JP2010027825A - Mounting substrate, mounting substrate set, panel unit, and method of manufacturing mounting substrate set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting substrate set that easily prevents a plurality of circuit elements from peeling from a mounting substrate, the mounting substrate suitable to the mounting substrate set, and a method of manufacturing the mounting substrate set. <P>SOLUTION: An FPC substrate 21 on which a circuit element 31 is mounted is fitted with a reinforcing sheet 11, which is shaped to enclose the periphery of a group 25GR of parts scheduled to be mounted as a set of a plurality of parts 25 scheduled to be mounted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mounting board on which various circuit elements can be mounted, a mounting board set in which the mounting board and various circuit elements are integrated, a panel unit that is a display panel connecting the mounting board sets, and a mounting board set It relates to the manufacturing method.

  In recent small electronic devices, for example, mobile tools such as mobile phones, flexible FPC (Flexible Printed Circuits) substrates are often used. Various circuit elements are mounted on such an FPC board (mounting board) via an adhesive. However, when a load is applied to an FPC board on which circuit elements are mounted (also referred to as a mounting board set st), the circuit elements are easily peeled off from the mounting board.

  For example, as shown in FIGS. 9A and 9B (a cross-sectional view taken along the line gg ′ in FIG. 9A), the load (stress) f is applied to the FPC board 121, so that the fillet 142 of the adhesive 141 is difficult to be formed. The corners of the circuit element 131 may be peeled off from the mounting surface 121U of the FPC board 121.

As such a countermeasure, it is conceivable to surround the circuit element 131 with a reinforcing sheet. For example, as shown in the cross-sectional view of FIG. 10, it is conceivable that the circuit element 131 (particularly, the integrated circuit 131 </ b> A) is surrounded by a reinforcing sheet 111. In particular, as shown in the plan view of FIG. 11, it is preferable that the reinforcing sheet 111 surrounds the corner of the IC 131 </ b> A (see Patent Document 1).
JP 2007-109904 A

  However, in the case of such a reinforcing sheet 111, the following problems occur. That is, as shown in the plan view of FIG. 12, when a plurality of ICs 131A are mounted on the FPC board 121, the number of reinforcing sheets 111 surrounding the IC 131A is required to be the same as the number of ICs 131A. 12, the adhesive 141 is omitted for the sake of convenience, and the member number 131B indicates a discrete component). In short, when a relatively large number of ICs 131A are mounted on the FPC board 121, the number of reinforcing sheets 111 is also large, and the cost increases.

  Moreover, the manufacturing process of the FPC board 121 (mounting board set st) to which such a plurality of reinforcing sheets 111 are attached is troublesome. Usually, the FPC board 121 is formed from a single sheet (substrate base sheet) 129 as shown in FIG. More specifically, the FPC board 121 is formed by dividing the substrate base sheet 129 having an area of a plurality of FPC boards 121.

  And on this board | substrate base material sheet | seat 129, the board | substrate scheduled part 126 by which formation of the FPC board | substrate 121 is planned is formed in matrix arrangement | positioning first. Furthermore, a plurality of scheduled mounting portions 125 where the circuit elements 131 are scheduled to be mounted are formed for each planned substrate portion 126 (note that a member number 123 near the planned mounting portion 125 indicates a supply wiring through which a current flows). .

  Thereafter, by cutting out the planned substrate portion 126 from the substrate base sheet 129, an FPC board 121 as shown in FIG. 14 is generated. Further, as shown in FIG. An element 131 is mounted. Thereafter, the reinforcing sheet 111 designed for each IC 131A is individually attached (see FIG. 12). Therefore, the number of steps of attaching the reinforcing sheet 111 is the same as the number of ICs 131A (in the case of the mounting board set st shown in FIG. 12, two steps of attaching the reinforcing sheet 111 are required).

  The present invention has been made in view of the above situation. An object of the present invention is to provide a mounting board set that can easily and inexpensively prevent a plurality of circuit elements from being peeled from the mounting board, a mounting board suitable for the mounting board set, and a method for manufacturing the mounting board set. There is to do.

  Various circuit elements are scheduled to be mounted on the mounting board. A reinforcing sheet that reinforces the mounting substrate is attached to such a mounting substrate. More specifically, when a part of the mounting substrate on which the circuit element is scheduled to be mounted is set as the mounting target part, the reinforcing sheet has a surrounding shape surrounding the periphery of the mounting target part group which is a group of a plurality of mounting target parts.

  With this configuration, the reinforcing sheet surrounds the mounting-scheduled part group, so that a partial region of the mounting board that overlaps the mounting-scheduled part group is not excessively bent. For this reason, the plurality of circuit elements to be mounted on the partial region are unlikely to be separated from the mounting substrate. That is, this reinforcing sheet makes it difficult to separate a plurality of circuit elements from the mounting substrate at a time.

  The reinforcing sheet is preferably attached to the mounting surface.

  For example, when the reinforcing sheet is attached to the non-mounting surface on the back side of the mounting surface instead of the mounting surface, the thickness of the mounting substrate set composed of the circuit element and the mounting substrate is the thickness of the circuit element, the thickness of the mounting substrate, and the reinforcing sheet. This is the total thickness. On the other hand, when the reinforcing sheet is attached to the mounting surface, the thickness of the mounting substrate set becomes the total value of the thickness of the circuit element by the amount exceeding the thickness of the mounting substrate, the thickness of the reinforcing sheet, and the thickness of the reinforcing sheet.

  Then, if the thickness of the circuit element mounted on the mounting surface is the same, and the reinforcing sheet is attached to the mounting surface, the thickness of the mounting board set is the thickness of the mounting board set with the reinforcing sheet attached to the non-mounting surface. Thinner. That is, the mounting board set is easily thinned.

Moreover, it is desirable that the mounting board satisfies the following conditional expression (1).
H1 ≧ T Conditional expression (1)
However,
H1: A circuit element to be mounted on the part to be mounted, having the highest height from the mounting surface
The thickness of the circuit element.
T: Thickness of the reinforcing sheet.

  In this case, the thickness of the mounting board set is a total value of the thickness of the mounting board and the thickness of the circuit element. Therefore, the thickness of the mounting board set does not increase by attaching the reinforcing sheet to the mounting board.

  An example of the thickness T of the reinforcing sheet is 200 μm or less.

  In addition, it is desirable that a part of the outer edge of the reinforcing sheet reaches and overlaps with a part of the outer edge of the mounting surface, and the inner edge of the reinforcing sheet surrounds the periphery of the mounting planned portion group.

  If it becomes like this, a reinforcement sheet will become a comparatively wide area, and it will become difficult to bend a mounting board | substrate also resulting from it.

  It should be noted that a mounting board set including the above mounting board and circuit elements mounted on the mounting board can also be said to be the present invention. A panel unit including the mounting substrate set and a liquid crystal display panel connected to the mounting substrate set can also be said to be the present invention.

  By the way, the manufacturing method of a mounting substrate set includes the following substrate base sheet processing steps, reinforcing base sheet processing steps, sheet unit forming steps, cutout steps, and mounting steps.

  In the substrate base sheet processing step, a plurality of planned substrate portions on which the mounting substrate is planned to be formed are formed on the substrate base sheet that is the base material of the mounting substrate, and circuit elements are mounted on the planned substrate portion. A plurality of planned mounting portions are formed.

  In the reinforcing base sheet processing step, a plurality of openings are formed on the reinforcing base sheet, which is a base material of the reinforcing sheet that reinforces the mounting substrate, so as to overlap a mounting planned portion group that is a collection of a plurality of mounting planned portions. .

  In the sheet unit forming step, the reinforcing base sheet is attached to the substrate base sheet by exposing the mounting planned portion group from the opening and overlapping the edge of the sheet on the planned substrate portion.

  In the cut-out process, the planned substrate portion is cut out from the sheet unit composed of the substrate base sheet and the reinforcing base sheet, and is extracted as a mounting substrate.

  In the mounting process, a mounting substrate set is formed by mounting circuit elements on the mounting scheduled portion.

  In the mounting board set manufacturing method as described above, the reinforcing sheets in the plurality of mounting board sets are collectively attached to the mounting boards. Therefore, the process of attaching the reinforcing sheet to the mounting board can be reduced.

  Further, when the mounting process is performed after the sheet unit forming process, the thickness of the reinforcing sheet is 200 μm or less, and in the mounting process, cream solder is provided through a mask having a larger area than the reinforcing sheet and including an aperture pattern. It is desirable to adhere to the mounting substrate.

  Alternatively, the substrate base sheet processing step and the mounting step may be performed before the sheet unit forming step, instead of performing the mounting step after the cutting step.

  According to the present invention, only one reinforcing sheet is attached to one mounting board, and even if a plurality of circuit elements are mounted on the mounting board, the circuit elements do not easily peel from the mounting surface. That is, the circuit element does not peel from the mounting surface due to the presence of one relatively inexpensive reinforcing sheet that can be easily attached to one mounting substrate.

[Embodiment 1]
The following describes one embodiment with reference to the drawings. For convenience, hatching, member codes, and the like may be omitted, but in such a case, other drawings are referred to. Conversely, even a plan view or the like may be hatched.

  The perspective view of FIG. 1 and the two views of FIG. 2 (plan view and sectional view taken along line AA ′ in the plan view) show a liquid crystal display panel PL built in an electronic device such as a mobile phone, A mounting substrate set ST connected to the liquid crystal display panel PL is shown (a liquid crystal display panel PL and the mounting substrate set ST are integrated with each other is referred to as a panel unit PU). The mounting board set ST includes an FPC (Flexible Printed Circuits) board 21, various circuit elements 31 (31 </ b> A and 31 </ b> B) mounted on the FPC board 21, and the reinforcing sheet 11.

  The FPC board (mounting board) 21 has flexibility as shown in FIG. Therefore, when the liquid crystal display panel PL is mounted on an electronic device, the FPC board 21 is relatively freely deformed even inside a narrow electronic device.

  As shown in the cross-sectional view of FIG. 2, the FPC board 21 includes a supply wiring 23 for supplying a current from a power source (not shown) to the circuit element. For example, a solder resist film and a coverlay film are used as protective films on both surfaces of the FPC board 21 (the mounting surface 21U on which the circuit element 31 is mounted and the non-mounting surface 21B which is the back side surface of the mounting surface 21U). However, it may be omitted from the drawings for convenience.

  Examples of the circuit element 31 include an IC (Integrated Circuit) 31A and a discrete component 31B (CR elements such as resistors and capacitors). These circuit elements 31 are configured as follows in order to receive a current supply. That is, as shown in the cross-sectional view of FIG. 2, the bump 32 of the IC 31A and the electrode 33 of the discrete component 31B are connected to the supply line 23 of the FPC board 21 (specifically, a pad that is one end of the supply line 23). .

  The adhesive 41 used for mounting these circuit elements 31 is, for example, ACF (Anisotropic Conductive Film), NCF (Non Conductive Film), or cream solder. A connector 51 required for electrical connection to various devices is also mounted on the FPC board 21.

  Here, the reinforcing sheet 11 attached to the FPC board 21 will be described in detail. The reinforcing sheet 11 is attached to the FPC board 21 to prevent excessive bending of the FPC board 21 and to prevent the various circuit elements 31 from peeling from the mounting surface 21U. In particular, the reinforcing sheet 11 prevents peeling of the corners of the circuit element 31 (for example, the four corners of the rectangular IC 31A) and the FPC board 21. That is, the reinforcing sheet 11 does not generate a bend that separates the FPC board 21 from the circuit element 31.

  For this reason, the reinforcing sheet 11 formed of a resin such as polyimide is as follows. That is, the reinforcing sheet 11 has a surrounding shape that surrounds the plurality of circuit elements 31 on the mounting surface 21U, for example, an annular shape.

  The mounting board 21 to which the reinforcing sheet 11 is attached is as follows. That is, as shown in the plan view of FIG. 3 showing the FPC board 21 from which the reinforcing sheet 11 and the circuit elements 31 have been removed, the planned mounting portion 25 (detailed description), which is a part where the circuit elements 31 are scheduled to be mounted on the FPC board 21. Then, there are a large number of planned mounting portions 25) that are a part of the mounting surface 21U. These mounting planned portions 25 are positioned so as to be relatively dense, and form a group (a region where the mounting planned portions 25 gather; a mounting planned portion group 25GR).

  This mounting planned portion group 25GR is located inside the outer edge Lo21 of the mounting surface 21U. Therefore, the outer edge Lo25 of the planned mounting portion group 25GR is separated from the outer edge Lo21 of the mounting surface 21U. Then, on the mounting surface 21U, an area excluding the scheduled mounting part group 25GR, for example, an annular area RA is generated. If the annular region RA becomes relatively hard so that it is less likely to bend than the planned mounting portion group 25GR, the planned mounting portion group 25GR is less likely to bend excessively.

  Therefore, as shown in FIG. 4, the reinforcing sheet 11 is attached so as to overlap the annular region RA on the mounting surface 21 </ b> U (this attachment is not particularly limited, for example, pasting using an adhesive or the like). It does not matter.)

  In this case, as shown in FIG. 1, even if the circuit element 31 is mounted on the mounting portion 25 of the mounting surface 21U and the FPC board 21 is further bent, the circuit element 31 on the mounting surface 21U. The mounting planned portion group 25GR, which is a region where the two are gathered, does not bend excessively. Therefore, the reinforcing sheet 11 prevents the circuit element 31 and the FPC board 21 from peeling off due to excessive bending of the FPC board 21.

  Since the size of the IC 31A is larger than the size of the discrete component 31B, the IC 31A is more susceptible to excessive deflection of the FPC board 21 than the discrete component 31B. That is, the corner of the IC 31A (the portion where the fillet of the adhesive 41 is not generated) is more easily peeled from the FPC board 21 than the corner of the discrete component 31B.

  However, the reinforcing sheet 11 reinforces the FPC board 21 so as to surround the IC 31A and the discrete component 31B. Therefore, both the circuit elements 31A and 31B are difficult to peel off from the FPC board 21 (in short, the entire mounting board set ST is reinforced by the reinforcing sheet 11).

  In other words, even if the reinforcing sheet 11 does not individually surround each specific circuit element 31 (for example, even if the two ICs 31A are not individually surrounded), the reinforcement sheet 11 can prevent the circuit elements 31 from being separated from the FPC board 21. To prevent. In short, the reinforcing sheet 11 prevents a plurality of circuit elements 31 from peeling from the FPC board 21 at a time. Therefore, the attachment of the reinforcing sheet 11 to the mounting surface 21U is simpler than, for example, a case where the reinforcing sheet is individually attached to each circuit element 31.

  Incidentally, the reinforcing sheet 11 is usually attached to the mounting surface 21U, but may be attached to the non-mounting surface 21B. However, when the reinforcing sheet 11 is attached to the non-mounting surface 21B, the thickness of the mounting substrate set ST is highest from the mounting surface 21U in the FPC substrate 21 thickness D and the circuit element 31 mounted on the mounting planned portion 25. This is the total value of the thickness H1 of the circuit element 31 having the height and the thickness T of the reinforcing sheet (note that the height H1 of the circuit element 31 is about 400 μm).

  On the other hand, when the reinforcing sheet 11 is attached to the mounting surface 21U, as shown in the sectional view of FIG. 2, the thickness of the mounting board set ST is the thickness D of the FPC board 21 and the thickness H1 of the circuit element 31 (however, the reinforcing sheet When the thickness T is equal to or less than the height H1, the total value of H1 ≧ T (conditional expression (1)) is obtained.

  That is, if the thickness of the circuit element 31 mounted on the mounting surface 21U is the same, if the reinforcing sheet 11 is attached to the mounting surface 21U, the thickness of the mounting board set ST is such that the reinforcing sheet 11 is applied to the non-mounting surface 21B. It becomes thinner than the thickness of the mounted substrate set ST. Therefore, in order to reduce the thickness of the mounting board set ST, it is desirable that the reinforcing sheet 11 is attached (for example, pasted) to the mounting surface 21U.

  Note that an adhesive 41 such as cream solder is often used for mounting the discrete component 31B. When the cream solder 41C is used, for example, as shown in FIG. 5, the mounting surface 21U of the FPC board 21 to which the reinforcing sheet 11 is attached is covered with a mask 54 having an opening pattern 53 (see dotted arrows). ). The cream solder 41 </ b> C placed on the mask 54 is pressed against the mask 54 using the squeegee 55 and adheres to the mounting surface 21 </ b> U through the hole pattern 53.

  Then, in mounting such discrete components 31B, it is desirable that the thickness T of the reinforcing sheet 11 be as thin as possible. This is because, if the thickness T of the reinforcing sheet 11 is excessively long, an appropriate amount of cream solder 41C does not adhere to the mounting surface 21U through the opening pattern 53 due to the squeegee 55 being pressed against the mask 54. Therefore, the thickness T of the reinforcing sheet 11 is desirably 200 μm or less (because the height H1 of the circuit element 31 such as the IC 31A is approximately 400 μm, and thus is preferably lower).

  In this case, even if the squeegee 55 further overlaps the mask 54 that overlaps the reinforcing sheet 11, the pressure applied by the squeegee 55 is appropriately applied to the mask 54 near the aperture pattern 53, and an appropriate amount of pressure is applied. The cream solder 41C adheres to the mounting surface through the opening pattern 53.

  Further, as shown in the plan view of FIG. 2 and the plan view of FIG. 4, a part of the outer edge Lo11 of the reinforcing sheet 11 reaches and overlaps with a part of the outer edge Lo21 of the mounting surface 21U to overlap the inner edge of the reinforcing sheet 11. Li11 desirably surrounds the periphery of the mounting-scheduled part group 25GR.

  If it becomes like this, the area of the reinforcement sheet 11 will cover the mounting surface 21U comparatively widely, enclosing the circumference | surroundings of the mounting plan part group 25GR. Therefore, the reinforcing sheet 11 can reliably prevent excessive bending of the FPC board 21.

  Note that the reinforcing sheet 11 does not overlap a portion that requires relatively high flexibility, for example, the portion AA1 connected to the liquid crystal display panel PL on the FPC board 21 and the portion AA2 near the connector 51. Therefore, the FPC board 21 can be wound around the liquid crystal display panel PE or the vicinity of the connector 51 can be bent.

  Here, the manufacturing method of the mounting board set ST as described above will be described in detail with reference to FIGS. 6 to 8, 4, and 2.

  First, as shown in FIG. 6, the FPC board 21 is formed from a single sheet (substrate base sheet) 29 such as polyimide or PET (polyethylene terephthalate). More specifically, the FPC board 21 is formed by dividing the substrate base sheet 29 having an area equivalent to the plurality of FPC boards 21.

  The substrate base sheet 29 is first formed with a planned substrate portion 26 on which the FPC board 21 is to be formed, for example, in a matrix arrangement (in short, the substrate base sheet 29 has a plurality of predetermined substrate portions). 26). Furthermore, a plurality of scheduled mounting portions 25 where the circuit elements 31 are scheduled to be mounted are formed for each planned substrate portion 26 (these steps are referred to as substrate base sheet processing steps).

  Next, the reinforcing sheet 11 will be described. As shown in FIG. 7, the reinforcing sheet 11 is also formed from a single sheet (reinforcing base sheet) 19 such as polyimide. However, as shown in FIG. 7, a plurality of openings HL <b> 1 are formed in the reinforcing base sheet 19 so as to overlap with the planned mounting portion group 25 </ b> GR that is a region where the plurality of planned mounting portions 25 gather. If the mounting planned part group 25GR is in a matrix arrangement on the substrate base material sheet 29, these openings HL1 are also arranged in a matrix).

  More specifically, the reinforcing base sheet 19 has an area equivalent to a plurality of reinforcing sheets 11, and a plurality of openings HL 1 having a slightly larger area than the outer edge of the mounting-scheduled portion group 25 GR are formed in the reinforcing base sheet 19. (Note that the step of forming the opening HL1 with respect to the reinforcing base sheet 19 is referred to as a reinforcing base sheet processing step).

  Further, a sheet edge LS that is a part of the outer edge Lo11 of the reinforcing sheet 11 is formed around the opening HL1 so as to overlap the planned substrate portion 26. For example, another opening (auxiliary opening) HL2 is formed between the lengths of the opening HL1 in the reinforcing base sheet 19, and the edge (sheet edge LS) facing the length of the opening HL1 is reinforced in the auxiliary opening HL2. A part of the outer edge Lo11 of the sheet 11 is used (a step of forming a part of the outer edge of the reinforcing sheet 11 with respect to the reinforcing base sheet 19 is also referred to as a reinforcing base sheet processing step).

  Next, as shown in FIG. 8 (in FIG. 8, for the sake of convenience, overlapping of each line is avoided), the reinforcing base sheet 19 is attached to the substrate base sheet 29. The integrated substrate base sheet 29 and the reinforcing base sheet 19 after attachment are referred to as a sheet unit SU.

  In addition, the attachment method of the reinforcement base material sheet 19 with respect to the board | substrate base material sheet 29 is not specifically limited, Affixing using an adhesive agent etc. is mentioned as an example. However, the reinforcing base sheet 19 is attached to the board base sheet 29 with the sheet edge (sheet edge) LS overlapped with the board planned part 26 while the mounting planned part group 25GR is exposed from the opening HL1 (this The process is referred to as a sheet unit forming process). Then, the sheet edge LS is a part of the outer edge Lo21 of the mounting surface 21U (that is, overlaps a part of the outer edge of the planned board portion 26).

  Then, the board | substrate scheduled part 26 is cut out from the sheet unit SU which consists of the board | substrate base material sheet 29 and the reinforcement base material sheet 19, and the FPC board | substrate 21 is extracted (this process is called a cutting process). As a result, an FPC board 21 as shown in FIG. 4 is formed. Then, the circuit element 31 is mounted on the mounting scheduled portion 25 of the FPC board 21 (this process is referred to as a mounting process). Then, a mounting board set ST as shown in FIG. 2 is formed.

  In manufacturing the mounting substrate set ST as described above, the reinforcing base sheet 19 is placed on the substrate base sheet 29, so that one reinforcing sheet 11 is attached to each of the plurality of mounting substrates 21 at a time. . Therefore, the trouble of attaching one reinforcing sheet 11 to each mounting board 21 is eliminated. As a result, the manufacturing efficiency of the mounting board set ST is improved (in short, the process of attaching the reinforcing sheet 11 to the FPC board 21 can be reduced).

  Further, the reinforcing sheet 11 surrounds the collected circuit elements 31 (in other words, the mounting planned part group 25GR), and does not surround the individual circuit elements 31. Therefore, the manufacture of the mounting board set ST as described above does not include, for example, a plurality of steps of attaching a reinforcing sheet that individually surrounds the plurality of circuit elements 31. Therefore, it can be said that the manufacturing method of this mounting board set ST has extremely high manufacturing efficiency.

  In the case where the mounting process is performed after the sheet unit forming process and after the cutting process, as shown in detail, as shown in FIG. 5, the mask has a larger area than the outer shape of the reinforcing sheet 11 and includes the opening pattern 53. In the case where the cream solder 41C is attached to the FPC board 21 through the circuit board 54 and the circuit element 31 is mounted, the thickness T of the reinforcing sheet 11 is preferably 200 μm or less.

  If this is the case, as described above, an appropriate amount of cream solder 41C adheres to the mounting surface through the hole pattern 53, and the circuit element 31 is appropriately mounted.

  Moreover, a mounting process may be performed after a sheet unit formation process, and a cutting process may be performed after that. For example, the cream solder 41C is attached to the substrate base material sheet 29 (and thus the FPC substrate 21) through the mask 54 having a larger area than the outer shape of the reinforcing sheet 11 that overlaps the outer shape of the planned substrate portion 26 and including the opening pattern 53. The circuit element 31 is mounted. In such a case, the thickness T of the reinforcing sheet 11 is preferably 200 μm or less.

  This is because if this is the case, an appropriate amount of cream solder 41C adheres to the mounting surface through the opening pattern 53 in the same manner as when the mounting process is performed after the sheet unit forming process and after the cutting process. This is because the circuit element 31 is appropriately mounted.

  However, the substrate base sheet processing step and the mounting step may be performed before the sheet unit forming step. In this case, the circuit element 31 is mounted on the FPC board 21 to which the reinforcing sheet 11 is not attached.

  For this reason, since the thickness T of the reinforcing sheet 11 is excessively large, a situation in which an appropriate amount of the cream solder 41C does not adhere to the mounting surface 21U through the opening pattern 53 due to the squeegee 55 being pressed against the mask 54 does not occur.

[Other embodiments]
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, the shape of the reinforcing sheet 11 is a series and annulus, but it is not essential to be a series. In short, it is only necessary to prevent a part of the mounting substrate 21 in which the circuit elements 31 are densely packed (the planned mounting portion group 25GR) from being excessively bent. More specifically, the shape of the reinforcing sheet 11 is not particularly limited as long as the reinforcing sheet 11 does not transmit the load applied to the mounting substrate 21 to the planned mounting portion group 25GR.

  In the above description, the liquid crystal display panel PL is described as the display panel included in the panel unit PU, but the present invention is not limited to this. For example, it may be an organic EL (electroluminescence) panel or a plasma panel.

FIG. 4 is a perspective view showing a mounting board set attached to a liquid crystal display panel. These are 2 views which write together the top view which shows the mounting substrate set attached to the liquid crystal display panel, and A-A 'arrow sectional drawing in the top view. These are top views which show a mounting substrate. These are top views which show the mounting board | substrate with which the reinforcement sheet | seat was attached. FIG. 5 is a perspective view showing a squeegee and a mask for attaching cream solder to a mounting substrate to which a reinforcing sheet is attached. These are top views of a substrate base sheet. These are top views of a reinforcement base material sheet. These are top views which show the state which affixed the reinforcement base material sheet on the board | substrate base material sheet. (A) is a perspective view showing a conventional circuit element and an FPC board, and (B) is a cross-sectional view taken along the line g-g ′ in (A). These are sectional drawings which show the conventional circuit element and FPC board. These are top views which show the conventional circuit element and FPC board. These are top views which show the conventional mounting board set which attached the reinforcement sheet | seat corresponding to every IC. These are the top views of the board | substrate base material sheet | seat used as the base material of a mounting board | substrate. These are top views which show the mounting substrate produced by punching from a board | substrate base material sheet. These are top views which show the mounting board | substrate (mounting board set) which mounted the circuit element.

Explanation of symbols

11 Reinforcement sheet Lo11 Reinforcement sheet outer edge LS Sheet edge (sheet edge)
Li11 Inner edge of reinforcing sheet 19 Reinforcing base sheet HL1 Opening HL2 Auxiliary opening 21 FPC board (mounting board)
21U mounting surface Lo21 outer edge of mounting surface RA annular region 21B non-mounting surface 23 supply wiring 25 mounting planned portion 25GR mounting planned portion group Lo25 outer edge of mounting planned portion group 26 substrate planned portion 29 substrate base sheet SU sheet unit 31 circuit element 31A IC (circuit element)
31B Discrete parts (circuit elements)
32 IC bump 33 Discrete component electrode 41 Adhesive 41C Cream solder (adhesive)
51 Connector 53 Opening Pattern 54 Mask 55 Squeegee ST Mounting Board Set PL Liquid Crystal Display Panel (Display Panel)
PU panel unit D thickness of FPC board T thickness of reinforcing sheet H1 thickness of circuit element having the highest height among a plurality of circuit elements

Claims (10)

In a mounting board on which circuit elements are mounted,
The reinforcing sheet for reinforcing the mounting board is attached to the mounting board,
When a part of the mounting board on which the circuit element is scheduled to be mounted is a mounting target part,
The mounting board is a mounting board having a surrounding shape surrounding a mounting scheduled portion group that is a group of a plurality of mounting planned portions.   The mounting board according to claim 1, wherein the reinforcing sheet is attached to the mounting surface. The mounting substrate according to claim 2, wherein the following conditional expression (1) is satisfied.
H1 ≧ T Conditional expression (1)
However,
H1: The highest height from the mounting surface in the circuit element mounted on the planned mounting portion.
The thickness of the circuit element having
T: The thickness of the reinforcing sheet.   The mounting board according to claim 3, wherein a thickness T of the reinforcing sheet is 200 μm or less. A part of the outer edge of the reinforcing sheet reaches and overlaps a part of the outer edge of the mounting surface,
The mounting board according to any one of claims 2 to 4, wherein an inner edge of the reinforcing sheet surrounds the periphery of the planned mounting portion group. The mounting substrate according to any one of claims 1 to 5,
A circuit element mounted on the mounting board;
Mounting board set including The mounting board set according to claim 6;
A liquid crystal display panel connected to the mounting board set;
Including panel unit. A plurality of planned substrate portions on which the mounting substrate is to be formed are formed on a substrate substrate sheet that is a base material of the mounting substrate, and the circuit element is scheduled to be mounted on the planned substrate portion. Forming a plurality of substrate base sheet processing steps,
A reinforcing base sheet processing step for forming a plurality of openings so as to overlap a mounting base portion group that is a collection of a plurality of the mounting base portions on a reinforcing base material sheet that is a base material of a reinforcing sheet that reinforces the mounting substrate. ,
A sheet unit forming step of attaching the reinforcing base sheet to the substrate base sheet, with the edge of the sheet overlapped with the base substrate portion while exposing the mounting planned portion group from the opening,
From the sheet unit consisting of the substrate base sheet and the reinforcing base sheet, a cut-out process of cutting out the substrate planned portion and extracting the mounting substrate,
A mounting step of mounting the circuit element on the planned mounting portion to form a mounting board set;
A mounting substrate set manufacturing method including: When performing the mounting step after the sheet unit forming step,
The thickness of the reinforcing sheet is 200 μm or less,
9. The mounting board set manufacturing method according to claim 8, wherein in the mounting step, cream solder is attached to the mounting board through a mask having a larger area than the reinforcing sheet and including an opening pattern.   The manufacturing method of the mounting substrate set according to claim 9, wherein the substrate base sheet processing step and the mounting step are performed before the sheet unit forming step.

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