JP4403647B2 - Recording medium card and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium card suitable for use in, for example, a PC card such as a memory card and a method for manufacturing the same, and more particularly to a recording medium that enables miniaturization and thinning and has excellent bending stress and twisting stress. The present invention relates to a medium card and a manufacturing method thereof.
[0002]
[Prior art]
2. Description of the Related Art In recent years, portable recording medium cards that can be inserted into and removed from an external electronic device such as a computer device or an AV (Audio Visual) device and have a built-in semiconductor memory and control circuit have become widespread. Specifically, in this type of recording medium card, a circuit board in which a chip part such as a semiconductor memory is mounted on a board to constitute an electronic circuit is packaged with an outer casing made of a plastic molding material composed of an upper half and a lower half. It is configured.
[0003]
FIG. 13 is a perspective view of a separation state of the memory card showing an example of the above-described recording medium card.
Reference numeral 30 is an upper half constituting one side of the outer casing, reference numeral 31 is a lower half constituting the other side of the outer casing, and reference numeral 32 is a circuit board which is sheathed by both the halves 30 and 31. A chip component 33 such as a semiconductor memory is barely mounted on the back surface of the circuit board 32 to constitute an electronic circuit.
[0004]
Here, the circuit board 32 is accommodated by positioning holes 35, 35 positioned in positioning pins 34, 34 formed in the lower half 31, the upper half 30 is joined to the lower half 31, and the outer circumferences of both halves 30, 31 are stored. The joint surfaces 30a and 31a of the parts are united together by ultrasonic welding to form a memory card. Note that a connection terminal 36 is provided on the back surface on one end side of the circuit board 32, the connection terminal 36 is exposed from a window hole 37 formed in the lower half 31, and is electrically connected to an external electronic device. The memory card thus configured has a length W ₁ in the longitudinal direction of 50 mm, a length W ₂ in the short direction of 21.5 mm, and a thickness D ₁ of 2.8 mm.
[0005]
[Problems to be solved by the invention]
By the way, the memory card described above has a structure in which the outer peripheral joint surfaces of the upper and lower halves 30 and 31 covering the circuit board 32 are ultrasonically welded, and the upper and lower halves 30 and 31 themselves are also thin. Therefore, for example, there is a limit to the cross-sectional secondary moment such as bending stress and twisting stress of the memory card, and so-called strength that can withstand external stress is insufficient.
[0006]
In addition, the method of ultrasonic welding the outer peripheral joint surfaces of the upper and lower halves 30 and 31 satisfies the dimensional specifications of the memory card itself, in particular, the central portion of both halves other than the joint surfaces bulges or is recessed. Sometimes it is not possible.
[0007]
Furthermore, in the method using ultrasonic welding, there is a possibility that chip components mounted on a circuit board may be damaged due to high-frequency vibration.
[0008]
The present invention has been made to solve the above-described problems, and has a sufficient strength against external stresses such as bending stress and twisting stress, and can satisfy a dimensional specification of a card. It aims at obtaining a card and its manufacturing method.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, a recording medium card according to the present invention has an outer casing constituted by a combination of an upper half and a lower half, and a circuit board on which chip components and the like are mounted. Filling the inner surface of the upper half and lower half of the body with a thermosetting filler, and sandwiching the circuit board between the upper half and the lower half and combining them, the outer casing and the circuit board are joined to the thermosetting filler. It is designed to be integrated together.
[0010]
According to the recording medium card described above, the chip component or the like mounted with the circuit board is molded with the thermosetting filler, and the exterior casing and the circuit board are integrated with the electrically insulating thermosetting filler. Thus, the recording medium card can have sufficient strength to withstand external stress such as bending stress and twisting stress. Moreover, since it is hermetically sealed with the thermosetting filler, the lead terminals of the chip component can be protected from disconnection as well as the moisture-proof and waterproof functions of the chip component and the like.
[0011]
In addition, the recording medium card of the present invention forms a highly viscous thermosetting resin dam material on the half inner surface at the boundary between the connection terminal and the switch component, and the thermosetting filler fills the connection terminal and the switch component. I'm trying not to be.
[0012]
Further, the recording medium card of the present invention makes the flow direction and filling amount of the thermosetting filler uniform by forming a streak-like groove in the longitudinal direction of the back surface of the upper half and the lower half of the outer casing. Is possible.
[0013]
In the recording medium card of the present invention, a plurality of compartments are formed by partition walls on the half back surface corresponding to the side where the chip parts are mounted, and the compartments are transferred to the compartments according to the volume of the chip parts corresponding to each compartment. The filling amount of the thermosetting filler is adjusted.
[0014]
The recording medium card manufacturing method of the present invention is a method for manufacturing a recording medium card in which a circuit board on which a chip component is mounted is housed in a united outer casing composed of an upper half and a lower half. Fill the upper half and lower half inner surfaces of the body with a thermosetting filler, sandwich the circuit board between the upper and lower halves and combine them, and the inner half of the boundary between the connection terminal and the switch component is highly viscous By forming a dam material of thermosetting resin so that the thermosetting filler is not filled into the connection terminal and the switch component, and further heat treating and curing the thermosetting filler, the outer casing and the circuit board Are integrated with the cured thermosetting filler.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a recording medium card and its manufacturing method according to the present invention will be described below with reference to the drawings, taking a memory card and its manufacturing method as an example.
[0017]
1 is an external perspective view of the memory card as seen from the front side, FIG. 2 is an external perspective view of the memory card as seen from the back side, and FIG. 3 is a separation of the upper half, lower half, and circuit board, which are the outer casings of the memory card. FIG. 4 is an external perspective view of the upper half viewed from the back side, and FIG. 5 is an enlarged cross-sectional view taken along line AA of FIG.
[0018]
The entire memory card is indicated by reference numeral 1, and the insertion direction side of the memory card 1 is indicated by an arrow marker 2. The outer casing 3 of the memory card 1 is composed of two halves of an upper half 4 and a lower half 5, and the outer casing 3 is made of, for example, polybutylene terephthalate (PBT) having high chemical resistance and mechanical strength. ) Is injection molded. Here, the longitudinal direction of the side length W ₃ being 31mm size of the memory card 1 is parallel to the insertion direction, the length W ₄ of the lateral direction of the side perpendicular to the insertion direction is 20 mm, the thickness D ₂ is 1. It is standardized to 6 mm.
[0019]
A circuit board 6 is built in the exterior casing 3 described above. The circuit board 6 has a wiring pattern formed on a mother board made of a glass epoxy board, and a plurality of chip components 7 such as a semiconductor memory are barely mounted on the upper surface side of the circuit board 6 to constitute an electronic circuit. Further, an erroneous erasure preventing slide switch 9 having a switching knob 8 for setting prohibition of writing and writing of data to the semiconductor memory is provided on the upper surface side of the circuit board 6 so as to straddle the opening window 10. Has been implemented. Furthermore, a plurality of connection terminals 11 are formed in a pattern on the tip side on the insertion direction side on the lower surface side of the circuit board 6.
[0020]
As shown in FIG. 4, the upper half 4 of the outer casing 3 has a side wall 4a on the outer periphery, and a rib wall 12 surrounding the housing portion 4b of the slide switch 9 described above on the back surface is the same height as the side wall 4a. Is formed. In addition, a pair of rib-like projections 13 and 13 are formed on the rear side wall of the upper half 4, and a positioning projection 14 is formed on the front side of the upper half 4. Reference numeral 15 denotes a label area formed on the surface of the upper half 4.
[0021]
The lower half 5 of the outer casing 3 has a side wall 5a on the outer peripheral portion, and a plurality of slit-like window holes 16 are formed on the front end side of the lower half 5, from which the circuit board 6 is connected. The terminal 11 is exposed from the lower surface of the lower half 5. A rib wall 17 is formed on the back surface of the lower half 5 so as to surround the housing portion 5b of the slide switch 9 described above, and the switching knob 8 of the slide switch 9 faces the portion of the lower half 5 surrounded by the rib wall 17. A hole 18 is formed. Further, a pair of recesses 19 and 19 that are engaged with the rib-like protrusions 13 and 13 of the upper half 4 and a groove 20 that is engaged with the positioning protrusion 14 of the upper half 4 are formed on the rear side wall of the lower half 5. ing.
[0022]
Here, the circuit board 6 that is sandwiched and accommodated between the upper half 4 and the lower half 5 of the outer casing 3 includes the surface portion 16 a of the window hole 16, the upper surface of the rib wall 17, and the step portions 21, 21. The lower surface of the circuit board 6 is substantially in contact with the upper surface of the lower half 5 and has a predetermined gap. This gap is filled with an adhesive filler made of, for example, an epoxy resin made of a thermosetting resin in an assembly process of the memory card 1 described later.
[0023]
The upper half 4 is mounted on the upper surface of the circuit board 6 such that the rib wall 12 abuts on the upper surface of the circuit board 6 and the side wall 4 a of the outer periphery of the upper half 4 is joined to the side wall 5 a of the outer periphery of the lower half 5. The upper surfaces of the chip component 7 and the slide switch 9 that are formed have a predetermined gap from the back surface of the upper half 4. The space on the circuit board 6 including the gap is filled with an epoxy resin adhesive filler made of a thermosetting resin in an assembly process of the memory card 1 described later.
[0024]
Next, a manufacturing procedure of the memory card 1 will be described with reference to FIGS. 6a to 6d. In the figure, a cross-sectional view of the memory card 1 cut in the short direction from the line BB in FIG. 1 is shown.
[0025]
First, as shown in FIG. 6a, the upper half 4 is turned upside down, and a predetermined amount of the adhesive filler 22 is filled in the back surface of the upper half 4 in a potting state. The adhesive filler 22 is relatively viscous, and therefore remains in the potting shape without flowing out over the entire surface of the upper half 4 in the filled state. Thus, the circuit board 6 on which the chip component 7 and the slide switch (not shown) are mounted is assembled while being pressed against the upper half 4 filled with the adhesive filler 22 with the mounting side facing downward. By this assembling operation, the adhesive filler 22 flows over the entire surface of the lower half 4 and fills the entire space of the circuit board 6 and the upper half 4 as shown in FIG. 6b.
[0026]
At this time, the adhesive filler 22 filled in the space of the upper half 4 is blocked by the rib wall 12 surrounding the accommodating portion 4b of the slide switch 9, and prevents the adhesive filler 22 from flowing into the slide switch 9 side. is doing. Before filling the upper half 4 with the adhesive filler 22, adhesive filling is performed by previously applying a dam material 23 having a higher viscosity than the adhesive filler 22 around the rib wall 12 as shown in FIG. The material 22 is blocked by the dam material 23, and the inflow of the adhesive filler 22 into the accommodating portion 4b can be effectively prevented.
[0027]
Further, when the circuit board 6 is assembled to the upper half 4, the volume of the chip component 7 is calculated with respect to the volume of the lower half 4 so that the adhesive filler 22 does not leak from the upper half 4. The filling amount of the filler 22 is determined.
[0028]
Further, when the circuit board 6 is pressed and assembled to the upper half 4 filled with the adhesive filler 22, by forming the narrow groove 24 parallel to the longitudinal direction of the back surface as shown in FIG. The adhesive filler 22 can easily flow along the narrow groove 24, whereby the adhesive filler 22 can be uniformly filled in addition to the slide switch housing portion 4 b of the upper half 4. The shape of the narrow groove 24 may be an arcuate groove 24a as shown in FIG. 9a, or may be a V groove 24b as shown in FIG. 9b, or other groove shapes.
[0029]
Further, as another filling method for filling the adhesive filler 22 into the upper half 4 to which the chip component 7 corresponds, as shown in FIGS. 10 and 11a, a plurality of, for example, 3 Adhesive filling of thermosetting fillers that are formed in two compartments 25a, 25b, and 25c and that fill the compartments 25a, 25b, and 25c according to the volume of the chip parts corresponding to the compartments 25a, 25b, and 25c. It adjusts the filling amount of the material. For example, since the volume of the chip component corresponding to the compartment 25a is small, the adhesive filler 22 has a large filling amount, and since the volume of the chip component corresponding to the compartment 25b is large, the adhesive filler 22 has a small filling amount. Thus, since the volume of the chip component corresponding to the compartment 25c is small, the adhesive filler has a large filling amount.
[0030]
In this way, by adjusting the filling amount of the adhesive filler 22 according to each compartment 25a, 25b, 25c, the adhesive filler 22 leaks from the compartment when the circuit board 6 is assembled to the upper half 4. Instead, each compartment can be reliably filled as shown in FIG. 11b.
[0031]
Thus, after the upper half 4 and the circuit board 6 are assembled, next, as shown in FIG. 12, the lower half 5 surrounds the slide switch housing 5b from the rib wall 17 to the side of the connection terminal window 16. Then, a dam material 27 having the same viscosity as that of the dam material 23 applied to the upper half 4 is applied, and thereafter, the adhesive filler 28 is put in the potting state in the back surface of the lower half 5 as shown in FIG. 6c. Fill a predetermined amount. This adhesive filler 28 also has the same viscosity as the adhesive filler 22 and remains in a potting shape without flowing out over the entire surface of the lower half 5 in the filled state. Then, the upper half 4 in which the circuit board 6 is assembled to the lower half 5 as shown in FIG. 6B is combined and assembled while pressing the circuit board 6 downward. By this assembling operation, the adhesive filler 28 flows over the entire surface of the lower half 5 and fills the entire space of the lower half 5 as shown in FIG. 6d, and the memory card according to the present invention is assembled.
[0032]
At this time, the adhesive filling material 28 filled in the space of the lower half 5 is blocked by the dam material 27 so as not to flow into the slide switch 9 and the connection terminal 11 side of the circuit board 6.
[0033]
Further, by forming the narrow groove 29 along the longitudinal direction on the back surface of the lower half 5 as in the case of the upper half 4, the adhesive filler 28 can easily flow along the narrow groove 29. The adhesive filler 28 can be uniformly filled in addition to the slide switch housing portion 5b of the lower half 5.
[0034]
Also in this case, the filling amount of the filler 28 is determined by calculating the volume of the lower half 5 so that the filler 25 does not leak from the lower half 5.
[0035]
Thus, the memory card assembled as shown in FIG. 6d is kept in a state where the upper half 4 and the lower half 5 are combined by the pressing means (not shown) and is put in a heating furnace at 70 ° C. for 30 minutes. The adhesive fillers 22 and 28 are cured. Thereafter, the upper half 4 and the lower half 5 are put in a heating furnace at 100 ° C. for 3 to 4 hours without a pressing means. As a result, the memory card 1 is manufactured in which the upper half 4, the lower half 5, and the circuit board 6 are integrated with the adhesive fillers 22 and 28 that are completely cured. In addition, since the curing temperature of the adhesive fillers 22 and 28 is 100 ° C. or less, the upper and lower halves 4 and 5 are molded from polybutylene terephthalate, so that shape deformation due to softening does not occur.
[0036]
In the memory card 1 manufactured as described above, the circuit board 6 on which the chip component 7 is mounted is completely sealed with the thermosetting adhesive fillers 22 and 28, and the upper half 4 and the lower half 5 are packaged. Since the thickness of the upper half 4 and the lower half 5 can be made extremely thin, the memory card 1 can be made extremely thin and ultra-miniaturized. The strength against bending stress and twisting stress is remarkably improved, and a highly reliable memory card suitable for portable use is obtained.
[0037]
In addition, since the chip component 7 bare-mounted on the circuit board 6 is completely sealed with the adhesive fillers 22 and 28, the reliability of the solder fixing portion between the circuit board 6 and the chip component 7 can be improved. Of course, it is possible to protect the barely mounted chip component 7 from deterioration due to ultraviolet rays, and to protect from external damage such as electrostatic breakdown.
[0038]
In addition, the narrow grooves 24 and 29 formed on the back surfaces of the upper half 4 and the lower half 5 have a directivity in the flow of the adhesive filler and can be uniformly filled into the half. Therefore, since the filler particles can be aligned, the strength when the adhesive filler is cured can be improved.
[0039]
The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.
[0040]
The adhesion between the upper half 4 and the lower half 5 and the adhesive filler is based on the fact that the surface area is enlarged by the narrow grooves 24 and 29 formed to give direction to the flow of the filler. In addition, the adhesion strength may be increased by applying a so-called blasting process having an uneven surface such as a texture on the half surface.
[0041]
Further, even a surface mounting or a discrete mounting of a package component or a bare component as a mounting component on the circuit board 6 can be widely applied.
[0042]
Further, in this example, the case where the chip component 7 or the like is mounted on one surface of the circuit board 6 has been described. Of course, even if the chip component 7 or the like is mounted on both surfaces of the circuit board 6, It can be manufactured by the same procedure.
[0043]
As a molding procedure of the memory card 1, the circuit board 6 is first assembled to the lower half 5 filled with the adhesive filler 28, and then the circuit board 6 is attached to the upper half 4 filled with the adhesive filler 22. The component mounting surface side may be assembled and integrated.
[0044]
In the embodiment of the present invention, the circuit board 6 is sandwiched and integrated by the upper half 4 and the lower half 5 filled with the thermosetting adhesive filler. The upper half 4 and the lower half 5 sandwich the circuit board 6 and combine them. Thereafter, the space between the upper halves 4 and 5 and the circuit board 6 is filled with an adhesive filler by injection. Is possible. In this case, a dam material is previously formed in the same manner as described above so that the adhesive filler does not flow into the slide switch 9 or the connection terminal 11.
[0045]
【The invention's effect】
As described above, the recording medium card according to the present invention has an outer casing constituted by a combination of an upper half and a lower half, and a circuit board on which chip components and the like are mounted. Filling the inner surface of the upper half and the lower half with a thermosetting filler, sandwiching the circuit board between the upper half and the lower half, and combining them, the exterior casing and the circuit board are integrated with the thermosetting filler. Therefore, the recording medium card can be miniaturized and thinned, has sufficient strength to withstand external stresses such as bending stress and twisting stress, and is convenient for carrying.
[0046]
A method of manufacturing a recording medium card according to the present invention, a thermosetting filler filled in half and the lower half inner surface on the exterior casing, coalesce and sandwiching the circuit board in the upper half and lower half, connected A highly viscous thermosetting resin dam material is formed on the half inner surface at the boundary between the terminal and the switch part so that the thermosetting filler is not filled into the connection terminal and the switch part, and the thermosetting filler. By heat-treating and curing, the exterior casing and circuit board are integrated with the cured thermosetting filler, enabling ultra-miniaturization and thinning, such as bending stress and twisting stress. A recording medium card that has sufficient strength to withstand external stress and is convenient to carry can be manufactured.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a memory card according to an embodiment of the present invention as viewed from the upper surface side.
FIG. 2 is an external perspective view of the memory card as seen from the lower surface side.
FIG. 3 is an external perspective view of a state in which a memory card is separated.
FIG. 4 is an external perspective view of the upper half of the outer casing as viewed from the back side.
5 is an enlarged cross-sectional view of the memory card taken along line AA in FIG.
6A is a cross-sectional view of the upper half filled with an adhesive filler before the circuit board is assembled. FIG.
b is a cross-sectional view in which a circuit board is assembled to the upper half.
c is a cross-sectional view of the lower half filled with an adhesive filler.
d is a cross-sectional view in which an upper half is assembled together with a circuit board to a lower half filled with an adhesive filler.
FIG. 7 is a rear view of an upper half in which a dam material is formed around a rib wall.
FIG. 8 is a back view of the upper half in which a narrow groove is formed on the back surface of the half.
FIG. 9 is a partially enlarged cross-sectional view of an example of a narrow groove.
b is a partially enlarged cross-sectional view of another example of a narrow groove.
FIG. 10 is a rear view of the upper half showing another example in which an adhesive filler is filled in each compartment.
FIG. 11A is a cross-sectional view of the upper half in which the compartment is filled with an adhesive filler before the circuit board is assembled.
b is a cross-sectional view in which a circuit board is assembled to the upper half.
FIG. 12 is a rear view of the lower half in which a dam material is formed around the rib wall and the connection terminal.
FIG. 13 is an external perspective view of a conventional memory card in a separated state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Memory card, 3 ... Exterior housing, 4 ... Upper half, 5 ... Lower half, 6 ... Circuit board, 7 ... Chip component, 9 ... Slide switch, 11 ... Connection terminal, 12 ... Rib wall of upper half, 17 ... lower half rib wall, 22, 28 ... adhesive filler, 23, 27 ... dam material, 24, 29 ... narrow groove, 25 ... partition wall, 25a, 25b, 25c ... compartment

Claims (5)

An exterior housing configured to be combined into an upper half and a lower half;
A circuit board which is housed in the exterior casing and has a chip part and a switch part having a switching operation part on at least one surface, and has a connection terminal exposed from the exterior casing on one end side. And
Filling the inner surfaces of the upper half and the lower half of the outer casing with a thermosetting filler, sandwiching the circuit board with the upper half and the lower half, and combining them, the outer casing and the circuit board Is a recording medium card integrated with the thermosetting filler. The recording medium card according to claim 1,
Form a dam material of a highly thermosetting resin on the half inner surface of the boundary portion between the connection terminal and the switch part,
A recording medium card that prevents the thermosetting filler from being filled into the connection terminal and the switch member. The recording medium card according to claim 1,
A recording medium card that makes the flow direction and filling amount of the thermosetting filler uniform by forming streak-like grooves in the longitudinal direction of the back surface of the upper half and the lower half of the outer casing. The recording medium card according to claim 1,
A plurality of compartments are formed by a partition wall on the half back surface corresponding to the side on which the chip component is mounted,
A recording medium card that adjusts a filling amount of the thermosetting filler into the compartment according to a volume of the chip component corresponding to each compartment. A method of manufacturing a recording medium card in which a circuit board in which chip components are mounted in a combined outer casing composed of an upper half and a lower half is housed,
Filling the inner surface of the upper half and the lower half of the outer casing with a thermosetting filler, sandwiching the circuit board with the upper half and the lower half, and combining them,
Form a dam material of a highly thermosetting resin on the half inner surface of the boundary portion between the connection terminal and the switch component, so that the thermosetting filler is not filled into the connection terminal and the switch component,
A method of manufacturing a recording medium card, wherein the outer casing and the circuit board are integrated with the cured thermosetting filler by heat-treating and curing the thermosetting filler.

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