United States Patent [191
`Kaizu et al.
`
`[54]
`[75]
`
`CLICK-ACTION MEMBRANE SWITCH UNIT
`Inventors:
`Masahiro Kaizu, Narita; Atsuhiro
`Horii, Sakura, both of Japan
`Assignee:
`Fujikura Ltd., Tokyo, Japan
`[73]
`[21]
`Appl. No.: 935,538
`[22] Filed:
`Aug. 25, 1992
`[30]
`Foreign Application Priority Data
`Sep. 10, 1991 [JP]
`Japan .... ..
`Feb. 7, 1992 [JP]
`Japan .... ..
`
`[58]
`
`[51] 1m. (21.5 .......................... ..
`............. .. H0111 1/10
`[52] U.S. Cl. .................................. .. 200/513; 200/521;
`200/310
`Field of Search ............. .. 200/512, 514, 516, 511,
`200/521, 293, 513, 310, 312, 317
`References Cited
`U.S. PATENT DOCUMENTS
`
`[56]
`
`4,046,981 9/1977 Johnson et a1. ................... .. 200/516
`4,463,234 7/1984 Bennewitz .... ..
`200/512
`4,501,938 2/1985 Kawauchi ..
`200/512
`4,618,754 10/1986 Gross ........ ..
`200/335
`5,144,104 9/1992 Bedoya ..........................
`200/512
`
`Illllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
`US005294762A
`Patent Number:
`5,294,762
`Date of Patent:
`Mar. 15, 1994
`
`[11]
`[451
`
`FOREIGN PATENT DOCUMENTS
`
`0322514 7/1989 European Pat. Off. .
`0100875 2/1984 Fed. Rep. of Germany .
`3333685A1 4/1985 Fed. Rep. of Germany .
`2133625A 7/1984 United Kingdom .
`Primary Examiner-Henry J. Recla
`Assistant Examiner-David J. Walczak
`Attorney, Agent. or Firm-Fishauf, Holtz, Goodman &
`Woodward
`ABSTRACT
`[57]
`A click-action membrane switch unit comprises a ?exi
`ble base ?lm having two surfaces, ?exible circuits
`formed on at least one of the two surfaces of the base
`?lm and having interdigitating electrode contacts, a
`resist ?lm formed on the ?exible circuits and having a
`window in the region of the electrode contacts, a dome
`shaped click spring made of electrically conducting
`material and having an edge placed on the circuits, and
`a layer fixed to the other surface of the base ?lm and
`having an opening formed in the portion of the layer
`which aligns with the click spring.
`
`10 Claims,4Drawing Sheets "
`
`D2
`
`109
`
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`D1
`1/108 100a,
`
`103
`107
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`101a
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`112
`105
`10s
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`1010
`152
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`D3
`111a 104
`110 112a
`110a
`152a
`
`Apple Inc., et al.
`Exhibit 1015
`Apple Inc., et al. v. Global Touch Solutions, Inc.
`IPR2015-01175
`
`Exhibit 1015, Page 001
`
`

`
`US. Patent
`
`Mar. 15,1994
`
`Sheet 1 of 4
`
`5,294,762
`
`FIGJ
`
`PRIOR ART
`
`F I G . 2
`
`PRIOR ART
`
`2b
`
`6
`
`Exhibit 1015, Page 002
`
`

`
`US. Patent
`
`Mar. 15, 1994
`
`‘Sheet 2 of 4
`
`5,294,762
`
`FIG .3
`
`PRIOR ART
`21 2022 21
`,7
`
`17
`
`DISPLACEMENT -——
`
`Exhibit 1015, Page 003
`
`

`
`U.S. Patent
`
`Mar. 15, 1994
`
`Sheet 3 of 4
`
`5,294,762
`
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`111 1O1b "2 105 10113104 152a 152 me 111
`
`Exhibit 1015, Page 004
`
`

`
`U.S. Patent
`
`Mar. 15, 1994
`
`Sheet 4 of 4
`
`5,294,762
`
`
`
`
`
`
`
`
`
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`101
`
`Exhibit 1015, Page 005
`
`
`

`
`1
`
`CLICK-ACTION MEMBRANE SWITCH UNIT
`
`5,294,762
`2
`pared with the ideal load-displacement characteristic 13
`shown in this ?gure.
`In view of this, the conventional click-action type
`switch unit has the drawback that it cannot provide the
`operator with suf?cient clicking sensation.
`In order to increase the clicking sensation, a click?
`action type membrane switch unit having a click spring
`provided with an increased squeezing force for enlarg
`ing the displacement thereof was thought of. However,
`this type of switch unit requires a thicker click spring,
`which entails drawbacks such that it is no longer possi
`ble to form the switch unit thin and the substantial in
`crease in the maximum load applied to the click spring
`degrades the durability of the switch unit. These are
`fatal drawbacks when the switch unit is to be miniatur
`ized.
`FIG. 3 shows a conventional click-action membrane
`switch with lighting, which is an application of the
`click-action membrane switch unit of the conventional
`type as shown in FIGS. 1 and 2. This switch comprises
`a base ?lm 1, upper and lower circuits 2 and 3, resist
`?lms 4 and 5, electric contacts 6, a circular window 7,
`and a click spring 8, all arranged similarly to the con
`ventional switch unit shown in FIGS. 1 and 2. The
`upper resist ?lm 4, a light-loading and diffusing sheet
`15, a formed rubber sheet 16 and an outer sheet 17 are
`laminated one on another. Formed in the light-loading
`and diffusing sheet 15 and the formed rubber sheet 16
`are holes 18 and 19 situated adjacent to each other. The
`hole 18 houses the click spring 8, and the hole 19 houses
`a lighting unit 20 comprising an LED bare-chip element
`21 mounted on one of the upper circuits 2 and electri
`cally connected to the other upper circuit 2 by means of
`a bonding wire 22.
`The above click-action type membrane switch with
`lighting also encounters the same problems as the
`switch unit shown in FIGS. 1 and 2, and described
`above.
`
`20
`
`35
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`This invention relates to a membrane switch unit of
`click action type.
`2. Description of the Related Art
`A click-action type membrane switch unit used on a
`solid printed circuit board has a number of advantages:
`it can be operated with high reliability, it can be formed
`thin, it occupies only a small amount of space and it can
`be manufactured at low cost. Because of these advan
`tages, this type of switch unit is widely used in the
`operating key portions of electrical equipment and the
`like. In particular, the click-action type membrane
`switch unit is frequently used in printed circuit boards
`as a switch unit which has a large number of key input
`portions and can endure high temperatures.
`A click-action type membrane switch can also be
`_ used in a ?exible circuit board.
`FIGS. 1 and 2 show a conventional click-action type
`membrane switch unit which is used in a ?exible printed
`circuit board and comprises a base ?lm 1, upper circuits
`2a and 2b and a lower circuit 3 formed on the upper and
`lower surfaces of the base ?lm 1, resist ?lms 4 and 5
`formed on the upper and lower circuits 2a, 2b, and 3,
`electrode contacts 6 extending from each upper circuit
`and arranged in an interdigitating manner in a circular
`window 7 formed in the intermediate portion of the
`resist ?lm 4 and a dome-shaped click spring 8 made of
`metal having a strong spring force or of any other mate
`rial having electrical conductivity and covering the
`electrode contacts 6 and the window 7.
`Referring to FIG. 4, when the click spring 8 is de
`pressed from its stationary state, as indicated by a bro
`ken line 9, its central portion is deformed by an amount
`indicated by A and contacts the electrode contacts 6 of
`the upper circuits 2, as indicated by a broken line 10,
`40
`whereby the upper circuits 2a and 2b are electrically
`connected. When the click spring 8 cannot be depressed
`more than A, a load required for this displacement A is
`represented by SA in FIG. 5, which does not provide
`suf?cient feeling to the operator, as indicated by the
`broken line 14 in FIG. 5.
`In order to produce suf?cient clicking sensation,
`however, it is required that the click spring 8 be de
`formed further by an amount B (i.e., the total displace
`ment indicated by C), as shown by a solid line 12 in
`FIG. 4. In this case, a load SB is required for the dis
`placement B, as shown in FIG. 5. In an ideal case, the
`load-displacement characteristic as indicated by a solid
`line 13 in FIG. 5 is required of a normal click spring,
`wherein an ample displacement C occurs under a load
`Sc, which is the sum of the loads SA and SB.
`When the click spring 8 of the conventional click
`action membrane switch unit is depressed, it is de
`formed and its central portion contacts the upper sur
`faces of the electrode contacts 6. Because the switch
`unit is usually placed on a rigid base, however, the
`central portion of the click spring 8 cannot be depressed
`below the level 11 shown in FIG. 4, as a result of which
`the click spring 8 assumes the form shown by the bro
`ken line 10, wherein the degree of depression or the
`sinking of the click spring 8 is less by the amount B than
`in the ideal case, resulting in the very poor load-dis
`placement characteristic 14 shown in FIG. 5, as com
`
`45
`
`60
`
`65
`
`SUMMARY OF THE INVENTION
`The object of this invention is to provide a click
`action type membrane switch unit which provides the
`operator with a strong clicking sensation which this
`type of switch unit is capable of.
`In order to achieve this object, a click-action mem
`brane switch unit according to this invention comprises
`a ?exible base ?lm having two surfaces, circuits formed
`on at least one of the two surfaces of the base ?lm and
`having interdigitating electrode contacts, a resist ?lm
`formed on the circuits and having a window in the
`region of the electrode contacts, a dome-shaped click
`spring made of electrically conducting material and
`having a peripheral edge placed on the electrode
`contacts, and a layer fixed to the other surface of the
`base ?lm and having an opening formed in the portion
`of the layer which aligns with the click spring.
`It is preferable that the opening of the layer have a
`smaller diameter than the diameter de?ned by the edge
`of the click spring.
`The switch unit of this invention provides excellent
`clicking sensation in spite of it using a thin click-action
`spring, and enables the contact time of the electrode
`contacts and the click spring to be prolonged so as to
`perform delayed recognition to avoid malfunction re
`sulting from chattering. Further, using a thin click- '
`action spring reduces the manufacturing cost of the
`switch unit.
`
`Exhibit 1015, Page 006
`
`

`
`15
`
`20
`
`35
`
`50
`
`5,294,762
`3
`4
`This click-action type membrane switch unit is appli
`with the circular window 108, with the circular edge
`cable to a click-action type membrane switch with
`109:: located to the outside of the circular edge 108a of
`lighting.
`the window 108.
`Formed in the lower circuit 104 is a circular opening
`BRIEF DESCRIPTION OF THE DRAWINGS
`110 having a larger inner diameter, de?ned by the circu
`This invention can be fully understood from the fol
`lar inner edge 110a thereof, than the inner diameter D1
`lowing detailed description of this invention by way of
`of the window 108 but smaller than the diameter D2 of
`the preferred embodiments with reference to the ac
`the circular edge 1090 of the click spring 109.
`companying drawings in which:
`Although smaller than the diameter D2 of the click
`FIG. 1 is a plan view of a conventional click-action
`spring 109, the inner diameter D1 of the window 108 is
`type membrane switch unit;
`large enough to allow the click spring 109 to freely
`FIG. 2 is a cross-sectional view taken along line 2—-2
`contact the electrode contacts 105 and 106 and to be
`of FIG. 1;
`'
`'
`depressed further.
`FIG. 3 is a vertical cross-sectional view of a conven
`Formed on the lower circuit 104 is a lower resist ?lm
`tional click-action type membrane switch with lighting;
`111 provided with a circular opening 112 disposed co
`FIG. 4- is a diagram showing the ideal amount of
`axially with the circular opening 110, the circular win
`movement of a click spring and the actual amount of
`dow 108, and the click spring 109. The inner edge 1100
`movement of the click spring of the conventional click
`of the opening 110 is covered by the inner peripheral
`action type membrane switch unit;
`portion of the lower resist ?lm 111. The combination of
`FIG. 5 is a graph illustrating the ideal load-displace
`the lower circuit 104 and the lower resist ?lm 111 is
`ment characteristic of the click spring of a normal click
`referred to as a layer 150. The opening 112 has a diame
`action type membrane switch unit and the actual load
`ter D3 smaller than the diameter D2 de?ned by the
`displacement characteristic of the click spring of the
`circular edge 1090 of the click spring 109 but larger
`conventional type membrane switch unit;
`than thediameter D1 of the circular window 108. The
`FIG. 6 is a plan view of a click-action type membrane
`25
`diameter D3 de?ned by the circular inner edge 112a of
`switch unit according to one embodiment of this inven
`the opening 112 is preferably 10% to 20% less than the
`tion;
`diameter D2 of the click spring 109.
`FIG. 7 is a cross-sectional view taken along line 7—7
`The switch unit is located on a rigid base 152 with the
`of FIG. 6, in which the click spring is not depressed;
`lower surface 1110 of the lower resist ?lm 111 in
`FIG. 8 is a cross-sectional view also taken along line
`7—-7 of FIG. 6, in which the click spring is depressed
`contact with the upper surface 1520 of the rigid base
`fully;
`152. The click spring 109 is designed such that when the
`FIG. 9 is a vertical cross-sectional view of a click
`lower surface l01b of the base ?lm 101 contacts the
`action type membrane switch with lighting according
`upper surface 1520 of the rigid base 152, the click action
`of the spring 109 is completed and provides the operator
`to one embodiment of this invention; and
`FIG. 10 is a vertical cross-sectional view of a click
`with sufficient clicking sensation.
`action type membrane switch with lighting according
`The exact dimensions of the click spring 109 and the
`to another embodiment of this invention.
`thickness of the base ?lm 101, the circuits 102, 103, and
`104 and the resist ?lms 107 and 111 are determined by
`the displacements B and C and the load-displacement
`characteristic of the click spring 1. For example, in the
`case of a total displacement C of 0.25 mm and an
`amount of sink B of 0.05 mm, the diameter D2 of the
`peripheral edge of the click spring 1 is 6.0 mm, and the
`thicknesses of the base ?lm 101, the circuits 102, 103,
`and 104 and the resist ?lms 107 and 111 are 0.025 mm,
`0.018 mm and 0.4 mm, respectively.
`The operation of the click-action type membrane
`switch unit according to this embodiment of the inven
`tion will now be described.
`Referring to FIGS. 4, 5 and 8, when the central por
`tion of the click spring 109 is fully depressed, the click
`spring 109 is deformed, together with the portion of the
`base ?lm 101 on which the electrode contacts 105 and
`106 are provided, until its central portion is fully low
`ered below the level of the upper surface 1010 of the
`base ?lm 101, i.e. at a level prior to the base ?lm 101
`having been deformed. The click spring 109 is shown in
`this state by the solid line 12 in FIG. 4, and possesses the
`ideal load-displacement characteristic, as shown by the
`solid line 13 in FIG. 5. Thus, the operator experiences a
`clear clicking sensation when he or she depresses the
`click spring 109, thereby con?rming that a switching
`operation has been performed.
`When the click spring 109 is released, the spring 109
`and the base ?lm 101 each return to their original
`shapes, respectively.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`Referring to FIGS. 6 to 8, a click-action type mem
`brane switch unit according to one embodiment of this
`invention includes a dielectric base ?lm 101 having an
`upper surface 101a and a lower surface 1011). Two
`45
`upper circuits 102 and 103 are formed one on each of
`the end portions 101:: and 101d of the upper surface
`101a of the base ?lm 101, and a lower circuit 104 is
`formed on the lower surface 101b thereof. Lower cir
`cuit 104 is electrically connected in the switch unit in a
`conventional manner. Parallel-arranged elongated elec
`trode contacts 105 extend from the inner end of the left
`upper circuit 102 toward the right upper circuit 103.
`Likewise,
`parallel-arranged
`elongated
`electrode
`contacts 106 extend from the inner end of the right
`55
`upper circuit 103 toward the left upper circuit 102. The
`electrode contacts 105 and 106 of the left and right
`upper circuits 102 and 103 are arranged alternately so as
`to have an interdigitating form as shown in FIG. 6.
`Formed on both upper circuits 102 and 103 is an
`60
`upper resist ?lm 107 provided with a circular window
`108 having an inner diameter D1 in the region thereof
`corresponding to the interdigitating electrode contacts
`105 and 106 of the upper circuits 102 and 103.
`A dome-shaped click spring 109 having a circular
`lower edge 1090 with a diameter D2, larger than the
`inner diameter D] of the window 108, is mounted on
`theupper resist ?lm 107 so as to be disposed coaxially
`
`65
`
`Exhibit 1015, Page 007
`
`

`
`5
`
`25
`
`30
`
`20
`
`5,294,762
`5
`6
`Illustrated in FIG. 9 is an embodiment of a click
`circular window 108. The adhesive layer 203 and the
`action type membrane switch with lighting, to which
`printed circuit plate 202 form a layer 151.
`this invention is directed.
`Although not shown in FIG. 9, the switch has a light
`loading and diffusing sheet on the uppermost resist layer
`The click-action type membrane switch unit has ?rst
`107, a formed rubber sheet covering the lighting unit
`and second printed circuit plates 201 and 202 fixed to
`gether by means of an adhesive layer 203.
`and the membrane switch unit and an outer sheet
`The ?rst printed circuit plate 201 includes a dielectric
`formed on the outer surface of the formed rubber sheet,
`like the conventional click-action type membrane
`?exible base ?lm 101, circuits 102 comprising a signal
`switch with lighting shown in FIG. 3.
`circuit 113 and a land pattern 114 both formed on the
`The operation of the embodiment of this click-action
`upper surface 101a of the base ?lm 101 in a separated
`type membrane switch with lighting will now be de
`fashion and interdigitating electrode contacts 105 and
`scribed.
`106 arranged in parallel to each other on the upper
`When the click spring 109 is fully depressed, it is
`surface 1010 of the base ?lm 101 between the signal _
`deformed downward and its central portion contacts
`circuit 113 and the land pattern 114, and a resist ?lm 107
`the electrode contacts 105 and 106, whereby the signal
`formed on the circuits 102.
`circuit 113 and the land pattern 114 are electrically
`A circular window 108 having a circular edge 108a
`connected. Thence, the LED bare-chip element 120 is
`de?ning an inner diameter D1 is formed in the portion
`energized to emit light to illuminate a number, a letter
`of the resist ?lm 107 which corresponds to the region of
`or another sign on the outer sheet. The formation of the
`the electrode contacts 105 and 106. A dome-shaped
`opening 126 allows the central portion of the click
`click spring 109 made of metal or any other material
`spring 109 to be depressed below the level of the upper
`having electrical conductivity and having a diameter
`surface 1010 of the base ?lm 101 before the click spring
`D2, larger than the inner diameter D1 of the window
`109 is depressed. This enables the membrane switch unit
`108, is disposed on the resist flm 107 so as to be coaxial
`to be deformed to the ideal degree shown in FIGS. 4
`with the window 108. This arrangement is similar to the
`and 5, ensuring satisfactory operation of the click-action
`click-action type membrane switch unit according'to
`membrane switch with lighting.
`the embodiment shown in FIGS. 6 to 8.
`FIG. 10 shows another embodiment of a click-action
`The second printed circuit plate 202 includes a resist
`type switch with lighting, employing the click-action
`?lm 111 similar to that of the embodiment of FIGS. 6 to
`type switch unit according to this invention.
`8 and having one surface ?xed to the adhesive layer 203,
`The structure of the switch is very similar to that of
`circuits 104 comprising an LED-mounting circuit 116
`the switch shown in FIG. 9, except that an LED 131
`connected to an electric-source terminal and a connect
`differs from the LED 204 of the switch of FIG. 9, and
`ing land pattern 117, one surface of each of which is
`the switch of FIG. 10 has an electric component 132
`formed on the other surface of the resist ?lm 111, and a
`such as a resistor, a capacitor or the like.
`dielectric layer 118 formed on the lower surfaces of the
`The LED 131 comprises an LED bare-chip element
`circuits 104.
`120, a bonding wire 121 for connecting the element 120
`A common hole 119 is formed in the ?rst printed
`to a lower circuit on a ceramic base 134, a capsule 133
`circuit 201, the adhesive layer 203 and the resist ?lm 111
`containing the element 120 and the wire 121 and
`above the region of adjacent parts of the LED-mount
`mounted on the ceramic base 134. The LED 131 is
`ing circuit 116 and the connecting land pattern 117. In
`located in a hole 119 formed in the switch similar to the
`the hole 119, an LED bare-chip element 120 is directly
`switch of FIG. 9, with the ceramic base 134 soldered to
`mounted on the LED-mounting circuit 116 which is
`an LED-mounting circuit 116 and a lower circuit 117.
`connected to the corresponding one of the circuits 104
`Another hole 135 extends through an upper resist ?lm
`by a bonding wire 121. The direct mounting of the LED
`107, a land pattern 114, a base ?lm 101, an adhesive
`bare-chip element 120 on the LED-mounting circuit
`layer 203 and a lower resist film 111. The electric com
`45
`116 is advantageous over the conventional click~action
`ponent 132 is located in the hole 135 and soldered to the
`type membrane switch with lighting, in order that the
`lower circuit 117.
`thickness of the switch itself can be reduced. The LED
`The other parts of the switch of FIG. 10 are the same
`bare-chip element 120 and the bonding wire 121 are
`as, and designated by the same reference numerals as
`held in a capsule 122 which is made of light-loading and
`those of the switch of FIG. 9, and thus description
`diffusing resin and whose top is dome-shaped with its
`thereof is omitted.
`circular edge limited by a circular dam member 123
`What is claimed is:
`formed on the outer surface of the uppermost resist
`.1. A click-action membrane switch unit comprising:
`layer 107. In this embodiment, the LED bare-chip ele
`a ?exible base film having a surface;
`ment 120, the bonding wire 121 and the capsule 122
`circuits formed on said surface of the base ?lm and
`constitute an LED 204.
`having interdigitating electrode contacts extending
`A hole 124 extends through the resist ?lm 107, the
`parallel with each other and with said ?exible base;
`land pattern 114, the adhesive layer 203 and the resist
`a resist ?lm’formed on said circuits and having a
`layer 111, and a connecting member 125 made of solder
`window in a region of said electrode contacts;
`paste or electrically conductive paste such as silver
`a dome-shaped click spring made of electrically con
`paste is used to ?ll it so as to electrically connect the
`ducting metal and having an edge placed on said
`land pattern 114 to the land pattern 117.
`resist ?lm; and
`An opening 126 having a circular inner peripheral
`a layer ?xed to the other surface of said base ?lm and
`wall 126a de?ning a diameter'D3, smaller than both the
`having an opening formed in a portion of said layer
`diameter D2 of the resist ?lm 107 and the diameter D1
`which aligns with said click spring, said opening
`65
`of the click spring 109, extends through those portions
`being dimensioned such that said click spring de
`of the adhesive layer 203 and the printed circuit plate
`presses said base ?lm into said opening when said
`click spring is depressed.
`202 which are coaxial with the click spring 109 and the
`
`35
`
`50
`
`Exhibit 1015, Page 008
`
`

`
`5,294,762
`7
`8
`2. The membrane switch unit according to claim 1,
`disposed adjacent to said LED in said click-action type
`wherein each of said window and said opening has a
`membrane switch unit with lighting, said click-action
`circular shape.
`type membrane switch unit comprising;
`3. The membrane switch unit according to claim 2,
`interdigitating electrode contacts formed on said ?rst
`wherein said click spring has a circular edge de?ning a 5
`surface of said base ?lm between said signal circuit
`diameter and said opening has an inner diameter which
`and said land pattern of said ?rst circuits and ex
`is smaller than said diameter of said circular edge of said
`tending therefrom,
`click spring.
`a dome-shaped click spring made of electrically con
`4. The membrane switch unit according to claim 3,
`ducting material and covering a region of said
`wherein said inner diameter of said opening is 10% to
`electrode contacts on said ?rst resist ?lm,
`20% smaller than said diameter of said circular edge of
`a window formed and disposed in said ?rst resist ?lm
`said click spring.
`so as to align with said electrode contacts, and
`5. The membrane switch unit according to claim 3,
`an opening formed coaxially with said click spring in
`wherein said window has an inner diameter smaller than
`said second printed circuit plate. ‘
`said inner diameter of said opening.
`7. The membrane switch unit according to claim 6,
`6. In a click-action type membrane switch unit with
`wherein each of said window and said opening has a
`lighting, including a ?rst printed circuit plate compris
`circular shape.
`ing a ?exible base ?lm having ?rst and second surfaces,
`8. The membrane switch unit according to claim 7,
`?rst circuits having a signal circuit and a land pattern,
`wherein said click spring has a circular edge de?ning a
`both formed on said ?rst surface of said base ?lm and a
`diameter and said opening has an inner diameter which
`?rst resist ?lm formed on said ?rst circuits, a second
`is smaller than said diameter of said circular edge of said
`printed circuit plate comprising a second resist ?lm
`click spring.
`having third and fourth surfaces, said third surface
`9. The membrane switch unit according to claim 8,
`being connected to the second surface of said base ?lm,
`wherein said inner diameter of said opening is 10% to
`second circuits having an LED-mounting circuit and a
`20% smaller than said diameter of said circular edge of
`connecting land pattern electrically connected to said
`said click spring.
`land pattern of said ?rst circuits and both formed on
`10. The membrane switch unit according to claim 8,
`said fourth surface of said second resist ?lm and a layer
`wherein said window has an inner diameter smaller than
`formed on said second circuits, an LED connected to
`said LED-mounting circuit and said connecting land
`said inner diameter of said opening.
`pattern, and a click-action type membrane switch unit
`i t i t t
`
`15
`
`20
`
`25
`
`35
`
`45
`
`50
`
`55
`
`65
`
`Exhibit 1015, Page 009