JP2000031173A - Molding method for board part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent liquid resin from leaking through a gap between a circuit board and a frame member by pasting the major surface of the frame member onto one adhesive face of a both-sided adhesive tape, parting the other adhesive face onto the board surface while surrounding a board part and then injecting liquid resin into the frame member and eventually curing the resin. SOLUTION: A both sided adhesive tape 5 is formed into annular square shape which is substantially identical to the end face of a frame member 4 and one end face, i.e., major face 6, of the frame member 4 is pasted onto the adhesive tape 5. Subsequently, an adhesive protective sheet on the other side of the adhesive tape 5 is then peeled off to expose the adhesive face which is then placed on the board surface 7 while surrounding a board part 2 mounted on a circuit board 1 thus pasting the frame member 4 fixedly to a specified position of the board surface 7. Thereafter, liquid resin is dripped into the secured frame member 4 and cured thus molding the board part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a board component to be molded with a liquid resin among board components such as semiconductor elements mounted on a circuit board.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor device in which a substrate component such as a semiconductor element is mounted on a circuit board, a method of molding using a liquid resin is generally used as a method of sealing the substrate component. A typical method is to drop a fixed amount of the liquid resin A and cure it as shown in FIG. 3 (a) to mold a substrate component 2 such as a semiconductor element mounted on the circuit board 1, or FIG. As shown in FIG. 1), a frame member 4 which is a sealing frame for a resin molded product is mounted on a circuit board 1, and a liquid resin A is dropped into the frame member, and the semiconductor is cured and mounted on the circuit board 1. A method of molding a substrate component 2 such as an element has been adopted.

[0003]

In the above-described molding method, in the molding method shown in FIG. 3A, the dropped liquid resin A is accurately applied only to the board component 2 to be molded on the circuit board 1. It is difficult to mold
As shown in FIG. 4, the liquid resin A leaks out of the region to be molded on the circuit board 1 and not only causes the inconvenience that the molding is performed to the substrate component 3 which does not require the molding, but also causes the inconvenience. Problems such as waste of the molding material and unevenness in quality due to unevenness of the cured resin shape occur.

[0004] Therefore, in order to prevent the board component 3 outside the area requiring the mold from being covered with the molding material, not only a skilled work technique is required, but also a mounting space for the board component may be increased in some cases. The circuit board 1 needs to be widened, which is a major problem in reducing the size of the circuit board 1.

As a solution to this problem, FIG.
As shown in (1), a form member 4 which is a sealing frame for a resin molded product is mounted on the circuit board 1, and the liquid resin A is dropped into the form member 4 and hardened to prevent unnecessary outflow of the liquefied resin. Measures have been taken to prevent it.

According to this method, it is possible to prevent the liquid resin A from flowing out, to achieve the fixed curing, and to keep the mounting space for the board component 2 relatively small. A new manufacturing process, such as a method for manufacturing the member 4 and a means for fixing the circuit board 1 to the substrate surface 7, is added, and this poses another problem that this hinders cost reduction.

Further, in the molding method using the form member which is the sealing frame, the circuit board 1 itself and the form member itself may be warped, twisted or formed at the time of molding, and may be formed with the joined circuit board. A gap may be created at the joint surface between the circuit board and the frame member due to, for example, deformation of the circuit board due to a difference in physical properties with the frame member. In this case, resin leakage occurs from the joint surface between the circuit board and the frame member, which also poses a problem that causes a defect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a predetermined size and a size sufficient to surround the periphery of a board component that needs to be molded among board components mounted on a circuit board. The frame-shaped frame member formed at a height of 2 mm can be easily fixed at a predetermined position, and is inexpensive and easy to use because the liquid resin does not leak from the gap between the circuit board and the frame member. It is an object of the present invention to provide a method for molding a board component suitable for production of various types.

[0009]

According to a first aspect of the present invention, there is provided a method of molding a board component such as a semiconductor element mounted on a circuit board using a liquid resin. A frame-shaped frame member of a size large enough to surround the periphery of the molded substrate object to be molded, and formed at a predetermined height, and a double-sided adhesive tape are prepared. The main surface of the frame member contacting the substrate surface is positioned on the surface and attached, and then the other adhesive surface protective paper is peeled off to expose the adhesive surface, and the adhesive surface is mounted on the substrate. It is characterized in that it is attached and fixed to the substrate surface in such a manner that it surrounds the periphery of the substrate component to be molded, and then the liquid resin flows into the form member and hardens.

In a second aspect of the present invention, there is provided a method for molding a substrate component, wherein the adhesive surface of the double-sided adhesive tape which is interposed between the substrate and the frame member, and which adheres and fixes the both, The pressure-sensitive adhesive surface has a thickness sufficient to absorb the uneven surface.

In a third aspect of the present invention, a method for molding a board component comprises forming the form member from a foamable resin.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an exploded perspective view of a main part showing a method of molding a board component according to a first embodiment of the present invention, and portions similar to those in the conventional method are denoted by the same reference numerals. In the figure, 1 is a circuit board, 2 is a board component that needs to be molded among board components mounted and arranged on the circuit board, 3 is a board component that does not require a mold, and 4 is a board component that requires the above-described mold. 2 is a frame-shaped frame member that is large enough to surround the periphery of 2 and has a predetermined height, and is formed by, for example, stamping out a foamable resin formed to a predetermined thickness. Alternatively, it is formed in a frame shape by cutting the foamable resin sheet into strips, wrapping them in a frame shape, and bonding the ends together.

Reference numeral 5 denotes a double-sided pressure-sensitive adhesive tape, which is formed in a square annular shape having substantially the same shape as the end face of the frame member 4. A certain main surface 6 is attached.

In molding the substrate component 2 that needs to be molded using the frame-shaped frame member 4 configured as described above, the frame member 4 is attached to the main surface 6 which is one end surface of the frame member 4. The other surface of the double-sided adhesive tape 5 is peeled off to expose the adhesive surface, and the adhesive surface is exposed so as to bend around the substrate component 2 to be molded mounted on the circuit board 1. The frame member 4 is stuck and fixed at a predetermined position on the substrate surface 7 by being placed on the base 7.

Thereafter, as shown in FIG. 2, the liquid resin A is dropped into the fixed frame member 4 and is caused to flow and harden, thereby completing the molding of the board component.

The pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive tape 5 is sufficient to absorb the unevenness of the substrate surface 7 or the thickness of the connection wiring portion between the wiring formed on the substrate surface 7 and the semiconductor element. The circuit board 1 and the frame member 4 are formed so that they can be sealed without gaps.

Embodiment 2 FIG. In the first embodiment,
The main surface 6 of the frame member 4 is attached to one side of the double-sided adhesive tape 5.
On the contrary, one adhesive surface of the double-sided adhesive tape 5 is pasted on the substrate surface 7 in such a manner as to bend around the substrate component 2 to be molded, and then exposed. It is also possible to peel off the other surface of the adhesive surface protection paper and fix the form member 4 by positioning the main surface 6 of the form member 4 on this adhesive surface. Which procedure is to be adopted may be determined appropriately depending on the ease of operation.

[0018]

As described above, according to the board component molding method according to the first aspect of the present invention, of the board components mounted on the circuit board, the periphery of the board component to be molded is bent. Molding can be performed accurately, and it is possible to prevent inconveniences such as liquid resin flowing out to a substrate component that does not require molding even if not a skilled operator and performing molding. In addition to this, there is no waste of the molding material, the shape of the cured resin is constant and uniform, and the quality can be stabilized.

Since the frame member is fixed to the circuit board with a double-sided adhesive tape, after the liquid resin is solidified,
Since the form member can be easily separated from the substrate and can be used repeatedly as long as the adhesive surface of the peeled adhesive tape functions, the cost can be reduced and the cost of manufacturing a new form member can be reduced.

According to the second invention, the circuit board and the frame member are not only securely sealed by the adhesive portion of the double-sided adhesive tape, but also by selecting the thickness of the adhesive surface. The unevenness of the surface and the thickness of the wiring portion formed on the substrate can be absorbed, and the liquid resin can be prevented from flowing out of the form member.

According to the third aspect of the present invention, the form member can be made inexpensive and the form member can be easily manufactured, so that it is possible to flexibly cope with the production of small quantities and many kinds.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a method for molding a board component according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a molded state of the board component of the first embodiment.

FIG. 3 is a cross-sectional view of a main part showing a conventional method of molding a board component.

FIG. 4 is an exploded perspective view showing a conventional method for molding a board component.

[Explanation of symbols]

1 circuit board, 2 board parts requiring mold,
3 Board components that do not require a mold, 4 Form members,
5 double-sided adhesive tape, 6 main surface, 7 substrate surface,
A Liquid resin.

Claims (3)

[Claims] In a method of molding a substrate component such as a semiconductor element mounted on a circuit board with a liquid resin, a predetermined size of the component surrounding the substrate component to be molded mounted on the substrate is provided. A frame-shaped frame member formed at a height, and a double-sided adhesive tape are prepared, and the main surface of the frame member that is in contact with the substrate surface is positioned on one adhesive surface of the double-sided adhesive tape. Paste the material, then peel off the other side of the adhesive surface protection paper to expose the adhesive surface, this adhesive surface on the substrate surface in a form to bend around the periphery of the substrate component to be molded mounted on the substrate A method of molding a board component, comprising: attaching the form member to the housing; and fixing the form member by flowing the liquid resin into the form member. 2. The adhesive surface of a double-sided adhesive tape which is interposed between a substrate and a frame member and adheres and fixes the both, the unevenness of the surface portion of the substrate surface at the portion where the frame member is adhered and fixed. 2. The method for molding a board component according to claim 1, wherein the method has a thickness of an adhesive surface sufficient to absorb the adhesive. 3. The method according to claim 1, wherein the form member is made of a foamable resin.