JP2006165055A - Video recorder cabinet and substrate fixing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sub-board fixing mechanism which has been minimized in the number of manufacturing steps and cost thereof. <P>SOLUTION: A slit is formed to a heat radiating plate 30 or the like erected to a main-board 10 and the deep area of the sub-board 20 is inserted into this slit. In this case, a belt type solder bump is formed to the location where the slit of the sub-board 20 is held from the thickness direction of the same slit. Accordingly, if the sub-board 20 is to be deviated in the thickness direction of the slit, the belt type solder and the periphery of slit can be placed in contact with each other to restrict such deviation. Therefore, the sub-board 20 can surely be fixed for the main-board 10. The number of processing steps is no longer increased for formation of the belt type solder bump because only the process similar to the other solder bump forming process is required. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a video cabinet and a board fixing mechanism, and more particularly to a video cabinet and a board fixing mechanism that are erected with respect to a main board.

Conventionally, as this type of substrate fixing mechanism, there has been known one in which a notch is provided in a sub substrate as well as a heat radiating plate (see, for example, Patent Document 1).
Further, there are known ones in which a heat sink is bent to the sub-board side to form a holding part for the sub-board, and further, this holding part and the sub-board are fixed with screws (for example, FIG. 1, see FIG.
According to this configuration, the sub-board can be reliably fixed to the heat sink in any configuration.
Japanese Patent Application No. 5-259661 Registration No. 3057627

  In the former video cabinet and board fixing mechanism, it is necessary to provide notches in the sub-board, and therefore, it is necessary to perform external processing of the sub-board which is not originally required. Therefore, there is a problem that the number of steps increases and the cost also increases. Furthermore, since the notch is provided in the sub-board, the strength around the notch in the sub-board becomes weak. For this reason, there is a problem that the sub-board is damaged when a load is applied to the sub-board by connecting a jack to the external connection terminal provided on the sub-board.

On the other hand, the latter board fixing mechanism also has a problem that the assembly work becomes complicated by screwing the sub board to the heat sink.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a video cabinet and a substrate fixing mechanism that minimize the number of steps and cost.

In order to achieve the above object, the invention according to claim 1 is a plate-like member that is erected and fixed on the main board, and a plate that is erected and fixed while being electrically connected to the main board. In a video cabinet comprising a plate-like member and a substrate holding portion for holding the sub-board in the plate-like member,
The substrate holding portion is a slit substantially perpendicular to the main substrate formed downward from the upper end portion of the plate-like member to a predetermined height, and the sub-substrate has only a portion higher than the lower end of the slit as the slit. An insertion part sandwiched in the thickness direction by the slit formed to extend deeper, an external connection terminal, and two slits that are substantially parallel to the slit at a position sandwiching the slit from both outer sides in the thickness direction in the insertion part. A floating land that is electrically connected to other portions formed in a belt shape, and a solder bump formed on the floating land higher than a gap formed by the insertion portion and the wall surface of the slit. It is as.

  In the invention of claim 1 configured as described above, the substrate holding portion is substantially perpendicular to the main substrate from the upper end portion of the plate-like member fixed in a standing state on the main substrate to a predetermined height downward. As a slit. The sub-substrate is formed with an insertion portion in which only a portion higher than the lower end of the slit is extended from the slit to the back, and the insertion portion is inserted into the slit. At this time, since the insertion portion is sandwiched and supported by the slit in the thickness direction, the sub-board can be supported in a state of being erected with respect to the main board.

  Since the plate-like member is a heat sink, it is not necessary to newly provide a dedicated member or the like for supporting the sub-board in a standing state. The heat radiating plate is composed of a wide surface and a narrow surface intersecting in a substantially L shape, and both the wide surface and the narrow surface are erected with respect to the main substrate. The slit is formed on the narrow surface. On the other hand, the sub-board is provided with an external connection terminal and is electrically connected to the main board. Floating lands that are not electrically connected to other locations are formed at positions where the slits in the insertion portion are sandwiched from both outer sides in the thickness direction. Two of the floating lands are formed so as to have a strip shape substantially parallel to the slit. Further, a solder bump having a height higher than a gap formed by the insertion portion and the wall surface of the slit is formed on the floating land.

  That is, when the solder bump is shifted in the thickness direction of the slit, the solder bump interferes with the periphery of the slit. The floating lands on which the solder bumps are formed are formed in two strips substantially parallel to the slits at positions sandwiching the slits from both outer sides in the thickness direction, so that the sub-board is formed in the thickness direction of the slits. Fixed. Therefore, it is possible to prevent the connection part electrically connected to the main board in the sub-board from wobbling. That is, it is possible to prevent the connection portion with respect to the main board from being damaged by a load applied when the external connection terminal provided on the sub-board is connected from the outside.

  The direction of the load in which the solder bump presses the periphery of the slit is the thickness direction of the slit. The direction of the load intersects the narrow surface of the heat radiating plate provided with the slit in a substantially L shape. This coincides with the width direction of the wide surface. That is, the lower end surface of the wide surface comes into contact with the main substrate, and the lower end surface counters the load applied to the heat sink. Therefore, it is easy to disperse the load applied to the heat radiating plate in the direction in which the load is applied, and the heat radiating plate is prevented from wobbling in the direction in which the load is applied.

  Further, when the sub-board is assembled, the solder bump guides the slit from both sides, so that the insertion portion can be easily inserted into the slit. Since the insertion position of the slit in the insertion portion is clarified by the solder bump, the sub-substrate can be easily positioned with respect to the main substrate.

  When an excessive load is applied to the contact portion between the solder bump and the slit, even if the floating land is peeled off from the base material of the sub-substrate together with the solder bump, the floating land is electrically connected to another portion. There is no possibility of causing an electrical failure because no process is performed.

  Here, when the floating land is formed, it may be formed when another printed wiring is formed on the sub-board. If formed in this way, the number of steps and cost can be minimized to form the floating land. Similarly, when forming the solder bumps, the number of steps and cost can be minimized if they are formed when other solder bumps are formed on the sub-board.

  According to a second aspect of the present invention, there is provided a plate-like member that is erected and fixed on the main board, a plate-like member that is erected and fixed while being electrically connected to the main board, and the above In a board fixing mechanism comprising a board holding part that holds the sub board in a plate-like member,

  The substrate holding portion is a slit substantially perpendicular to the main substrate formed downward from the upper end portion of the plate-like member to a predetermined height, and the sub-substrate has only a portion higher than the lower end of the slit as the slit. An insertion part sandwiched in the thickness direction by the slit formed to extend deeper, a land formed at a position adjacent to the slit and the thickness direction in the insertion part, and a solder formed on the land The configuration includes bumps.

  In the invention according to claim 2 configured as described above, the substrate is held substantially perpendicularly to the main substrate from the upper end of the plate-like member fixed in a standing state on the main substrate to a predetermined height. A slit is formed as a part. The sub-substrate is formed with an insertion portion in which only a portion higher than the lower end of the slit is extended from the slit to the back, and the insertion portion is inserted into the slit. At this time, since the insertion portion is sandwiched and supported by the slit in the thickness direction, the sub-board can be supported in a state of being erected with respect to the main board.

  A land is formed at a position adjacent to the slit in the insertion portion in the thickness direction, and a solder bump is formed on the land. That is, when the sub-board is moved in the thickness direction of the slit, the solder bumps and the periphery of the slit interfere with each other, thereby preventing the sub-board from wobbling in the same direction. In addition, since the portion where the main substrate and the sub substrate are electrically connected does not wobble, the possibility of contact failure between the main substrate and the sub substrate can be reduced.

Here, the land may be formed when another printed wiring is formed on the sub-board. If formed in this way, the number of steps and cost can be minimized to form the land. Similarly, when forming the solder bumps, the number of steps and cost can be minimized if they are formed when other solder bumps are formed on the sub-board. Further, the invention according to claim 3 is configured such that the plate-like member is a heat radiating plate.
The heat sink is usually required to dissipate the heat generated from various IC chips mounted on the main board away from the main board. Therefore, the heat sink is fixed while standing on the main board. There are many cases. Therefore, in the invention of claim 3 configured as described above, since the plate-like member is a heat radiating plate, it is not necessary to newly provide a dedicated member or the like for supporting the sub-board in a standing state. I'll do it.

  According to a fourth aspect of the present invention, the radiator plate is formed of a wide surface that stands on the main substrate and intersects with each other in a substantially L shape, and a narrow surface on which the slit is formed. As a configuration.

  In the invention concerning Claim 4 comprised as mentioned above, the said heat sink is comprised by the wide surface and narrow surface which cross | intersect substantially L shape, and both the said wide surface and a narrow surface are the above-mentioned. Stand up against the main board. The slit is formed on the narrow surface. On the other hand, the load direction in which the solder bump presses the periphery of the slit is the thickness direction of the slit. The direction of the load is substantially L-shaped with the narrow surface of the heat radiating plate provided with the slit. This coincides with the width direction of the wide surface that intersects. That is, the lower end surface of the wide surface comes into contact with the main substrate, and the lower end surface counters the load applied to the heat sink. Therefore, it is easy to disperse the load applied to the heat radiating plate in the direction in which the load is applied, and the heat radiating plate is prevented from wobbling in the direction in which the load is applied.

In the invention according to claim 5, the plate-like member is a shield plate.
In the invention of claim 5 configured as described above, since the plate-like member is a shield plate, it is not necessary to newly provide a dedicated member or the like for supporting the sub-board in a standing state. .

In the invention according to claim 6, the sub-board includes an external connection terminal.
In the invention of claim 6 configured as described above, since the sub-board is prevented from wobbling, even if the external connection terminal is connected from the outside, the external connection terminal is not wobbled. It's easy to do. In addition, since the portion where the main substrate and the sub substrate are electrically connected does not wobble, the possibility of contact failure between the main substrate and the sub substrate can be reduced.

According to a seventh aspect of the present invention, the land is a floating land that is not electrically connected to another portion.
In the invention of claim 7 configured as described above, even if the land is peeled off from the base material of the sub-substrate together with the solder bumps by a load, it is possible to prevent an electrical failure from occurring.

Further, the invention according to claim 8 is configured such that the land is formed in two strips substantially parallel to the slit at a position sandwiching the slit from both outer sides in the thickness direction in the insertion portion.
In the invention of claim 8 configured as described above, lands that are not electrically connected to other portions are formed at positions where the slits in the insertion portion are sandwiched from both outer sides in the thickness direction. Two of the lands are formed so as to form a strip shape substantially parallel to the slit. That is, the land on which the solder bumps are formed is formed in two strips substantially parallel to the slit in a position sandwiching the slit from both outer sides in the thickness direction. Fixed to. Therefore, it is possible to prevent wobbling of the connection part that is electrically connected to the main board in the sub board. Further, when the sub-board is assembled, the solder bump guides the slit from both sides, so that the insertion portion can be easily inserted into the slit. Since the insertion position of the slit in the insertion portion is clarified by the solder bump, the sub-substrate can be easily positioned with respect to the main substrate.

According to a ninth aspect of the present invention, the land has a belt-like shape divided by aligning a plurality of independent lands substantially parallel to the slit.
In the invention of claim 9 configured as described above, since the area of a plurality of independent individual lands can be reduced, the volume of solder on the individual lands can be reduced. Therefore, when the solder is melted, the solder tends to aggregate due to surface tension, and the height tends to increase accordingly. That is, the height of the solder bump can be increased.

Furthermore, the invention according to claim 10 is configured such that the solder bump is formed higher than a gap formed by the insertion portion and the wall surface of the slit.
In the invention of claim 10 configured as described above, if the solder bump is formed higher than the gap formed by the insertion portion and the wall surface of the slit, the solder bump is surely secured to the periphery of the slit. Can be interfered with.

As described above, according to the first and second aspects of the invention, it is possible to provide a substrate fixing mechanism that minimizes the number of steps and the cost.
Moreover, according to the invention concerning Claim 3, the existing member can be used effectively.
Furthermore, according to the invention concerning Claim 4, it can make it hard to generate the rattling of a heat sink and a main board | substrate.
Furthermore, according to the invention concerning Claim 5, the existing member can be used effectively.

Moreover, according to the invention concerning Claim 6, an external connection apparatus can be connected stably.
Furthermore, according to the seventh aspect of the present invention, it is possible to make it difficult for an electrical failure to occur even if a portion supporting the sub-board is destroyed.
According to the eighth aspect of the present invention, the sub-board is prevented from wobbling and positioning is facilitated.
Moreover, according to the invention concerning Claim 9, a solder bump can be formed highly.
Furthermore, according to the invention concerning Claim 10, a solder bump can be reliably made to interfere with the periphery of a slit.

Here, embodiments of the present invention will be described in the following order.
(1) First embodiment:
(2) Second embodiment:
(3) Formation of solder bumps:

(1) First embodiment:
FIG. 1 shows the main substrate and sub-substrate according to the first embodiment of the present invention as seen from an oblique direction. The main board 10 and the sub board 20 according to the present embodiment are housed in a substantially box-shaped video cabinet 50 indicated by a broken line in FIG. On the board of the main board 10, a voice IC 11 and other electronic components 12 are mounted. At a position adjacent to the audio IC 11 on the main board 10, a metal heat radiating plate 30 for vertically radiating the heat generated by the audio IC 11 is erected vertically to the main board 10. The heat radiating plate 30 is formed orthogonally to each other so that the first surface 30a having a large width and the second surface 30b having a small width are substantially L-shaped when viewed from above. The heat sink 30 is fixed in a state of standing on the main substrate 10 by joining to the main substrate 10 at the lower end surfaces of the first surface 30a and the second surface 30b.

  FIG. 2 shows the heat sink 30 as viewed from an oblique direction. In the drawing, the second surface 30b having a narrow width in the heat sink 30 is oriented in the width direction of the video cabinet 50, and the slit 31 extends from the upper end to a predetermined height at a substantially central portion in the width direction of the second surface 30b. Is formed. The slit 31 is formed substantially perpendicular to the main substrate 10 and is formed with a uniform width from the upper end to the lower end of the slit 31. The thickness direction of the slit 31 coincides with the depth direction of the video cabinet 50, and the width direction of the wide first surface 30a also coincides with this.

  FIG. 3 shows the sub-board 20 as viewed from the back (right side in FIG. 1). In the figure, an insertion portion 20a is formed by extending an upper portion of a substantially square sub-board 20 in the right direction. The height of the lower end of the insertion portion 20a substantially matches the height of the lower end of the slit 31. Therefore, when the insertion portion 20 a is inserted into the slit 31, a portion lower than the slit 31 in the second surface 30 b does not interfere with the sub-substrate 20. A pair of strip-like solder bumps 21a and 21b are formed so as to sandwich a portion sandwiched by the slit 31 in the insertion portion 20a indicated by a broken line from both outer sides in the thickness direction of the slit 31. The strip-like solder bumps 21 a and 21 b are parallel to each other and also to the slit 31. Further, the strip-like solder bumps 21 a and 21 b are strip-like having substantially the same length as the slit 31.

  A plurality of solder bumps 24 are formed on the back surface of the sub-board 20. The solder bumps 24 are provided with through holes (not shown) penetrating the board, and connecting pins 24a such as various electronic elements mounted on the front surface of the sub board 20 are passed through the through holes. Then, by soldering the connecting pins 24a protruding to the back side by penetrating on the back side, various electronic elements mounted on the front surface are electrically connected to a printed wiring (not shown) formed on the sub-board 20. Or physically fixed. Note that the surface of the sub-substrate 20 other than the solder bumps 24 and the strip-like solder bumps 21a and 21b on the back surface is covered with a solder resist mask 25 having no conductivity.

  Among the components mounted on the front surface of the sub-board 20, there are RCA jacks 22a and 22b as external connection terminals, which are similarly fixed by soldering on the rear surface. The RCA jacks 22a and 22b can output stereo sound, the right sound is output from the RCA jack 22a, and the left sound is output from the RCA jack 22b. These are electrically connected to the audio IC 11 mounted on the main board 10, and an output signal from the audio IC 11 is transmitted to the RCA jack 22a by interposing another electronic element mounted on the front surface of the sub board 20 as an interface. , 22b is adjusted to an audio signal that can be output.

  Note that the substantially cylindrical tip portions of the RCA jacks 22a and 22b protrude outward from the circular holes 51a and 51b formed in the video cabinet 50 indicated by broken lines in FIG. Since the circular holes 51a and 51b have substantially the same diameter as the outer diameters of the substantially cylindrical tip portions of the RCA jacks 22a and 22b, the substantially cylindrical tip portions of the RCA jacks 22a and 22b protrude from the video cabinet 50. Just fit into the circular holes 51a, 51b. Therefore, the RCA jacks 22a and 22b are fixed in a direction perpendicular to the axial direction of the RCA jacks 22a and 22b.

  Here, in order to electrically connect the RCA jacks 22 a and 22 b and the audio IC 11 mounted on the main board 10, it is necessary to electrically connect the sub board 20 and the main board 10. Therefore, the sub board 20 and the main board 10 are electrically connected by a connector 23 shown by a broken line in FIG. Similarly to the RCA jacks 22a and 22b and other electronic elements, the connector 23 is also mounted on the front side of the sub-board 20, and the connection pins 24a are passed through the back side through the through holes and soldered from the back side. . The connector 23 also includes a connection pin 23 a that protrudes downward. The connection pin 23 a protrudes from the upper surface side of the main substrate 10 to the lower surface side of the main substrate 10 through a through hole formed in the main substrate 10. Yes. Then, the sub-board 20 and the main board 10 are electrically connected by soldering the protrusions of the connection pins 23 a to the main board 10 on the lower surface side of the main board 10.

  4 shows the heat sink 30 in FIG. 1 as viewed from the back of the video cabinet 50. FIG. In the drawing, the back side of the second surface 30 b is visible, and the insertion portion 20 a of the sub-board 20 is supported by the slit 31 so that the thickness direction is sandwiched between the slits 31. The band-like solder bumps 21b are raised in a bowl shape on the left side in the drawing, and the height thereof is higher than the size of the gap formed by the insertion portion 20a of the sub-board 20 and the wall surface of the slit 31. Similarly, the height of the band-shaped solder bump 21a formed at a position sandwiching the second surface 30b from the band-shaped solder bump 21b is also larger than the size of the gap formed by the insertion portion 20a of the sub-board 20 and the wall surface of the slit 31. Is also formed high.

  With this configuration, the sub-board 20 can be fixed in the thickness direction of the slit 31. That is, if the sub-board 20 is moved to the back side in the thickness direction of the slit 31, the band-shaped solder bump 21a and the periphery of the slit 31 come into contact with each other and cannot move further back. Similarly, if the sub-board 20 is to be moved to the front side in the thickness direction of the slit 31, the belt-like solder bump 21 b and the periphery of the slit 31 come into contact with each other and cannot move further forward. If the sub-board 20 can be fixed in the thickness direction of the slit 31, when the RCA pin is inserted into the RCA jacks 22a and 22b from the outside, the sub-board 20 mainly resists the load applied in the axial direction of the RCA jacks 22a and 22b. be able to. Therefore, the RCA jacks 22a and 22b are not shaken while the RCA pins 22a and 22b are externally inserted and removed, and the RCA pins can be easily inserted and removed. As described above, the circular holes 51a and 51b of the cabinet 1 are fixed in the direction perpendicular to the axial direction of the RCA jacks 22a and 22b.

  Further, the load applied in the axial direction of the RCA jacks 22a and 22b when the RCA pin is inserted and removed is propagated to the heat radiating plate 30 through the strip-shaped solder bumps 21a and 21b. The load propagated to the heat sink 30 is finally absorbed by the main board 10 through the lower end surface of the heat sink 30. At this time, the direction of the load and the width direction of the wide first surface 30a coincide. Therefore, the load can be dispersed on the contact surface with the main substrate 10 that is long in the load direction of the width of the first surface 30a. Further, the heat radiation plate 30 is stable because it contacts the main board 10 widely in the rotation direction even with respect to the moment to rotate the sub board 20 generated by the load applied in the axial direction of the RCA jacks 22a and 22b. . Therefore, durability against insertion / removal of the RCA pin at the joint portion between the heat sink 30 and the main substrate 10 is high, and rattling is also suppressed. If rattling of the heat dissipation plate 30 is prevented, rattling of the sub-board 20 is also prevented at the same time.

  As described above, when rattling of the sub-board 20 is prevented, rattling of the connection portion between the sub-board 20 and the main board 10 is also prevented. Accordingly, it is possible to reduce the possibility that an excessive load is applied to the connection portion between the sub-board 20 and the main substrate 10 and the connection portion is damaged. Specifically, since the connection pin 23a is prevented from moving with respect to the main substrate 10, the soldered portion between the main substrate 10 and the connection pin 23a on the lower surface side of the main substrate 10 is prevented from being broken. Accordingly, it is possible to prevent a problem that the audio IC 11 and the RCA jacks 22a and 22b cause a connection failure and cannot output audio to the outside.

  On the other hand, when the sub-board 20 is assembled to the main board 10, the strip-like solder bumps 21 a and 21 b are easy to insert because they guide the progress of the insertion portion 20 a in the slit 31. In particular, since solder does not generate a large frictional resistance, the insertion portion 20a can smoothly enter the slit 31. In addition, since the strip-shaped solder bumps 21a and 21b are formed, it is clear that the slit 31 should be positioned between the strip-shaped solder bumps 21a and 21b. Is possible.

(2) Second embodiment:
FIG. 5 shows the main board and the sub board according to the second embodiment of the present invention as seen obliquely. The main board 110 and the sub board 120 according to the present embodiment are housed in a substantially box-shaped video cabinet 150 indicated by a broken line in FIG. In this embodiment, the configuration is almost the same as in the first embodiment, but the sub-board 120 is further extended to the back of the video cabinet 150, and the insertion portion 120a is inserted into the slit 141 provided in the shield plate 140. I am letting.

  That is, the slit that supports the sub-board is not limited to that formed in the heat radiating plate, and may be a shield plate as in the present embodiment, for example. In particular, since the shield plate is formed of a metal having high electromagnetic shielding properties and has rigidity for supporting the sub-board, it is suitable as a support for the sub-board. In recent years, with the increase in the density and frequency of electronic devices and the combination of devices, shielding measures have become important as well as heat dissipation measures. Therefore, by effectively using such an essential member for fixing the substrate, a new member is not added only for fixing the substrate, and the cost can be reduced.

  FIG. 6 shows the sub-board 120 as viewed from the back. In the figure, the solder bumps formed in the form of two strips in the first embodiment are divided into seven small solder bumps 121a1 to 121a7 and 121b1 to 121b7, respectively. A solder resist mask 25 is interposed between the solder bumps 121a1 to 121a7 and 121b1 to 121b7. Other configurations are almost the same as those in the first embodiment.

  FIG. 7 shows the shield plate 140 as viewed from the back of the video cabinet 150. In the figure, each of the solder bumps 121b1 to 121b7 is formed in a substantially dome shape, and the height thereof is higher than that of the belt-like solder bump 21b of the first embodiment. Similarly, the solder bumps 121a1 to 121a7 formed on the opposite side of the shield plate 140 from the solder bumps 121b1 to 121b7 are also formed higher than the band-shaped solder bumps 21a of the first embodiment. Thus, by forming the solder bumps 121a1 to 121a7 and 121b1 to 121b7 high, the sub-board 120 can be reliably brought into contact with the periphery of the slit 141. Therefore, it is possible to reliably prevent the sub substrate 120 from moving in the thickness direction of the slit 141.

  The solder bumps 121a1 to 121a7 and 121b1 to 121b7 each have a smaller solder volume than the band-shaped solder bumps 21a and 21b in the first embodiment. That is, the surface area per solder volume increases. Accordingly, the surface tension in the curing process of the solder bumps 121a1 to 121a7 and 121b1 to 121b7 is larger than that of the belt-like solder bumps 21a and 21b, and the solder tends to aggregate more. Then, since the curing proceeds in a nearly spherical state, it becomes possible to form the solder bumps 121a1 to 121a7 and 121b1 to 121b7 high in height.

(3) Formation of solder bumps:
FIG. 8 schematically shows a process of forming solder bumps according to the present invention. The upper diagram shows a state where the sub-substrate pattern is formed. In this state, a copper wiring and a copper land 28 are formed on the epoxy base material 26, and a through hole 27 that penetrates the base material 26 is formed in the approximate center of each copper land 28. On the other hand, band-like lands 29a and 29b are formed independently of these. That is, the band-like lands 29a and 29b are floating lands that are not electrically connected to other portions.

  As described above, the band-like lands 29a and 29b are set as floating lands that are not electrically connected to other places, so that even when the band-like lands 29a and 29b are peeled off from the epoxy base material 26, the electric charges are generated. The possibility of causing defects is low. That is, although a load is applied to the band-shaped solder bumps 21a and 21b formed later, electrical defects can be prevented by setting the band-shaped lands 29a and 29b as floating lands.

  Various methods for forming a copper pattern such as a copper wiring, a copper land 28, or strip-like lands 29a and 29b on the substrate 26 can be adopted. Here, a resist-etching method will be described as an example. In the resist-etching method, a copper foil is applied to the entire surface of the base material 26 in which the through holes 27 are formed in advance, or a state in which copper plating is applied, and a photo-curable resist resin is laminated on the surface layer. Or applied. Then, predetermined light (for example, ultraviolet rays) is irradiated on the entire surface while pressing a photomask that is not shielded only on a portion where a pattern is to be formed on the photocurable resist resin. Then, since light is irradiated only to the part which wants to form a pattern, resist resin hardens | cures only a pattern part. Therefore, the resist resin other than the pattern portion is removed by a predetermined developer. Thereafter, the entire portion is immersed in an etching solution, so that portions other than the pattern portion from which the resist resin has been removed are exposed to the etching solution. Therefore, only copper other than the pattern portion is removed, and a desired copper pattern can be formed as shown in the upper part of FIG.

  Here, the difference in the pattern formation process is only the light-shielding pattern of the photomask depending on whether or not the band-like lands 29a and 29b for forming the solder bumps according to the present invention are patterned. That is, since no process change or addition is required, the cost for forming the strip lands 29a and 29b does not increase. Since the change of the light-shielding pattern of the photomask is a normal design change, this does not increase the cost.

  The middle part of FIG. 8 shows a state where the solder resist mask is formed on the sub-substrate 20. In the figure, the portions other than the copper lands 28 and the belt-like lands 29a and 29b (non-opening portions of the solder resist mask) are covered with a solder resist mask 25 made of a non-conductive resin. Various methods for forming the solder resist mask can be employed. Here, a pattern printing method will be described as an example. In the pattern printing method, an uncured liquid solder resist resin is transferred onto the sub-substrate by scanning a squeegee while pressing a print mask having an opening only on a portion where the solder resist mask 25 is to be coated on the sub-substrate in the upper stage state. And formation of the soldering resist mask 25 is completed by performing hardening processing of soldering resist resin, such as thermosetting and ultraviolet curing.

  Also in the formation of the solder resist mask described above, no additional process is required depending on whether or not the portions of the belt-like lands 29a and 29b are opened in addition to the normal portion of the copper lands 28. The only difference is the above-described print mask opening pattern, but this is also an ordinary design change, so that the cost is not particularly increased.

  The lower part of FIG. 8 schematically shows how solder bumps are formed on the sub-board. In the figure, molten solder 70 is placed in a solder bath. Then, by immersing the sub-board on which the solder resist mask has been formed in the molten solder 70, solder bumps are formed only on the portions where the solder resist mask 25 is opened. That is, due to the difference between the wettability of copper and the wettability of the solder resist mask 25, the solder is adsorbed only in the opening of the solder resist mask 25 where the copper is exposed. Therefore, no additional process is required by adding the strip-shaped solder bumps 21a and 21b in the solder formation of the sub-board. Of course, even if solder bump formation is performed by solder printing or solder plating, no additional process is required.

  As described above, no additional process is required when forming the solder bump according to the present invention. Therefore, it is possible to provide a substrate fixing mechanism capable of minimizing the cost.

1 is a perspective view of a main board and a sub board according to a first embodiment. It is a perspective view of the heat sink concerning a first embodiment. It is a rear view of the sub board | substrate concerning 1st embodiment. It is a rear view of the heat sink concerning 1st embodiment. It is a perspective view of the main board | substrate and sub board | substrate concerning 2nd embodiment. It is a rear view of the sub board | substrate concerning 2nd embodiment. It is a rear view of the shield board concerning 2nd embodiment. It is a schematic diagram which shows the formation process of a solder bump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,110 ... Main board | substrate 20,120 ... Sub board | substrate 50,150 ... Video cabinet 30 ... Heat sink 140 ... Shield plate 31,141 ... Slit 21a, 21b ... Strip-shaped solder bump 121a1-a7, 121b1-b7 ... Solder bump 25 ... Solder resist masks 22a, 22b ... RCA jack 70 ... molten solder

Claims (10)

A plate-like member that is erected and fixed on the main board, a plate-like member that is erected and fixed while being electrically connected to the main board, and the sub-board is held by the plate-like member In a video cabinet comprising a substrate holder,
The substrate holding portion is a slit substantially perpendicular to the main substrate formed downward from the upper end of the plate-like member to a predetermined height,
The sub-board is
An insertion part sandwiched in the thickness direction in the slit formed by extending only the part higher than the lower end of the slit to the back from the slit, and
An external connection terminal;
A floating land that is formed in two strips substantially parallel to the slit at a position sandwiching the slit from both outer sides in the thickness direction in the insertion portion, and is not electrically connected to other places,
A video cabinet comprising solder bumps formed on the floating land higher than a gap formed by the insertion portion and a wall surface of the slit. A plate-like member that is erected and fixed on the main board, a plate-like member that is erected and fixed while being electrically connected to the main board, and the sub-board is held by the plate-like member In a substrate fixing mechanism comprising a substrate holding part,
The substrate holding portion is a slit substantially perpendicular to the main substrate formed downward from the upper end of the plate-like member to a predetermined height,
The sub-board is
An insertion part sandwiched in the thickness direction in the slit formed by extending only the part higher than the lower end of the slit to the back from the slit, and
A land formed at a position adjacent to the slit and the thickness direction in the insertion portion;
A board fixing mechanism comprising a solder bump formed on the land.   The board fixing mechanism according to claim 2, wherein the plate-like member is a heat radiating plate.   The said heat sink is formed by the wide surface which each stands in the main board | substrate and cross | intersects substantially L-shape, and the narrow surface in which the said slit was formed, The Claim 3 characterized by the above-mentioned. Board fixing mechanism.   The substrate fixing mechanism according to claim 2, wherein the plate-like member is a shield plate.   The board fixing mechanism according to claim 2, wherein the sub-board includes an external connection terminal.   The substrate fixing mechanism according to claim 2, wherein the land is a floating land that is not electrically connected to another portion. 8. The land according to any one of claims 2 to 7, wherein the land is formed in two strips substantially parallel to the slit at a position sandwiching the slit from both outer sides in the thickness direction in the insertion portion. The board fixing mechanism according to the above.   9. The substrate fixing mechanism according to claim 8, wherein the lands are formed in a band shape divided by aligning a plurality of independent lands substantially parallel to the slits.   10. The board fixing mechanism according to claim 2, wherein the solder bump is formed higher than a gap formed by the insertion portion and a wall surface of the slit. 11.

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