JP4527035B2 - Shield structure - Google Patents

Description

  The present invention relates to a shield structure for shielding a circuit chip on a printed wiring board.

  Conventionally, the circuit chip is divided and soldered for each functional block on both sides or one side of one printed wiring board, and the characteristic deterioration occurs due to the electrical influence between the circuit chips of each functional block. In some cases, a shield was applied to prevent deterioration of characteristics.

  As an example, a plurality of circuit chips, a shield frame that surrounds these circuit chips, and a shield case that includes a shield cover that closes the shield frame are collectively reflow-soldered on at least one side of the printed wiring board. A circuit board having a shield case and a manufacturing method thereof are provided (for example, see Patent Document 1).

  In the circuit board described in Patent Document 1, the shield case includes a shield frame that surrounds a plurality of circuit chips and a shield cover that closes the central opening of the shield frame. Some shield cases in which a shield cover that closes the central opening of the frame is integrated are similarly subjected to batch reflow processing.

  However, in recent electronic devices, particularly portable devices, downsizing has become an important item, and how to incorporate a printed wiring board and a circuit chip into a limited space has become a big problem. Therefore, the printed wiring board is divided into a plurality of printed wiring boards for each function, and the printed wiring boards (including circuit chips and shield cases) are stacked in layers in the chassis frame so that they do not overlap each other. Can be considered.

For example, consider a case where a second printed wiring board is stacked on a first printed wiring board provided with a shield case. In this case, the thickness from the first printed wiring board to the second printed wiring board is the sum of the following four, which causes a problem that the thickness of the electronic device increases.
(1) Height from the bottom surface of the first printed wiring board to the top of the circuit chip mounted on the top surface of the first printed wiring board (2) Clearance from the top of the circuit chip to the bottom surface of the shielding case top plate (3) Shield case Top plate thickness (4) Shield case Clearance from top of top plate to bottom of second printed wiring board

  The reason (4) “the gap from the top surface of the shield case top plate to the bottom surface of the second printed wiring board” is necessary is that the second printed wiring board and the shield case top plate are in contact with or separated from each other. This is so as not to affect the electrical characteristics.

Japanese Patent Laid-Open No. 10-335869, page 5, FIG.

  Since the conventional electronic device shield structure is configured as described above, to reduce the size of the electronic device, the printed wiring board is divided into a plurality of printed wiring boards for each function, and the chassis frame of the housing However, there is a problem that the thickness of the electronic device increases.

  The present invention has been made to solve the above-described problems. When the printed wiring boards are stacked and used in the casing, the space in the casing required for the shield structure of the conventional electronic device is reduced. It aims at providing the shield structure of the electronic device which reduced the thickness of the whole electronic device by reducing.

The shield structure according to the present invention includes a first printed wiring board, a circuit chip having a bottom surface attached to the first printed wiring board, and a surface of the first printed wiring board to which the circuit chip is attached. A first connector mounted on the same plane, and a first connector mounted on the first printed wiring board, covering a side surface of the circuit chip, surrounding the circuit chip, and corresponding to a top surface of the circuit chip A shield frame provided with an opening, an opening stacked on the first printed wiring board to accommodate the circuit chip, a shield pattern portion provided around the opening, and the first connector. shield structure comprising a second printed circuit board having a second connector attached to the shielding pattern portion, and a shield member covering the circuit chip to fit A.

According to the present invention, even when the printed wiring boards are stacked and used in the casing, the circuit chip can be sufficiently shielded and the thickness of the entire electronic device can be reduced.
A shield having a sufficient shielding effect even if the height of the circuit chip mounted on the first printed wiring board is equal to or higher than the height between the first printed wiring board and the second printed wiring board. Structure can be applied.

Reference example.
Hereinafter, reference examples of the present invention will be described. FIG. 1 is an assembly diagram showing an internal configuration of a mobile phone to which a shield structure according to a reference example of the present invention is applied. 2 is a cross-sectional view of the printed wiring board 11 in FIG. 1 taken along line 11a-11b. 3 is a cross-sectional view of the printed wiring board 12 in FIG. 1 taken along line 12a-12b. 4 is a diagram showing a state in which the printed wiring board 11 of FIG. 2 and the printed wiring board 12 of FIG. 3 are connected and further assembled into the chassis frame 51 of FIG. FIG. 5 is an assembly diagram illustrating the next stage of FIG. 1. Hereinafter, description will be given with reference to FIGS.

1 and 2, a printed wiring board 11 (second printed wiring board) is an operation unit board, and a dome-shaped key switch 41 on the key switch sheet 4 so as to cover the key switch pad 42 on one side. Is arranged.
When a key press switch (not shown) on the operation unit casing is pressed, the key switch 41 is pressed down. The key switch pad 42 includes a copper foil double ring, and when the key switch 41 is pressed down, the rings are short-circuited to turn the switch on and off.
5, on the back surface of the printed wiring board 11 in FIG. 2, that is, on the opposite side surface of the key switch sheet 4, a shield copper foil pattern 33, a connector 61 connected to the connector 62 of the printed wiring board 12, and a digital storage medium 23, an audio jack connector 68, an RF audio circuit and a control circuit (not shown) around the audio jack connector 68, a connector 66 connected to the connector 65 of the printed wiring board 13, and an external connection connector 67 connected to an external device. Has been placed.

3 and 5, the printed wiring board 12 (first printed wiring board) is a control unit board, and on one side, a BGA type CPU circuit chip 22, a BGA type memory circuit chip 21, and other circuit chips 2. And a shield frame 31 having a shield structure without a top plate portion surrounding them (which is attached to the first printed wiring board, covers the side surface of the circuit chip, surrounds the circuit chip, and corresponds to the top surface of the circuit chip) Shield frame provided with an opening at a position) is arranged. In addition, a connector 62 connected to the connector 61 of the printed wiring board 11 is disposed outside the shield frame 31.
The circuit chip 2 is also arranged on the back surface of the printed wiring board 12 and soldered by batch reflow.

  Here, the shield frame body is formed by bending a metal plate to form a mass and then cutting off the lower surface. Since digital circuits with a relatively low frequency such as a CPU chip and a memory chip are mounted on the inside, the bending of the printed wiring board on the lid side, the gap due to the unevenness of the shield frame body on the lid side, etc. Does not affect the shielding effect.

  In FIG. 1, the flexible printed wiring board 14 is manufactured in an integrated structure with the printed wiring board 12, and connects the connector 63 on the flexible printed wiring board 14 to the connector 64 of the printed wiring board 13. As a result, the printed wiring board 12 is also connected to the printed wiring board 13.

In FIG. 1, a printed wiring board 13 is a radio unit board, and transmits and receives a cellular phone by an antenna control RF circuit. A connector 65 for connecting to the circuit chip 2 and the connector 66 of the printed wiring board 11 is arranged on one side and soldered by batch reflow.
A connector 64 that is connected to the connector 63 of the flexible printed wiring board 14 is disposed on the back surface.

  In FIG. 1, the structure can be integrated into the chassis frame 5 in the order of the printed wiring boards 12 and 11 from the front side and then the printed wiring board 13 from the back side in the direction of the arrow in FIG. ing.

Next, referring to FIGS. 1 to 5, a shield frame that surrounds the CPU chip 22, the memory chip 21, and the circuit chip 2 of the printed wiring board 12 and has no top plate at a position corresponding to the CPU chip 22 and the memory chip 21. 31 and the shield structure of the portion surrounded by the printed wiring board 11 will be described. The shield frame 31 is soldered to the cream solder application pattern 8 by the solder layer 9, and the cream solder application pattern 8 and the shield cushion pad 53 are through holes (not shown) provided in the printed wiring board 12. Connected).
Here, the shield cushion pad 53 and the shield cushion 52 provided on the magnesium chassis frame 51 are in contact with each other, so that a shield case shape without a top plate is formed as a whole (FIG. 4).
Further, the shield copper foil pattern 33 on the opposing printed wiring board 11 is brought into contact with the shield frame 31 of the shield case so as to close the upper surface opening of the shield frame 31 to form a shield structure. The contact is performed by pressing the shield frame 31 on the printed wiring board 12 against the shielding copper foil pattern 33 on the printed wiring board 11 using the shield cushion 52 on the chassis frame 51. The shield frame 31 is formed such that the top plate facing the shield copper foil pattern 33 is shaped in a direction toward the shield copper foil pattern 33 rather than the horizontal direction. Therefore, the top plate can be easily brought into contact with the shielding copper foil pattern, and the shielding frame 31 and the shielding copper foil pattern 33 can be reliably brought into conduction by further restoring force.

  Thus, instead of the shield case top plate, the shield copper foil pattern 33 on the printed wiring board 11 facing the top plate of the CPU chip 22 and the memory chip 21 is used, and the printed wiring is used instead of the shield case bottom plate. By using the chassis frame 51 facing the lower portion of the board 12 and further fitting the printed wiring board 13 facing the opposite side of the chassis frame 51, the printed wiring boards 11 to 13 and the shields are alternately stacked. As a result, the total thickness of the combined substrates is reduced, and the GND potential is directly joined by the shielding copper foil pattern 33, the shield frame 31, the shield 52 on the chassis frame 51, and the like. It eliminates the electrical effects.

  Further, the amount of bending of the printed wiring board 11 due to the key pressing of the key switch 41 is kept small by the rigidity of the shield frame 31, and the bending of large parts such as the digital storage medium 23 is restricted and the key of the solder part Pushing fatigue is reduced.

  Next, the manufacturing method of the printed wiring board 12 is demonstrated using FIG. It should be noted that the printed wiring board 11 is similarly processed, and is assembled into a mobile phone casing (chassis frame 5) after being manufactured.

The following assembly is performed using a board (hereinafter referred to as a base board) having a cutting margin for assembling the printed wiring board 12.
First, in the first step, the first cream solder pattern for bonding the plurality of circuit chips 2 and the second cream solder for bonding the shield frame 31 to the surface of the cream solder coating pattern 8 on one side of the base substrate. A pattern is formed by screen printing or the like.
In the second step, the plurality of circuit chips 2 are mounted on the first cream solder pattern, and the shield frame 31 is mounted on the second cream solder pattern.
In the third step, the base substrate on which the plurality of circuit chips 2 and the shield frame 31 are mounted is heated in a reflow furnace to perform a batch reflow process.
In the 4th process, it is checked by an automatic inspection machine whether a solder bridge and a non-wetting part exist in the part joined by solder.
In the fifth step, the base substrate is turned over, and the same steps from the first step to the fourth step are performed again. In that case, since the shield frame 31 exists only on one side, the process which concerns on the frame is not performed.
In the sixth step, the cut margin of the printed wiring board 12 that has been completed is cut off, and an electrical test is performed using the test pad 7.
Finally, in the seventh step, an underfill is applied to the lower part of the BGA or the like in order to make the structure resistant to the drop and key press tests.

As described above, the shield structure according to this reference example includes the first printed wiring board (printed wiring board 12) and the circuit chip (the CPU chip 22, the memory having the bottom surface attached to the first printed wiring board). Chip 21), and a shielding frame body attached to the first printed wiring board, covering the circuit chip so as to cover the side surface of the circuit chip, and having an opening at a position corresponding to the top surface of the circuit chip. Shield frame 31) and a second printed wiring board in which a shielding pattern (shielding foil pattern 33 for shielding) is formed on a surface facing the top surface of the circuit chip and is laminated on the first printed wiring board (Printed wiring board 11). Therefore, even when a plurality of printed wiring boards (printed wiring boards 11 and 12) are stacked and used in the housing, the circuit chip can be sufficiently shielded and the thickness of the entire shield structure can be reduced.

The shield structure according to this reference example, the second printed wiring board, on the back surface of the shielding pattern is formed, the switch element is on and off switched by pressing (key switch pad 42) distribution It has been established. Note that when a switch element that can be switched on and off by pressing is provided, stress is repeatedly applied to the substrate, and thus a printed wiring board (printed wiring) on which such a switch element is generally attached. It is difficult to arrange surface mount components on the board 11). The shield pattern according to the reference example effectively uses such a difficult place as a place to provide the shield pattern, and eliminates the need to take various measures for attaching the surface mount component.

In the shield structure according to this reference example , the second printed wiring board is supported by the shield frame. Therefore, when the switch element is pressed, the stress applied to the second printed wiring board by the shield frame can be reduced.

In the shield structure according to this reference example , the wall surface of the shield frame is arranged at a position where the shield frame corresponds to the switch element. Therefore, the stress applied to the second printed wiring board can be further effectively reduced.

Further, in the shield structure according to this reference example , the shield frame provided on the first printed wiring board is in contact with the shield pattern provided on the second printed wiring board, and the shield pattern and the shield The pattern wiring provided on the first printed wiring board and the pattern wiring provided on the second printed wiring board are electrically connected via the frame.
On the other hand, when conducting the first printed wiring board and the second printed wiring board, for example, it is conceivable that the first printed wiring board and the second printed wiring board are conducted only by the connector. .
However, in this case, it is assumed that the GND portion of the first printed wiring board located away from the connector and the GND portion of the second printed wiring board located away from the connector are located at opposite positions. However, the potential between the portions may differ to the extent that the electrical performance is affected.
On the other hand, in the shield structure according to this reference example , the shield frame provided on the first printed wiring board and the pattern wiring board provided on the second printed wiring board are electrically connected. There is little difference in the GND potential between the first printed wiring board and the second printed wiring board, and the electrical characteristics can be effectively improved.

The shield structure according to this reference example, the first printed wiring board includes a first connector, the second printed wiring board, a second connector, the second connector and the This is a shield structure in which one connector is fitted to each other.
On the other hand, when determining the relative positional relationship between the first printed wiring board and the second printed wiring board, the first printed wiring board is attached to the frame and the second printed wiring board is attached to the frame. Is also possible.
However, in this case, only the positioning accuracy required between the second printed wiring board and the frame is added to the positioning accuracy required between the first printed wiring board and the frame. Therefore, the positioning system between the first printed wiring board and the second printed wiring board is not sufficient. As a result, the contact between the shield frame provided on the first printed wiring board and the shield pattern provided on the second printed wiring board is not sufficient, and the electrical performance is not sufficiently improved. Can be considered.
On the other hand, the shield structure according to this reference example determines the relative positional relationship by fitting the connector provided on the first printed wiring board and the connector provided on the second printed wiring board. Therefore, the first printed wiring board and the second printed wiring board can be positioned with high accuracy. As a result, the electrical performance is good with high accuracy.

In the shield structure according to this reference example , the circuit chip is a CPU chip or a memory chip.
On the other hand, the part to be shielded may be a high-frequency part used for transmission and reception. Even in this case, it is possible to shield sufficiently by joining the shield frame provided on the first printed wiring board and the shield pattern provided on the second printed wiring board. is there.
However, when the second printed wiring board is laminated on the first printed wiring board, the shield frame provided on the first printed wiring board and the shield pattern provided on the second printed wiring board are joined. Then, the joining operation becomes complicated.
On the other hand, the shield structure according to this reference example is a relatively low frequency chip such as a memory chip or a CPU chip as a part to be shielded.
Therefore, it is not necessary to join the shield frame and the shield pattern, and the assembly work is not complicated.
Even if the second printed wiring board provided with the shield pattern is bent, or the gap due to the unevenness of the shield frame provided on the first printed wiring board is 100 μm or more, the circuit chip to be shielded Since a chip or a CPU chip has a relatively low frequency, a sufficient shielding function can be applied.

Further, in the shield structure according to this reference example , since the circuit chip is a BGA type, the effect of reducing the thickness of the entire shield structure is particularly remarkable.
The reason will be specifically described below.
Consider a case where a second printed wiring board is stacked on a first printed wiring board provided with a shield case. In this case, the thickness from the first printed wiring board to the second printed wiring board is the sum of the following four, which causes a problem that the thickness of the entire shield structure increases.
(1) Height from the bottom surface of the first printed wiring board to the top of the circuit chip mounted on the top surface of the first printed wiring board (2) Clearance from the top of the circuit chip to the bottom surface of the shielding case top plate (3) Shield case Top plate thickness (4) Shield case Clearance from top of top plate to bottom of second printed wiring board

The above (2) “gap from the top of the circuit chip to the bottom surface of the shield case top” means that when the circuit chip is a BGA chip, the height of the BGA chip component apex after soldering the component is 40-50 μm. Therefore, it is necessary to set the limit value after soldering to about 40 to 50 μm larger than the limit value of the minimum interval (2) before soldering.
Therefore, when the circuit chip is a BGA type, if the shield frame with the exposed top surface of the circuit chip is used, the top surface of the circuit chip is covered with the shield case when the circuit chip is the BGA type. Compared to the configuration, the effect of reducing the thickness of the entire shield structure becomes significant.

Further, in the shield structure according to this reference example , since the top plate of the shield frame is biased toward the shield pattern provided on the second printed wiring board, the shield frame and the second printed wiring The shield pattern on the plate will not come into contact with or leave the shield pattern. Therefore, the thickness of the entire shield structure can be reduced as compared with the case where the shield frame and the second printed wiring board are sufficiently separated so as not to contact each other.
When the first printed wiring board and the second printed wiring board are fitted by a connector, the second printed wiring board swings with respect to the first printed wiring board by the restoring force of the connector. It becomes easy. In such a case, if the shield frame provided on the first printed wiring board and the second printed wiring board are not brought into contact with or separated from each other, the thickness of the shield structure is further increased.
Therefore, when the 1st printed wiring board and the 2nd printed wiring board are being fixed by the fitting of a connector, the composition of this application which fully contacts the shield frame and the shield pattern of the 2nd printed wiring board According to this, the thickness reduction effect of the shield structure becomes remarkable.

In the shield structure according to this reference example , the opening of the shield frame has a shape in which the solder attaching the circuit chip to the first printed wiring board is exposed.
Accordingly, after the circuit chip and the shield frame body are automatically mounted on the first printed wiring board and batch reflow soldering is performed, the inside of the shield case can be confirmed. Specifically, since the shield cover top plate does not exist after the collective reflow, the shield structure of this time can do the following.
(1) In the fourth step, by performing an image comparison with a non-defective product from above the substrate with an automatic solder wetness inspection machine, it is possible to confirm solder bridges and solder non-wetting.
(2) In the sixth step, the electrical inspection can be performed by automatically bringing the test point 7 into contact with the robot tester.
(3) In the seventh step, it is possible to reinforce the non-defective product that has passed all the tests by underfilling the lower part of the component that is vulnerable to dropping / impact such as BGA.

In the shield structure according to this reference example , the first printed wiring board is held by a shield frame that covers the back surface of the surface on which the circuit chip is mounted.
Therefore, since the frame that holds the first printed wiring board has both the function of holding the first printed wiring board and the function of shielding the bottom surface side of the first printed wiring board, the thickness of the shield structure Can be reduced. Further, since the shield frame and the first printed wiring board are directly conducted via the shield cushion, it is possible to reduce the difference in the GND potential between the shield frame and the first printed wiring board. The electrical characteristics can be improved.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below. FIG. 6 is a perspective view showing the internal structure of the mobile phone to which the shield structure of the electronic device according to Embodiment 1 of the present invention is applied. FIG. 7 is a cross-sectional view taken along the line 11a-11b in FIG. 6 and 7 are substantially the same as the internal configuration of the mobile phone shown in FIG. It shows an applied example.

FIG. 7A shows an assembled method after the printed wiring boards 11 and 12 are assembled, and FIG. 7B shows an assembled method.
In FIG. 7B, the circuit chip 24 on at least one side of the printed wiring board 12 (first printed wiring board) contacts or overlaps the shielding copper foil pattern 33 of the printed wiring board 11 in FIG. In this case, in order to secure a space with the circuit chip 24 on the printed wiring board 12, an opening is provided in the printed wiring board 11 (second printed wiring board), and the shield case has an upward convex depression. 32 is attached. At that time, the copper foil pattern 111 for shielding is formed on the back surface (circuit chip 24 side) of the printed wiring board 12 so as to surround the opening, and the end portion of the shield case 32 is brought into contact therewith.

  Next, assembly of the printed wiring boards 11 and 12 will be described. The printed wiring board 11 is assembled to the printed wiring board 12 in the direction of the arrow in FIG. Then, as shown in FIG. 7A, the connectors 61 and 62 are fitted, the shield frame 31 is pressed against and comes into contact with the shielding copper foil pattern, and the shield case 32 closes the circuit chip 24. .

7 includes a shield copper foil pattern 121, a cream solder coating pattern 8, a shield frame 31 (above, printed wiring board 11), a shield copper foil pattern 111, and a shield case 32 (above, printed wiring board). 12) formed by contacting each other.
The printed wiring boards 11 and 12 are separately assembled by batch reflow as in the reference example, and then assembled as described above at the stage of assembling the mobile phone.

As described above, the shield structure according to the first embodiment includes a first printed wiring board, a circuit chip having a bottom surface attached to the first printed wiring board, and the circuit chip to which the circuit chip is attached. A first connector (connector 62) mounted on the same surface as the surface of the first printed wiring board, and attached to the first printed wiring board, covering a side surface of the circuit chip and enclosing the circuit chip; A shield frame having an opening provided at a position corresponding to the top surface of the circuit chip, an opening stacked on the first printed wiring board and accommodating the circuit chip, and a shield provided around the opening A second printed wiring board having a pattern portion (shielding copper foil pattern 111) and a second connector (connector 61) fitted to the first connector; and the shield Attached to the pattern portion, and a shield member (shield cover 32) covering the circuit chip.
Therefore, in addition to the effects of the reference example , even if the height of the circuit chip mounted on the first printed wiring board is equal to or higher than the height between the first printed wiring board and the second printed wiring board. A shield structure having a sufficient shielding effect can be applied.

Embodiment 2 FIG .
The second embodiment of the present invention will be described below. FIG. 8 is a side view showing an internal configuration of a mobile phone to which the shield structure for an electronic device according to Embodiment 2 of the present invention is applied. FIG. 8A shows an example in which the printed wiring boards 102, 112, 122, and 132 (first to fourth printed wiring boards) are stacked in order of four levels. Moreover, FIG.8 (b) has shown the assembly method (arrow direction) of Fig.8 (a).

In FIG. 8, the shield frames 311 and 312 have a structure without the top plate portion of the shield frame 32 of FIG. Instead, the printed wiring board 122 (shielding copper foil pattern 83) and 132 (shielding copper foil pattern 344) serve as a shield case top plate.
If the circuit chip 26 is further high, a printed wiring board provided with a shield case having a sufficient height, such as the printed wiring board 11 of FIG. Also good.
Further, when the circuit chip 26 is not present, the printed wiring board 122 can be omitted and a stacked configuration of up to three stages can be employed.

  8 includes a shield copper foil pattern 341, a cream solder coating pattern 8, a shield frame 31 (above, printed wiring board 102), a shield copper foil pattern 81, and a shield frame 311 (above, printed wiring). Board 112), a copper foil pattern 82 for shielding, a shield frame (hereinafter, printed wiring board 122), and a copper foil pattern 344 for shielding (printed wiring board 132).

  Further, since the heights of the circuit chip 25 and the circuit chip 26 are different, from the printed wiring board 102 to the shield frame 311 of the printed wiring board 112, the shield frame 312 of the printed wiring board 122, and the printed wiring board 132 serving as the shield case top plate. Is a reverse staircase shape (FIG. 8A).

Furthermore, by alternately combining the shield frame and the shield copper foil pattern, it is possible to stack any number of printed wiring boards. Further, the four printed wiring boards are independent of each other and can be easily disassembled.
Other configurations are substantially the same as those of the reference example and the first embodiment .

As described above, the shield structure according to the second embodiment includes the first printed wiring board (printed wiring board 102) and the first circuit chip (bottom surface attached to the first printed wiring board). A second circuit chip 25) and a second taller than the first circuit chip, the bottom surface of which is mounted on the same surface as the surface of the first printed wiring board to which the first circuit chip is mounted. Circuit chip (circuit chip 26) and the first printed wiring board, and covers side surfaces of the first and second circuit chips to surround the first and second circuit chips. A shield frame (shield frame 311) having an opening provided at a position corresponding to the top surface, and a surface stacked on the first printed wiring board and facing the top surface of the first circuit chip. First seal formed A second pattern portion (shield copper foil pattern 82), an opening for accommodating the second circuit chip, and a second shield pattern portion (shield copper foil pattern 82) provided around the opening. A printed wiring board (printed wiring board 122), and a shield member (shielding copper foil pattern 344) attached to the second shield pattern portion and covering the second circuit chip. Therefore, the distance between the first printed wiring board and the second printed wiring board can be adjusted to the height of the short circuit chip.
In the shield structure according to the second embodiment , the shield member covers the side surface of the second circuit chip and surrounds the second circuit chip, and the top surface of the second circuit chip. And a third printed wiring board laminated on the first printed wiring board. Therefore, a circuit chip having an arbitrary height can be used within the range of the total thickness of the printed wiring boards.
Further, as shown in FIG. 8A, the height of each printed wiring board is set so that the printed wiring board on which the circuit chip to be shielded is mounted to the printed wiring board serving as the shield case top plate has a reverse staircase shape. By selecting, it is possible to mount circuit chips etc. on each layer pattern other than one side of the printed wiring board used for the shield case top board, or on the printed wiring board not used for the shield case top board. It can be used.
In addition, the same effects as those of the reference example can be obtained except for the effect of reducing fatigue of each part due to key pressing.

  1 to 8, for the sake of convenience, the description has been made using expressions such as up, down, left, and right. Is not to be done.

It is an assembly drawing which shows the internal structure of the mobile telephone which applied the shield structure of the electronic device which concerns on the reference example of this invention. It is the 11a-11b sectional view taken on the line of the printed wiring board 11 in FIG. It is the 12a-12b sectional view taken on the line of the printed wiring board 12 in FIG. 4 is a diagram showing a state in which the printed wiring board 11 of FIG. 2 and the printed wiring board 12 of FIG. 3 are connected and further assembled into the chassis frame 51 of FIG. It is an assembly drawing which shows the next step of FIG. It is a perspective view which shows the internal structure of the mobile telephone to which the shield structure of the electronic device which concerns on Embodiment 1 of this invention is applied. It is the 11a-11b sectional view taken on the line of FIG. It is sectional drawing which shows the internal structure of the mobile telephone to which the shield structure of the electronic device which concerns on Embodiment 2 of this invention is applied.

  2 Circuit chip, 4 Key switch sheet, 5 Chassis frame, 7 Test pad, 8 Cream solder coating pattern, 9 Solder layer, 11 Printed wiring board, 12 Printed wiring board, 13 Printed wiring board, 14 Flexible printed wiring board, 21 Memory chip, 22 CPU chip, 23 Digital storage medium, 24 circuit chip, 25 circuit chip, 26 circuit chip, 31 shield frame, 32 shield cover, 33 copper foil pattern for shield, 41 key switch, 42 key switch pad, 51 Chassis frame, 52 shield cushion, 53 shield cushion pad, 61-66 connector, 67 external connector, 68 audio jack connector, 81 shield copper foil pattern, 82 shield copper foil pattern, DESCRIPTION OF SYMBOLS 102 Printed wiring board, 111 Shielding copper foil pattern, 112 Printed wiring board, 121 Shielding copper foil pattern, 122 Printed wiring board, 132 Printed wiring board, 311 Shield frame, 312 Shield frame, 341 Shielding copper foil pattern 344 Copper foil pattern for shielding.

Claims (7)

A first printed wiring board;
A circuit chip having a bottom surface attached to the first printed wiring board;
A first connector attached on the same surface as the surface of the first printed wiring board to which the circuit chip is attached;
A shield frame that is attached to the first printed wiring board, covers the side surface of the circuit chip, surrounds the circuit chip, and has an opening at a position corresponding to the top surface of the circuit chip;
A second printed circuit having an opening for receiving the circuit chip, a shield pattern portion provided around the opening, and a second connector fitted to the first connector, which are stacked on the first printed wiring board. A wiring board;
A shield structure comprising: a shield member attached to the shield pattern portion and covering the circuit chip. A first printed wiring board;
A first circuit chip having a bottom surface attached to the first printed wiring board;
A second circuit chip having a bottom surface attached to the same surface as the surface of the first printed wiring board to which the first circuit chip is attached, and being taller than the first circuit chip;
Attached to the first printed wiring board, covers the side surfaces of the first and second circuit chips, surrounds the first and second circuit chips, and has an opening at a position corresponding to the top surface of the circuit chip. A first shielding frame provided;
A first shielding pattern portion formed on a surface of the first printed wiring board that is laminated and opposed to the top surface of the first circuit chip, an opening for accommodating the second circuit chip, and an opening of the opening A second printed wiring board having a second shielding pattern portion provided in the periphery;
Attached to the first and second shielding pattern portions, covers the side surface of the second circuit chip, surrounds the second circuit chip, and opens at a position corresponding to the top surface of the second circuit chip. A second shielding frame provided with
A third shield pattern portion is formed on a surface facing the top surface of the second circuit chip, and a third printed wiring board laminated on the first printed wiring board is provided. Shield structure. The second printed wiring board is
2. The shield structure according to claim 1, wherein a switch element that is switched on and off by pressing is disposed on the back surface of the surface on which the shield pattern portion is formed. The second printed wiring board is
The shield structure according to claim 1, wherein the shield structure is supported by a shield frame. The shield frame
The shield structure according to claim 4, wherein a wall surface of the shield frame is disposed at a position corresponding to the switch element. The shield frame provided on the first printed wiring board is
Abutting with the shielding pattern provided on the second printed wiring board;
The pattern wiring provided on the first printed wiring board is electrically connected to the pattern wiring provided on the second printed wiring board via the shield pattern portion and the shield frame. The shield structure according to claim 1, wherein: Circuit chip
3. The shield structure according to claim 1, wherein the shield structure is a CPU chip or a memory chip.

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