JP2008071902A - Wiring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To absolutely connect electrodes even at the occurrence of displacement between the two electrodes to be connected, and to absolutely connect electrods even between substrates having steps. <P>SOLUTION: Assuming that the distance between a central axis of a first electrode and a central axis of a second electrode in an array direction is ΔX, a distance perpendicular to the array direction is ΔY, tanθ=(ΔX/ΔY) with ΔY as an opposed side and ΔX as an adjacent side, the standard deviation of a landing-on position of a conductive material is σ, a diameter of the landing-on of the conductive material is D, the width in the array direction of the first electrode and the second electrode is L<SB>0</SB>, an arrangement space in the array direction of the first electrode and the second electrode is S<SB>0</SB>, wiring is formed when a condition cosθ>ä(6σ+D)/(L<SB>0</SB>+S<SB>0</SB>)} is satisfied, and the wiring is not formed when the condition is not satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wiring method, and more particularly to a wiring method for electrically connecting a first electrode and a second electrode by forming a wiring by landing a conductive member using an inkjet method.

As a conventional technique related to a wiring method in which electrodes are electrically connected, there is an ACF that connects electrodes of an FPC and a substrate. In Patent Document 1, as a conventional technique related to a wiring method in which electrodes of two substrates are electrically connected to each other, a wiring such as an organic EL element is connected to a signal line using an inkjet method or a gas deposition method. A wiring method is disclosed.
JP 2003-152299 A

  However, the connection between the FPC and the substrate by the ACF or the like is performed with the electrode surfaces facing each other. For this reason, if the dimensional accuracy due to the difference in thermal expansion between the FPC and the substrate is not ensured when the necessary heating is performed at the time of connection, especially when this is a wiring of about several tens of μm, the dimensional deviation will occur and the connection state should be secured You may not be able to.

  Further, in the wiring method disclosed in Patent Document 1, the flexible cable has a large step (50 to 100 [μm]) and a large width. It is difficult to connect while correcting.

  The present invention has been made in view of such circumstances, and even when a displacement between two electrodes to be connected occurs, the connection between the electrodes can be reliably ensured, and there is a step. An object of the present invention is to provide a wiring method that can ensure the connection between electrodes even between substrates, and does not require high-precision positioning, and enables high-yield electrical connection. .

In order to achieve the above object, according to the first aspect of the present invention, a conductive member is landed using an ink jet method to form a wiring, thereby forming a first electrode and a second substrate arranged on the first substrate. In the wiring method in which the arrangement directions of the second electrodes arranged are parallel to each other while being parallel to each other, the arrangement direction of the central axis of the first electrode and the central axis of the second electrode The distance in the direction perpendicular to the arrangement direction is ΔY, ΔY is the adjacent side, ΔX is the opposite side, tan θ = (ΔX / ΔY), and the standard deviation of the landing position of the conductive member is σ. The landing diameter of the conductive member is D, the width of the first electrode and the second electrode in the arrangement direction is L _0, and the arrangement interval of the first electrode and the second electrode in the arrangement direction is S _0. when a, cosθ> {(6σ + D ) / (L + S ₀₎ under the _conditions}, if and when the condition is satisfied does not satisfy the conditions to form a wiring that does not form the wiring, characterized by.

According to the present invention, even when there is a positional deviation between the first electrode and the second electrode, the above condition is satisfied under the condition of cos θ> {(6σ + D) / (L ₀ + S ₀ )}. In this case, the wiring is not formed if the above conditions are not satisfied, and therefore, it is ensured that adjacent wirings do not come into contact with each other as long as the above conditions are satisfied while considering the variation in the landing position of the conductive member. The first electrode and the second electrode can be connected.

Further, under the condition of cos θ> {(6σ + D) / (L ₀ + S ₀ )}, the range of θ can be adjusted by changing the liquid volume of the conductive member and adjusting the value of the landing diameter D. Therefore, it is possible to reliably wire corresponding to the amount of positional deviation between any first electrode and second electrode. Similarly, it is possible to reliably wire corresponding to the width L ₀ between any first electrode and the second electrode.

  In order to achieve the object, the invention according to claim 2 is the wiring method according to claim 1, wherein the insulating member is landed by using an ink jet method, and the insulating layer is formed in a staircase shape. A step between the surface on which the first electrode is arranged and the surface on which the second electrode is arranged is filled, and the conductive member is landed on the stepped step portion.

  According to the present invention, even when there is a step between the surface on which the first electrode is arranged and the surface on which the second electrode is arranged, by filling the step with the step-shaped insulating layer, It is possible to reliably connect the first electrode and the second electrode by forming a wiring by using an ink jet method.

  In addition, since the conductive member is landed on the stepped step portion, the landing shape of the conductive member can be controlled, and the first electrode and the second electrode are connected more reliably by using the ink jet method. be able to.

  According to the wiring method of the present invention, even if a positional deviation occurs between the electrodes to be connected, the wiring can be reliably connected. Further, even when a step is generated between the electrodes to be connected, the wiring connection can be surely performed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment>
First, the first embodiment will be described. The first embodiment is an embodiment when there is no step between the substrate and the wiring substrate, or when the step between the substrate and the wiring substrate is equal to the droplet size of the conductive ink.

  FIG. 1 is a diagram showing an electrode surface in a state where a substrate electrode and a wiring substrate electrode are connected when there is no positional deviation between the substrate and the wiring substrate. FIG. 1 (a) is a top view, FIG. 1 (b) is a side view. On the other hand, FIG. 2 is a diagram showing an electrode surface in a state where the electrode of the substrate and the electrode of the wiring substrate are connected when there is a positional deviation between the substrate and the wiring substrate. FIG. 3 is an enlarged view of the wiring portion shown in FIG. FIG. 3A shows a case where the insulating ink is not landed, and FIG. 3B shows a case where the insulating ink is landed. FIG. 4 corresponds to FIG. 3 and is an explanatory diagram for various dimensions of the wiring portion.

  When there is no positional deviation between the substrate and the wiring substrate, as shown in FIG. 1, the substrate 11 and the wiring substrate 12 on which the electrodes 21 and 22 are arranged at a predetermined interval are face-up, and the ink jet method is used. Electrical connection is made by connecting the electrodes 21 and 22 using the. The substrate 11 and the wiring substrate 12 are respectively provided with alignment marks 13A and 13B at positions symmetrical to the boundary portion.

  Here, in this embodiment, as shown in FIGS. 2 to 4, the electrodes 21 and 22 are connected using the ink jet method even when there is a positional shift between the substrate 11 and the wiring substrate 12. A wiring method for electrical connection is proposed. As shown in FIG. 3B, the insulating ink 26 may be landed between the adjacent wirings in order to ensure the insulation between the adjacent wirings.

  Therefore, when taking the X axis and the Y axis as shown in FIG. 4, between the electrode 21a of the substrate 11 and the electrode 22a of the wiring substrate 12 connected corresponding to the electrode 21a, in the X axis direction. The connection between the electrodes when a positional shift has occurred will be described.

As shown in FIG. 4, the positions of the alignment marks 13A and 13B in the XY coordinates are (X _A , Y _A ) and (X _B , Y _B ).

If the distance in the X-axis direction between the central axes of the electrodes 21 and 22 on both substrates is ΔX, ΔX is equal to the amount of positional deviation in the X-axis direction between the electrodes 21 and 22 on both substrates, and the alignment marks 13A and 13B. The relationship of ΔX = (X _A −X _B ) is established from the XY coordinates of Further, the distance in the Y-axis direction of each alignment mark 13A, 13B is equal to the distance in the Y-axis direction of the tip portions of the electrodes of both substrates, and the relationship ΔY = (Y _A −Y _B ) is established.

Further, as shown in FIG. 4, the landing diameter of the conductive ink 23 which is a conductive member is D, the shortest distance between the ends of the adjacent wiring portions (hereinafter referred to as the distance between the adjacent wirings) is S, and the electrode The width is L ₀ , and the interval between the adjacent electrodes is S ₀ . Further, as shown in the figure, the angle θ is taken as shown by the relationship tan θ = (ΔX / ΔY).

With the above settings, the relational expression S = {(L ₀ + S ₀ ) × cos θ−D} is established.

  Here, since there is a variation in the droplet ejection position of the conductive ink 23 that is landed using the ink jet method, the distance S between the adjacent wirings must be a value that considers the variation in the droplet ejection position of the conductive ink 23. I must. FIG. 5 is a schematic diagram regarding the standard deviation σ in consideration of variations in the droplet ejection position of the conductive ink 23, and shows the variation in the droplet ejection position of the conductive ink 23 and the normal distribution.

As shown in FIG. 5, when a value in consideration of variations in the droplet ejection position of the conductive ink 23 is expressed as a function of the standard deviation σ, 3σ is obtained for each wiring. For this reason, in the most adjacent portion, in consideration of variations between adjacent wirings, a distance of 6σ or more in total is required as the distance S between the adjacent wirings. This relationship is expressed by an equation: S = {(L ₀ + S ₀ ) × cos θ−D}> 6σ, which is summarized as follows.

  Therefore, when the condition of the above equation 1 is satisfied, even if the electrode 21 and the electrode 22 are misaligned and the droplet ejection position of the conductive ink 23 varies, adjacent wirings are in contact with each other. Nothing will happen. Therefore, it is possible to reliably connect the electrodes 21 and 22 on both substrates without contact between adjacent wirings. Therefore, in the present embodiment, a wiring method is proposed in which the conductive ink 23 is landed using the ink jet method under the conditions of the mathematical formula 1 to form the wiring of the electrodes 21 and 22.

As a specific example, the droplet ejection size of the conductive ink 23 is 10 pl, and L ₀ = 50 μm, S ₀ = 50 μm, D = 54 μm, and σ = 3 μm. Therefore, from the equation (1), cos θ> 0.72, and the electrodes 21 and 22 can be wired with respect to a positional shift in the range of −44 deg <θ <44 deg.

According to the first embodiment as described above, even if there is a displacement in the X-axis direction between the electrode 21a and the corresponding electrode 22a, the displacement amount ΔX and the electrode from the alignment marks 13A and 13B. The distance ΔY in the Y-axis direction between the tip of the electrode 21a and the electrode 22a is detected, and wiring is performed between the corresponding electrodes 21 and 22 under the condition of cos θ> {(6σ + D) / (L ₀ + S ₀ )}. Thus, the electrodes 21 and 22 can be reliably connected without reliably contacting adjacent wirings.

Further, from the equation (1), the range of θ can be adjusted by changing the liquid volume of the conductive ink 23 and adjusting the value of the landing diameter D, so the position between any electrodes 21 and 22 can be adjusted. Wiring can be reliably performed according to the amount of deviation. Similarly, it is possible to reliably wire corresponding to the width L ₀ of the arbitrary electrodes 21 and 22.

The above is the description of the first embodiment.
<Second Embodiment>
Next, a second embodiment will be described. FIG. 6 shows a schematic diagram of the second embodiment, and FIG. 7 shows a more specific process diagram of the second embodiment.

  As shown to Fig.6 (a), 2nd Embodiment is embodiment about the case where a level | step difference exists in the board | substrate 11 and the electrode substrate 12. FIG. FIG. 6B is an external perspective view of a connection portion between both substrates in a state where wiring is performed by the wiring method according to the second embodiment, and FIG. 6C is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 6B and 6C, in the second embodiment, a step-shaped insulating layer is formed using insulating ink, and wiring is connected on the insulating layer to connect the electrodes. Yes.

  A specific process of the second embodiment will be described with reference to FIG. First, as shown in FIG. 7 (a), the distance between the alignment marks 13A and 13B (alignment pattern width) is recognized by the long working lens, and the lens is adjusted at the portion where the focus is matched (the portion where the alignment pattern width is the smallest). The height H of the step is determined from the working distance.

  Next, as shown in FIG. 7B, the insulating ink 24 is printed on the substrate 11, and then cured to form the first layer of the insulating layer.

  Next, as shown in FIG. 7C, the insulating ink 24 is printed on the first layer of the insulating layer, and then cured to form the second layer of the insulating layer. At this time, the printing width of the second layer is made smaller than that of the first layer, and the tip portion is stepped.

  Thereafter, as shown in FIG. 7D, printing and curing are repeated until the height of the insulating layer by the insulating ink 24 reaches the height H of the step of the substrate. Thereby, a step-shaped insulating layer having a height H is formed. The reason for forming the stepped shape in this way is that when it is formed in a slope shape, the landing shape of the conductive ink 23 described later can be controlled.

  Next, as shown in FIG. 7E, a conductive layer is formed by printing the conductive ink 23 on the insulating layer and then curing. The conductive layer serves as a wiring between the first electrode 21 and the second electrode 22. Here, when the conductive ink 23 is printed over the insulating layer, the conductive ink 23 is conductive in accordance with the step portion 31 (see FIG. 7D) of the stepped portion of the insulating layer formed in the stepped shape. The ink 23 is landed. This is because when the conductive ink 23 is printed according to the step portion 31 of the staircase shape portion of the insulating layer, the landing shape can be controlled without flowing after the conductive ink 23 has landed.

  According to the second embodiment as described above, the connection between the electrodes can be reliably ensured even when a step is generated between the two substrates.

  Here, it is conceivable that the surface of the insulating layer is sloped so as to fill a step formed on both substrates. However, if the surface of the insulating layer is sloped, the conductive ink 23 tends to flow after landing on the surface of the insulating layer, so that the landing shape of the landing conductive ink 23 cannot be controlled.

  On the other hand, when the surface of the insulating layer is stepped to fill the step formed on both substrates as in this embodiment, the conductive ink 23 lands and stabilizes so as to be stacked on the surface of the stepped portion of the insulating layer. The landing shape of the conductive ink 23 to be landed can be controlled. Conductive ink 23 is ejected onto the portion corresponding to the step of the staircase, and the portion on the step is ejected a plurality of times, so that electrical conduction on the top, bottom, left and right of the staircase can be ensured.

  The wiring method of the present invention has been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the scope of the present invention. It is.

It is a schematic diagram of a state in which the electrode of the electrode substrate and the electrode of the wiring substrate are connected when there is no positional deviation between the substrate and the wiring substrate. It is a schematic diagram of a state in which the electrode of the substrate and the electrode of the wiring substrate are connected when there is a positional deviation between the substrate and the wiring substrate. It is an enlarged view of the wiring part shown in FIG. FIG. 4 corresponds to FIG. 3, and is an explanatory view of the positional relationship and various dimensions of a substrate electrode and a wiring substrate electrode. It is the figure which showed the mode of droplet ejection position accuracy of a conductive ink, the mode of variation in droplet diameter, and normal distribution. It is a schematic diagram of 2nd Embodiment. It is a more specific process diagram of the second embodiment.

Explanation of symbols

11 Substrate 12 Wiring substrate 21 Electrode 22 Electrode 23 Conductive ink 24 Insulating ink

Claims (2)

By forming the wiring by landing the conductive member using the ink jet method, the arrangement direction of the first electrode arranged on the first substrate and the second electrode arranged on the second substrate is made parallel. In the wiring method in which each pair is electrically connected,
The distance between the central axis of the first electrode and the central axis of the second electrode in the arrangement direction is ΔX, the distance in the direction perpendicular to the arrangement direction is ΔY, ΔY is the adjacent side, ΔX is the opposite side, and tan θ = (ΔX / ΔY), the standard deviation of the landing position of the conductive member as σ, the landing diameter of the conductive member as D, and the width of the first electrode and the second electrode in the arrangement direction as L ₀ , When the arrangement interval of the first electrode and the second electrode in the arrangement direction is S ₀ ,
Under the condition of cos θ> {(6σ + D) / (L ₀ + S ₀ )}, a wiring is formed when the above condition is satisfied, and a wiring is not formed when the above condition is not satisfied.
Wiring method characterized by. The wiring method according to claim 1,
Insulating members are landed using an inkjet method to form the insulating layer in a staircase shape, filling a step between the surface on which the first electrode is arranged and the surface on which the second electrode is arranged, Landing the conductive member on the stepped step portion;
Wiring method characterized by.

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