Electricity: conductors and insulators – Conduits – cables or conductors – Preformed panel circuit arrangement
Reexamination Certificate
1998-06-10
2001-05-29
Reichard, Dean A. (Department: 2831)
Electricity: conductors and insulators
Conduits, cables or conductors
Preformed panel circuit arrangement
C029S832000, C029S846000, C174S254000, C438S107000, C438S108000, C361S761000, C361S707000, C361S719000
Reexamination Certificate
active
06239381
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board for a semiconductor device and a method of making the same.
In
FIG. 15
, a conventional circuit board
10
for a semiconductor device is shown. A metal plate
14
for radiating heat is adhered on a bottom face of a base board
12
of the circuit board
10
by an adhesive.
The base board
12
has a chip hole
15
, in which an IC chip
17
is accommodated, and a set of wire patterns
18
, which is electrically connected with the IC chip
17
, is printed on an upper face of the base board
12
. An upper face of the metal plate
14
corresponding to the chip hole
15
acts as a chip mounting section
16
.
The conventional circuit board
10
, which is formed into a small piece, is made by the steps of: forming the base board
12
having the chip hole
15
and the set of wire patterns
18
; and fixing the metal plate
14
on the bottom face of the base board
12
. Each circuit board
10
is made by these steps, so the manufacturing efficiency cannot be increased.
To improve on the method of making the conventional circuit board
10
, the inventor proposed another method as shown in FIG.
16
. In the method shown in
FIG. 16
, a plurality of circuit boards are made by the steps of: forming a common base board
12
having a plurality of chip holes
15
and a plurality of sets of wire patterns
18
; fixing a common metal plate
14
for radiating heat on a bottom face of the base board
12
by an adhesive; and cutting the base board
12
and the metal plate
14
along borders between adjacent pattern units “A” by cutting means, e.g., a rooter, a die set, a press machine. By this method, a plurality of circuit boards
10
, each of which is formed into a small piece, can be made.
In the method shown in
FIG. 16
, the common metal plate
14
is fixed by the adhesive in one step, so the manufacturing efficiency of the circuit boards
10
can be improved.
However, as shown in
FIG. 17
, flashes
19
are apt to be formed in cut faces of the metal plate
14
.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a circuit board having no flashes and a method of making the circuit board.
The circuit board of the present invention comprises:
a base board having a first face and a second face, in which a plurality of sets of wire patterns, to which semiconductor chips are respectively connected, are printed on the first face; and
a metal plate for radiating heat, the metal plate being fixed on the second face of the base board,
wherein the base board includes a V-notch being formed along a border between the sets of wire patterns, and the metal plate includes a V-notch being formed to correspond to the V-notch of the base board, whereby the circuit board is divided into a plurality of circuit units, which are mutually connected by a thin section corresponding to the V-notches of the metal plate.
With this structure, the circuit board is divided into a plurality of the circuit units, which are mutually connected by the thin section corresponding to the V-notches. So the circuit board can be cut along the thin section; a plurality of the circuit units, each of which is formed into a small piece, can be easily made without forming the flashes.
Side faces of the circuit units are formed into chamfered sections by the V-notches.
If a groove is formed on an exposed face of the metal plate, heat can be effectively radiated.
The method of the present invention comprises the steps of:
forming a base board having a first face and a second face, in which a plurality of sets of wire patterns, to which semiconductor chips are respectively connected, are printed on the first face;
fixing a metal plate for radiating heat on the second face of the base board;
forming a V-notch in the first face of the base board along a border between the sets of wire patterns;
forming a V-notch formed in the metal plate to correspond to the V-notch of the base board; and
cutting the base board and the metal plate along a thin section corresponding to the V-notches of the metal plate, whereby the circuit board is divided into a plurality of circuit units.
With these steps, a plurality of the circuit units can be easily made by cutting along the thin section, so that the manufacturing efficiency of the circuit units can be increased.
Another circuit board of the present invention comprises:
a base board having a first face and a second face, in which a plurality of sets of wire patterns, to which semiconductor chips are respectively connected, are printed on the first face; and
a metal plate for radiating heat, the metal plate being fixed on the second face of the base board,
wherein the base board includes a V-notch, which reaches the metal plate, being formed along a border between the sets of wire patterns, whereby the circuit board is divided into a plurality of circuit units, which are mutually connected by a thin section corresponding to the V-notch.
With this structure, a plurality of the circuit units are mutually connected by the thin section corresponding to the V-notch, so
With this structure, the circuit board can be cut along the V-notch; a plurality of the circuit units, each of which is formed into a small piece, can be easily made without forming the flashes.
Side faces of the circuit units are formed into chamfered sections by the V-notches.
If a groove is formed on an exposed face of the metal plate, heat can be effectively radiated.
Another method of the present invention comprises the steps of:
forming a base board having a first face and a second face, in which a plurality of sets of wire patterns, to which semiconductor chips are respectively connected, are printed on the first face;
fixing a metal plate for radiating heat on the second face of the base board;
forming a V-notch, which reaches the metal plate, in the base board along a border between the sets of wire patterns;
cutting the base board and the metal plate along a thin section corresponding to the V-notch of the metal plate, whereby the circuit board is divided into a plurality of circuit units.
With these steps, the V-notch is mainly formed in the base board, namely on the base board side only. So cutting steps can be reduced. And an outer face of the metal plate is flat, so the circuit board can be stably conveyed on a manufacturing line. By cutting along the thin section, the circuit units can be made easily. Further, a sectional shape of the circuit unit is formed into a trapezoid, so it can be stably conveyed on the manufacturing line, and the manufacturing efficiency can be increased.
REFERENCES:
patent: 5047279 (1991-09-01), Nasu et al.
patent: 5196738 (1993-03-01), Bean et al.
patent: 5508089 (1996-04-01), Schulz-Harder
patent: 5528456 (1996-06-01), Takahashi
patent: 5583378 (1996-12-01), Marrs et al.
patent: 5783866 (1998-07-01), Lee et al.
patent: 550731 (1993-07-01), None
patent: 6120271 (1994-04-01), None
Aruga Misao
Hara Kaoru
Kasai Yoshiji
Birch & Stewart Kolasch & Birch, LLP
Kabushiki Kaisha Eastern
Ngo Hung V
Reichard Dean A.
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