JPH10287069A - Sealing structure and method for printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely seal a printed circuit board by providing a frame member used both to position and reinforce the board in a cavity in engagement with the board, and providing an outer cover for molding to cover a connector of the board to the member. SOLUTION: In the case of executing for a semiconductor memory card module, the module is obtained by mounting an IC package 2, electronic components 3 on an upper surface of a printed circuit board 1. Engaging holes 6 are formed at four corners and substantially a center of the board 1. A frame member 7 is superposed on the board 1, and a plurality of lower side protrusions 9c protruded down from a frame body 9 are inserted into the holes 6 to relatively position the board 1 to the member 7, and integrated to a connecting body. This engaging body is mounted in a mold, resin is poured in a cavity formed between the board 1 and an inner surface of the mold to mold an outer cover covering the board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing structure and a sealing method for a printed wiring board on which electronic components used for, for example, a semiconductor memory card are mounted, and more particularly to a sealing structure for resin-molding the entire printed wiring board.

[0002]

2. Description of the Related Art A non-contact type IC card mounts an IC chip and a coil for power supply and electromagnetic coupling for a signal, and supplies power and stores and calculates data without having a terminal exposed to the outside. It has the feature that it can be performed.

[0005] FIG. 15 shows a conventional system disclosed in JP-A-8-300860.
FIG. 1 is a partial cross-sectional view illustrating a module core for a non-contact type IC card proposed in Japanese Patent Application Laid-Open Publication No. H10-209,873. As shown in the drawing, although not shown, predetermined electronic components are mounted on the printed wiring board 50, and a plurality of projections 51 are provided on both front and back surfaces of the printed wiring board 50 by printing.

The printed wiring board 5 provided with the projections 51
0 is mounted in the molding dies 52a and 52b,
The non-contact type I in which the printed wiring board 50 is sealed
A module core for a C card was configured.

[0005]

Various electronic components mounted on the printed wiring board are not uniform on the front and back sides of the printed wiring board. For example, the mounting volume on the back side is larger than the mounting volume on the front side of the printed wiring board. There are many things that are small.
Then, the amount of resin mold on the front side of the printed wiring board is small, and the amount of resin mold on the back side is large, the amount of mold becomes unbalanced, and the amount of shrinkage when cooling the resin is different between the front and back sides.

As described above, the non-contact type IC conventionally proposed
In the card module core, the projections 51 are formed by printing, and are individually and simply attached to the printed wiring board 50. Therefore, the projection 51 has no reinforcing effect on the printed wiring board 50, and the printed wiring board 50 warps due to the difference in the amount of shrinkage of the resin, causing a connection failure on the printed wiring board 50,
Various troubles such as an increase in resistance when inserting the C card into the reader / writer occur.

Further, since the projections 51 are formed by printing, it is difficult to secure a sufficient height.
1 is easy to vary in height. Therefore, the printed wiring board 5
0 and the molds 52a and 52b are not sufficiently secured, and the gaps are not uniform. As a result, the printed wiring board 50 cannot be reliably sealed.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to provide a sealing structure and a sealing method for a printed wiring board having a stable sealing effect on the printed wiring board and having a stable quality without deformation such as warpage. To provide.

[0009]

According to a first aspect of the present invention, there is provided a printed wiring board on which electronic components are mounted, and wherein the printed wiring board is engaged with the printed wiring board to form the printed wiring board in a cavity. It is characterized by comprising a frame member for positioning and reinforcing the wiring board, and an outer covering body for molding and covering an engagement body between the printed wiring board and the frame member.

According to a second aspect of the present invention, there is provided a printed wiring board on which electronic components are mounted, and a frame member for positioning and reinforcing the printed wiring board in a cavity. Making an engaging body, mounting this engaging body in a mold, and positioning and reinforcing the printed wiring board in the cavity by abutting a part of the frame member on the inner surface of the mold. Forming a gap between the inner surface of the mold, injecting a resin into the cavity, filling the cavity with the resin through the gap, and forming an outer coating covering the printed wiring board. is there.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention uses a frame member for positioning and reinforcing a printed wiring board in a cavity and integrally forming an engaging body with the printed wiring board to form an engaging body. The union is mounted in a mold to form an outer covering that covers the printed wiring board.

Therefore, even when an imbalance occurs in the shrinkage of the resin between the upper and lower surfaces of the printed wiring board when the outer cover is formed, deformation such as warpage of the printed wiring board can be prevented by the reinforcing effect of the frame member. Therefore, it is possible to provide a sealed structure and a sealed method for a printed wiring board, which have a reliable sealing effect on the printed wiring board and have stable quality.

An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining a semiconductor memory card module according to a first embodiment of the present invention. FIG. 1 is an exploded perspective view of a printed wiring board and a frame member, and FIG. FIG. 3 is an enlarged sectional view of a circle in FIG. 2, and FIG. 4 is a perspective view of a completed card module.

In a card module according to an embodiment of the present invention, an IC package 2 and other electronic components 3 are mounted on an upper surface of a printed wiring board 1 and a thin flat plate is formed near a corner of the lower surface of the printed wiring board 1. Power supply electromagnetic coil 4
And a signal electromagnetic coil 5. Engagement holes 6 are formed at four corners and substantially at the center of the printed wiring board 1.

As shown in FIG. 1, this printed wiring board 1
From above, the frame member 7 is overlaid. The frame member 7 is made of, for example, polyphenylene sulfide (PP
S), a frame-shaped frame body 8 made of a heat-resistant hard synthetic resin such as a liquid crystal polymer (LCP) and having substantially the same size as the printed wiring board 1, and protruding upward from the frame body 8 A plurality of upper protrusions 9a,
It has a plurality of side projections 9b projecting horizontally from the frame main body 8, and a plurality of lower projections 9c projecting downward from the frame main body 8, and each of the projections 9a to 9c is a predetermined one. They are provided at intervals.

As shown in FIG. 3, a slit 10 is formed in the lower protruding portion 9c so as to extend from the front end toward the base portion, and an engaging step 11 is provided on the outer periphery in the middle. As shown in FIGS. 1 and 3, each lower projection 9 c is inserted into the engagement hole 6 of the printed wiring board 1, and the engagement step 11 is locked on the lower surface of the printed wiring board 1. The relative positioning of the printed wiring board 1 and the frame member 7 and the integration of the printed wiring board 1 and the frame member 7 by sandwiching the printed wiring board 1 between the lower surface of the frame member 7 and the engagement step portion 11 are performed. I can do it.

The printed wiring board 1 and the frame member 7
As shown in FIG. 2, the engaging body in which
Set in 2. With this set, the frame member 7
The tip of each upper projection 9a is on the lower surface of the upper mold 12a, and the tip of each side projection 9b is on the inner side surface of the upper mold 12a.
The tip of the lower protruding portion 9c abuts on the upper surface of the lower mold 12b to position the printed wiring board 1 in the cavity 13 in both the vertical and horizontal directions. It is installed almost in the center.

The printed wiring board 1 and the frame member 7
When the power supply electromagnetic coil 4 and the power supply electromagnetic coil 4 in the cavity 13 are located near the power supply electromagnetic coil 4 and the signal electromagnetic coil 5 as shown in FIG. The position of the signal electromagnetic coil 5 is properly regulated.

In this state, the molten resin is injected from the gate 14 into the cavity 13 and passes through the gap between the printed wiring board 1 and the mold 12 held by the projections 9a to 9c. All over the world,
The outer cover 15 is molded.

As a resin material constituting the outer covering 15, it is preferable to use a thermoplastic resin such as a glass epoxy resin. Note that a transfer mold that can be used at a low temperature and a low pressure may be used as the mold in consideration of the reliability of connection of the electronic component.

In this manner, the card module is formed by covering substantially the entire printed wiring board 1 and the frame member 7 with the outer cover 15, thereby providing a waterproof, moisture-proof, and environment-resistant material such as a corrosive gas. It can improve the nature.

FIG. 5 is a perspective view of a frame member 7 according to a second embodiment of the present invention. In the case of this example, a resin flow promoting portion 16 such as a notch or a recess is formed in a part of the frame body 8. The use of the frame member 7 has a feature that the flow of the resin in the cavity at the time of molding the outer cover 15 becomes smoother.

FIGS. 6 to 9 illustrate a card module according to a third embodiment of the present invention. FIG. 6 is an exploded perspective view of a printed wiring board and upper and lower frame members, and FIG. 8 is a perspective view of an engagement body between the wiring board and the upper and lower frame members, FIG. 8 is a partial cross-sectional view of the card module at the time of molding, FIG.
FIG. 2 is a partially enlarged sectional view of the card module.

In the case of the card module according to this embodiment, a signal coil block supporting a large number of signal electromagnetic coils 5 on one long side of the printed wiring board 1 as shown in FIGS. A power supply electromagnetic coil 4 is mounted on one short side of the printed wiring board 1.

A plurality of positioning holes 18 are formed on the upper and lower surfaces of the signal coil block 17 at predetermined intervals, and engagement holes 6 are formed on the other long side of the printed wiring board 1 at predetermined intervals. A plurality is formed.

An upper frame member 19 is arranged on the upper side of the printed wiring board 1, and a lower frame member 20 is arranged on the lower side.
As shown in FIG. 7, the printed wiring board 1 is sandwiched from above and below by an upper frame member 19 and a lower frame member 20, and the three members are integrated.

The upper frame member 19 has a frame-shaped frame body 21 having substantially the same size as the printed wiring board 1.
A plurality of upper protrusions 22a protruding upward from the frame main body 21, a plurality of side protrusions 22b protruding horizontally from the frame main body 21, and a plurality of protruding downward from the frame main body 21. And lower projections 22c, and the projections 22a to 22c are provided at predetermined intervals.

The lower frame member 20 has a frame-shaped frame body 23 having substantially the same size as the printed circuit board 1.
And a plurality of side protrusions 24b protruding horizontally from the frame main body 23 and a plurality of lower protrusions 24c protruding downward from the frame main body 23 (see FIG. 8). 24b and 24c are provided at a predetermined interval. An engagement hole 25 is formed in the frame body 23 at a position corresponding to the engagement hole 6 of the printed wiring board 1 (see FIG. 6).

As shown in FIG. 6, among the side protrusions 24b of the lower frame member 20, the upper surface of each side protrusion 24b provided at a position facing the signal coil block 17 is provided.
A chevron-shaped coil positioning projection 27 is integrally formed. As shown in FIG. 10, the upper frame member 19 also has a mountain-shaped coil positioning projection 26 on the lower surface of each side projection 22 b provided at a position facing the signal coil block 17 in the side projection 22 b. It is formed integrally.

As shown in FIG. 6, the lower frame member 20,
By overlapping the printed wiring board 1 and the upper frame member 19 in this order, the lower protrusion 22c of the upper frame member 19 is formed.
Are inserted into the engagement holes 6 of the printed wiring board 1 and the engagement holes 25 of the lower frame member 20. This lower projection 22
3, a slit and an engagement step are provided in the same manner as the lower projection 9c shown in FIG. 3, and by inserting the lower projection 22c into the engagement hole 25, the engagement step becomes the lower frame. The printed wiring board 1 is engaged with the lower surface of the member 20 and sandwiched between the lower frame member 20 and the upper frame member 19 in a sandwich manner.
And the upper frame member 19 together form an engagement body.

Further, as shown in FIG. 10, the coil positioning projection 26 of the upper frame member 19 is
7 is fitted from above the positioning hole 18, and the coil positioning projection 27 of the lower frame member 20 is fitted from below the positioning hole 18 of the signal coil block 17.

As shown in FIG. 7, the power supply electromagnetic coil 4 protruding from the printed wiring board 1
Is held from above and below by the side protrusion 22b of the lower frame member 20 and the side protrusion 24b of the lower frame member 20 to hold (protect)
Is done.

The engaging body of the lower frame member 20, the printed wiring board 1 and the upper frame member 19 is set in the mold 12 as shown in FIG. With this set, the tip of each upper protruding portion 22a of the upper frame member 19 is moved to the upper mold 1
On the lower surface of 2a, the tip of each side protrusion 22b is the upper mold 1
2a, the tip of the lower protruding portion 22c is the lower
2b, respectively. The tip of each side protrusion 24b of the lower frame member 20 contacts the inner side surface of the lower mold 12b, and the tip of the lower protrusion 24c contacts the upper surface of the lower mold 12b.

Thus, the printed wiring board 1 is positioned both vertically and horizontally in the cavity 13, and the printed wiring board 1 is positioned in the cavity 1.
It is installed almost at the center of 3. Each side protrusion 22
b and 24b are in contact with the inner side surface of the mold 12, and as shown in FIGS.
10 and the coil gap G2 of the signal electromagnetic coil 5 as shown in FIG.

In this state, the molten resin is injected from the gate 14 into the cavity 13, and the protrusions 22a to 22c, 24
Printed wiring board 1 held by b, 24c
The outer cover 15 is molded throughout the entire cavity 13 through the gap between the outer cover 15 and the mold 12 (see FIG. 10).

The power supply electromagnetic coil 4 and the signal electromagnetic coils 5 of the card module thus constructed
When the semiconductor memory card is mounted on the card reader / writer, the position of the power supply electromagnetic coil (not shown) and the signal electromagnetic coil 28 (see FIG. 10) on the card reader / writer side are ensured. The target (vertical direction and horizontal direction) is matched, and power and signal are supplied efficiently.

FIGS. 11 and 12 are views for explaining the fourth embodiment, and FIG.
FIG. 12 is a perspective view of an engagement body between the printed circuit board 1 and the lower frame member 20, and FIG. 12 is a perspective view of a completed card module.

In the case of this example, as shown in FIG. 11, on the opposite side of the signal coil block 17 of the frame main bodies 21 and 23 and in the vicinity of the power supply electromagnetic coil 4, a bent portion 29 having a substantially "V" -shaped planar shape is provided. Are formed.

By molding the outer covering 15 along the bent portion 29, a module positioning groove 30 having a substantially "V" -shaped planar shape is formed.
By providing the module positioning groove 30 in the above-described positional relationship, when the semiconductor memory card is mounted on the card reader / writer, the positioning lever 31 provided on the card reader / writer side has elasticity in the “V” -shaped groove 30. Tentatively fit. And the pressing force F of the positioning lever 31
Is shown on the side of the power supply electromagnetic coil 4 (arrow F
1) and the signal electromagnetic coil 5 side (arrow F2), and eventually, the power supply electromagnetic coil 4 and the signal electromagnetic coil 5 are pressed against the power supply electromagnetic coil and the signal electromagnetic coil side of the card reader / writer. , The proximity state between the coils is reliably maintained.

In the case where the upper frame member 19 and the lower frame member 20 are used as in the third and fourth embodiments, the amount of resin molded above and below the printed wiring board 1 or the amount of When the volume of the electronic components is not balanced, the warpage of the card can be reduced by adjusting the thermal expansion coefficients of the upper and lower frame members, that is, by making the thermal expansion coefficients of the upper and lower frame members different. Specifically, the following measures should be taken.

[0041] The thermal expansion coefficient of the frame member on the side where the total resin mold amount is large is made smaller than the thermal expansion coefficient of the frame member on the side where the total resin mold amount is small.

[0042] The thermal expansion coefficient of the frame member on the side where the total mounting volume of the electronic component is small is made smaller than the thermal expansion coefficient of the frame member on the side where the total mounting volume of the electronic component is large.

FIG. 13 is a cross-sectional view of a part of an engaging body between the printed wiring board 1 and the frame member 7 for explaining the fifth embodiment. The difference between this embodiment and the frame member 7 according to the first embodiment is that the lower protrusion 9c is provided.
Is formed in a claw shape, and the printed wiring board 1 and the frame member 7 are mutually positioned and integrated by being elastically held from the outer periphery of the printed wiring board 1.

FIG. 14 is a perspective view of a frame member for explaining the sixth embodiment. The frame member 32 of this example has a substrate insertion opening 33 on one side surface, forms a substrate storage space 34 on the inside, and has a U-shaped cross section on three sides. Printed wiring board (not shown)
Is inserted in the direction of the arrow from the board insertion opening 33 to form an engagement body between the printed wiring board and the frame member 32. Note that, in the figure, upper projections, side projections, and lower projections are omitted because the drawing becomes complicated.

In the above embodiment, the case of a semiconductor memory card has been described. However, the present invention is not limited to this, and various fields such as a television receiver, an image forming apparatus, a precision machine, and a measuring instrument are used. The present invention can be applied to various other types of printed wiring board sealing structures used in the present invention.

[0046]

According to the present invention, as described above, the frame is used for positioning and reinforcing the printed wiring board in the cavity, and the frame and the printed wiring board are integrally formed to form an engaging body. The outer cover is mounted in a mold to cover the printed wiring board.

Therefore, even when an imbalance occurs in the amount of resin shrinkage on the upper and lower surfaces of the printed wiring board when the outer cover is formed, deformation such as warpage of the printed wiring board can be prevented by the reinforcing effect of the frame member. Therefore, it is possible to provide a sealed structure and a sealed method for a printed wiring board, which have a reliable sealing effect on the printed wiring board and have stable quality.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a printed wiring board and a frame member in a semiconductor memory card module according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the card module during molding.

FIG. 3 is an enlarged sectional view in a circle of FIG. 2;

FIG. 4 is a perspective view of a completed card module.

FIG. 5 is an exploded perspective view of a frame member in a semiconductor memory card module according to a second embodiment of the present invention.

FIG. 6 is an exploded perspective view of a printed wiring board and upper and lower frame members in a card module according to a third embodiment of the present invention.

FIG. 7 is a perspective view of an engagement body between the printed wiring board and upper and lower frame members.

FIG. 8 is a partial cross-sectional view of the card module during molding.

FIG. 9 is an enlarged sectional view in a circle of FIG. 8;

FIG. 10 is a partially enlarged cross-sectional view of the card module.

FIG. 11 is a perspective view of an engagement body between a printed wiring board and upper and lower frame members in a card module according to a fourth embodiment of the present invention.

FIG. 12 is a perspective view of the card module.

FIG. 13 is a partial sectional view of an engagement body between a printed wiring board and a frame member in a card module according to a fifth embodiment of the present invention.

FIG. 14 is a perspective view of a frame member in a card module according to a sixth embodiment of the present invention.

FIG. 15 is a partial cross-sectional view of a conventionally proposed module core for a non-contact type IC card.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 IC package 3 Other electronic components 4 Power supply electromagnetic coil 5 Signal electromagnetic coil 6 Engagement hole 7 Frame member 8 Frame main body 9 Projection 9a Upper projection 9b Side projection 9c Lower projection 12 Molding Mold 12a Upper die 12b Lower die 13 Cavity 15 Outer cover 17 Signal coil block 18 Positioning hole 19 Upper frame member 20 Lower frame member 21 Frame body 22 Projection 22a Upper projection 22b Side projection 22c Lower projection 23 Frame main body 24 Projection 24a Upper projection 24b Side projection 24c Lower projection 25 Engagement hole 26, 27 Coil positioning projection

Claims (11)

[Claims] 1. A printed wiring board on which electronic components are mounted, a frame member engaged with the printed wiring board, and positioning and reinforcing the printed wiring board in a cavity; and the printed wiring board and a frame. A sealed structure for a printed wiring board, comprising: an outer covering body that covers an engaging body with a member by molding. 2. The frame member according to claim 1, wherein the frame member includes a frame main body, and a projection integrally provided on the surface of the frame main body at a predetermined interval and in contact with an inner surface of a molding die. A sealed structure for a printed circuit board. 3. The sealed structure for a printed wiring board according to claim 1, wherein the frame members are arranged on both upper and lower surfaces of the printed wiring board, and the printed wiring board is sandwiched between the upper and lower frame members. . 4. The printed wiring board according to claim 1, wherein positioning means for positioning the printed wiring board and the frame member relative to each other is provided on the printed wiring board and the frame member. Sealing structure. 5. The printed wiring board according to claim 2, wherein at least a part of the electronic component is an electromagnetic coupling coil, and the protrusion is provided near the electromagnetic coupling coil. Sealing structure. 6. The sealed structure for a printed circuit board according to claim 1, wherein at least a part of said electronic component is a semiconductor memory chip. 7. A printed circuit board on which an electronic component is mounted and a frame member which also serves as positioning and reinforcing the printed circuit board in a cavity are integrally formed to form an engaging body, and the engaging body is placed in a mold. By mounting, a part of the frame member abuts against the inner surface of the mold to position and reinforce the printed circuit board in the cavity, and form a gap between the printed circuit board and the inner surface of the mold; A resin is injected into the cavity, and the cavity is filled with the resin through the gap to form an outer cover covering the printed circuit board. 8. The frame member according to claim 7, wherein the frame member includes a frame main body, and a projection integrally provided on the surface of the frame main body at a predetermined interval and in contact with the inner surface of the molding die. A method for sealing a printed wiring board. 9. The method for sealing a printed wiring board according to claim 7, wherein the frame members are arranged on both upper and lower surfaces of the printed wiring board, and the printed wiring board is sandwiched between the upper and lower frame members. . 10. The printed wiring board according to claim 7, wherein positioning means for relatively positioning the printed wiring board and the frame member is provided on the printed wiring board and the frame member. Sealing method. 11. The printed circuit board according to claim 8, wherein at least a part of said electronic component is a coil for electromagnetic coupling, and said projection is provided near said coil for electromagnetic coupling. Sealing method.