JPS6211295A - Mounting of electronic component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for mounting electronic components.

(Prior Art) Conventionally, various methods have been proposed for mounting electronic components on a circuit board using a film carrier.

For example, 1 document “Oki Research and Development J, 51, (3), p.
sa~68 is a semiconductor electronic component (hereinafter simply referred to as IC) that integrates shift registers, latches, drivers, and other functional circuits to drive printing of a single-row multi-dot thermal head used in thermal recording devices. ) is mounted on a circuit board two-dimensionally by a film carrier method at a ratio of one heating element for every 32 heating elements.

FIG. 2 is a plan view of the main parts of this conventional thermal head, mainly showing schematically the components of the heating resistor and the IC mounted on the board using the tape carrier method. FIG. 3 is a side view showing a method of mounting the illustrated IC.

In both figures, 11 is an alumina substrate, 12 is a glaze layer coated on the substrate 11 and has a smooth surface, and 13 is obtained by photo-etching a deposited film of Ta2N, NiCr, Au, etc. on the glaze layer 12.

A conductor pattern connected to each heating resistor 14! Reference numeral 5 indicates an IC 118 which is a ground pattern which is one of the input signal systems; 17 is made of polyimide or other suitable tape carrier film resin; 18 is formed of electrolytic copper foil through the film resin 17, and is coated with tin or solder plating (plating). 18 is ICl3
A bump electrode 20 connects the conductor 13 and the thin wire lead 18 by inner lead bonding.
7 and 7, and 21 are resin-based pattern protective layers, and since these are conventionally known, detailed explanation thereof will be omitted.

In FIG. 2, reference numeral 22 indicates a drive voltage supply pattern commonly connected to, for example, 32 heating resistors 14, and terminal patterns for external connection are not shown. In the structure of this illustrated example, three heating resistors are arranged in odd-numbered columns and even-numbered columns in units of 32 heating resistors, with the heating resistor 14 at the center.
8mm wide ICs are mounted planarly at a 4mm pitch.

(Problem to be Solved by the Invention) However, when mounting an IC on a flat surface on an ultra-high density thermal head with a resolution of 24 dots/mm or more, for example, the size of the heating resistor must be I
Since it is smaller than the size of C, it consists of a row of heating resistors.
Compared to the effective heating element length of the line thermal head, the IC
The implementation queue is much longer.

Furthermore, in order to form an IC mounting row, it is necessary to mount the IC at a location away from the heat generating resistor, so that the conductor, that is, the lead-out pattern from the heat generating resistor also becomes long.

For these reasons, in the conventional IC mounting method, the area of the board becomes large, and there is a problem that further miniaturization of the thermal head cannot be achieved.

The purpose of this invention is to solve the problem of the conventional thermal head substrate having a large area, and to improve its effectiveness even in ultra-high density thermal heads of, for example, 24 dots/mm or more. It is an object of the present invention to provide a mounting method for electronic components which makes it possible to obtain mounting rows that are almost the same as the length of a heating element.

(Means for Solving the Problems) In order to achieve this object, according to the mounting method of the present invention, electronic components are first mounted on a film carrier by inner lead bonding.

Next, the outer leads disposed on one side of the film carrier are bonded onto the circuit board to form electrical connections, and electronic components are mounted on the board using the film carrier.

Thereafter, the film carrier is pulled up from the substrate surface side using the film edges of the protruding portions of these outer leads as fulcrums.

In this case, if a notch is formed diagonally on one of the short sides of the film carrier, it will be helpful if other large components, such as a platen roller, are located near the location where electronic components are mounted. However, it can be implemented closer to that.

(Effect) How is the Jugen, TT, M rod waxed product? [1. Since the film carriers can be arranged upright in a direction substantially perpendicular to the substrate surface, a large number of film carriers each carrying an electronic component can be arranged at high density on the substrate. Therefore, the mounting area of electronic components on the board can be significantly reduced.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, the same components as those shown in FIGS. 2 and 3 are indicated by the same reference numerals, and detailed explanation thereof will be omitted.

FIGS. 1(A) and CB) are a side view and a plan view of an IC mounting part for explaining the electronic component mounting method of the present invention.
The shape, dimensions, and arrangement relationship are schematically shown.

In the structure shown in FIGS. 1(A) and 1(B), for example, a 50 μm thick
A driving voltage power supply pattern 22 is formed by forming a glaze layer 12 with a certain thickness, and on this glaze layer 12, a metal having a thin film structure of Ni, Cr, and Au is formed by photoetching.
It is a fine circuit such as.

Reference numeral 23 denotes an outer lead constituting a drive voltage circuit disposed at the outermost side within the film carrier, and the outer lead 23 and the drive voltage power supply pattern 22 are connected to each other by outer lead bonding.

24 is a film carrier (also referred to as a tape carrier), and a perforation (hereinafter referred to as a device hole) 25 is formed in this carrier 24. ICl3 has thin wire leads 18a and 1 protruding from the device hole 25 from the side opposite to ICl3 of this carrier 24.
8b and bump electrode 19 are connected to each other by inner lead bonding. The thin wire lead tea is a driving signal lead part, and 18b is a 32-wire lead part for driving a heating element, each of which is schematically shown in FIG. 1(B). Furthermore, 26 is a thin film lead pattern drawn out from the heating resistor, and 27 is a thin film ground pattern. Further, 28 is a signal system thin film lead pattern. These patterns 26 to 28 (all of which correspond to the drive voltage feeding pattern 22 shown in FIG. 1A) and the thin wire leads 18a and 18b are respectively appropriately connected by outer lead bonding.

Further, reference numeral 29 denotes a notch portion which is cut diagonally on the short side of the film carrier 24 so that the IC mounting portion can be placed closer to the platen roller 30 side with respect to the substrate.

In this way, the film carrier 2 loaded with ICl3
By bending the film carrier 24 in the direction of the arrow A using the film edge 4 (point F in the figure) as a fulcrum, the driving voltage circuit 23 (thin wire leads 18, 18a, 1
8b) and the drive voltage feeding pattern 22 (26, 27, 2 days) without applying bending stress to the connection part between the
As shown by the broken line in A), the IC mounting section can be erected almost perpendicularly or nearly perpendicularly to the board surface.

(Effects of the Invention) As is clear from the above description, according to the present invention, since the IC mounting section can be mounted in a direction substantially perpendicular to the substrate surface, the Since each IC can be arranged three-dimensionally at high density, the substrate area can be reduced.

Furthermore, by cutting diagonally at least a portion of the short side of the film carrier on the platen roller side, the mounting area can be further reduced.

In the above explanation, an example of mounting electronic components on a thermal head was explained, but the mounting method of the present invention is not limited to thermal heads, but can be applied to any other electronic components that require high-density mounting. Can only be applied to implementations of

[Brief explanation of drawings]

Figures 1 (A) and (B) are a side view and a plan view of an electronic component mounting part for explaining the electronic component mounting method of the present invention, and Figure 2 is a partial view of the main parts of a conventional thermal head. FIG. 3 is a side view showing a conventional electronic component mounting method. 11...Substrate, 12...Glaze layer 1
5...Electronic components (IC) 18a, 18b-...Thin wire lead 19...Bump electrode 22...Drive voltage power supply pattern 23...Outer lead 24...Film carrier 25...Perforation, 26. ...Thin film lead pattern 27...Thin film ground pattern 28...Signal system thin film lead pattern 29...Notch portion, 30...Platen roller. Patent Applicant Oki Electric Industry Co., Ltd. Agent Patent Attorney Takashi Ogaki Pattern 23: Complete Utari Lead 24° 7 Rum Heilia 25: g Akane rc Shiki Suzubun I Rule 6: J Trouble Figure 1 (B) /8a, b: Pure Cotton Lead 26:1 Miscellaneous - Dobacoon 27: Usufuji Defundo Jf7-n28: I No. 1fi IH member Lead Ha Turn 2f:
R'J 2-b order p JO near degree fudenloaf I (1: If! kesabu/) hand ω field Fig. 1 Kenzuka's - Malheld's t*vmm Fig. 2 Conventional ΦEC pulling direction Amended Book of Procedures for Figure 3 of the Hoi Kenmenden July 1, 1986

Claims (2)

[Claims] (1) When mounting electronic components on a circuit board using a film carrier, the electronic components are mounted on the film carrier using inner lead bonding, and the outer leads arranged on one side of the film carrier are bonded onto the circuit board. A method for mounting an electronic component, which comprises performing lead bonding and then pulling up a film carrier from the substrate surface side using the film edges of protruding portions of these outer leads as fulcrums. (2) The electronic component mounting method according to claim 1, wherein one short side of the film carrier is cut diagonally.