JP2007059528A - Hybrid multilayered circuit board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid multilayered circuit board where an unnecessary part of an outer layer material can easily be removed, and to provide the manufacturing method of the board. <P>SOLUTION: The hybrid multilayered circuit board has a cable Q projected from multilayered component mounting parts P. The hybrid multilayered circuit board is formed by removing the unnecessary part of the outer layer material 101. A material is used as the outer layer material with such characteristic that smaller stress is required in the outer layer material when it is torn, than tearing strength of the outer layer material of the multilayered component mounting part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hybrid multilayer circuit board and a method for manufacturing the same, and more particularly to a hybrid multilayer circuit board configured by a multilayer portion on which components are mounted and a cable portion connected to the multilayer portion, and a method for manufacturing the same.

  As this type of hybrid multilayer circuit board, there are a rigid flex circuit board in which a rigid circuit board is bonded to both sides of a flexible circuit board, or a multilayer flexible circuit board in which a plurality of flexible circuit boards are bonded together.

  As a method for manufacturing a multilayer flexible circuit board, a single-sided film-based metal foil laminate, which is an outer layer material, is laminated on the component mounting part of the flexible circuit board that is the inner layer material via an adhesive and the cable part without an adhesive. In some cases, the outer layer material of the cable portion is removed after a predetermined treatment.

  Accordingly, it is possible to provide a hybrid multilayer circuit board that can be bent at the cable portion and three-dimensionally arranged to be compact. In addition, since the outer layer material is removed after a predetermined process (drilling, plating, outer layer pattern formation), it is possible to perform the process in a state where the inner layer part is protected by the outer layer.

  Patent document 1 shows one of the manufacturing methods. In this method, a separation groove or a through hole is provided at a boundary portion between a hard portion to be mounted with a component and an unnecessary portion of the outer layer material.

However, grooving requires strict depth accuracy, making it difficult to work, and even when a through hole is provided, it is necessary to place the punching boundary part of the adhesive member in the immediate position of the through hole, and the position during lamination The alignment accuracy is strict and workability is poor. Moreover, in order to easily peel off unnecessary portions of the outer layer material while preventing intrusion of the processing liquid from the separation grooves and the transparent holes, it is necessary to achieve severe processing accuracy.
JP-A-64-7697 Japanese Patent Laid-Open No. 5-13958 JP-A-5-90756

  In order to solve such a problem, for example, Patent Document 2 discloses that a part where the adhesive member is punched is filled with a releasable reinforcing material. However, the work of fitting the releasable replenishment material and the removal piece is complicated.

  Patent Document 3 discloses a method of laser processing a separation groove. However, laser processing has a problem of increasing the number of steps.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a hybrid multilayer circuit board that can easily remove unnecessary portions of the outer layer material and a method for manufacturing the same.

In order to achieve the above object, in the present invention,
In a hybrid multilayer circuit board in which at least one cable portion protrudes from a multilayer component mounting portion obtained by laminating an outer layer material made of a film-based metal foil laminate on an inner layer material, the outer layer material has a peeling strength. A multilayer multilayer circuit board characterized in that the stress when tearing the film of the outer layer material is smaller than the outer layer material, and an outer layer material made of a film-based metal foil laminate is laminated on the inner layer material. In the manufacturing method of a hybrid multilayer circuit board for manufacturing a multilayer circuit board in which at least one cable part protrudes from the multilayer component mounting part by removing unnecessary portions, stress at the time of tearing than the peel strength Laminating an outer layer material having a small thickness on the inner layer material, and tearing the outer layer material at a boundary portion between the multilayer component mounting portion and the cable portion A method for producing a hybrid multilayer circuit board, wherein unnecessary portions are removed,
Is to provide.

  Here, examples of the inner layer material include a single-sided flexible circuit board, a double-sided flexible circuit board, a multilayer flexible circuit board, and a rigid flex circuit board. The film base metal foil laminate is formed by laminating a resin film and a metal foil. Examples of the resin film include polyimide resin, polyester resin, polysulfone resin, etc. Various metals having excellent properties can be used, but copper foil is usually used.

  As described above, the present invention uses an outer layer material whose stress at the time of tearing is smaller than the peel strength of the outer layer material of the multilayer component mounting portion. Therefore, a special groove such as a separation groove or laser processing is used. An unnecessary part of the outer layer material can be removed by a simple process without requiring a process.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1

  FIGS. 1A to 1D are a plan view showing a configuration of each layer material for manufacturing a hybrid multilayer circuit board according to the present invention, and a front view showing a state in which they are laminated.

  First, FIG. 1A shows a planar shape of a single-sided film base metal foil laminate 101 as an outer layer material in the laminate 100. The outer layer material 101 has a rectangular overall shape, and the contour positions of the two component mounting portions P and the cable portion Q connecting these component mounting portions P are indicated by imaginary lines on the left and right sides thereof.

  Next, FIG. 1B shows a planar shape of the adhesive member 102 disposed between the outer layer material 101 and the inner layer material 103 (inner layer circuit board). The adhesive member 102 is disposed in a part corresponding to the component mounting part P and the discard part R that holds the substrate until the component mounting, but is not provided in the cable part Q and the vicinity thereof. Therefore, the cable portion Q and the vicinity thereof are notches 102A.

  Next, FIG. 1C shows the planar shape of the inner layer material 103. The inner layer material 103 constitutes the circuit 103P of the component mounting portion and the cable portion 103Q that connects the circuits. Therefore, a cutout 103 </ b> A is formed in the cable portion Q and its vicinity in the same manner as the adhesive member 102. However, in order to prevent the cable portion Q from drooping, a connection portion BB that connects a part of the cable portion Q and the discard portion R is provided.

  FIG. 1 (d) shows the laminated plate 100 formed by laminating the outer layer material 101, the adhesive member 102, and the inner layer material 103 shown in FIGS. 1 (a) to (c) from the side of the central portion in the longitudinal direction. FIG.

  As shown in FIG. 1 (d), in the illustrated central portion of the hybrid multilayer circuit board, there is a space between the inner layer material 103 and the outer layer material 101 at the upper and lower positions in the drawing, the outer layer material 101 and the inner layer material 103. And are not fixed to each other.

  2 (a) to 2 (c), the predetermined process (plating, outer layer pattern formation, etc.) is applied to the laminated board formed through the process of FIG. 1, and the exposure process is completed from the state immediately before the cable portion is exposed. It is the top view which showed until after.

  First, in FIG. 2 (a), since the processing for removing the outer layer material 101, which is not shown in FIG. 1 (c), is performed, the detailed shape is different from that in FIG. 1 (c). First, the outer layer material 101 is composed of a component mounting part 101P, a cable part 101Q, and a discarding part 101R. The component mounting part 101P and the cable 101Q are continuous, but the discarding part 101R is a connecting part (breaking part) BB. Is only connected in several places.

  The illustrated area A indicates a boundary portion between the component mounting portion P and the cable portion Q, and both are separated by a fracture portion (connection portion) AA. In the illustrated region B, a connection portion BB that connects the component mounting portion P or the cable portion Q and the discard portion R is provided. The illustrated region C is provided in the center portion of the cable portion Q, and the outer layer material 101Q corresponding to the cable portion Q is torn at the break portion CC and broken to the left and right sides in the drawing.

  That is, the outer layer material 101Q is sequentially cut by the three broken portions (connection portions) AA, BB, and CC. And the fracture | rupture part (connection part) CC protrudes in the width direction so that it may become a finger hook for peeling off the outer layer material 101Q, and also a partial cut is provided so that it may become a cut | interruption in the center part of a longitudinal direction. ing.

  FIG. 2B shows a state where the outer layer material 101Q is removed from the cable portion Q. In this operation, a finger tip is applied to a partial cut of the fracture portion CC, the outer layer material 101Q is turned up while being turned up, and then the outer layer material 101Q is pulled up in the horizontal direction in the drawing. When the fractured portion AA is reached, the outer layer material 101Q is pulled strongly to separate the outer layer material 101Q of the cable portion Q from the outer layer material 101P of the component mounting portion P along the fractured portion AA.

  FIG. 2C shows a state where the outer layer material 101Q of the cable portion Q is removed. By removing the outer layer material 101Q, the cable portion 103Q is exposed.

  FIGS. 3 (a) to 3 (c) show examples of the structures of the fracture portions AA, BB and CC, all of which make it easy to tear using the strength of the metal foil. First, the fractured portion AA shown in FIG. 3A leaves the metal foil in the outer layer material 101Q of the cable portion Q up to the boundary with the component mounting portion P. As a result, the fracture portion AA, which is the boundary between the component mounting portion P and the cable portion Q, has a large strength difference, and can be removed by tearing at this boundary portion.

  Next, in the fracture portion BB shown in FIG. 3B, for example, the metal foil at the boundary between the outer layer material 101Q of the cable portion Q and the outer layer material 101R of the discard portion R is removed when the outer layer circuit is formed. As a result, the strength of the portion without the metal foil is reduced, and it can be removed by tearing at this boundary portion.

  Then, in the fracture portion CC shown in FIG. 3 (c), the metal foil at the finger hook portion in the outer layer material 101Q of the cable portion Q is removed when the outer layer circuit is formed. Thereby, it can tear and isolate | separate using the intensity | strength difference of the part with and without a metal foil.

  In the first stage of tearing according to the present invention, for example, a strong stress is momentarily applied to the end of the fractured portion AA in FIG. The peel strength when a general adhesive is used is approximately 1.52 N / mm as measured by the freewheeling rotary drum method shown in IPC TM650 2.4.9. Therefore, for example, the stress for peeling off a bonded portion having a width of 0.01 mm is about 0.015N.

  The characteristic value of the mechanical stress when the end portion is torn in the initial stage is indicated by the end tear resistance value. In the case of a general polyimide resin film, it is approximately 19 kg / mm (1.94 N / mm) as measured by the compliant standard ASTM D-1004-66. Therefore, when it is desired that the peeled-off portion at the first stage of tearing is within 0.01 mm width, a film-based metal foil laminate using a polyimide resin film thinner than about 8 μm may be used as the outer layer material. Become.

  Similarly, when it is desired to peel off the bonded portion within 0.02 mm width, the stress for peeling the bonded portion is about 0.03 N. Therefore, a polyimide resin film thinner than about 15 μm may be used.

  Other than polyimide, for example, a polyester resin film having a small end tear resistance value is 18 kg / mm (1.84 N / mm). A thinner polyester resin film may be used. Moreover, since the end tear resistance value of the polysulfone resin film is 4.2 kg / mm (0.43 N / mm), it is thinner than about 70 μm when it is desired that the peel-off of the bonded portion is within 0.02 mm width. A polysulfone resin film may be used.

  In FIG. 3A, the outer layer material is not left on the side where the outer layer material remains at the tearing point AA. Although it may be left as it is, the outer layer material in which the metal foil is left has higher apparent peel strength than the outer layer material from which the metal foil has been removed. For this reason, it is preferable to leave the metal foil along the tear boundary line from the position where tearing starts from the position where the outer layer material remains at the location where the outer layer material is torn.

  4 (a) and 4 (b) show other examples of tearing points AA of the outer layer material. For example, as shown in FIG. 4A, it is preferable to leave the metal foil along the tear boundary line from the position where tearing starts.

  However, once the end portion is torn, the stress (tear propagation resistance value) to which the tear is transmitted is smaller than the end tear resistance value, so that the tear portion is torn smoothly. Therefore, when the metal foil is left along the tear boundary line from the above-described tear start position, it is not always necessary to leave the metal foil continuously along the tear boundary line as shown in FIG. For example, as shown in FIG. 4 (b), a metal foil may be arranged at a position where tearing starts. In this case, a metal foil having a length of at least 0.5 mm or more and a width of 0.1 mm or more is sufficient.

Embodiment 2

  5 (a) to 5 (c) show the manufacturing process of the second embodiment of the present invention. In this case, one of the board configurations is the component mounting portion P, the other is a terminal, and the cable portion Q connects both of them.

  Therefore, the right end of the cable portion Q shown in the figure becomes a terminal, and as shown in FIG. 5A, this terminal portion is not connected to the discarding portion 103R but left as a free end and used as a finger hook. Can do. Then, as shown in FIG. 5B, the outer layer material 101Q is peeled from the portion of the terminal 103S on the left side of the drawing to the fractured portion AA.

  As a result, as shown in FIG. 5C, the inner layer material 103Q and the terminal 103S from which the outer layer material 101Q in the cable portion Q has been removed are exposed.

Embodiment 3

  6A to 6C show the manufacturing process of the third embodiment of the present invention. In this case, since the cable portion Q is bent in an L shape, the outside of the bent portion can be used as a finger hook.

  That is, by making the bent part of the cable part Q into a free end shape without connecting to the discard part 101R, it can be used as a finger hook. As shown in FIG. 6 (a), when the cable portion Q becomes L-shaped as a result of the 90 ° orientation difference between the connection portion of one component mounting portion and the connection portion of the other component mounting portion, the cable portion Q The outer periphery of the cable Q and the discarding portion R are not connected, and the bent portion of the cable Q is substantially free-end.

  As a result, as shown in FIG. 6B, the outer layer material 101Q is peeled off from the free end-shaped portion of the cable portion Q, and the broken portion AA is removed. As a result, as shown in FIG. 6 (c), the outer layer material of the cable portion Q is removed to expose the inner layer material 103Q, and a hybrid multilayer circuit board in which the component mounting portions P are connected by the cable portion Q is formed. can do.

Embodiment 4

  FIG. 7 shows a fourth embodiment of the present invention, and FIGS. 7A to 7D are plan views showing the configuration of each layer material for manufacturing a hybrid multilayer circuit board according to the present invention. It is a front view which shows the state which laminated | stacked them. In order to ensure the thickness of the insulating layer, a resin layer that has been cured in advance may be incorporated and laminated. FIG. 7 shows an application to a hybrid multilayer circuit board having a component mounting portion and a cable portion having the same shape as that in FIG. 1, and incorporating and laminating a pre-cured resin layer at the time of lamination. .

  Fig.7 (a) has shown the planar shape of the single-sided film base metal foil laminated body 101 as the same outer layer material as Fig.1 (a). FIG. 7B shows a planar shape of the resin layer 104 that has been cured in advance to ensure the thickness of the insulating layer. Here, the boundary part between the component mounting part P and the cable part Q, which is a part to be peeled off later, of the resin layer 104, the center part of the cable part Q, and the part where the cable part Q is connected to the discard part R are shown. The region 104A is punched and removed in advance.

  The outer layer material 101 and the resin layer 104 are bonded together via an adhesive member (not shown) in which the same portion as the resin layer 104 is punched out. FIG. 7 (c) shows this state as viewed from the front (cross section) along XX.

  FIG. 7D shows a state in which the adhesive member 102 in FIG. 1B and the inner layer material 103 in FIG. Thereafter, a hybrid multilayer circuit board can be formed by the same process as in the first embodiment.

  The outer layer material 101, the adhesive member 102, the inner layer material 103, and the resin layer 104 may be laminated together. However, if the outer layer material 101 and the resin layer 104 are bonded together, the adhesion is more reliably performed. preferable.

  In addition, the punching and removing region of the resin layer 104 may be punched over the entire portion of the cable portion Q. However, if it is left as in the present embodiment, the mechanical strength in the processing step can be secured, which is preferable.

FIGS. 1A to 1D are explanatory views showing a step of forming a laminated plate in the manufacturing steps of the first embodiment of the present invention. FIGS. 2A to 2C are explanatory views showing a process of peeling the outer layer material from the hybrid multilayer circuit board following the process of FIG. FIGS. 3A to 3C are explanatory diagrams showing an example of the structure of a fracture portion used when removing the outer layer material of the cable portion from the hybrid multilayer circuit board. FIGS. 4A to 4B are explanatory views showing an example in which a metal foil is left along a tearing boundary line at a fracture portion used when the outer layer material of the cable portion is removed from the hybrid multilayer circuit board. FIGS. 5A to 5C are explanatory views showing a process of peeling the outer layer material in the manufacturing process of the second embodiment of the present invention. FIGS. 6A to 6C are explanatory views showing a process of peeling the outer layer material in the manufacturing process of the third embodiment of the present invention. FIGS. 7A to 7D are explanatory views showing a step of forming a laminated plate in the manufacturing steps of the fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Hybrid multilayer circuit board 101 Outer layer material 102 Adhesive member 103 Inner layer material 104 Hardened resin layer P Component mounting part Q Cable part R Throwing part S Terminal A, B, C area AA, BB, CC Broken part (connection part)

Claims (5)

In a hybrid multilayer circuit board in which at least one cable portion protrudes from a multilayer component mounting portion formed by laminating an outer layer material made of a film-based metal foil laminate on an inner layer material,
The hybrid multilayer circuit board, wherein the outer layer material has a smaller stress when tearing the film of the outer layer material than the peel strength. A multilayer circuit board in which at least one cable portion protrudes from a multilayer component mounting portion by laminating an outer layer material made of a film-based metal foil laminate on the inner layer material and removing unnecessary portions of the outer layer material. In the manufacturing method of the hybrid multilayer circuit board to be manufactured,
Laminating an outer layer material having a smaller stress when tearing than the peel strength on the inner layer material,
A method for manufacturing a hybrid multilayer circuit board, comprising: tearing the outer layer material and removing unnecessary portions at a boundary portion between the multilayer component mounting portion and the cable portion. In the manufacturing method of the hybrid multilayer circuit board according to claim 2,
Including a cured resin layer for securing the insulating layer thickness in the component mounting part during lamination,
The resin layer is preliminarily slit at a boundary portion between the component mounting portion and the cable portion and a portion where the outer layer material is torn, laminated with the outer layer material, and an unnecessary portion of the outer layer material is torn and removed. When removed together with the resin layer,
A method for manufacturing a hybrid multilayer circuit board. In the manufacturing method of the hybrid multilayer circuit board according to claim 2 or 3,
In the step of removing the unnecessary portion of the outer layer material, the metal foil is left in advance along the boundary line of the portion to be removed.
A method for manufacturing a hybrid multilayer circuit board. In the manufacturing method of the hybrid multilayer circuit board according to any one of claims 2 to 4,
The metal foil is left along the tearing boundary line at least at the position where the outer layer material remains at the position where the outer layer material is left, at least at the position where tearing starts.
A method for manufacturing a hybrid multilayer circuit board.

Images