TWI547382B - Method of making a fluid channel in a printhead structure, and fluid flow structure - Google Patents

Description

Method of manufacturing a fluid passage in a print head structure, and fluid flow structure

The present invention relates to a fluid structure having a compression molded fluid passage.

A row of printhead dies in an inkjet pen or printbar includes a plurality of fluid ejection elements on a surface of a substrate. Fluid flows to the ejection elements via a fluid delivery channel formed between the opposing body surfaces in the substrate. While the fluid delivery slot adequately delivers fluid to the fluid ejection element, such a groove has some disadvantages. For example, from a cost perspective, the fluid delivery slot takes up valuable silicon real estate and adds significant tank processing costs. In addition, lower printhead die cost is achieved in part by shrinking the die size. A smaller grain size results in a tighter groove pitch and/or groove width in the tantalum substrate. However, shrinking the die and the pitch increases the cost of integrating the small die into the associated inkjet pen in the inkjet pen during assembly. From a structural point of view, removing material from the substrate to form an ink delivery channel can weaken the printhead die. Thus, when a single printhead die has multiple grooves (for example, to provide different colors in a multi-color printhead die, or to come in a single color column) As the print quality and speed are improved in the print head die, the print head die becomes more fragile with additional grooves.

The present invention provides a method of fabricating a fluid channel in a printhead structure comprising the steps of: placing a row of die pads on a carrier; compressing the die into a molded printhead structure Simultaneously compressing a die, compressing a first portion of a fluid passageway in the molded printhead structure; and materially removing a second portion of the fluid passageway to The channel is coupled to a fluid feed aperture in the die.

100‧‧‧Print head structure, fluid flow structure, compression molded flow structure

118‧‧‧ shot chamber

120‧‧‧ hole

102‧‧‧Microdevices, print head die

122‧‧‧Conductor, conductor stitch

104‧‧‧Single body, molded body, molded object

124‧‧‧Electrical terminals

126‧‧‧Insulation

106‧‧‧Grain substrate, enamel sheet substrate, enamel substrate

128, 168‧‧‧ fluid passage

160‧‧‧ Carrier

108‧‧‧Fluid feed hole, ink feed hole

162‧‧‧Thermal release zone

110‧‧‧First outer surface

163‧‧‧Grain carrier assembly

112‧‧‧Second outer surface

164‧‧‧

114‧‧‧ Covers

166‧‧‧上模

116‧‧‧ layer

169‧‧‧Compression molded channel section, first Channel section

304‧‧‧Printing substrate

170‧‧‧ residual layer

306‧‧‧Flow Regulator

172‧‧‧Protective layer

308‧‧‧Substrate conveying mechanism

174‧‧‧Channel section and second channel section removed by material

310‧‧‧Printing fluid supply

312‧‧‧ Controller

200‧‧‧ system

400‧‧‧

204‧‧‧ Fluid propeller

800‧‧‧Abrasive material

202‧‧‧ Fluid source

Steps of 1102, 1104, ..., 1124‧‧

300‧‧‧Printer

S1, S2‧‧‧ side wall

302‧‧‧Printing rod

The embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which:

1 is a perspective view of an example of a compression molding fluid flow structure realized as a print head structure; FIG. 2 is a view showing a compression molding fluid which realizes, for example, the print head structure of FIG. A block diagram of one example system of a flow structure; FIG. 3 is a block diagram showing an ink jet printer that implements a fluid flow structure in a substrate wide print bar; FIGS. 4-6 illustrate an implementation The molded flow structure is an ink jet print bar of a compression example suitable for use in a print head structure of a printer; Figures 7-10 illustrate the process by both compression molding and material removal. An exemplary method for fabricating a compression molding printhead fluid flow structure having a fluid passage; FIG. 11 is for manufacturing a compression molding shown in FIGS. 7-10. A flow chart of one such exemplary method of printing head fluid flow structures.

Figures 12-14 illustrate an example of a molded top having a varying profile design that can be used in a compression molding process to create fluid passages of different shapes.

Throughout the drawings, the same reference numerals indicate similar, but not necessarily identical, elements.

Overview

Reducing the cost of conventional inkjet printhead dies has been achieved by reducing die size and wafer cost. The grain size is apparently dependent on the pitch of the fluid delivery slot that delivers ink from a reservoir on one side of the die to the fluid ejection element on the other side of the die. Therefore, the conventional methods for reducing the grain size mostly involve reducing the groove pitch and size through a silicon slotting process, which can include, for example, laser processing, anisotropic wet etching, dry etching. , combinations of them, etc. Unfortunately, the gutter process itself adds significant cost to the printhead die. In addition, the successful reduction in slot pitch increases the benefit of diminishing returns, and the cost associated with integrating the reduced die with an inkjet pen (caused by the tighter slot pitch) can become excessive.

A compression molded fluid flow structure enables the use of smaller printhead dies and a simplified method of forming a fluid delivery channel/groove that passes ink from one side of a row of die pads One of the upper reservoirs is delivered to the fluid ejection element on the other side of the die. The fluid flow structure includes one or more print head dies that are compression molded A single piece of plastic, epoxy molding or other moldable material. For example, a row of stamps that implement the fluid flow structure includes a plurality of printhead dies that are molded into an elongate, single molded body. The molding enables the use of smaller grains by unloading the fluid delivery channels (i.e., ink delivery channels) from the die to the molded body of the structure. Thus, the molded body grows in size of each die, which enhances the chance of external fluid connections and attachment of the die to other structures.

At the wafer or panel level, a fluid delivery channel or channel is within the fluid flow structure during the compression molding process in which the die is compressed within the fluid flow structure. form. The material delivery channel is then completed using a material ablation process, such as powder blasting, which removes the remaining channel material and fluidly couples the channel to the printhead. This compression molding process provides an overall reduced cost when forming a fluid delivery channel as compared to conventional gutter processes. First, the compression molded section of the fluid delivery passage formed during the compression molding process acts as an automatic alignment mask for subsequent material removal processes to complete the passage. The compression molding process is capable of adding flexibility in the shape of the molding channel/groove, its length, and its sidewall profile through a change in the design of the slot member of the upper die.

The fluid flow structure described is not limited to print bars or other types of print head structures for ink jet printing, and may be implemented in other devices and implemented for other fluid flow applications. Thus, in one example, the molded structure includes a micro-device embedded in a molding having a passage or other path for fluid to flow directly into or into the device. For example The micro device may be an electronic device, a mechanical device, or a microelectromechanical system (MEMS) device. The fluid stream can be, for example, a stream of cooling fluid flowing into or flowing to one of the microdevices, or a stream of fluid flowing into a column of die or other fluid dispensing microdevice. These and other examples are shown in the drawings and are not intended to limit the invention, and the invention is defined by the scope of the claims.

As used in this document, a "microdevice" means a device having one or more dimensions of less than or equal to 30 mm; "thin" means a thickness of less than or equal to 650 μm; a "long sheet" (sliver)" means a thin microdevice having an aspect ratio (L/W) of at least three; a "printing head structure" and a "printing head die" means an ink jet printer Some are other inkjet type dispensers that dispense fluid from one or more openings. A row of printhead structures includes one or more printhead dies. The "print head structure" and "print head die" are not limited to printing with ink or other printing fluids, and also include ink jet types that are dispensed for printing other than printing or other fluids for printing.

Illustrative embodiment

1 is a perspective elevational cross-sectional view of an example of a compression molded fluid flow structure 100 implemented as one of the printhead structures 100 of a row of printheads suitable for use in an ink jet lead machine. The printhead structure 100 includes a microdevice 102 that is compression molded into a monolithic body 104 of plastic or other moldable material. A molded body 104 can also be referred to herein as a molded article 104. In general, a micro device 102 can be, for example, an electronic device, a mechanical device, or a microelectromechanical system (MEMS) device. Printing of the invention in Figure 1 In the head structure 100, the microdevice 102 is implemented as a row of print head dies 102. The printhead die 102 includes a germanium die substrate 106 comprising a thin long die having a thickness of about 100 microns. The thin long sheet substrate 106 includes a fluid feed aperture 108 formed therein by dry etching or other means to enable fluid to flow from a first outer surface 110 through the substrate 106 to a second outer surface. Surface 112. The crucible substrate 106 further includes a cover member 114 that abuts and covers the first outer surface 110 (ie, over one of the cover members 106). The cover member 114 is approximately 30 microns in thickness and can be formed of tantalum or other suitable material, such as a polymer layer, a thick metal layer, or a thick dielectric layer. In one implementation, for example, a polymeric film can be laminated to the thin long sheet to cover the tantalum substrate 106 such that an epoxy molding compound will not enter the compression molding during the compression molding process. The fluid feed hole 108 is equal.

Formed on the second outer surface 112 of the substrate 106 is one or more layers 116 that define a fluidic structure that promotes the ejection of fluid droplets from the printhead structure 100. The fluidic architecture defined by the layer 116 generally includes an ejection chamber 118 having a corresponding aperture 120, a manifold (not shown), and other fluidic channels and structures. The layer 116 can include, for example, a chamber layer formed on the substrate 106 and a separately formed aperture layer above the chamber layer, or they can include the chambers and small The pore layer combines one of the monolithic layers. The (etc.) layer 116 is typically formed from a SU8 epoxy resin or some other polyimide material.

In addition to the fluidic architecture defined by layer 116 on germanium substrate 106, the printhead die 102 includes an integrated circuit formed on substrate 106. The integrated circuit utilizes a thin film layer and other features not specifically shown in FIG. Formed by components. For example, corresponding to each of the ejection chambers 118 is a thermal ejection element or a piezoelectric emitter element formed on the second outer surface 112 of the substrate 106. The ejection elements are actuated to eject droplets or streams of ink or other printing fluid from the chamber 118 through the apertures 120.

The printhead structure 100 also includes signal tracking or other conductors 122 that are coupled to the printhead die 102 via electrical terminals 124 formed on the substrate 106. Conductor 122 can be formed on structure 100 in a variety of ways. For example, a conductor 122 can be formed in an insulating layer 126 as shown in FIG. 1 using a lamination or deposition process. The insulating layer 126 is typically a polymeric material that provides physical support and insulation for the conductors 122. In other implementations, the conductor 122 can be molded into the molded body 104, such as shown in Figure 6 below.

A fluid passageway 128 is formed through the molded body 104, and the thin cover member 114 is fluidly coupled to the printhead die substrate 106 at the outer surface 110. A first section of the channel 128 is formed during the compression molding of molding the die die 102 into the printhead structure 100. The remainder of the passage 128 is formed via a material removal process that utilizes the first passage section as an automatic alignment mask to remove the channel material. The fluid passageway 128 provides a path through the molded body and the thin shroud 114 that enables fluid to flow directly over the helium substrate 106 at the outer surface 110 and into the helium base through the fluid feed holes 108. The material 106, and then enters the chamber 118. As will be discussed in further detail below, the fluid channel 128 is partially formed in the molded body 104 using a compression molding process that can form several types of transfer molding processes. The different channel shapes, each of which may reflect the inverted shape of the mold chase topography, which is used during the molding process.

2 is a block diagram of a system 200 that implements one of the compression molded fluid flow structures 100 of the printhead structure 100 of FIG. By compression molding and material ablation processes, system 200 includes a fluid source 202 that is operatively coupled to a set of fluid impellers 204 that are configured to move fluid to a fluid passage 128 formed in fluid flow structure 100. A fluid source 202 may, for example, include air as a source of gas to cool an electronic microdevice 102, or a print fluid supply for one of the rows of printhead dies 102. Fluid mover 204 behaves as a pump, a fan, gravity, or other suitable mechanism for moving fluid from source 202 to fluid structure 100.

3 is a block diagram of an inkjet printer 300 that implements a fluid flow structure 100 in a substrate wide print bar 302. The printer 300 includes a print bar 302 spanning the width of a column of printed substrates 304, a flow conditioner 306 associated with the print bar 302, a substrate transport mechanism 308, ink or other printing fluid supply source 310, and A printer controller 312. Controller 312 is shown as the (and other) planning processor and associated memory, as well as electronic circuitry and components that control the operational elements of a printer 300. The print bar 302 includes an arrangement of printhead dies 102 for dispensing print fluid onto a sheet of paper or other print substrate 304. Each of the printhead dies 102 receives a print fluid through a flow path that extends from the supply source 310 to the flow conditioner 306, through the flow conditioner 306, and then through compression molding within the print bar 302. Fluid passage 128.

4-6 illustrate an example inkjet print bar 302 that implements a compression molded flow structure 100 that is suitable for use with a printhead structure 100 of the printer 300 of FIG. Referring to the plan view of FIG. 4, the printhead die 102 is embedded in an elongate, monolithic molding 104 and is generally end-to-end configured in rows 400. The printhead dies 102 are arranged in a staggered configuration wherein the dies in each row overlap with another of the other dies in the same row. In this configuration, each row 400 of printhead die 102 receives print fluid from a different compression molding fluid channel 128 (depicted in phantom in Figure 4). Although four fluid passages 128 for feeding four rows of 400 staggered print head dies 102 are shown (e.g., for printing four different colors), other suitable configurations are possible. 5 is a top cross-sectional view of the ink jet print bar 302 taken along line 5-5 of FIG. 4, and FIG. 6 is also taken along line 5-5 of FIG. A cross-sectional view of the ink jet print bar 302. The cross-sectional view of Figure 6 shows various details of the printhead structure 100 of one of Figure 1 as discussed above.

7-10 illustrate a method for fabricating a compression molded printhead fluid flow structure 100 having a fluid passageway 128 formed by a process including both compression molding and material removal. Figure 11 is a flow chart 1100 of the method illustrated in Figures 7-10. As shown in the "A" portion of FIG. 7, a row of print head dies 102 is attached to a carrier 160 (step 1102 in FIG. 11) using a thermal release tape 162 to form a die carrier assembly 163. The print head die 102 is disposed on the carrier 160 with the apertures 120 facing downward. The printhead die 102 is in a preliminary processing state such that it includes a layer 116 defining a fluidic structure (e.g., exit chamber 118, aperture 120), and electrical terminals 124, and a thin long sheet substrate formed thereon. Shot on 106 Out of component (not shown). The fluid feed aperture 108 has been dry etched or otherwise formed in the long sheet substrate 106.

Referring to portion "B" of Figure 7, the printhead die 102 is compression molded into a molded body 104 (step 1104 in Figure 11). In general, a compression molding process involves preheating a molding material such as a plastic or an epoxy molding compound, and placing the material having the die 102 in a heated molding cavity. For example, it is an area inside the lower mold 164. The upper die 166 is lowered to access the molded article, and heat and pressure drive the molding material into all areas of the interior of the cavity such that it forms a molding 104 encapsulating the printhead die 102. In addition to encapsulating the die 102, the molding 104 takes a shape that follows the contour of the upper die 166. In this example, the molding 104 forms a portion of a fluid passage 168 that constitutes a first compression molded section 169 of the fluid passage 128 on the first outer (rear side) surface 110 of the substrate 106, such as This is shown in the "C" section of Figure 7.

Still referring to Figure 7, "B" and "C" portions, it is apparent that during the compression molding process, the cover member 114 prevents molding material from entering the fluid feed holes 108 in the long sheet substrate 106. . In addition, the compression molding process leaves a residual layer 170 of molding material over the cover member 114. Therefore, as shown in the "C" portion, the portion of the fluid passage 168 (the first compression molded passage section 169) does not extend all the way to the ink feed holes 108. Thus, the fluid passage 128 is then completed in a material removal process as discussed below. As shown in the "C" portion of FIG. 7, the die carrier assembly 163 is removed from the lower and upper dies (164, 166), and the carrier 160 is released from the thermal strip 162, and the strip The system is removed from the die (step 1106 in Figure 11).

As shown in the portion "D" of Fig. 7, a polymer insulating layer 126 is laminated on the side of the small holes 120 of the head die 102, and then patterned and hardened (step 1108 in Fig. 11). An SU8 firing chamber protective layer 172 is deposited over the fluid network structure layer 116, as shown in the "E" portion of Figure 7 (step 1110 in Figure 11). As shown in FIG. 7, in the "F" portion, a metal layer (Cu/Au) is deposited on the polymer insulating layer 126 and patterned into conductor traces 122 (step 1112 in FIG. 11). A top polymer insulation layer 126 is spin coated over the conductor traces 122 and then patterned and hardened as shown in the "G" portion of Figure 7 (step 1114 in Figure 11). In the "H" portion of FIG. 7, the emitter chamber protective layer 172 is removed and a final hardening action of the polymer insulating layer 126 is performed (step 1116 in FIG. 11). As shown in the "I" portion of FIG. 7, the residual layer 170 of molding material over the area of the fluid feed holes 108 in the substrate 106 and the cover member 114 are removed to form a finished fluid. Channel 128 (step 1118 in Figure 11). In one example, a material ablation process is used to remove the residual layer 170 and the cover member 114. Thus, the completed fluid passageway 128 includes a first compression molded passage section 169 and a second section that is a material removed passage section 174.

Figures 8-10 further illustrate the material removal (cutting) procedure steps shown in the "I" portion of Figure 7. There are various processes that can be used to remove material from the cover member 114 and the residual layer 170 of molding material remaining over the cover member 114. These material ablation processes can include, for example, powder blasting, etching, laser, grinding, drilling, electrical discharge machining, and the like. These processes typically involve the use of a mask that prevents material movement in areas where material that should not be removed is located except. In the present case, first, the compression molded channel section 169 formed during the compression of the "B" and "C" portions of Figure 7 acts as an automatic alignment mask that directs etching or other abrasive material 800. Material is removed from the cover member 114 and the residual layer 170 in the region where the channel is extended and completed. The material ablation process forms a second material removed channel section 174 that extends the first channel section 169 to form the completed fluid channel 128. The completed fluid passage 128 is provided through the molded body and through a path of the thin cover member 114 to allow fluid to flow directly onto the outer surface 110 of the crucible substrate 106 and through the fluid feed holes 108 flows into the crucible substrate 106 and then into the chamber 118.

As shown in Figure 8, the etch or other abrasive material 800 is guided by the first channel section 169 to remove material at the closed end of the channel by removal. The removal process begins by removing the residual layer 170 of molding material remaining over the cover member 114 (step 1120 in FIG. 11). Thus, the material removal process shown in the "I" portion of FIG. 7 first removes the residual layer 170 and exposes the cover member 114 to the etch or other abrasive material 800, as shown in FIG. The material removal procedure is then performed to remove material from the cover member 114 in the channel region of the channel extending to the outer surface 110 of the substrate 106 (step 1122 in Figure 11). Removing the residual layer 170 and the haptic material will form a second (material-removed) channel section 174 that completes the fluid channel 128 and open the fluid feed holes 108 to the channel 128 (FIG. 11 Step 1124). Thus, the completed fluid passageway 128 includes a first section and a second section, the first section being a compression molded channel section 169 and the second section being a material removed passage section 174.

As can be seen in the figures discussed above, the compression molding process can produce a varying shape within the fluid passageway 128. More specifically, Figures 1, 5 and 6 illustrate fluid passages 128 of generally upright side walls that are parallel to each other, while Figures 7-10 show fluid passages 128 that are erected in a side wall but are tapered or bifurcated from one another. Different fluid passage shapes can be created during the compression molding process by using a mold 166 having a modified outer design. In general, the resulting shape of the fluid passage 128 reversely follows the contour of the upper mold 166 used during the compression molding.

Figures 12-14 illustrate several additional examples of a modified outer mold 166 having variations that can be used in a compression molding process to create fluid passages 128 of different shapes. As shown in Figure 12, the upper die 166 has a profile that results in a fluid passage 128 having molded sidewalls S1 and S2 mirrored to each other. The side walls S1 and S2 each have two substantially upright sections, the side walls being parallel to each other in one section, and in the other section, the side walls are in a tapered configuration. In Figure 13, the upper die 166 profile results in a fluid passageway 128 having molded side walls S1 and S2 each having two substantially upright sections. The two sections of the side walls are in the form of a cone and, once again, mirror images as they taper away from one another. As shown in FIG. 14, an upper die 166 can also have a curved (or other shape) profile that creates a curved sidewall shape within the fluid passageway 128.

In general, the molded fluid channel 128 shown in the drawings and discussed above has channel sidewalls S1 and S2 that are parallel and/or tapered and/or mirrored to each other upright and/or The bending configuration is formed. In most cases, the sidewalls of the channels are made to follow the length of the printhead It may be beneficial for the substrate 106 to recede or move away from each other in a bifurcated or tapered configuration. This bifurcation provides the benefit of assisting air bubbles from the apertures 120, the ejection chamber 118, and the fluid feed apertures 108, where they may otherwise impede or avoid the flow of fluid during operation. Accordingly, the fluid passages 128 discussed and shown in the drawings include side walls that are typically bifurcated but at least partially parallel as they retreat from the long sheet substrate 106. However, the illustrated channel sidewall shape and configuration are not intended to be limiting with respect to one of the other shapes and configurations of the sidewalls within the fluid passage 128 that can be formed using a compression molding process. Rather, the present disclosure contemplates that other compression molded fluid passages may have sidewalls that are shaped in various other configurations not illustrated or discussed.

104‧‧‧Molded ontology

106‧‧‧矽 substrate

108‧‧‧Fluid feed hole

110‧‧‧First outer surface

114‧‧‧ Covers

128‧‧‧ fluid passage

169‧‧‧Compression molded channel section, first channel section

174‧‧‧Channel section and second channel section removed by material

800‧‧‧Abrasive material

Claims (17)

A method of fabricating a fluid channel in a printhead structure, comprising the steps of: placing a row of die pads on a carrier; compressing the die into a molded printhead structure; and compressing Simultaneously molding the die, compressing and molding a first portion of a fluid passage in the molded printhead structure; materially removing a second portion of the fluid passage to the passage and the crystal A fluid feed hole in the particle is coupled. The method of claim 1, further comprising: utilizing the first segment of the channel as a mask during removal. The method of claim 1, wherein the step of materially removing comprises removing a residual layer of molding material from the first section of the channel and the die. The method of claim 3, wherein the step of materially removing further comprises: removing material from a cover on the die to expose the fluid feed aperture. The method of claim 4, wherein the step of removing material from the cover comprises removing material selected from the group consisting of ruthenium, polymer, metal, and dielectric. The method of claim 1, wherein the step of materially removing comprises: removing a program selected from the group consisting of powder blasting, etching, laser, grinding, drilling, and electrical discharge machining. material. A fluid flow structure comprising: a micro device embedded in a molding; a fluid feed hole formed through the micro device; and a fluid channel fluidly coupled to the fluid feed hole It includes a first compression molded channel section and a second warp material removal channel section. The structure of claim 7, wherein the compression molded passage section is formed through the molded article, and the through material removal passage section is formed through a cover member covering the fluid feed hole. The structure of claim 8, wherein the cover member comprises a material selected from the group consisting of ruthenium, polymers, metals, and dielectrics. The structure of claim 7, wherein the compression molded channel section has a shape having a contour that inversely follows an extension of a top mold chase for forming the molded article. Park exterior. The structure of claim 7, wherein the channel comprises first and second side walls that are spaced apart from each other as they extend away from the micro-device and that converge toward each other as they approach the micro-device. The structure of claim 7, wherein the channel comprises first and second upstanding sidewalls substantially parallel to each other. The structure of claim 7, wherein the channel comprises first and second upstanding sidewalls that are tapered relative to one another. The structure of claim 7, wherein the channel comprises first and second curved sidewalls mirrored to each other. The structure of claim 7, wherein the channel comprises first and second side walls, Each of the side walls has a plurality of contours selected from the group consisting of an upright profile, a tapered profile, and a curved profile. A fluid flow structure comprising: a compression die placed in a molding; a printhead die long sheet; extending from a first outer surface through the printhead die length sheet to a second outer surface a fluid feed aperture; having a compression molded channel section and a fluid passageway through the material removal passage section, the material removal passage section being directly coupled to the first outer surface. The structure of claim 16, wherein the molding comprises compression molding a monolithic body about a plurality of printhead die length sheets, the body having a fluid passage molded therein, wherein the fluid is wearable The fluid passage flows directly to each of the print head die length sheets.