat resin 16 reaches the frame of the solder resist 13 shown in FIG. 1A, the spot coat resin is dropped from the syringe (not shown) onto the semiconductor element 14 and spreads while flowing on the wiring board. 16 is repelled by the surface tension of the solder resist 13 having the property of repelling, and the flow onto the solder resist is prevented as shown in FIG. The thickness of the spot coat resin 16 is, for example, about 2 mm, and the thickness of the semiconductor element 24 is about 0.6 m.
m, the height of the metal wire 15 is about 0.6 mm, and the coating thickness is about 0.4 mm.
mm. Accordingly, the flow of the viscous liquid resin having a thickness of about 2 mm, which is the spot coat resin 16, is repelled and stopped at the position in contact with the solder resist 13.

Next, the spot coat resin 16 is subjected to a resin curing reaction process, and the resin sealing process is completed.
According to this example, there is an effect that excessive flow can be prevented without particularly increasing the space. FIG. 2 is a view showing a second embodiment using an oil frame having a viscosity that repels a spot coat resin.

FIG. 2A is a plan view showing the arrangement before the spot coat resin coating, and FIG. 2B is an enlarged cross-sectional view taken along the line AA after the spot coat resin coating. As in FIG. 1, 21 is a wiring board portion, 22 is a wiring pattern, and 23 is a solder resist. 24 is a semiconductor element, 25 is a metal wire, 2
6 is a spot coat resin. Reference numeral 27 denotes an oil frame having a property of repelling the spot coat resin, which is applied on the solder resist 23 with a thickness of about 0.1 mm. The flow of the viscous liquid resin of the dropped spot coat resin 26 is oil. It is repelled and stopped at the position in contact with the frame. As the oil 27, a silicone or fluororesin-based oil having a property of repelling the spot coat resin 26 is used. Since it is oil, it can be removed particularly by washing.
Incidentally, only the oil frame may be applied to a desired position on the outer periphery of the semiconductor element 24 without providing the solder resist 23 in particular.

Next, the spot coating resin 26 is subjected to a resin curing reaction process, and the resin sealing process is completed.
According to this example, if the oil is washed after the sealing with the resin, it is possible to prevent extra components from remaining on the substrate. FIG. 3 is a view showing a third embodiment using a wax (solid fat) frame.
FIG. 3A is a plan view showing the arrangement before the spot coat resin coating, and FIG. 3B is an enlarged cross-sectional view taken along the line AA after the spot coat resin coating. 31 is a wiring board part, 32 is a wiring pattern, and 33 is a solder resist. 34 is a semiconductor element, 35 is a metal wire, and 36 is a spot coat resin. Reference numeral 37 denotes a frame to which a wax having a property of repelling the spot coat resin is applied, which is applied with a thickness of about 0.7 mm on the solder resist 33, thereby forming a wall and forming a viscous liquid of the spot coat resin 36 dropped. The flow of a certain liquid resin is blocked and stopped at a position in contact with the wax frame 37. As the wax 37, apiezone wax having a property that can be removed by washing in a later step is used.
Since the wax of this embodiment does not repel the spot coat, the thickness of the frame is set higher than that of the first and second embodiments.

Next, the spot coat resin 36 is subjected to a curing reaction of the resin, the wax is removed, and the resin sealing process is completed. According to this example, since the wax that has become unnecessary after the curing of the resin can be removed, a special effect is achieved in that there is no extra material on the wiring board. FIG. 4 is a diagram showing a fourth embodiment in which an electronic component mounted around the outside of the semiconductor element and a viscous oil for forming a protective layer for preventing the fillet from being covered with the spot coat resin are applied.

FIG. 4A is a plan view showing the arrangement before the spot coat resin coating, and FIG. 4B is an enlarged cross-sectional view taken along the line AA after the spot coat resin coating. 41 is a wiring board part, 42 is a wiring pattern, and 43 is a solder resist. Also, 4
4 is a semiconductor element, 45 is a metal wire, and 46 is a spot coat resin. Reference numeral 47 denotes an electronic component such as a resistor mounted on the same wiring board 41 adjacent to the semiconductor element 44. Reference numeral 48 denotes a fillet of a solder connection portion of the electronic component 47. 49 denotes an electronic component 47 and a fillet 48
Is an oil that is applied to protect from the spot coat resin 46. The flow of the viscous liquid resin of the dropped spot coat resin 46 is repelled and stopped at the position in contact with the oil, and the electronic component 47 and the fillet 4 are prevented from flowing.
8 can be prevented from being covered with the spot coat resin 46. The oil is the same as that described above in FIG.

Next, the spot coating resin 46 is subjected to a resin curing reaction process, and the resin sealing process is completed.
Incidentally, even if the solder resist 43 is not provided, the oil 49 is not required.
May be applied to desired positions around the electronic component 47 and the fillet 48. FIG. 5 is a view showing a fifth embodiment using a casting mold. FIG. 5A shows the first
FIG. 4B is a cross-sectional view using the casting mold of the example, and FIG. 4B is a cross-sectional view using the casting mold of the second example.

Reference numeral 51 denotes a wiring board, 52 denotes a wiring pattern,
53 is a solder resist, 54 is a semiconductor element, 55 is a metal wire, and 56 and 58 are spot coat resins. 5
Reference numeral 7 denotes a casting mold whose lower surface opening has a shape of a mouth. Reference numeral 591 shown in (b) denotes a connecting rod that crosses the opening in the casting mold. In both cases, the lower surface of the casting mold is brought into contact with the solder resist 53 so as to surround the outer periphery of the semiconductor element.

In the embodiment shown in FIG. 5A, the casting mold 57 has an opening at the center of the shell, and the spot coat resin 56 is dropped from the opening to perform casting. Since the casting mold 57 is cast in contact with the position where the coating is required, accurate shape and dimensional accuracy can be obtained. In the embodiment shown in (b), the casting mold 59 has an opening between the outer periphery and the center of the shell of the casting mold, and the spot coating resin 58 is dropped from a plurality of positions of the opening. can do. Therefore, adjustment according to the fluidity of the spot coat resin 58 is facilitated. The outer periphery and the center of the shell of the casting mold 59 are connected by a connecting rod 591.

Next, after the spot coat resin 58 is covered with the casting mold, or after the spot coating resin 58 is temporarily cured to some extent, the casting mold is removed, and then the resin is subjected to a curing treatment, whereby the resin sealing is performed. Completed. According to the present example, since the casting mold that has become unnecessary after the resin is cured can be removed, there is a specific effect that an unnecessary thing on the wiring board can be eliminated.

[0020]

As described above in detail, according to the present invention, by maintaining the range of the resin coating in an appropriate shape and performing the resin curing treatment, the flow of the resin is prevented and the defect relating to the resin coating is prevented. Prevent occurrence. In addition, the spot coat resin can be kept within the minimum range.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a first embodiment, wherein FIG. 1A is a plan view before coating with a spot coat resin, and FIG. 1B is an enlarged cross-sectional view taken along the line AA after coating with a spot coat resin.

FIGS. 2A and 2B are diagrams showing a second embodiment, in which FIG. 2A is a plan view before coating with a spot coat resin, and FIG.

FIGS. 3A and 3B are views showing a third embodiment, in which FIG. 3A is a plan view before coating with a spot coat resin, and FIG.

4A and 4B are diagrams showing a fourth embodiment, in which (a) is a plan view before coating with a spot coat resin, and (b) is an enlarged cross-sectional view along AA after coating with a spot coat resin.

FIGS. 5A and 5B show a fifth embodiment, in which FIG.
FIG. 7B is a cross-sectional view illustrating an example casting mold, and FIG. 8B is a cross-sectional view illustrating a second example casting mold.

6A and 6B are views showing a conventional example, wherein FIG. 6A is a plan view before spot coating resin coating, FIG. 6B is a cross-sectional view after spot coating resin coating, and FIG. 6C is a defect after spot coating resin coating. It is an AA sectional enlarged view of a case.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Wiring board 12 ... Wiring pattern 13 ... Solder resist 14 ... Semiconductor element 15 ... Metal wire 16 ... Spot coat resin 27 ... Oil 37 ... Wax 47 ...・ Electronic components 48 ・ ・ ・ Fillet 57, 59 ・ ・ ・ Cast mold 591 ・ ・ ・ Cast mold connecting rod

Claims (5)

[Claims] In a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, a resist for protecting the wiring board is provided around the outside of the semiconductor element. A resin sealing structure for a semiconductor element, wherein the resist is formed of a material repelling the resin. 2. In a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, a resist for protecting the wiring board around the outside of the semiconductor element is provided. A resin sealing structure for a semiconductor element, wherein an oil formed of a material that repels the resin is applied on the resist in a frame shape. 3. A resin sealing structure for a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, wherein a resist for protecting the wiring board is provided around the outside of the semiconductor element. A resin sealing structure for a semiconductor element, wherein a wall-shaped solid fat or oil is applied on the resist in a frame shape. 4. A resin sealing structure for a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, wherein the electronic component adjacent to the semiconductor element is made of a material that repels the resin. A resin sealing structure for a semiconductor element, characterized by being coated with an oil. 5. In a resin sealing structure of a semiconductor element in which a semiconductor element is mounted on a wiring board and the semiconductor element is sealed with a resin, an opening of a casting mold is joined to an outer periphery of the semiconductor element. A resin sealing structure for a semiconductor element, wherein a resin is injected into the casting mold.