JP5143372B2 - Method for manufacturing hybrid multilayer circuit board - Google Patents

Description

  The present invention relates to a hybrid multilayer circuit board in which a cable portion is drawn from a component mounting portion and a method for manufacturing the same, and more particularly to a hybrid multilayer formed by peeling an outer layer material to expose an inner layer material when forming a cable portion. The present invention relates to a circuit board and a manufacturing method thereof.

  As a method of exposing the inner layer portion of the multilayer circuit board, for example, there is a method disclosed in Patent Document 1. In this method, slits are made in portions where unnecessary portions of the outer layer material are removed in advance, and the slit portions are temporarily closed with an adhesive member to prevent infiltration of chemicals such as plating, and the unnecessary portions are peeled off and removed during external processing. .

  In addition, at least one cable portion protrudes from the multilayer component mounting portion, including a step of laminating an outer layer material made of a film-based metal foil laminate on a circuit board as an inner layer and removing an unnecessary portion of the outer layer material. As a method for manufacturing a hybrid multilayer circuit board, there is one disclosed in Patent Document 2.

In this method, an outer layer material that is an insulating base film whose tear strength is smaller than the peel strength of the outer layer material is used, and a method of peeling off at the boundary between the component mounting portion and the cable portion is employed.
Japanese Patent No. 3427011 Application documents for Japanese Patent Application No. 2005-241188

  However, in the technique of Patent Document 1, depending on how the adhesive member flows out, the slit portion may not be completely blocked, and in this case, a plating chemical solution or the like penetrates. Further, if the flow-out amount is large, the unnecessary portion is adhered more than necessary, and it becomes difficult to remove the unnecessary portion.

  On the other hand, in the technique of Patent Document 2, there is a problem that an area where the outer layer material of the component mounting portion is peeled becomes too large depending on how to apply stress when tearing an unnecessary portion at the start of peeling. In particular, this tendency tends to be prominent when a stress that is strongly pulled obliquely is applied. In addition, the peeling strength may be locally reduced, and in this case as well, there is a problem that an area where the outer layer material of the component mounting portion is peeled becomes too large.

  The variation in the peeling strength is caused by the variation in local pressure and temperature distribution at the time of the laminating press, and this problem occurs even when there is a portion where the peeling strength is rare at the position where tearing starts.

  The present invention has been made in consideration of the above-mentioned points. When forming the cable portion by removing the unnecessary portion of the outer layer material, the inner layer is not soaked with chemicals such as plating, and the outer layer material is torn and removed. An object of the present invention is to provide a hybrid multilayer circuit board that can prevent the outer layer material of the component mounting part from being unnecessarily peeled off, and a method for manufacturing the same.

In order to achieve the above object, in the present invention,
Component mounting portion having an outer layer and the inner layer, and the cable portion which the inner layer material is formed is drawn from the component mounting portion is disposed inwardly of the planar direction, outwardly of the planar direction, the component mounting section and the A hybrid multilayer circuit board configured to be provided with a discarding portion that is separated from a cable portion and removed, and to peel off an unnecessary portion in the outer layer material provided to cover the inner layer material to expose the cable portion. In the manufacturing method,
The outer layer material composed of the inner layer material and the film-based metal foil laminate is provided with an adhesive member that is disposed on a part holding the substrate of the component mounting portion and the discarding portion and is not provided in the cable portion and the vicinity thereof. To form a laminate,
Plating the laminate,
When forming the outer layer pattern , leave the metal foil to the tearing boundary in the unnecessary portion of the outer layer material that covers the cable portion of the outer layer material in the laminate and reaches the discarding portion ,
The unnecessary portion located in the discarding portion, forming an opening or a cut at a position away from the component mounting portion,
The hybrid multilayer is characterized in that the unnecessary portion is turned up by using the opening or cut as a finger, and the unnecessary portion in the outer layer material is separated and peeled along the tear boundary to expose the cable portion in the inner layer material. Circuit board manufacturing method,
Is to provide.

  As described above, since the inner layer material is covered with the outer layer material in the present invention, in the process such as plating, the circuit formed in the inner layer material is completely protected by the outer layer material, so that the chemical solution such as plating is completely infiltrated. Since the outer layer material is torn and removed by using the finger hook as a finger hook at the disposal part of the outer layer material, it is easy to tear the outer layer material covering the cable part as planned, and even the outer layer material of the component mounting part It can prevent peeling.

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

Embodiment 1

  1 (a) to 1 (c) are plan views showing the structure of each layer material for manufacturing a hybrid multilayer circuit board according to the present invention, and FIG. 1 (d) is a front view showing a state in which they are laminated. is there.

  First, Fig.1 (a) has shown the planar shape of the film base metal foil laminated body 101 as an outer layer material. This outer layer material 101 has a rectangular overall planar shape, and two cable parts connecting the two component mounting parts P on the left and right sides in the drawing, and a cable part connecting these parts mounting parts P, by an imaginary line drawn to further partition the inside of the rectangle The contour position of Q is shown. The portion surrounding the component mounting portion P and the cable portion Q in the outer layer material 101 is a discarding portion S that is separated and removed from the component mounting portion P and the cable portion Q when the hybrid multilayer circuit board is mounted.

  FIG. 1B shows the planar shape of the adhesive member 102 disposed between the outer layer material 101 and an inner layer material 103 described later. The adhesive member 102 is disposed on the component mounting portion P and a portion corresponding to the discard portion S that is connected to the substrate and holds the substrate up to the component mounting, and is not provided in the cable portion Q and the vicinity thereof. Therefore, the cable portion Q and the vicinity thereof are cutout portions 102A.

  FIG. 1C shows a planar shape of the inner layer material 103. The inner layer material 103 constitutes a circuit of the component mounting portion 103P and a cable portion 103Q that connects the circuits. Therefore, a cutout portion T is formed on the side portion of the cable portion Q in the same manner as the adhesive member 102. However, in order to prevent the cable portion Q from drooping during transportation or the like, a connection portion D that connects a part of the cable portion Q and the discard portion S is provided.

  FIG. 1 (d) shows a 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). It is the front view seen from.

  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. Are separated from each other.

  2 (a) to 2 (d) show an exposure process from a state immediately before the cable portion is exposed by applying predetermined processing (plating, outer layer pattern formation, etc.) to the laminated board formed through the process of FIG. It is the top view which showed each state after completion | finish.

  First, in FIG. 2A, a process for removing the unnecessary portion 101R of the outer layer material 101 is performed. The outer layer material 101 includes a component mounting part 101P, a cable part 101Q, and a discarding part 101S.

The outer layer material 101 and the unnecessary portion 101R of the outer layer material that is not fixed to the inner layer material 103, which will be removed later, are configured to connect the two component mounting portions 101P. Finger hooks C are formed at the four corners of the unnecessary portion 101R, and an operator puts a finger on the finger hook C to move the unnecessary portion 101R along the broken portion B from the component mounting portion 101P and the discarding portion 101S. The unnecessary portion 101R is removed by tearing.

The finger hook C is practically provided at the corner of the unnecessary portion 101R, but is not limited thereto. And the finger hook C should just be a structure where a fingertip of an operator can be hung, and it should just be set as the structure where finger hook is improved further.

FIG. 2 (b) is an enlarged view of the finger hook C shown in FIG. 2 (a). This can turn up the unnecessary portion 101R from the apex C1 having an L-shape, and becomes a finger hook. Further, it is preferable to make the tip angle θ of the tip portion C2 of the L-shaped through-hole more acute because the mechanical stress at the beginning of the tearing and peeling operation becomes smaller and tearing becomes easier as will be described later.

Here, the finger hooking C is necessarily it is without requiring intended to penetrate the laminate 100 may be any opening that at least the outer layer material 101 is penetrated. Furthermore, it may be a cut by a Thomson blade or the like instead of punching.

  FIG. 2C shows a state where the unnecessary portion 101R of the outer layer material 101 is being peeled and removed. In this operation, the operator puts the tip of the finger on the finger hook C, lifts and removes the unnecessary portion 101R, and then pulls it toward the lower right in the drawing, so that the unnecessary portion 101R becomes the component mounting portion. It is peeled off from the outer layer material 101P of P and the substrate discarding part 101S. Thus, the cable portion 103Q and the discard portion 103S that are covered with the unnecessary portion 101R are exposed.

  FIG. 2D shows a state in which all unnecessary portions 101R of the outer layer material 101 are removed. By removing the unnecessary portion 101R, the inner layers of the cable portion 103Q and the discard portion 103S are exposed.

FIG. 3 shows a step following FIG. In this step, a slit E that separates the product along the product outline is punched, and the component mounting portion P (FIG. 1) and the cable portion Q (FIG . 1) are connected to the discard portion S (FIG. 1). It will be in the state of the finished product for shipment connected only by.

  Here, the component mounting part 101P and the cable part 103Q are connected by the connecting part D to the discarding part S until the circuit board is mounted, and maintain a strength that does not hinder handling during handling.

  Here, FIG. 1 and FIG. 2 show an example in which slit processing is performed in advance with the discarding portion 103S along the outer shape of the cable portion 103Q and then the outer layer material is laminated. When punching out, slit processing may be performed between the cable portion 103Q and the discarding portion 103S.

  4 (a) and 4 (b) show an example of the configuration of the fractured portion B shown in FIG. 2 (a). By leaving the metal foil originally possessed by the circuit board, the strength of the metal foil is increased. It is easy to tear using. First, the broken portion Ba shown by the oblique lines in FIG. 4A leaves the metal foil in the unnecessary outer layer material 101R to the tear boundary. As a result, the boundary portion with the unnecessary portion 101R has a large difference in strength, and thus the unnecessary portion 101R can be torn and removed at this boundary portion.

  In the first stage of tearing according to the present invention, for example, a strong stress is momentarily applied to the end of the finger hook C in FIG. The peel strength of the outer layer material when using a general adhesive 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 the adhesive 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, it is approximately 19 kg / mm (1.94 N / mm) as measured by the compliant standard ASTM D-1004-66. However, this numerical value becomes smaller depending on the shape of the end portion of the finger hook C, and approaches the tear propagation resistance value described later as the end portion becomes an acute angle.

  Once the end portion is torn, the stress (tear propagation resistance value) through which tearing is transmitted is as small as about 1/8 to 1/30 of the end tear resistance value. In this way, by setting the position at the beginning of tearing at which stress is applied strongly and momentarily to a position away from the component mounting portion P, it is possible to suppress peeling to the outer layer material 101P of the component mounting portion P when peeling. The

  For example, in the case of a polyimide resin, the tear propagation resistance value is approximately 0.32 N / mm. Therefore, when the outer layer material based on a polyimide film having a thickness of 0.05 mm is calculated, the peeling of the outer layer material P is about 8 μm wide. Become.

In FIG. 4A, the copper foil (or metal foil) is not left on the side where the outer layer material remains in the portion B (FIG. 2A) where the outer layer material is torn. Although it may be left as it is, the outer layer material in which the copper foil is left has higher apparent peel strength than the outer layer material from which the copper foil has been removed.

  For this reason, it is preferable to leave the copper foil Bb along the boundary line that tears from the position where tearing starts, as shown in FIG. In this case, a copper foil piece having a length of at least 0.5 mm and a width of at least 0.1 mm is sufficient. As shown in FIG. 4B, if the copper foil piece Bb is formed in the portion near the finger hook C outside the component mounting portion P, the tearing characteristics can be improved without affecting the product pattern.

Embodiment 2

  FIG. 5 is a plan view showing Embodiment 2 of the present invention. In order to secure an area for inserting the finger hook C, the unnecessary portion 101R that is not fixed to the outer layer material 101 and the inner layer material 103 discards the boundary line between the component mounting portion 101P and the cable portion 101Q in the direction of the portion 101S. However, there is an inconvenience that a region to be removed as the unnecessary portion 101R becomes large.

  In this case, as shown in FIG. 5, if a protruding portion of the component mounting portion P indicated by the symbol F is provided at the boundary portion between the component mounting portion P and the cable portion Q, the region to be removed as the unnecessary portion 101R The size can be reduced.

  The tearing of the boundary portion with the component mounting portion 101P in the second embodiment is performed in the same manner as in the first embodiment.

Embodiment 3

  FIG. 6 shows Embodiment 3 of the present invention. When the finger hook C can be processed as a cut by a Thomson blade or the like, it can be removed by tearing with a small stress close to the above-described tear propagation resistance value. In this case, it is necessary to set the unnecessary portion 101R that is not fixed to the outer layer material 101 and the inner layer material 103 so that the boundary line between the component mounting portion 101P and the cable portion 101Q extends in the direction of the discard portion 101S. Instead, it can be set beside the component mounting portion 101P as shown in FIG.

Embodiment 4

  FIGS. 7A to 7B show a fourth embodiment of the present invention, which is an example in which the cable portion Q is bent in an L shape.

When the unnecessary portion 101R of the outer layer material is torn and removed, it is preferable that the unnecessary portion 101R has a quadrangular shape because the tearing direction is linear. For this reason, when the cable portion Q is bent, a portion indicated by an imaginary line in FIG. 7A may be set as the unnecessary portion 101R so as to follow the bending of the cable portion Q.

  However, if the unnecessary portion 101R is set wide, a useless space can be widened in the work area. Therefore, as shown in FIG. 7B, the unnecessary portion 101R may be divided by the dividing portion G and divided in two directions to be removed by tearing.

  In this case, if the metal part of the G part is removed in a straight line and the notches as shown in FIGS. 7 (c) and 7 (d) are made in the G part both ends CG1 and CG2, respectively, FIG. ) And can be torn in two directions. The tearing of the boundary portion with the component mounting portion 101P is performed in the same manner as in the first embodiment.

FIGS. 1A to 1D are explanatory views showing a step of forming a laminated body in the manufacturing steps of Embodiment 1 of the present invention. FIGS. 2A to 2D are explanatory views showing a process of peeling the outer layer material from the hybrid multilayer circuit board following the process of FIG. FIG. 3 is an explanatory view showing a state where a hybrid multilayer circuit board is completed by punching slits E for separating products along the product outline. FIGS. 4A and 4B are explanatory views showing an example in which a metal foil is left along a tearing boundary line at a breakage portion used when the outer layer material of the cable portion is removed from the hybrid multilayer circuit board. FIG. 5 is an explanatory view showing a region where an outer layer material is peeled in a manufacturing process according to Embodiment 2 of the present invention. FIG. 6 is an explanatory view showing a region where the outer layer material is peeled in the manufacturing process according to the third embodiment of the present invention. FIGS. 7A to 7E are explanatory views showing a process of peeling the outer layer material in the manufacturing process of Embodiment 4 of the present invention.

Explanation of symbols

100 Laminate (Hybrid multilayer circuit board)
DESCRIPTION OF SYMBOLS 101 Outer layer material 102 Adhesive member 103 Inner layer material P Component mounting part Q Cable part R Outer layer material unnecessary part S Throwing part T Cut-out part A Outer part of the outer layer material or area B of the laminated member B Component mounting part P and outer layer material Boundary area Ba with unnecessary part R Broken part Bb Metal foil C, GC1, GC2 Notch D Connection part E with discard part S Slit F Projection part G to the cable part side of component mounting part Split part of unnecessary part

Claims (1)

Component mounting portion having an outer layer and the inner layer, and the cable portion which the inner layer material is formed is drawn from the component mounting portion is disposed inwardly of the planar direction, outwardly of the planar direction, the component mounting section and the A hybrid multilayer circuit board configured to be provided with a discarding portion that is separated from a cable portion and removed, and to peel off an unnecessary portion in the outer layer material provided to cover the inner layer material to expose the cable portion. In the manufacturing method,
The outer layer material composed of the inner layer material and the film-based metal foil laminate is provided with an adhesive member that is disposed on a part holding the substrate of the component mounting portion and the discarding portion and is not provided in the cable portion and the vicinity thereof. To form a laminate,
Plating the laminate,
When forming the outer layer pattern , leave the metal foil to the tearing boundary in the unnecessary portion of the outer layer material that covers the cable portion of the outer layer material in the laminate and reaches the discarding portion ,
The unnecessary portion located in the discarding portion, forming an opening or a cut at a position away from the component mounting portion,
The hybrid multilayer is characterized in that the unnecessary portion is turned up by using the opening or cut as a finger, and the unnecessary portion in the outer layer material is separated and peeled along the tear boundary to expose the cable portion in the inner layer material. A method of manufacturing a circuit board.

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