JPS61136283A - Electric circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to electrical circuit boards.

<Prior Art> Conventionally, electrical connection terminal portions are electrically connected to each other using bonding wires. However, as the density of the connecting terminal increases, the probability that the adjacent bonding wires will come into contact with each other and cause a short circuit becomes extremely high. In order to prevent short-circuits between the poding wires caused by various factors and also to prevent breakage of the poding wires, the poding wires are fixed with a pair of resin or other members.

However, there have been cases in which a short-circuit has already occurred at the time the connection is made using the pondin wire, or a short-circuit occurs when the sealing member is fixed.

Further, as the density of the two connection terminal portions increases, a problem arises in that the rate of occurrence of short circuits as described above increases. Furthermore, a problem arises in that the longer the length of the bonder, f-glue, and f-ya is (the farther apart the connection terminals are connected), the more likely the above-mentioned short circuit will occur.

This short circuit is a serious problem because it directly leads to damage or malfunction of the electric circuit, leading to a decrease in the reliability of the device as a whole.

<11> The present invention has been made in view of the above-mentioned problems, and provides an electric circuit board that does not cause short-circuits between adjacent bonding wires or short-circuits between the bonding wires and the electric circuit board. The purpose is to

A further object of the present invention is to provide an electrical circuit board that allows for even higher density electrical connections.

<Summary of the Invention> 1. The stated purpose is to form a convex portion between one electrical connection end and a terminal portion other than the connection terminal portion connected to the connection terminal portion of +iii. This is achieved by an electric circuit board characterized by:

<Example> - The present invention will be explained below using the drawings.

FIG. 1 is a schematic perspective view for explaining the present invention.
102, 105 are electrodes, 103 is a bonding wire, 104 is a flexible board, 106 is an electrical circuit board;
, 107 are electrical connection terminal portions, and 1013 is a convex portion.

In the present invention, as shown in FIG.

The bonding wire 103 connects the base poles 102 and 1.
Electrical connection terminal portions (hereinafter referred to as "pads") 106 and 107 provided at the terminal ends of the pads 03 are electrically connected to each other. Bonde Inquire 103 is #tt
At the time of connection, it is connected beyond the northern part of the convex portion lO8.

At this time, if the length of the bonding wire 103 is made as short as possible to the extent that no stress is applied, the movement of the bonding wire 103 is regulated by the convex portion 108.

Therefore, occurrence of short circuit caused by movement of adjacent bonding wires 103 is eliminated.

Furthermore, if this convex portion and the bonding wire are sealed with a sealing member such as a resin, movement of the bonding wire 103 will not occur, and the movement of the bonding wire 103 will be restricted by the convex portion. There is no possibility that a short circuit will occur when the power is stopped.

FIG. 2 shows an example in which the present invention is applied to an electrical connection terminal portion of an inkjet recording head.

In FIG. 2, 201 is a substrate, 202 and 212 are electrodes, 204 is a wall, and 205 is a top plate.

206 is an energy generator, 207 is an orifice, 20
8, 211- is a pad, 209 is a convex portion, 210 is a flexible substrate, 213 is a bonding wire, 214
215 is an ink supply port, and 216 is a liquid chamber.

The recording head shown in FIG. 2 has a wall 204 on a substrate 201 on which an energy generator 206 is provided.
After forming the top plate 205 having an ink supply port 215
An orifice 207. It has an ink passage 214 and a liquid chamber 216. An electrode 202 is electrically connected to the energy generator 206 . A pad 208 provided at the end of the electrode 202 and an electrode 212 of the flexible substrate 210, which is an external wiring, are electrically connected by a bonding wire 213. A bonding wire 213 passes over the convex portion 209 provided on the substrate 201 and connects the electrodes 202 and 212 .

In addition, the electrode 212, the bonding wire 213, the electrode 20
When power is supplied to the energy generator 206 through the ink supply port 215, the energy generator 206 generates energy that is used to discharge the liquid supplied through the ink supply port 215 from the orifice 207, and applies it to the liquid.

The liquid is then discharged from the orifice 207 to form flying droplets.

The inkjet recording head of this example can be manufactured by the following method.

FIGS. 3(a) to 3(e) are schematic explanatory diagrams for explaining the steps of manufacturing the inkjet recording head of this example.

First, place the energy generator 306° pad 3 in a predetermined position.
Electrode 302-1 with 08.302-2. are arranged in glass and ceramics.

A photosensitive resin film 30 is formed on a substrate 301 made of resin, metal, etc.
4 P- (film thickness 25pm-100pm) from 0.5 to 0
．． Speed of 4 f/min, 1~3Kg/c
The photosensitive resin film 30'4P provided on the substrate 301h is laminated under the pressure conditions of ~2 (FIG. 3(a)).
A photomask having a pattern of a light transmitting part 317 and a light not transmitting part 317F corresponding to the orifice, the ink passage, the liquid chamber, the wiring part having the electrode and the pad, and the convex part is superimposed on the hill. (arrow in the figure) (Fig. 3(b)).

The portion corresponding to the ink passage of the light-impermeable portion 317F of the pattern sufficiently covers the installation area of the energy generator 306 disposed on the substrate 301h, and is located inside the ink passage formed after exposure and development processing. The above generator 306
The pattern described above is formed so that the photomask and the substrate 301 are aligned, and the photomask and the substrate 301 are aligned.

When the exposure is performed in this way, the area other than the area covered by the pattern, that is, the exposed part of the photosensitive resin film 304P is polymerized and hardened, whereas the unexposed part remains solvent-soluble.

Becomes insoluble in solvents.

Next, this is immersed in a volatile organic solvent, for example, trichloroethane, and the unpolymerized (uncured) portion of the photosensitive resin film 304P, which is solvent-resistant, is dissolved and removed from the substrate 301. The cured photosensitive resin 111304H left behind (FIG. 3(c)) is then further cured for the purpose of increasing the solvent resistance of the oil film 304H from north to south. Cured photosensitive resin film 304
As a method to further harden H, 130°0-160
The photosensitive resin cured film 304H is heated at °C for about 10 to 60 minutes to undergo thermal polymerization. Alternatively, methods such as irradiation with ultraviolet rays can be mentioned, but it is desirable to use these methods in combination.

In this way, the ink passage 314 made of the photosensitive resin cured film 304H. Side wall and convex portion 30 of liquid chamber 316
9 (Fig. 3 c)). Finally, the top plate 305 covering the liquid chamber 316 and the ink passage 314 is joined (FIG. 3(e)).

A schematic sectional view taken along the dashed line a-'a' shown in the second factor corresponds to FIG. 3(e). However, in FIG. 3(e), the recording head is in a state 1ii in which electrical connection with the outside of the recording head is made by a bonding wire.

By using the electrical circuit board of the present invention for the electrical connection of an inkjet recording head as in this example, it is possible to conduct higher density wiring, which has caused problems that have not occurred with conventional high-density multi-orifice type inkjet recording heads. This eliminates droplet ejection failure due to faulty wiring. Furthermore, an inkjet recording head using the present invention has excellent vibration resistance and reliability.

In addition, forming the convex portion using a cured film of photosensitive resin as in this embodiment means that the convex portion is formed at the same time as the wall for forming the inkjet recording head's input passage, liquid chamber, etc. can be formed, which is very preferable since the number of manufacturing steps does not increase.

In the schematic cross-sectional perspective view shown in FIG. 4, the convex portion 401 does not have a shape in which the convex portion is formed in a d-direction as shown in FIG. 2 (or FIG. 1); This is a case where the protrusions are formed intermittently. In this case, bonding wire 2
13 is basically disposed between the convex portions 401, it is possible to further prevent short circuits between adjacent bonding wires 213. Of course, even if the wiring is routed through the upper part of the convex portion 401, the convex portion 401 has the same effect as described above, so no short circuit occurs between the bonding wires 213. Therefore, in this embodiment as well, by using the present invention, a high-density multi-orifice recording head with high reliability is provided.

It should be noted that since the numbers in FIG. 2 are the same as those in FIG. 4, a detailed explanation will be omitted.

As shown in the schematic plan view of FIG. 5(a), the pad 5
If the '01's are arranged in a staggered manner, the 'b
), by providing a convex portion 502 between the pad 501-1 of the first row and the pad 501-2 of the second row, the bonding wires can be connected to each other. Can prevent short circuits.

Of course, the convex portion 502 is flexible J, (i2
It may be provided between the pad 501-1 on the 10 side and the flexible substrate 210, or it may be provided between the pad 501-1 on the flexible substrate side.
01-1 and the flexible substrate 210 and the pad 50
It may be provided both between pad 1-1 and pad 501-2.

, the pad is 2 in Fig. 5(a) and Fig. 5(b).
Although an example in which the pads are arranged in rows has been shown, the convex portions 502 can be provided in the same way even when pads are arranged in three or more rows.

Note that since the numbers in FIG. 2 and the numbers in FIG. 5(b) are the same, detailed explanation will be omitted.

Effect> As explained above, in the electrical circuit board of the present invention,
Since a convex portion made of an insulating material is provided on the substrate, it is difficult to prevent bonding between the bonding wires and/or between the bonding ink wire and the head substrate during wire bonding between the external wiring board and the bonding pad. No short circuit occurs.

Furthermore, by forming the convex portions intermittently, short circuits between adjacent bonding wires become even more difficult to occur.

By eliminating the occurrence of short circuits as described above, the productivity and reliability of devices using electrical circuit boards can be improved, and furthermore, it becomes possible to increase the density of electrical wiring.

Incidentally, the convex portion may be made of any material as long as it has electrical insulation properties.For example, in addition to the above-mentioned cured film of photosensitive resin, resin, wood, paper, glass, etc. may be used. Among these, cured films of photosensitive resins, which have excellent processability and moldability, are very preferable materials. Further, even if the electrical conductor is a metal or the like, the surface thereof, that is, at least the portion that comes into contact with the bonding wire, may be insulated using the above-mentioned material.

[Brief explanation of drawings]

1 to 5(b) are diagrams for explaining the present invention, respectively. FIG. 1 is a schematic perspective view, and FIGS. 214, 4, and 5(b) are schematic partial views. 3(L) to 3(e) are schematic explanatory views, and FIG. 5 (gourd) is a schematic plan view. 101----One electrical circuit board 201---One board' 102, 105, 202, 212---One electrode 2
04------One wall 205---One top plate 206------Energy generator 207---Orifice 106.107, 208, 211, 501-1.501
-2-----Electrical connection terminal part (pad) 209.40
1,502--m-Convex portion 104.210--Flexible substrate 103.213--Bonding wire 214--Ink passage 215--Ink supply port 216--Liquid chamber

Claims (1)

[Claims] An electrical circuit board characterized in that a convex portion is formed between an electrical connection terminal portion and a terminal portion other than the connection terminal portion that is electrically connected to the connection terminal portion.