JPH0248429B2

JPH0248429B2 - SAAMARUHETSUDO

Info

Publication number: JPH0248429B2
Application number: JP5792284A
Authority: JP
Inventors: Yoshihiko Sato
Original assignee: Nippon Electric Co Ltd
Current assignee: NEC Corp
Priority date: 1984-03-26
Filing date: 1984-03-26
Publication date: 1990-10-25
Anticipated expiration: 2004-03-26
Also published as: JPS60201967A

Description

【発明の詳細な説明】本発明は、サーマルヘツドに関し、とくにその
導電体の形状に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal head, and more particularly to the shape of its conductor.

以下、従来例を図面を参照して説明する。第１
図はラインプリンタ用サーマルヘツドの要部平面
図例を示す。同図において、単一のドライバ用
ICに接続される発熱抵抗体R₁〜R_nは、共通電極
Ｃから短冊形に分岐した導電体C₁〜C_nに接続し
て形成される。抵抗体の他端には多数の個別導電
体L₁〜L_nが接続され、これらの個別導電体はIC
のボンデイング端子T₁〜T_nまで延長して形成さ
れる。個別導電体L₁〜L_nには、抵抗部と接する
パタン幅（例えば0.115mm）よりも小さい幅の導
体抵抗補正領域‘n'が一般には設けられる。‘n'
の領域のパタン幅は例えば0.08mmとすることがで
きる。個別導電体上には、絶縁層を介して破線で
示すICが搭載される。発熱抵抗体R₁〜R_nを通電
発熱せしめた記録電流は、IC内の記録電流接地
電極からボンデイングワイヤ、又は半田バンプ等
の手段によりICの両側に配置されたサーマルヘ
ツド基板上の各々の接地端子Ｇへ流れ、その記録
電流はｍ本又はｍ／２本の発熱抵抗体に流れた分
が集つて外部記録電流接地導体P_Gへ流れる（図
面矢印方向へ流れる）。接地導体は同一幅の寸法
で基板端子部まで延長して形成される、本構造を
基本形として基板上に多数配置したものがライン
プリンタ用サーマルヘツドである。 A conventional example will be described below with reference to the drawings. 1st
The figure shows an example of a plan view of the main parts of a thermal head for a line printer. In the same figure, for a single driver
The heating resistors R ₁ to _{R n} connected to the IC are connected to conductors C ₁ to _{C n} branched from the common electrode C into rectangular shapes. A large number of individual conductors L ₁ to _{L n} are connected to the other end of the resistor, and these individual conductors are connected to the IC.
The bonding terminals T ₁ to _{T n} are formed to extend from each other. The individual conductors L ₁ to _{L n} are generally provided with a conductor resistance correction region 'n' having a width smaller than the pattern width (for example, 0.115 mm) in contact with the resistance portion. 'n'
The pattern width of the region can be, for example, 0.08 mm. An IC indicated by a broken line is mounted on the individual conductor through an insulating layer. The recording current generated by the heating resistors R ₁ to _{R n} is transferred from the recording current ground electrode in the IC to the respective grounds on the thermal head substrates placed on both sides of the IC by means such as bonding wires or solder bumps. The recording current flows to the terminal G, and the portion of the recording current that flows through m or m/2 heating resistors is collected and flows to the external recording current grounding conductor _PG (flows in the direction of the arrow in the figure). The ground conductor has the same width and is formed to extend to the terminal portion of the board.A thermal head for a line printer is based on this structure and is arranged in large numbers on a board.

さて総抵抗体本数が1728本であり、解像度が８
本／mmであるA4版サーマルヘツドを一例として
説明する。単一のICが32本の抵抗体を駆動する
場合（即ちｍ＝32）には、ICは4.0mmのピツチで
合計54個基板上に配置される。抵抗体R₁〜R_nの
パタン幅を各々0.115mmとし抵抗体の間隔を0.01
mmとすると、‘a'で示す距離は3.99mmとなる。ま
た‘b'で示す距離は前述した通り4.0mmとなる。 Now, the total number of resistors is 1728, and the resolution is 8.
An example of an A4 size thermal head with a size of book/mm will be explained. If a single IC drives 32 resistors (ie, m=32), a total of 54 ICs are placed on the board at a pitch of 4.0 mm. The pattern width of resistors R ₁ to R _n is each 0.115 mm, and the spacing between the resistors is 0.01.
If mm, the distance indicated by 'a' is 3.99mm. Also, the distance indicated by 'b' is 4.0 mm as described above.

ICの幅を２mmとすると、ボンデイングに要す
る端子Tp及びTgの長さは好ましくは0.5mm程度
以上であることから、ボンデイング端子T₁〜T_n
の両側に配置された外部記録電流接地導体P_Gの
幅寸法‘l'は凡そｌ≒（４−２−0.5×２）mm／２
＝0.5mmとなる。記録電流接地導体P_Gの幅寸法‘l'
は所望により隣接したICの接地導体と相互に短
絡されて総合で１mm程度の幅寸法とすることがで
きる。 If the width of the IC is 2 mm, the length of the terminals Tp and Tg required for bonding is preferably about 0.5 mm or more, so the bonding terminals T ₁ to _{T n}
The width dimension 'l' of the external recording current grounding conductor P _G placed on both sides of is approximately l≒(4-2-0.5×2) mm/2.
=0.5mm. Recording current ground conductor P _G width dimension 'l'
If desired, they can be mutually short-circuited with the ground conductors of adjacent ICs to have a total width of about 1 mm.

半導体ICは技術の進歩に伴なつて高集積度化
し、現在では単一のICが64本の発熱抵抗体（即
ちｍ＝64）を駆動することができるようになつ
た。従つて上記例においてはICは8.0mm（即ちｂ
＝８）のピツチで合計27個基板上に配置される。
この場合には、ICの長さが従来の２倍程度とな
り、駆動される発熱抵抗体本数も２倍となるの
で、記録電流接地導体P_Gの幅寸法は従来の４倍
程度とする必要が生じる。〓即ち接地導体P_Gの導
体抵抗をｍ＝32のときに0.1Ωとし、各々の発熱
抵抗体R₁〜R_nに流れる記録電流を0.04Aとする
と、記録電流による損失電圧は最大でも32×0.04
×0.1V≒0.13V程度にすぎない。しかし、接地導
体P_Gと同一の幅寸法をｍ＝64の場合にも適用す
ると、ICの長さが凡そ２倍となり、接地導体も
２倍の長さとなるために、この導体抵抗は２倍の
0.2Ω程度となる。従つて損失電圧は最大でも64
×0.04×0.2≒0.51Vにも達する。この損失電圧は
同時駆動発熱抵抗体本数に依存して印加記録電圧
（例えば12V）を実効的に下げることになり、ひ
いては印字記録濃度ムラを生じさせることにな
る。 As technology advances, semiconductor ICs have become highly integrated, and now a single IC can drive 64 heating resistors (that is, m=64). Therefore, in the above example, IC is 8.0 mm (i.e. b
A total of 27 pieces are arranged on the board with a pitch of =8).
In this case, the length of the IC is approximately twice as long as the conventional one, and the number of heat-generating resistors to be driven is also twice as large, so the width of the recording current ground conductor _PG needs to be approximately four times that of the conventional one. arise. 〓That is, if the conductor resistance of the ground conductor P _G is 0.1Ω when m=32, and the recording current flowing through each heating resistor R ₁ to R _n is 0.04A, the loss voltage due to the recording current is at most 32 × 0.04
×0.1V≒0.13V only. However, if the same width dimension as the ground conductor P _G is applied to the case where m = 64, the length of the IC will be approximately twice as long, and the ground conductor will also be twice as long, so the resistance of this conductor will be doubled. of
It will be about 0.2Ω. Therefore, the maximum loss voltage is 64
×0.04×0.2≒0.51V. This loss voltage effectively lowers the applied recording voltage (for example, 12 V) depending on the number of simultaneously driven heating resistors, which in turn causes uneven print density.

本発明は上記の欠点を除去するためなされたも
のであり、ボンデイング端子がT₁からTpあるい
はT_nからTgへ移行するにつれて、即ち個別導電
体がICのセンタ側へ近づくにつれて、ボンデイ
ング端子の距離を実効的に短かくし、もつて記録
電流接地導体P_Gの幅寸法を段階的にあるいは単
調に広げたものである。 The present invention has been made to eliminate the above-mentioned drawbacks, and as the bonding terminal moves from _T1 to Tp or from _Tn to Tg, that is, as the individual conductor approaches the center side of the IC, the distance of the bonding terminal increases. is effectively shortened, and the width of the recording current grounding conductor _PG is increased stepwise or monotonically.

以下図面にそつて本発明の一実施例を説明す
る。 An embodiment of the present invention will be described below with reference to the drawings.

第２図は本発明の一実施例を示したものであ
る。単一のICが駆動できる発熱抵抗体本数を64
本（即ちｍ＝64）とし、前例のR₁〜R_nのパタン
幅を各々0.115mmとすると、‘a'で示す距離は7.99
mmとなる。また、ボンデイングに所要とする端子
長の寸法を各々0.5mmとし、IC搭載下の個別導電
体ピツチを0.091mmとすると、‘p′'で示す距離は、
例えばT₅〜T₆₀部においてはb′≒｛0.091×（60−
５＋１）＋0.5×２｝≒6.1mmとなる。従つてボン
デイング端子T₁〜T_nの両側に配置された外部記
録電流接地導体P_Gの幅寸法‘l'はｌ≒（８−6.1）
mm／２＝0.95mmとなり、従来の幅の２倍にも達し
ない。しかし、Tp（ｐ＝32）及びTg（ｇ＝33）に
おいては、ICの幅を２mmとすると外部記録電流
接地導体P_Gの幅寸法‘l′'はl′＝（８−２−0.5×２）
mm／２＝2.5mmとなり、従来の５倍程度の幅寸法
とすることができる。上記幅の狭い接地導体（ｌ
領域）においては、導体を流れる電流はR₁〜R₈
及びR₆₄〜R₅₇程度の少数の発熱抵抗体を通電発
熱せしめた記録電流にのみ限定されるために、実
効的損失電圧は低い。また大電流が流れる領域に
おいては、接地導体P_Gの幅が広く実効的損失電
圧は低いものとなる。従つて本発明のサーマルヘ
ツドは単一のICが駆動できる発熱抵抗体本数を
従来の２倍以上としても、均一な印字記録濃度を
提供できるものである。 FIG. 2 shows an embodiment of the present invention. The number of heating resistors that a single IC can drive is 64.
If the pattern width of R ₁ to R _n in the previous example is each 0.115 mm, then the distance indicated by 'a' is 7.99
mm. Also, assuming that the terminal length required for bonding is 0.5 mm each, and the individual conductor pitch under the IC is 0.091 mm, the distance indicated by 'p'' is
For example, in T ₅ to T ₆₀ parts, b′≒{0.091×(60−
5+1)+0.5×2}≒6.1mm. Therefore, the width dimension 'l' of the external recording current grounding conductor P _G arranged on both sides of the bonding terminals T ₁ to _{T n} is l≈(8-6.1).
mm/2=0.95mm, which is less than twice the conventional width. However, in Tp (p=32) and Tg (g=33), if the width of IC is 2 mm, the width dimension 'l'' of external recording current grounding conductor P _G is l'=(8-2-0.5× 2)
mm/2 = 2.5 mm, making it possible to make the width dimension about five times that of the conventional one. The narrow ground conductor (l
In the region), the current flowing through the conductor is R ₁ to _{R 8}
Since the recording current is limited only to the recording current generated by energizing a small number of heat generating resistors such as R ₆₄ to R ₅₇ and generating heat, the effective loss voltage is low. Furthermore, in a region where a large current flows, the width of the ground conductor _PG is wide and the effective loss voltage is low. Therefore, the thermal head of the present invention can provide uniform printing density even if the number of heating resistors that can be driven by a single IC is more than twice that of the conventional one.

本発明が上記の効果を呈する以上、外部記録電
流接地導体P_Gの材質や膜厚、パタン幅、導体の
強化法（メツキ法、印刷法等により膜厚を部分的
に厚くする方法）、単一のICが駆動できる抵抗体
本数、ボンデイング端子を短かくするステツプ数
（即ち前記接地導体P_Gを段階的に幅広くするステ
ツプ数）、あるいは端子を短かくする方法（段階
状、あるいは単調減少等）、発熱抵抗体の解像度
等、何ら制約されるものではないことは当然であ
る。また、本発明のサーマルヘツドの用途も特に
限定されるべきものではなく、ラインヘツド、シ
リアルヘツド等に用いることも当然できる。更に
また、前記接地導体P_Gは配線の都合により局部
的に細くすることも当然できる。 As long as the present invention exhibits the above-mentioned effects, the material, _film thickness, pattern width, method of reinforcing the conductor (method of partially increasing film thickness by plating method, printing method, etc.) of the external recording current grounding conductor PG, The number of resistors that one IC can drive, the number of steps to shorten the bonding terminal (that is, the number of steps to gradually widen the ground conductor _PG ), or the method of shortening the terminal (stepwise, monotonically decreasing, etc.) ), resolution of the heating resistor, etc., are of course not subject to any restrictions. Further, the use of the thermal head of the present invention is not particularly limited, and it can naturally be used for line heads, serial heads, etc. Furthermore, the ground conductor _PG can naturally be made thinner locally depending on the wiring.

[Brief explanation of drawings]

第１図は従来のサーマルヘツドの要部を示す平
面図。第２図は本発明の一実施例によるサーマル
ヘツドの要部を示す平面図。１……Ｃ（C₁〜C_n）共通電極、２……R₁〜R_n
発熱抵抗体、３……L₁〜L_n個別導電体、４……
T₁〜T_nボンデイング端子、５……P_G外部記録電
流接地端子、６……ｎ領域導体抵抗補正領域。 FIG. 1 is a plan view showing the main parts of a conventional thermal head. FIG. 2 is a plan view showing the main parts of a thermal head according to an embodiment of the present invention. 1...C ( _C1 to _Cn ) common electrode, 2... _R1 to _Rn
Heating resistor, 3...L ₁ ~ _{L n} individual conductor, 4...
_T1 to _Tn bonding terminal, 5...P _G external recording current ground terminal, 6...n area conductor resistance correction area.

Claims

[Claims]

1 Individual conductors connected to the heating resistor and extending from the resistor are placed on both sides of the mounted IC as bonding terminals to the IC, and the heating resistor is placed between the bonding terminals of the adjacent mounted ICs. In a thermal head provided with a grounding conductor for grounding the recording current that generates heat through the body, the width of the pattern of the grounding conductor is set by the individual conductor.
1. A thermal head characterized in that the bonding terminals are gradually or monotonically widened as they approach the center side of the IC, and the bonding terminals are correspondingly shortened toward the IC side.