Note: Descriptions are shown in the official language in which they were submitted.
13(~
ELECTRICAL C0~NECT0R
This invention relates to an electrical material
having a desired characteristic impedance and a contact
made of the electrical material, and particularly to
a multi-contact connector including contacts of the
05 electrical material and more particularly to a connector
for high frequency electrical or electronic appliances
such as high speed processing computers and the like.
In order to improve high speed processing
faculties of computers and their terminal equipment,
the frequency to be used has become higher and higher.
On the other hand, such a higher frequency has
encountered a great problem in that reflection is caused
by mismatching of characteristic impedance to produce
detrimental noises which obstruct the improvement of
high speed processing faculty. Therefore, it has been
indispensable to match characteristic impedances of
semiconductors such as IC and the like and substrates
equipped with the IC and the like for constituting
computers and their terminal equipment and transmission
lines between the substrates and between appliances.
Under such circumstances, with connectors used in
circuits and transmission lines, matching of
- 2-
~3(1~
characteristic impedances is required.
In hitherto used multi-contact connectors, in
general, contacts of required numbers made of the same
material and in the same shape are arranged in apertures
05 of required number formed in plastic blocks. Such
a construction is designed and produced mainly in
consideration of interchangeability, strength and heat-
resistance of the connectors, but matching of
characteristic impedances between mated connectors and
between the connectors and other instruments is not
considered.
Among connectors of the prior art, therefore,
there are few connectors having matched characteristic
impedances to exhibit required performances.
16 In multi-connectors used for transmission of
high frequency waves, moreover, the characteristic
impedance is determined by inductance and capacitance
between signal contacts and between signal and ground
contacts. With connectors of the prior art, it is
possible to make some contacts of one connector have
different or same characteristic impedance to a certain
extent by changing dielectric constants of plastic
blocks supporting contacts, thicknesses of contacts,
distances between contacts on signal and ground sides,
and numbers and distributions of ground contacts.
However, in order to make some contacts have
13~31'~'i'
different characteristic impedances, it is necessary to
use contacts of different thicknesses, to change
distances between contacts, and numbers and
distributions of ground contacts. As a result,
05 connectors become complicated in construction and
difficult and expensive to manufacture.
Moreover, shape and construction of a member
in which a connector is fitted is limited so that the
interchangeability of connectors is considerably
reduced. Further, there is a problem to be solved
in that the thickness of contacts and distances
therebetween may become impracticable depending upon
values of impedance.
It is an object of the invention to provide
an electrical material from which is produced
a laminated contact having a desired characteristic
impedance.
It is a further object of the invention to
provide a connector including laminated contacts having
different desired characteristic impedances.
In order to achieve these objects, according to
the invention an electrical material made of a laminated
material having a conductive layer, a springy layer and
a dielectric layer therebetween comprises at least one
2~ removed part selected from parts of said electrical
material, said conductive layer, said springy layer and
said dielectric layer.
Moreover, according to the invention at least
one parameter among thickness, material and component of
said dielectric layer was changed.
05 According to a method of adjusting charac-
teristic impedance of a contact formed by a laminated
material having a conductive layer, a springy layer and
a dielectric layer therebetween, the characteristic
impedance is adjusted by changing at least one parameter
among parameters of width of at least one of said
conductive, springy and dielectric layers and thickness
and specific inductive capacity of said dielectric
layer.
In a contact formed by a laminated material
16 having a conductive layer, a springy layer and
a dielectric layer therebetween and having an electrical
contacting portion at least at one end, according to the
invention at least part of an end of at least one of
said conductive, springy and dielectric layers on
a contacting portion side was removed, said removed
portion starting from a point slightly spaced from
a contacting point of the contacting portion.
In a multi-contact connector including a housing
block and at least two contacts each formed by
a laminated material having a conductive layer,
a springy layer and a dielectric layer therebetween and
~3(~
assembl~d in the housing block, according to the invention at
least one of the contacts comprises at least one removed part
selected from parts of the contact, the conductive layer, the
springy layer and the dielectric layer.
In a connector including a housing block and at
least two contacts each formed by a laminated material having
a conductive layer, a springy layer and a dielectric layer
therebetween and assembled in the housing block, according to
the invention at least one parameter among thickness, material
lo and component of the dielectric layer was changed.
In accordance with one aspect of the invention there
is provided a connector comprising: a housing block; and
at least one contact formed of a laminated material, the
laminated material having a conductive layer, a springy layer
and a dielectric layer located between said conductive layer
and said springy layer, said contact having a contacting
portion, for contacting a contacting portion of a mating
connector, and a tail portion, wherein; said tail portion is
for connection to an external circuit, said conductive layer
is narrower than said springy layer and said dielectric layer
in said contacting portion and narrower than the conductive
layer in said tail portion to thereby form a narrowed
conductive layer region; and wherein the width of said
narrowed conductive layer region is more than one half of the
width of said springy layer and said dielectric layer in the
contacting portion and less than the width of the contact in
the tail portion.
, .~,
~ ~t~
The invention will be more fully understood by
referring to the following detailed specification and claims
taken in connection with the appended drawings.
6a
~J31~'~
Fig. 1 is a perspective view of an electrical
material according to the invention;
Fig. 2 is a perspective view of a laminated
contact according to the invention;
05 Fig. 3 illustrates a laminated contact whose
characteristic impedance is shown in Fig. 4;
Fig. 4 is a graph illustrating a relation
between the characteristic impedance and width of the
laminated contact;
Fig. 5 shows a laminated contact whose
characteristic impedance is shown in Fig. 6;
Fig. 6 is a graph showing a relation between the
characteristic impedance and thickness of a dielectric
layer;
1~ Figs. 7a-7d illustrate various laminated
contacts according to the invention;
Figs. 8a and 8b illustrate male and ~emale
connectors including laminated contacts according to the
invention;
Figs. 9a and 9b illustrate other male and female
connectors including laminated contacts according to the
invention;
Fig. 10 shows fitted male and female connectors
whose contacts are in contact with each other with
deformations of contacting portions of the contacts;
Figs. 11, 12 and 13 illustrate multi-contacts
formed by etching and pressing with dies;
Figs. 14 and 15 illustrate other multi-contact
connectors;
Fig. 16 illustrates an overlapping portion of
05 laminated contacts;
Figs. 17 and 18 illustrate a laminated contact
whose characteristic impedance is shown in Fig. 19;
Fig. 19 is a graph illustrating a relation
between the characteristic impedance of the contact
shown in Figs. 17 and 18;
Figs. 20 and 21a-21d illustrate laminated
contacts whose parts are removed according to the
invention;
Fig. 22 is a perspective view illustrating
laminated contacts according to the invention;
Figs. 23a-23e illustrates ends of the laminated
contacts according to the invention;
Figs. 24a illustrates contacting condition of
the contacts shown in Fig. 23e;
Fig. 24b shows the shape of the contact of
Fig. 23c which is applied to the contacts shown in
Fig. 12:
Figs. 25a-25d are explanatory views illustrating
a plug connector according to the invention; and
Figs. 26a-26c are explanatory views illustrating
- a receptacle connector according to the invention.
A laminated material explained in this
specification is very thin. For example, thicknesses of
a conductive layer 1, a springy layer 2 and a dielectric
layer 3 therebetween are usually 9-70 ~m, 100-300 ~m and
05 10-200 ~m, respectively. It is therefore understood
that the respective layers are shown on exaggerated
scales in respective drawings.
The multi-contact connector comprises a block
of a plastic material and a plurality of laminated
contacts arranged therein. As shown in Fig. 1, a thin
metal plate 1 having a high conductivity such as copper
and a thin metal plate 2 having a superior spring
performance are attached onto both sides of a dielectric
plate 3 to form a laminated plate 4. The laminated
plate 4 is worked by etching or pressing with dies to
form a plurality of laminated contacts 5 having the same
or different characteristic impedances, respectively.
These laminated contacts are assembled into the plastic
block to form the multi-contact connector.
According to the invention, the required
characteristic impedances are given to the contacts by
the following methods.
1. Changing widths of contacts
2. Changing thicknesses of a dielectric layer
3. Changing specific inductive capacities of
a dielectric layer, and
4. Suitable selective combination of the above
three changes.
These methods will be explained in detail
herein.
05 l. Chan~ing width of contacts
The characteristic impedance can be set at
a certain constant value typically by changing widths
of the conductive layers. In case of contacts as shown
in Fig. 3, a relation between the width of the contacts
and the characteristic impedances is shown in Fig. 4,
wherein the impedances are measured between the
conductive layers and the springy layers. The abscissa
indicates the widths mm of the contacts and the ordinate
indicates the characteristic impedance Q. From Fig. 4,
when the width w of the contact is 0.3 mm, the charac-
teristic impedance is about 50 Q, and on the other hand,
when the width is 1 mm, the impedance is about 22 n.
In Fig. 3, the springy layer 2 is a stainless
steel plate having a thickness 0.15 mm. The dielectric
layer 3 is a plastic layer mainly made of polyimide
having a thickness of 0.15 mm and a dielectric constant
of 4. The conductive layer l is a copper plate having
a thickness 35 ~m and partially removed with pitches p
of 2.54 mm.
The purpose of changing widths of contacts is to
change capacitances. Therefore, it is clear that such
- 10 -
a purpose is accomplished by partially notching part of
the conductive layer 1 or by changing widths of
a springy layer in an independent contact as shown in
Fig. 2. Moreover, the purpose is also accomplished by
05 changing widths of a dielectric layer.
A contact having a desired width is easily
produced by pressing with dies in case of the contact
shown in Fig. 2 and in case of the contact shown in
Fig. 13 by chemical etching or additive method which is
a method for producing printed circuit patterns.
2. Changing thicknesses of a dielectric layer
A film-shaped dielectric layer can be used for
the dielectric layer in the invention. Such a film-
shaped dielectric layer can be easily produced to have
a desired thickness of the order of 10 ym. Actually,
moreover, film-shaped dielectric layers having various
thicknesses and made of various materials are com-
mercially available. Therefore, the dielectric layer
used in the present invention can be made in a desired
thickness at will.
In case of contacts as shown in Fig. 5,
a relation between thicknesses D of the dielectric
layers and characteristic impedances measured between
the conductive layer and the springy layer is shown
in Fig. 6. The abscissa indicates the thicknesses D ~m
of the dielectric layer and ordinate indicates the
- 11 -
~3~
characteristic impedance Q.
In Fig. 6, when the thickness D of the
dielectric layer is 50 ~m, the characteristic impedance
is about 27 Q. On the other hand, when the thickness D
05 is 170 ~m, the characteristic impedance is about 50 n.
The contact shown in Fig. 5 is similar to the
contact shown in Fig. 3 with the exception that the
width w of the contact is 0.4 ~m and the thickness D of
the dielectric layer is changed.
3. Changing specific induction capacities of
a dielectric layer.
The specific inductive capacities of
a dielectric layer can be achieved typically by
the following manners.
(1) Changing materials of the dielectric layer
(2) In case of the dielectric layer consisting of
different materials more than two,
1) changing ratios of thicknesses in case
of laminated body, or
2) changing ratios of mixing in case of
kneaded body, and
(3) Changing densities of bubbles in case of
dielectric layer including the bubbles at least
in part of the dielectric layer
The ~aterial now used for the dielectric layer
is typically Teflon having a low dielectric constant
* trade mark
- 12-
,, .~
.
of ~r = about 2 and polyimide having a relatively high
dielectric constant of Er = about 3.5. Various
dielectric materials having intermediate dielectric
constants therebetween are commercially available.
05 Dielectric materials of various thicknesses are also
available.
Moreover, various dielectric materials having
various dielectric constants are also available which
are produced by kneading dielectric materials more than
two to have particular dielectric constants by changing
ratios of the mixed dielectric materials, or changing
densities of bubbles produced in parts of the materials.
With the contact according to the invention,
the above means are realized by utilizing the easily
available dielectric materials and phenomena of the
specific inductive capacity and capacitance in
electromagnetism.
4. Combination of above three changes
In order to change the capacitance or
characteristic impedance of the contact, the above three
changes can be suitably selectively combined to more
finely adjust the characteristic impedance without
causing any problems.
Figs. 7a-7d perspectively illustrate ends of
plate-like laminated contacts 5 having the charac-
teristic impedances in the manner above described.
- 13-
13V~
The laminated contact 5 shown in Fig. 7a comprises
a conductive layer l, a springy layer 2 and a dielectric
layer 3 having a uniform width and a uniform thickness.
In this case, the characteristic impedance determined by
05 widths and thicknesses of the laminated contact 5 and
a dielectric constant of the dielectric layer 3 is
substantially constant at any positions in a longi-
tudinal direction of the laminated contact 5 when the
springy layer 2 is grounded.
With the laminated contact 5 shown in Fig. 7b,
either of the conductive layer and the springy layer is
partially removed by etching or the like to obtain
a uniform width. The dielectric layer 3 may be
partially removed i~ no troubles.
Elongated or circular apertures of desired
numbers and shapes may be formed in the contact as
examples of partially removing at least the conductive
layer as shown in Figs. 7c and 7d.
The laminated contacts 5 having desired
characteristic impedances formed as above described are
assembled into plastic blocks to obtain a multi-contact
male connector 8 and female connector 9 as shown in
Figs. 8a and 8b and Figs. 9a and 9b. As shown in
section in Fig. lO, when the male and female connectors
8 and 9 are fitted, contact elements lO extending from
the laminated contacts 5 in opposition to each other are
- 14-
brought into contact with each other to electrically
connect these contacts by resilient forces caused by
deformations of the contact elements 10.
The laminated contacts 5 shown in Figs. 2 and
05 7a-7d are sin~le contacts by way of example. However,
one laminated plate is formed with a desired number of
contacts 11 by, for example, etching a conductive layer
1 of the laminated plate and the laminated plate is then
formed into multi-contacts by, for example, pressing
with dies as shown in Figs. 11, 12 and 13. Thereafter,
the multi-contacts are assembled in plastic blocks 6 and
7 to form multi-contact male contacts 8 and female
contacts 9 as shown in Figs. 14 and 15. In this case,
Figs. 11 and 12 illustrate contacts having the same
characteristic impedances and different characteristic
impedances, respectively. The characteristic impedance
of a single laminated connector is determined by the
characteristic impedance of the laminated contacts.
However, there is a problem to be considered in
that a characteristic impedance under a fitted condition
between laminated connectors or between a laminated
connector and a member of a printed circuit board or the
like, is often greatly different from a characteristic
impedance of the single laminated connector. In such
a case, it is required to adjust the characteristic
impedance of the single laminated connector so that the
- 15-
characteristic impedance under the fitted condition
matches an impedance of an IC or substrate.
Fig. 16 illustrates fitted male and female
connectors including the laminated contacts 5 shown in
05 Fig. 2, wherein plastic blocks are removed. The male
and female laminated contacts 5 and 5' are in contact
with each other at their contact elements 12 to be
electrically connected as in Fig. 16. The charac-
teristic impedance under this fitted condition is
different from the characteristic impedance of the
single laminated contact in the overlapping portions e
of the laminated contacts S and 5'. In other words, as
the overlapping portions e are under a condition of
condensers being connected in parallel with each other,
the capacitance of the overlapping portions e becomes
a large value which is the sum of the capacitances of
the respective overlapping portions of the laminated
contacts 5 and 5'. In such a case, the characteristic
impedance under the condition of the fitted laminated
connectors is smaller than the characteristic impedance
of the single laminated connector.
Fig. 19 is a graph illustrating one example of
the relation between the characteristic impedance and
overlapping length of laminated contacts, wherein
laminated contacts as shown in Fig. 17 are electrically
connected with their front ends being overlapped by the
i3U3~
distance e as shown in Fig. 18. The characteristic
impedance is measured between the conductive layer and
the springy layer which is grounded. Although the
contacted condition of the laminated contacts shown in
05 Fig. 18 is different from that of shown in Fig. 16, the
measured values of the characteristic impedance of the
overlapping portions e are substantially ~imilar to each
other. The laminated contact 5 shown in Fig. 17
comprises the springy layer 2 made of a stainless steel
of a thickness of 0.15 mm, the dielectric layer made of
a plastic layer of a specific inductive capacity 4, and
a conductive layer 1 consisting of copper stripes having
a width of 0.4 mm and a thickness of 3S ~m with pitches
of 1.27 mm.
1~ As can be seen from Fig. 19, as the overlapping
length increases, the characteristic impedance of the
overlapping portions decreases. The degree of
mismatching of the characteristic impedance becomes
large at the overlapping portions.
In order to solve this problem or to make the
characteristic impedance of the overlapping portions as
equal to that of the remaining portions of the laminated
contacts as possible, the following means are employed
according to the invention.
1. Shortening the length of at least one of the
conductive, springy and dielectric layers to make small
the overlapping portions
2. Narrowing the width of the overlapping portion
of at least one of the conductive, springy and
dielectric layers
05 3. Suitably selectively combining the above means 1
and 2.
1. Shortening the length of at least one of the layers
As the overlapping portions of the laminated
contacts are shorter, the characteristic impedance of
the overlapping portions becomes near to the
characteristic impedance of the single laminated
contact. For this purpose, parts of the overlapping
portions are removed as shown in phantom lines in
Figs. 20a and 20b.
1~ In the embodiments shown in Figs. 20a and 20b,
the parts of the laminated contacts are completely
removed. Parts of either of conductive and springy
layers may be removed as shown in Figs. 21a-21d.
Figs. 21a and 21b illustrate embodiments removing parts
Of conductive and springy layers 1 and 2. Fig. 21c or
21d illustrates another embodiment removing parts of
front ends of conductive or springy layer 1 or 2 in
width directions of the contacts 5 and 5' to form
notches extending in the width directions. Such
2~ a removing the parts may be effected on both the
conductive and springy layers 1 and 2. Moreover, the
3i~
cut front ends of the conductive and springy layers may
be short-circuited.
Fig. 22 illustrates an embodiment in which the
contacts shown in Fig. 21a are applied to the contacts
05 shown in Fig. 12. Fig. 22 shows the contacts omitting
their tail ends. As the fitted portionC of contacts are
similar in variation in characteristic impedance to the
tail ends of the contacts which serve to secure the
contacts to a printed circuit board or the like, the
above means can be applicable to the tail ends in the
same manner.
The contacts shown in Fig. 17 were brought into
contact with each other as shown in Fig. 16 with
an overlapping length of 20 mm. The characteristic
impedance which was 46 n under non-contacted condition
lowered to about 29 Q. On the other hand, the contacts
shown in Fig. 17 were worked into the shapes as shown in
Fig. 21c. In this case, the characteristic impedance
lowered only to about 42 n in the same measurement.
2. Narrowing the width of overlappin~ portion of at
least one of the layers
Figs. 23a-23e illustrate ends of contacts
applicable to fitted portions and tail portions.
In embodiments shown in Figs. 23a and 23b, part
on one side or parts on both sides of laminated contacts
5 are completely removed in thick directions. Parts of
- 19 -
either of conductive and springy layers l and 2 may be
removed by etching or the like as shown in Figs. 23c,
23d and 23e. Part or parts of a dielectric layer may
be removed, if possible. In the embodiment shown in
0~ Fig. 23e, a part of the conductive layer l is
progressively narrowed to form a triangular portion.
In the embodiments shown in Figs. 23a-23d,
if the dielectric layers are uniform in thickness and
material, the width of the narrowed portions is
preferably more than one half of the width and less than
the width of the remaining portions of the contactsO
Fig. 24a illustrates a contacting condition of
the contact shown in Fig. 23e. When the overlapping
condition of the conductive layes is that shown in
Fig. 24a, the characteristic impedance is uniform which
is advantageous.
Fig. 24b illustrates an embodiment wherein the
shape of ends of the contact shown in Fig. 23c is
applied to the contact shown in Fig. 12. Fig. 24b
illustrates only a fitted end of the contact. The above
means may be applicable to the tail portion of the
contact to obtain desired characteristic impedance at
the end.
As can be seen from the above explanation, the
2~ characteristic impedance of a connector can be adjusted
by changing the capacitance of laminated contacts
-20-
13V~
without changing thickness and intervals of the
contacts, the number and distribution of ground contacts
and the dielectric constant of a plastic material of
housings including the contacts. In other words, the
05 characteristic impedance can be adjusted, while the
connector fulfills requirements as a connector.
It is of course that with laminated contacts,
the characteristic impedance can be adjusted by changing
widths or int`ervals of the contacts.
In the laminated contacts according to the
invention, the characteristic impedance can also be
adjusted by changing the dielectric constant and
thickness of dielectric layer. In this manner, the
invention has superior effects which could not be
accomplished by the prior art.
~n embodiment of an electrical connector for
a printed circuit board, including eight signal lines
and having characteristic impedance of 50 n will be
explained hereinafter.
Figs. 25a-25d illustrate a plug connector and
Figs. 26a-26c show a receptacle connector to be fitted
with the plug connector shown in Figs. 25a-25d.
In Fig. 25a, tail ends of contacts 15 of the
type shown in Fig. ll are bent perpendicularly outwardly
26 and distal ends of the tail ends are folded inwardly.
The shape shown in Fig. 23c is applied to ends of
13U31~'~
conductive layers of the contacts.
Fig. 25b illustrates a connector housing 17
having the contacts 15 shown in Fig. 25a and attached to
a printed circuit board 19 by means of screws and nuts.
05 Fig. 25c is a sectional view of the connector shown in
Fig. 25b taken along a plane vertical to the surface of
Fig. 25b.
Fig. 26a illustrates contacts 21 formed by
perpendicularly bending tail portion of the contacts
shown in Fig. 12 and having front ends of conductive
layer to which the shape shown in Fig. 23c is applied.
Fig. 26b shows a connector comprising the
contacts 21 shown in Fig. 26a and a connector housing 23
receiving the contacts 21 and mounted onto a printed
16 circuit board 25 by means of screws and nuts.
Fig. 26c is a sectional view of the connector
shown in Fig. 26b taken along a plane vertical to the
surface of Fig. 26b.
The connector housings 17 and 23 are made of
polyphenylenesulfide. In order to support the contacts,
moreover, a column is provided in a center space of
the contact housing as its part as shown in Fig. 25c.
Dimensions of the connector housing are not important
for the subject matters of the invention and it is
26 sufficient to produce the connector by the usual
manufacturing manner.
- 22-
13(J~
Figs. 25a and 26a will be explained in more
detail. There are provided exposed portions 27 of the
springy layer 2 on both sides of the eight conductive
layers l for connecting the springy layer 2 to the
05 ground. When the connectors shown in Figs. 25b and 26b
are fitted, the exposed portions 27 provided at
contacting portions of the contacts among the exposed
portions are in contact with each other. Fig. 25d is
an enlarged drawing of the exposed portion 27 of the
springy layer. As shown in Figs. 25a and 25b, the
exposed portions 27 are also provided at the tail
portions.
In these embodiments, soldering by vapor
reflowing is preferable for connecting the conductive
16 layers of the plug connector and the receptacle
connector and the pattern of a printed circuit board.
The contacts shown in Figs. 25a and 26a are
produced in the followins manner.
A polyimide film of a thickness of lO0 ~m having
a specific inductive capacity of 3.5 is attached onto
one surface of a copper plate having a thickness of
35 ~m by a thermosetting adhesive of a thickness of
25 ~m of epoxy. Another surface of the polyimide film
is attached to a stainless steel plate of a thickness of
150 ~m by a thermosetting adhesive of a thickness of
45 ~m. In attaching these members, they are pressed,
- 23-
~J3~
while heating. In these embodiments, the resulting
specific inductive capacity of the dielectric layers is
about 4.
The conductive layer pattern is then formed
05 by etching. Thereafter, the layers are formed by
pressing into the shapes shown in Fig. 25a or 26a.
In the pattern, the wide portions of the conductive
layer have a width of 0.4 mm and narrowed portions of
the contacting portions and tail portions have a width
of 0.2 mm. The contacting portions of the conductive
layer are arranged with pitches 1.0 mm.
While the invention has been particularly shown
and described with reference to preferred embodiments
thereof, it will be understood by those skilled in the
art that the foregoing and other changes in form and
details can be made therein without departing from the
spirit and scope of the invention.
- 24-
