JPH0516407A - Thermal head - Google Patents

Abstract

PURPOSE:To prevent the separation of connection or breaking of wire between a conductive lead at the side of a semiconductor device and a signal line of a heat, generating substrate. CONSTITUTION:A base film 12 of a film carrier is bonded to an end of a heat, generating substrate 16. At the same time, an opening 12a is formed at, the center of the base film 12. A semiconductor device 11 is disposed within the opening 12a. The semiconductor device 11 is connected to a signal line on the heat generating substrate 16 via a conductive lead 14 provided on the base film at both sides of the semiconductor device 11. Since the semiconductor device 11 is connected single-sidedly to the heat generating substrate 16 according to this invention, such problems that the connecting part is separated or the conductive lead is broken, etc., due to the thermal stress can be solved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head which is a printing component for printers, facsimiles and the like.

[0002]

2 and 3, inner lead bonding portions (hereinafter referred to as ILB portions) 4a and 4b of conductive leads 4 extending from base films 2a and 2b of a film carrier are connected to a semiconductor element 1 by thermocompression bonding. Has been done. Further, outer lead bonding portions (hereinafter referred to as OLB portions) 3a and 3b of the conductive leads 4 are respectively a heating element substrate 6 made of ceramics or the like and a printed circuit board 7 made of glass epoxy or the like adhered on the base 5.
Are connected to the electrodes (not shown) formed on each of them by thermocompression bonding.

Further, on the heating element substrate 6, the heating resistor row 8 and the OLB portion 3a of the conductive lead 4 and the heating resistor row are connected, and the pitch of the OLB portion 3a and the heating resistor row 8 are connected. An individual signal line 9 for converting the pitch is formed.

[0004]

As described above, in the prior art, the method of fixing the heating element substrate 6 and the printed circuit board 7 to the base 5 is simply fixed by pressing with screws or adhesive tape. Therefore, the heating element substrate 6 and the printed circuit board 7 expand and contract with respect to the center by the coefficient of thermal expansion. In particular, in the case of a thermal head on which a large number of semiconductor elements 1 are mounted, the dimension in the direction in which a large number of semiconductor elements 1 are mounted becomes long. Therefore, in the semiconductor device part which is mounted on both end portions near the heat generating element substrate 6 and the printed circuit board 7 due to the difference in the movement amount Y ₂ moving amount Y ₁ and the printed circuit board 7 of the heating element substrate 6 increases Of the conductive lead 4 and the IL of the conductive lead 4
The B parts 4a and 4b are subjected to mechanical stress, and there is a problem such as peeling or disconnection of the connection part.

Therefore, the present invention aims to prevent such peeling or disconnection of the connection.

[0006]

In order to achieve this object, the present invention is to adhere a base film of a film carrier to an end portion of a heating element substrate and to provide an opening in the center portion of the base film. A semiconductor element is placed inside, and the semiconductor element and the signal line on the heating element substrate are
The connection is made through the lead wires provided on the base film on both sides of the semiconductor element.

[0007]

According to the above means, the semiconductor element moves only in accordance with the coefficient of thermal expansion of the heating element substrate, and the problems such as peeling of the connection portion and disconnection of the conductive lead due to thermal stress are solved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIGS. 1 and 2, only one end of the base film 12 of the tape carrier is bonded and fixed on the end of the heating element substrate 16.

Further, the base film 12 is provided with an opening 12a, and the semiconductor element 11 is arranged in the opening 12a. And in this state, the base film 12
ILB portions 14a and 1 of the conductive lead 14 extended from above
4b is connected to the semiconductor element 11 by thermocompression bonding.
Further, the OLB portion 13 of the conductive lead 14 and the electrode (not shown) formed on the heating element substrate 16 made of ceramics or the like adhered on the base 15 are connected by thermocompression bonding.

On the heating element substrate 16, the heating resistor row 17 is connected to the OLB portion 13 of the conductive lead 14 of the semiconductor device for driving the heating resistor row 17 and the heating resistor row 17, and the OLB is connected. Individual signal drive lines 18 for converting the pitch of the portions 13 and the pitch of the heating resistor rows 17 and various control signal lines 19 for connecting the respective tape carriers are formed. The various control signal lines 19 are connected to the conductive leads 14 on the base film 12 by thermocompression bonding.

As described above, various control signals are transmitted to each semiconductor element 11 via the heating element substrate 16, the tape carrier and the semiconductor element 11.

[0013]

As described above, according to the present invention, since only one end side of the base film of the film carrier on which the semiconductor device is mounted is adhered to the heating element substrate, problems such as peeling of the connecting portion and disconnection due to thermal stress are solved. It

[Brief description of drawings]

FIG. 1 is a plan view of a thermal head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line A-A ′ in FIG.

FIG. 3 is a plan view of a conventional thermal head

4 is a cross-sectional view taken along the line A-A ′ of FIG.

[Explanation of symbols]

 11 semiconductor element 12 base film 14 conductive lead of ILB part 15 base 16 heating element substrate

Claims (1)

Claim: What is claimed is: 1. A base, a heating element substrate provided on the base, and a base film of a film carrier having an end portion adhered to an end portion of the heating element substrate, The base film has an opening in the middle thereof, a semiconductor element is arranged in the opening, and the semiconductor element and the signal line on the heating element substrate are conductive wires provided on the base film on both sides of the semiconductor element. Thermal head connected via leads.