JPH03158255A - Thermal head device - Google Patents

Abstract

PURPOSE:To obtain a thermal head with higher density by a method wherein on an FPC, intervals for an insulating parts are set wider than those for a conductive part by a designated dimensional difference, whereas on a chip, intervals for a pattern width of the conductive part are set wider than those for the insulating part with a same dimensional difference for the pattern on the FPC. CONSTITUTION:On a chip 1, a common electrode 3 which is connected to all of respective heating elements and individual electrodes 4 which are individually connected to respective heating elements jointly exist. Also on an FPC side, the same common electrode and individual electrodes exist. On this chip 1, (p) shows a pattern pitch for a conductive part 1b and insulating part 1a, (b) shows a pattern width for the conductive part 1b, and (a) shows a pattern width for the insulating part 1a. In addition, on the FPC 2, (p) is a pattern pitch for a conductive part 2b and insulating part 2a just as on the chip 1, (a) is a pattern width for the conductive part 2b and (b) is a pattern width for the insulating part 2a. In this case, (a) and (b) have a relationship as a>b. By this method, it becomes possible to discriminate a good or bad condition of the actual fitting by existence of protrusion of the conductive part of the chip from the insulating part of the FPC on an interval which has a width of (b).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a thermal printer, particularly a serial type thermal printer, in which electrical conduction is achieved at the connection between a chip and an FPC above a thermal head. This relates to the pitch dimension of the pattern between the section and the insulating section.

[Conventional technology]

Conventionally, in thermal printers, chips and FPCs have been connected using solder or the like, as shown in FIG.

However, as shown in Fig. 4, the number of heating elements on the thermal head was small, 7 to 9 yen, or 24 dots at most, so the number of heating elements on the chip side was small, and the number of heating elements was small. The pattern pitch between the conductive part and the insulating part on the FPC is exactly the same as that of the FPC, and little consideration has been given to the dimensional relationship between the chip and the FPC pattern.

Alternatively, as shown in Figure 5, in response to the recent demands for a higher number of dots and higher density for thermal heads, technologies such as a chip-ON type, in which an IC is placed on top of the chip, are often used. , little attention was paid to the connection technology between FPC and chips.

Therefore, the FPC and the chip have been mounted using a fairly rough method.

[Problems and Objectives to be Solved by the Invention] However, as the number of dots in the thermal head is increasing from 24 dots or more to 48,56,64 dots, the chip ON type as shown in FIG. In the case of serial type thermal printers, which are often used in the cost-oriented printer market such as word processor printers, placing an IC on the chip leads to an increase in the chip size, which has the biggest impact on cost, It was not suitable for thermal printers.

Moreover, in order to cope with the increase in the number of dots and the increase in density, taking the 24-dot type serial type thermal head as shown in Fig. 4 as an example, in order to increase the number of dots from 24 dots to 48 dots, it is necessary to increase the number of dots. In order to maintain the pattern pitch between the conductive part and the insulating part of FPC and chip up to In order to supply thermal serial printers, we must provide chips and FPs.
Regarding the pattern pitch dimension of the electrodes on C, it was necessary to pursue higher density.

Also, the chip and FPC in the conventional thermal head device
The relationship between the pattern pitch between the conductive part and the insulating part of the individual electrode during mounting is as shown in Figure 3 (C), where p is the pattern pitch interval, and the pattern width of the conductive part and the insulating part. is generally set to p/2, which is the dimensional relationship of the pattern pitch between the conductive part and the insulating part, which has been used in most Herad chips of 24 dots or less.

However, if high-density mounting of 48 dots or more is performed using this dimensional relationship, the pattern pitch between the conductive part and the insulating part will be the same value as p/2, as shown in Figure 3 (C). If the pattern pitch is half the pattern pitch p, theoretically both pitches are perfectly aligned. Implementation is possible.

However, during actual mounting, pattern pitch deviations occur in most cases, and the higher the density of mounting, the more difficult it is to discover simple defective locations by visual inspection, etc., as there is no characteristic method for detecting defective states. There was a drawback.

An object of the present invention is to provide a thermal head device that can meet the market demand for thermal serial printers that achieve high printing quality due to high density and multi-dot printing, and at the same time reduce costs. It is in.

[Means for solving Section U]

The present invention provides a thermal printer device in which a plurality of heating elements are arranged near the end face of a chip and prints on printing paper via thermal paper or an ink ribbon. Insulates the conductive parts formed on the FPC and chip at the connection part with the FPC, which mediates conduction with the printer system and the a-board, which supplies power to any heating element and enables printing. In an electrode pattern consisting of two parts, on an FPC, the insulating part is set wider than the conductive part by a certain dimensional difference; on the other hand, on a chip, the pattern width of the conductive part is wider than the insulating part. This thermal head device is characterized in that the spacing is set wider with a dimensional difference similar to that of the pattern on the FPC.

〔Example〕

Examples according to the present invention will be described in detail below.

Figure 1 shows an example of mounting a thermal head device in which a 48-dot thermal head with a dot pitch of 300 DP is connected to an FPC.
is FPC.

Here, the FPC 2 connects the head control board (not shown) and the chip, and connects any heating element (not shown) on the chip.
It supplies electricity to enable printing.

FIG. 2 is an enlarged view of the Herad chip 1 and FPC shown in FIG. There is an individual electrode section 4 that is electrically connected to the FPC side, and a similar common electrode section and individual electrodes are also present on the FPC side.

The present invention relates to the pattern pitch between the insulating part and the conductive part of the FPC and chip in the mounting part of FIG. 1 and the individual electrode part of FIG. 2, and the details are shown in FIG. 3(a) 1: .

In FIG. 3(a), 1a represents an insulating portion, 1b represents a conductive portion, and similarly, 2a represents an insulating portion and 2b represents a conductive portion.

In this chip 1, p represents the pattern pitch between the conductive part and the insulating part, b represents the pattern width of the conductive part, and a represents the pattern width of the insulating part.

Furthermore, on the FPC, p is the pattern pitch between the conductive part and the insulating part, as on the chip, a is the pattern width of the conductive part, and b is the pattern width of the insulating part.

At this time, al and b have the relationship a>b.

〔Effect of the invention〕

According to the present invention, the width of the conductive part on the chip of the individual electrode part as shown in FIG. The width of the conductive part on the FPC is wide.

Therefore, when mounting, the FPC is on the top side and the chip is on the bottom side, so the quality of the mounting is determined by whether or not the conductive part of the chip protrudes over the gap that is wider than the insulation part of the FPC. becomes possible.

In other words, in the case of this embodiment, the pattern pitch is a+b=p
Therefore, in each pattern on the chip, even if the mounting position of the FPC and the chip deviates by the narrowness of the pattern width of the insulating part, it will not be confirmed from the FPC that the pattern position is misaligned.

Therefore, if the conductive part of the chip cannot be seen from above the FPC, it is possible to confirm that the chip is mounted properly.

However, as shown in Figure 3(b), unlike in Figure 3(a), if the magnitude relationship of the conductive parts between the FPC and the chip is reversed, it is difficult to view the chip from the FPC side during mounting. Therefore, the end face of the conductive part of the chip is always visible on the FPC side, and it is abnormal if it is no longer visible on the FPC.

This identification method is the opposite of the method shown in FIG. 3(a) in which something is visible in the event of an abnormality, and it becomes extremely difficult to detect mounting defects.

In this way, if the dimensional relationship of the pattern pitch between the conductive part and the insulating part of the chip and FPC as shown in Figure 3(a) is realized, it will be possible to supply thermal serial heads at high density and at low cost. .

According to the present invention, pattern pitch 1, which was extremely difficult in the past,
70 micron, pattern distribution 80 micron and 90
It is possible to mount a thermal head and FPC with settings on the order of microns.

In addition, in future technological development, according to the method of the present invention, it will be possible to realize mounting with a pattern pitch of 100 microns and a pattern distribution of about 55 microns or 45 microns.

[Brief explanation of the drawing]

FIG. 1 is an outline diagram of a thermal head and an FPC mounted using the present invention. Figure 2 shows the thermal head chip and FPC shown in Figure 1.
It is an enlarged view of. FIG. 3 is a diagram showing the pattern pitch dimension relationship between the insulating part and the conductive part in the individual electrode parts of the chip and the FPC, and FIG. 3(a) shows an embodiment of the present invention. FIG. 3(b) shows the pattern pitch relationship when the pattern pitch relationship is different from that in the embodiment of the present invention, and FIG. 3(C) shows the pattern pitch relationship when the insulating part and the conductive part are the same as in the conventional example. This shows the pattern pitch relationship when there is a width. FIG. 4 is an outline drawing of a 24-dot type Herad chip mounted thereon. FIG. 5 is an outline drawing when a chip-ON type Herad chip is mounted. a b a b Thermal head chip insulation part conduction part PC insulation part conduction part common electrode part individual electrode part driver IC Figure 3 (a)

Claims (1)

[Claims] 1) A plurality of heating element elements are arranged near the end surface of a thermal head chip (hereinafter referred to as a chip), and thermal paper,
Alternatively, in a thermal printer device that prints on printing paper via an ink ribbon, power is supplied to the chip and any heating element on the chip to enable printing.
FP located at the connection part with the flexible printed circuit board (hereinafter referred to as FPC) that mediates the conduction with the printer control board.
In the electrode pattern formed on the C and the chip, which consists of a conductive part and an insulating part, on the FPC, the insulating part is set to have a wider interval than the conductive part with a certain dimensional difference,
On the other hand, the thermal head device is characterized in that, on the chip, the pattern width of the conductive part is set wider than the insulating part with a dimensional difference similar to that of the pattern on the FPC. 2) The thermal head device according to claim 1, wherein in the electrode patterns of the FPC and the chip, the pattern pitch of the conductive part and the insulating part is the same.